Primum Non Nocere

Question: Where can a practice find everything they need to manage Keratoconus?
Answer: You can get off to a flying start right here!



Keratoconus (KC) broadly requires a thorough comprehension of the disorder and of its management. In simple sum-up, KC is a corneal disorder that progresses and necessitates prompt early diagnosis and the treatment of progression when it's required and on-going monitoring is required too. Read more...

Detection of early Keratoconus remains challenging as there is no globally accepted definition for defining the diagnosis and progression of Keratoconus. There is currently no standard diagnostic or grading system for keratoconus which everyone agrees on. Additionally, there is no accepted definition of progression, and no ability to predict the prognosis and outcomes of treatment for individual patients.

The economic burden and vision-related quality of life are factors which can be run away to be disproportionately high in it's toll, which is a real concern including the incidence of the disease being historically reported significantly lower than we at length have known it to really be. Furthermore than that, there are much more increased incidences in certain populations which are very concerning in scope.

The aetiology of Keratoconus remains unknown, although it appears to be a complex, heterogeneous disorder with multiple causative factors that can be broadly classified as environmental, biomechanical, biochemical and genetic. The most likely mode of inheritance has been suggested as autosomal dominant although recessive genes may also exist. An association with environmental and biomechanical factors is often described, with mechanical trauma from eye-rubbing, stimulation through contact lens wear or kerato-refractive laser surgery reported as contributing factors in the progression of Keratoconus. The possible role of biochemical factors has also been implicated in the aetiology of this disease with elevated levels of matrix metalloproteinases and inflammatory cytokines found in Keratoconus. However, it is unclear if this is reflective of a cause or effect.

Contact lenses and surgical procedures can both be used to improve vision. The most crucial aspect of management is provider cooperation to achieve the best outcome. If you want to learn more, you should use other educational resources in addition to what information you have. Sadly, numerous resources will cover approaches which are contradictory or conflicting to each other. This may be due to 'bad science' or incomplete science or because there is one or more financial interests at play, and which is what is at the center of the matters becoming skewed and the reason for the information being corrupt. However Peer-Reviewed studies from respected Journals are the standard bearers to rely on for well developed critical observation, examination and scrutiny, which may take long term results to achieve. 

‘The patient is the final judge of what success is.’

The aim in this review is to:
(1) provide a comprehensive overview of the current therapeutic modalities of keratoconus; 
(2) propose a systematic and practical treatment algorithm; and 
(3) discuss the future directions of the management of keratoconus.


Resources & Literature

For further insight on the key topics please take a moment to lookup the listed resources above and the below widely accepted literature publications.

Further Reading Index

a) Keratoconus Prevalence

b) Etiology, Pathophysiology, Genetics, and Associated Disease

c) Corneal Biomechanics and Its Relationship to Keratoconus

d) Optics of Keratoconus and Correcting Aberrations with Wavefront-Guided Lenses

e) Diagnostics and Monitoring

f 1) Pediatrics and Keratoconus

f 2) Corneal Crosslinking for Keratoconus and Corneal Ectasia

g) Surgical Management of Keratoconus

h) Specialty Contact Lenses for Keratoconus

i) Collaborative Care in Keratoconus

j) Clinical Pearls for Communicating with Keratoconic Patients

a} Keratoconus Prevalence

1 Randleman JB, Khandelwal SS, Hafezi F. Corneal cross-linking. Surv Ophthalmol. 2015;60(6):509-523.

2 Kennedy RH, Bourne WM, Dyer JA. A 48-Year Clinical and Epidemiologic Study of Keratoconus. American Journal of Ophthalmology. 1986;101(3):267-273.

3 Ihalainen A. Clinical and epidemiological features of keratoconus genetic and external factors in the pathogenesis of the disease. Acta Ophthalmol Suppl (1985). 1986;178:1-64.

4 Gorskova EN, Sevost’ianov EN. Epidemiology of keratoconus in the Urals. Vestn Oftalmol. 1998;114(4):38-40.

5 Gomes JAP, Rodrigues PF, Lamazales LL. Keratoconus epidemiology: A review. Saudi J Ophthalmol. 2022;36(1):3-6.

6 Georgiou T, Funnell CL, Cassels-Brown A, O’Conor R. In©uence of ethnic origin on the incidence of keratoconus and associated atopic disease in Asians and white patients. Eye (Lond). 2004;18(4):379-383.

7 Nielsen K, Hjortdal J, Pihlmann M, Corydon TJ. Update on the keratoconus genetics. Acta Ophthalmol. 2013;91(2):106-113.

8 Pizzarello LD. Refractive changes in pregnancy. Graefes Arch Clin Exp Ophthalmol. 2003;241(6):484-488.

9 Tanabe U, Fujiki K, Ogawa A, Ueda S, Kanai A. Prevalence of keratoconus patients in Japan. Nippon Ganka Gakkai Zasshi. 1985;89(3):407-411.

10 Chan E, Chong EW, Lingham G, et al. Prevalence of Keratoconus Based on Scheimp- ©ug Imaging: The Raine Study. Ophthalmology. 2021;128(4):515-521.

11 Jonas JB, Nangia V, Matin A, Kulkarni M, Bhojwani K. Prevalence and associations of keratoconus in rural maharashtra in central India: the central India eye and medical study. Am J Ophthalmol. 2009;148(5):760-765.

12 Xu L, Wang YX, Guo Y, You QS, Jonas JB, Beijing Eye Study G. Prevalence and asso ciations of steep cornea/keratoconus in Greater Beijing. The Beijing Eye Study. PLoS One. 2012;7(7):e39313.

13 Assiri AA, Yousuf BI, Quantock AJ, Murphy PJ. Incidence and severity of keratoconus in Asir province, Saudi Arabia. Br J Ophthalmol. 2005;89(11):1403-1406.

14 Hashemi H, Khabazkhoob M, Fotouhi A. Topographic Keratoconus is not Rare in an Iranian population: the Tehran Eye Study. Ophthalmic Epidemiol. 2013;20(6):385-391.

15 Hashemi H, Khabazkhoob M, Yazdani N, et al. The prevalence of keratoconus in a young population in Mashhad, Iran. Ophthalmic Physiol Opt. 2014;34(5):519-527.

16 Millodot M, Shneor E, Albou S, Atlani E, Gordon-Shaag A. Prevalence and associated factors of keratoconus in Jerusalem: a cross-sectional study. Ophthalmic Epidemiol. 2011;18(2):91-97.

17 Ziaei H, Jafarinasab MR, Javadi MA, et al. Epidemiology of keratoconus in an Iranian population. Cornea. 2012;31(9):1044-1047.

18 Torres Netto EA, Al-Otaibi WM, Hafezi NL, et al. Prevalence of keratoconus in paedi atric patients in Riyadh, Saudi Arabia. Br J Ophthalmol. 2018;102(10):1436-1441.

19 Lucas SEM, Burdon KP. Genetic and Environmental Risk Factors for Keratoconus. Annu Rev Vis Sci. 2020;6:25-46.

20 Weed KH, MacEwen CJ, Giles T, Low J, McGhee CN. The Dundee University Scottish Keratoconus study: demographics, corneal signs, associated diseases, and eye rubbing. Eye (Lond). 2008;22(4):534-541

21 Gordon-Shaag A, Millodot M, Shneor E, Liu Y. The genetic and environmental factors for keratoconus. Biomed Res Int. 2015;2015:795738.

22 Hafezi F, Hafezi NL, Pajic B, et al. Assessment of the mechanical forces applied during eye rubbing. BMC Ophthalmol. 2020;20(1):301.

23 Mazharian A, Panthier C, Courtin R, et al. Incorrect sleeping position and eye rubbing in patients with unilateral or highly asymmetric keratoconus: a case-control study. Graefes Arch Clin Exp Ophthalmol. 2020;258(11):2431-2439.

24 Zadnik K, Barr JT, Edrington TB, et al. Baseline «ndings in the Collaborative  Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998;39(13):2537-2546.

25 Nowak DM, Gajecka M. The genetics of keratoconus. Middle East Afr J Ophthalmol. 2011;18(1):2-6.

26 Gupta PD, Johar K, Sr., Nagpal K, Vasavada AR. Sex hormone receptors in the human eye. Surv Ophthalmol. 2005;50(3):274-284.

27 Spoerl E, Zubaty V, Raiskup-Wolf F, Pillunat LE. Oestrogen-induced changes in biomechanics in the cornea as a possible reason for keratectasia. Br J Ophthalmol. 2007;91(11):1547-1550.

28 Pobelle-Frasson C, Velou S, Huslin V, Massicault B, Colin J. Keratoconus: what happens with older patients?. J Fr Ophtalmol. 2004;27(7):779-782.

29 Torres-Netto EA, Randleman JB, Hafezi NL, Hafezi F. Late-onset progression of kera toconus after therapy with selective tissue estrogenic activity regulator. J Cataract Refract Surg. 2019;45(1):101-104.

30 Lee R, Hafezi F, Randleman JB. Bilateral Keratoconus Induced by Secondary Hypo thyroidism After Radioactive Iodine Therapy. J Refract Surg. 2018;34(5):351-353.

31 Tuft SJ, Hassan H, George S, Frazer DG, Willoughby CE, Liskova P. Keratoconus in 18 pairs of twins. Acta Ophthalmol. 2012;90(6):e482-486.

32 Wang Y, Rabinowitz YS, Rotter JI, Yang H. Genetic epidemiological study of kerato conus: Evidence for major gene determination. American Journal of Medical Genetics. 2000;93(5):403-409.

33 McComish BJ, Sahebjada S, Bykhovskaya Y, et al. Association of Genetic Variation With Keratoconus. JAMA Ophthalmol. 2020;138(2):174-181.

34 Lapeyre G, Fournie P, Vernet R, et al. Keratoconus Prevalence in Families: A French Study. Cornea. 2020;39(12):1473-1479.

35 Abu-Amero KK, Al-Muammar AM, Kondkar AA. Genetics of keratoconus: where do we stand? J Ophthalmol. 2014;2014:641708.

36 Burdon KP, Vincent AL. Insights into keratoconus from a genetic perspective. Clin Exp Optom. 2013;96(2):146-154.

37 Sza¥ik JP, Sza¥ik J, Blasiak J, Wojcik KA. Role of biochemical factors in the pathogen esis of keratoconus. Acta Biochimica Polonica. 2014;61(1


b) Etiology, Pathophysiology, Genetics, and Associated Disease

1 Mathan JJ, Gokul A, Simkin SK, Meyer JJ, Patel DV, McGhee CNJ. Topographic screening reveals keratoconus to be extremely common in Down syndrome. Clin Experiment Ophthalmol. 2020;48(9):1160-1167. doi:10.1111/ceo.13852

2 Rabinowitz YS. Keratoconus. Surv Ophthalmol. 1998;42(4):297-319. doi:10.1016/s0039-6257(97)00119-7

3 Loukovitis E, Sfakianakis K, Syrmakesi P, et al. Genetic Aspects of Keratoco[1]nus: A Literature Review Exploring Potential Genetic Contributions and Possi[1]ble Genetic Relationships with Comorbidities. Ophthalmol Ther. 2018;7(2):263-292. doi:10.1007/s40123-018-0144-8

4. Rabinowitz YS. The genetics of keratoconus. Ophthalmol Clin N Am. 2003;16(4):607-620, vii. doi:10.1016/s0896-1549(03)00099-3

5 Zadnik K, Barr JT, Edrington TB, et al. Baseline findings in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci. 1998;39(13):2537-2546.

6 Wang Y, Rabinowitz YS, Rotter JI, Yang H. Genetic epidemiological study of keratoconus: evidence for major gene determination. Am J Med Genet. 2000;93(5):403-409.

7 Romero-Jiménez M, Santodomingo-Rubido J, Wolffsohn JS. Keratoconus: a review. Contact Lens Anterior Eye J Br Contact Lens Assoc. 2010;33(4):157-166; quiz 205. doi:10.1016/j.clae.2010.04.006

8 Burdon KP, Vincent AL. Insights into keratoconus from a genetic perspective. Clin Exp Optom. 2013;96(2):146-154. doi:10.1111/cxo.12024

9 Tyynismaa H, Sistonen P, Tuupanen S, et al. A locus for autosomal dominant keratoconus: linkage to 16q22.3-q23.1 in Finnish families. Invest Ophthalmol Vis Sci. 2002;43(10):3160-3164.

10 Pathak D, Nayak B, Singh M, et al. Mitochondrial complex 1 gene analysis in keratoconus. Mol Vis. 2011;17:1514-1525.

11 Cankaya C, Gunduz A, Cumurcu T, Demirel S, Savaci SS, Cavdar M. Familial association of keratoconus and granular corneal dystrophy: The familial case series. North Clin Istanb. 2019;6(2):176-183. doi:10.14744/nci.2018.08860

12 Bechara SJ, Waring GO, Insler MS. Keratoconus in two pairs of identical twins. Cornea. 1996;15(1):90-93.

13 Hao X dan, Chen X nian, Zhang Y yang, et al. Multi-level consistent changes of the ECM pathway identified in a typical keratoconus twin’s family by multi-omics analysis. Orphanet J Rare Dis. 2020;15(1):227. doi:10.1186/s13023-020-01512-7

14 Gordon-Shaag A, Millodot M, Essa M, Garth J, Ghara M, Shneor E. Is consan[1]guinity a risk factor for keratoconus? Optom Vis Sci O‹ Publ Am Acad Optom. 2013;90(5):448-454. doi:10.1097/OPX.0b013e31828da95c

15 Shapiro MB, France TD. The ocular features of Down’s syndrome. Am J Oph[1]thalmol. 1985;99(6):659-663. doi:10.1016/s0002-9394(14)76031-3

16 Hardcastle AJ, Liskova P, Bykhovskaya Y, et al. A multi-ethnic genome-wide association study implicates collagen matrix integrity and cell differentiation pathways in keratoconus. Commun Biol. 2021;4(1):266. doi:10.1038/s42003-021-01784-0

17 Jafri, B., Lichter, H., & Stulting, R. D. (2004). Asymmetric keratoconus attributed to eye rubbing. Cornea, 23(6), 560–564. https://doi.org/10.1097/01. ico.0000121711.58571.8d

18 Goldich Y, Barkana Y, Gerber Y, et al. Effect of diabetes mellitus on biomechan[1]ical parameters of the cornea. J Cataract Refract Surg. 2009;35(4):715-719. doi:10.1016/j.jcrs.2008.12.013

19 Kuo IC, Broman A, Pirouzmanesh A, Melia M. Is there an association between diabetes and keratoconus? Ophthalmology. 2006;113(2):184-190. doi:10.1016/j.ophtha.2005.10.009

20 Seiler T, Huhle S, Spoerl E, Kunath H. Manifest diabetes and keratoconus: a retrospective case-control study. Graefes Arch Clin Exp Ophthalmol Albrecht Von Graefes Arch Klin Exp Ophthalmol. 2000;238(10):822-825. doi:10.1007/s004179900111

21 Woodward MA, Blachley TS, Stein JD. The Association Between Sociodemo[1]graphic Factors, Common Systemic Diseases, and Keratoconus: An Analysis of a Nationwide Heath Care Claims Database. Ophthalmology. 2016;123(3):457 465.e2. doi:10.1016/j.ophtha.2015.10.035

22 Merdler I, Hassidim A, Sorkin N, et al. Keratoconus and allergic diseases among Israeli adolescents between 2005 and 2013. Cornea. 2015;34:525–9.

23 Thyssen, J. P., Toft, P. B., Halling-Overgaard, A. S., Gislason, G. H., Skov, L., & Egeberg, A. (2017). Incidence, prevalence, and risk of selected ocular disease in adults with atopic dermatitis. Journal of the American Academy of Derma[1]tology, 77(2), 280–286.e1. https://doi.org/10.1016/j.jaad.2017.03.003

24 Harrison RJ, Klouda PT, Easty DL, Manku M, Charles J, Stewart CM. Associa[1]tion between keratoconus and atopy. Br J Ophthalmol. 1989;73(10):816-822. doi:10.1136/bjo.73.10.816

25 Bawazeer AM, Hodge WG, Lorimer B. Atopy and keratoconus: a multivariate analysis. Br J Ophthalmol. 2000;84(8):834-836. doi:10.1136/bjo.84.8.834

26 Bak-Nielsen S, Ramlau-Hansen CH, Ivarsen A, Plana-Ripoll O, Hjortdal J. A nationwide population-based study of social demographic factors, associated diseases and mortality of keratoconus patients in Denmark from 1977 to 2015. Acta ophthalmologica. 2019B;97(5):497-504. doi: 10.1111/aos.13961. PubMed PMID: 30426693.

27 Farjadnia M, Naderan M, Mohammadpour M. Gene therapy in keratoconus. Oman J Ophthalmol. 2015;8(1):3-8. doi:10.4103/0974-620X.149854

28 Karolak JA, Gajecka M. Genomic strategies to understand causes of kerato[1]conus. Mol Genet Genomics. 2017;292(2):251-269. doi:10.1007/s00438-016-1283-z

29 Moussa S, Grabner G, Ruckhofer J, Dietrich M, Reitsamer H. Genetics in Keratoconus – What is New? Open Ophthalmol J. 2017;11(1):201-210. doi:10.2174/1874364101711010201

30 Bykhovskaya Y, Margines B, Rabinowitz YS. Genetics in Keratoconus: where are we? Eye Vis. 2016;3(1):16. doi:10.1186/s40662-016-0047-5

31 Abu-Amero KK, Al-Muammar AM, Kondkar AA. Genetics of Keratoconus: Where Do We Stand? J Ophthalmol. 2014;2014:1-11. doi:10.1155/2014/641708

32 Burdon KP, Macgregor S, Bykhovskaya Y, et al. Association of Polymorphisms in the Hepatocyte Growth Factor Gene Promoter with Keratoconus. Investig Opthalmology Vis Sci. 2011;52(11):8514. doi:10.1167/iovs.11-8261

33 Fram, Nicole R., Say Anything: What Is the Role of Genetic Testing for Kerato[1]conus and Corneal Dystrophies in Your Practice? CRST 20


c) Corneal Biomechanics and Its Relationship to Keratoconus

1 Abahussin, M., Hayes, S., Cartwright, N. E. K., Kamma-Lorger, C. S., Khan, Y., Marshall, J., & Meek, K. M. (2009). 3D collagen orientation study of the human cornea using X-ray diffraction and femtosecond laser technology. Investigative Ophthalmology & Visual Science, 50(11), 5159–5164.

2 Meek, K. M., Tuft, S. J., Huang, Y., Gill, P. S., Hayes, S., Newton, R. H., & Bron, A. J. (2005). Changes in collagen orientation and distribution in keratoconus corneas. Investigative Ophthalmology & Visual Science, 46(6), 1948–1956.

3 Sherwin, T., & Brookes, N. H. (2004). Morphological changes in keratoconus: Pathology or pathogenesis. Clinical & Experimental Ophthalmology, 32(2), 211–217.

4 Seiler, T. G., Shao, P., Eltony, A., Seiler, T., & Yun, S.-H. (2019). Brillouin spectroscopy of normal and keratoconus corneas. American Journal of Ophthalmology, 202, 118–125.

5 Torres-Netto, E. A., Hafezi, F., Spiru, B., Gilardoni, F., Hafezi, N., Gomes, J. A. P., Randleman, J. B., Sekundo, W., & Kling, S. (2020). Contribution of Bowman layer to corneal biomechanics. Journal of Cataract & Refractive Surgery.

6 Kling, S., Torres-Netto, E. A., Spiru, B., Sekundo, W., & Hafezi, F. (2020). Quasi Static Optical Coherence Elastography to Characterize Human Corneal Biomechanical Properties. Investigative Ophthalmology & Visual Science, 61(6), 29–29.

7 Gatinel, D. (2016). Eye rubbing, a sine qua non for keratoconus. Int J Kerat Ect Cor Dis, 5(1), 6–12.

8 Kenney, M. C., & Brown, D. J. (2003). The cascade hypothesis of keratoconus. Contact Lens and Anterior Eye, 26(3), 139–146.

9 Torres-Netto, E. A., Abdshahzadeh, H., Abrishamchi, R., Hafezi, N. L., Hillen, M., Ambrósio Jr, R., Randleman, J. B., Spoerl, E., Gatinel, D., & Hafezi, F. (2022). The Impact of Repetitive and Prolonged Eye Rubbing on Corneal Biomechanics. Journal of Refractive Surgery, 38(9), 610–616.

10 Li, D.-Q., & Pflugfelder, S. C. (2005). Matrix metalloproteinases in corneal inflammation. The Ocular Surface, 3(4), S-198.

11 Nishtala, K., Pahuja, N., Shetty, R., Nuijts, R. M., & Ghosh, A. (2016). Tear biomarkers for keratoconus. Eye and Vision, 3(1), 1–7.

12 Shao, P., Eltony, A. M., Seiler, T. G., Tavakol, B., Pineda, R., Koller, T., Seiler, T., & Yun, S.-H. (2019). Spatially-resolved Brillouin spectroscopy reveals biomechanical abnormalities in mild to advanced keratoconus in vivo. Scientific Reports, 9(1), 1–12.

13 Lopes, B. T., Padmanabhan, P., Eliasy, A., Zhang, H., Abass, A., & Elsheikh, A. (2022). In vivo Assessment of Localised Corneal Biomechanical Deterioration With Keratoconus Progression. Frontiers in Bioengineering and Biotechnology, 10.

14 Scarcelli, G., Besner, S., Pineda, R., & Yun, S. H. (2014). Biomechanical characterization of keratoconus corneas ex vivo with Brillouin microscopy. Investigative Ophthalmology & Visual Science, 55(7), 4490–4495.

15 De Stefano, V. S., Ford, M. R., Seven, I., & Dupps, W. J. (2020). Depth-depen[1]dent corneal biomechanical properties in normal and keratoconic subjects by optical coherence elastography. Translational Vision Science & Technology, 9(7), 4–4.

16 Andreassen, T. T., Simonsen, A. H., & Oxlund, H. (1980). Biomechanical prop[1]erties of keratoconus and normal corneas. Experimental Eye Research, 31(4), 435–441.

17 Nash, I. S., Greene, P. R., & Foster, C. S. (1982). Comparison of mechanical properties of keratoconus and normal corneas. Experimental Eye Research, 35(5), 413–424.

18 Fontes, B. M., Ambrósio Jr, R., Velarde, G. C., & Nosé, W. (2011). Ocular response analyzer measurements in keratoconus with normal central corneal thickness compared with matched normal control eyes. Journal of Refractive Surgery, 27(3), 209–215.

19 Hafezi, F., Frigelli, Matteo, Torres-Netto, Emilio A., & Kling, Sabine. (2022). OCT Elastography In Normal And Keratoconus Subjects. Annual Meeting of the European Society of Cataract and Refractive Surgery, Milano.

20 Blackburn, B. J., Gu, S., Ford, M. R., de Stefano, V., Jenkins, M. W., Dupps, W. J., & Rollins, A. M. (2019). Noninvasive assessment of corneal crosslinking with phase-decorrelation optical coherence tomography. Investigative Ophthalmology & Visual Science, 60(1), 41–51.

21 Blackburn, B., Murray, J., Ford, M. R., Jenkins, M. W., Dupps, W. J., & Rollins, A. M. (2020). Detection of weakening in an enzymatic ex vivo model of corneal ectasia with phase-decorrelation OCT. Optical Coherence Tomography, OW1E-4

 

d) Optics of Keratoconus and Correcting Aberrations with Wavefront-Guided Lenses

1 Mannis M, Ling J, Kyrillos R, et al. Keratoconus and personality—a review: Cornea 2018; 37: 400–4.

2 Applegate R, Donnelly III W, Marsack J, et al. Three-dimensional relationship between high-order root-mean-square wavefront error, pupil diameter, and aging. J Opt Soc Am A. 2007; 24: 578–87.

3 Salmon TO, van de Pol C. Normal-eye Zernike coefficients and root-mean[1]square wavefront errors. J Cataract Refract Surg. 2006; 32: 2064-74.

4 Pantanelli S, MacRae S, Jeong TM, et al. Characterizing the wave aberration in eyes with keratoconus or penetrating keratoplasty using a high-dynamic range wavefront sensor. Ophthalmol. 2007; 114:2013-21.

5 Hastings GD, Applegate RA, Nguyen LC, et al. Comparison of wavefront-guided and best conventional scleral lenses after habituation in eyes with corneal ectasia. Optom Vis Sci. 2019; 96: 238–47.

6 Chen M, Yoon G. Posterior corneal aberrations and their compensation effects on anterior corneal aberrations in keratoconic eyes. Invest Ophthalmol Vis Sci. 2008; 49: 5645-52.

7 Sabesan R, Johns L, Tomashevskaya O, et al. Wavefront-guided scleral lens prosthetic device for keratoconus. Optom Vis Sci 2013; 90: 314–23.

8 Marsack JD, Ravikumar A, Nguyen C, Ticak A, Koenig DE, Elswick JD, Applegate RA. Wavefront-guided scleral lens correction in keratoconus. Optom Vis Sci. 2014 Oct;91(10):1221-30. doi: 10.1097/OPX.0000000000000275. PMID: 24830371; PMCID: PMC4232493.

9 Gelles JD, Cheung B, Akilov S, et al.. Ocular Impression-Based Scleral Lens With Wavefront-Guided Optics for Visual Improvement in Keratoconus. Eye Contact Lens. 2022 Jul 29.

10 https://patents.google.com/patent/US6086204A/en?inventor=Peter+C.+Mag[1]nante


e) Diagnostics and Monitoring

1 Shah H, Pagano L, Vakharia A, Coco G, Gadhvi KA, Kaye SB, Romano V. Impact of COVID-19 on keratoconus patients waiting for corneal cross linking. Eur J Ophthalmol. 2021 Nov;31(6):3490-3493. doi: 10.1177/11206721211001315. Epub 2021 Mar 15. PMID: 33719638.

2 Wilson SE, Lin DT, Klyce SD. Corneal topography of keratoconus. Cornea 1991;10:2-8.

3 Wilson SE, Ambrosio R. Computerized corneal topography and its importance to wavefront technology. Cornea 2001;20:441-54.

4 Rabinowitz YS, McDonnell PJ. Computer-assisted corneal topography in keratoconus. Refractive & corneal surgery 1989;5:400-8.

5 Maeda N, Klyce SD, Smolek MK, Thompson HW. Automated keratoconus screening with corneal topography analysis. Investigative ophthalmology & visual science 1994;35:2749-57.

6 Maguire LJ, Bourne WM. Corneal topography of early keratoconus. American journal of ophthalmology 1989;108:107-12.

7 Maeda N, Klyce SD, Smolek MK. Comparison of methods for detecting keratoconus using videokeratography. Archives of ophthalmology 1995;113:870-4.

8 Wilson SE, Klyce SD. Advances in the analysis of corneal topography. Surv Ophthalmol 1991;35:269-77.

9 Klyce SD. Chasing the suspect: keratoconus. Br J Ophthalmol 2009;93:845-7.

10 Ambrosio R, Jr., Alonso RS, Luz A, Coca Velarde LG. Corneal-thickness spatial pro«le and corneal-volume distribution: tomographic indices to detect keratoconus. Journal of cataract and refractive surgery 2006;32:1851-9.

11 Reinstein DZ, Silverman RH, Rondeau MJ, Coleman DJ. Epithelial and corneal thickness measurements by high-frequency ultrasound digital signal processing. Ophthalmology 1994;101:140-6.

12 Salomao MQ, Ho¥ing-Lima AL, Lopes BT, et al. Role of the corneal epithe[1]lium measurements in keratorefractive surgery. Curr Opin Ophthalmol 2017;28:326-36.

13 Reinstein DZ, Gobbe M, Archer TJ, Silverman RH, Coleman DJ. Epithelial, stromal, and total corneal thickness in keratoconus: three-dimensional display with artemis very-high frequency digital ultrasound. Journal of refractive surgery (Thorofare, NJ : 1995) 2010;26:259-71.

14 Reinstein DZ, Archer TJ, Urs R, Gobbe M, RoyChoudhury A, Silverman RH. Detection of Keratoconus in Clinically and Algorithmically Topographically Normal Fellow Eyes Using Epithelial Thickness Analysis. Journal of refractive surgery (Thorofare, NJ : 1995) 2015;31:736-44.

15 Li Y, Chamberlain W, Tan O, Brass R, Weiss JL, Huang D. Subclinical kerato[1]conus detection by pattern analysis of corneal and epithelial thickness maps with optical coherence tomography. Journal of cataract and refractive surgery 2016;42:284-95.

16 Li Y, Tan O, Brass R, Weiss JL, Huang D. Corneal epithelial thickness mapping by Fourier-domain optical coherence tomography in normal and keratoconic eyes. Ophthalmology 2012;119:2425-33.

17 Chandapura R, Salomao MQ, Ambrosio R, Jr., Swarup R, Shetty R, Sinha Roy A. Bowman’s topography for improved detection of early ectasia. J Biophotonics 2019;12:e201900126.

18 Colak HN, Kantarci FA, Yildirim A, et al. Comparison of corneal topographic measurements and high order aberrations in keratoconus and normal eyes. Contact Lens and Anterior Eye 2016;39:380-4.

19 Jafri B, Li X, Yang H, Rabinowitz YS. Higher order wavefront aberrations and topography in early and suspected keratoconus. J Refract Surg 2007;23:774-81.

20 Gobbe M, Guillon M. Corneal wavefront aberration measurements to detect keratoconus patients. Cont Lens Anterior Eye 2005;28:57-66.

21 Alio JL, Shabayek MH. Corneal higher order aberrations: a method to grade keratoconus. J Refract Surg 2006;22:539-45.

22 Maeda N, Fujikado T, Kuroda T, et al. Wavefront aberrations measured with Hartmann-Shack sensor in patients with keratoconus. Ophthalmology 2002;109:1996-2003.

23 Ambrosio R, Jr., Caldas DL, Silva RS, Pimentel LN, Valbon BF. Impacto da análise do “wavefront” na refractometria de pacientes com ceratocone. Rev Bras Oftalmol 2010;29:294-300.

24 Luz A, Faria-Correia F, Salomão MQ, Lopes BT, Ambrósio Jr R. Corneal biome[1]chanics: Where are we? Journal of current ophthalmology 2016;28:97.

25 Luce DA. Determining in vivo biomechanical properties of the cornea with an ocular response analyzer. Journal of cataract and refractive surgery 2005;31:156-62.

26 Pinero DP, Alcon N. In vivo characterization of corneal biomechanics. Journal of cataract and refractive surgery 2014;40:870-87.

27 Roberts CJ. Concepts and misconceptions in corneal biomechanics. Journal of cataract and refractive surgery 2014;40:862-9.

28 Shah S, Laiquzzaman M, Bhojwani R, Mantry S, Cunliffe I. Assessment of the biomechanical properties of the cornea with the ocular response analyzer in normal and keratoconic eyes. Invest Ophthalmol Vis Sci 2007;48:3026-31.

29 Fontes BM, Ambrosio Junior R, Jardim D, Velarde GC, Nose W. Ability of corneal biomechanical metrics and anterior segment data in the di´erentiation of keratoconus and healthy corneas. Arquivos brasileiros de oftalmologia 2010;73:333-7.

30 Fontes BM, Ambrosio R, Jr., Jardim D, Velarde GC, Nose W. Corneal biome[1]chanical metrics and anterior segment parameters in mild keratoconus. Ophthalmology 2010;117:673-9.

31 Ambrósio Jr R, Ramos I, Luz A, et al. Dynamic ultra high speed Scheimpflug imaging for assessing corneal biomechanical properties. Revista Brasileira de Oftalmologia 2013;72:99-102.

32 Salomao MQ, Hofling-Lima AL, Faria-Correia F, et al. Dynamic corneal deformation response and integrated corneal tomography. Indian journal of ophthalmology 2018;66:373-82. 33 Roberts CJ, Vinciguerra R, Vinciguerra P, et al. Biomechanical Assessment with the Corvis ST Integration with Tomography. Oculus Special Supplement 2016:2.

34 Francis M, Pahuja N, Shroff R, et al. Waveform analysis of deformation amplitude and deflection amplitude in normal, suspect, and keratoconic eyes. Journal of cataract and refractive surgery 2017;43:1271-80.

35 Kuebler AG, Wiecha C, Reznicek L, et al. Comparison of different devices to measure the intraocular pressure in thyroid-associated orbitopathy. Graefe’s archive for clinical and experimental ophthalmology. Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie 2019.

36 Pillunat KR, Herber R, Spoerl E, Erb C, Pillunat LE. A new biomechanical glaucoma factor to discriminate normal eyes from normal pressure glaucoma eyes. Acta ophthalmologica 2019.

37 Lee H, Roberts CJ, Ambrosio R, Jr., Elsheikh A, Kang DSY, Kim TI. Effect of accelerated corneal crosslinking combined with transepithelial photorefractive keratectomy on dynamic corneal response parameters and biomechanically corrected intraocular pressure measured with a dynamic Scheimpflug ana[1]lyzer in healthy myopic patients. Journal of cataract and refractive surgery 2017;43:937-45.

38 Salomão MQ, Faria-Correa F, Ramos I, Luz A, Ambrósio R. J. Corneal deformation response with dynamic ultra-high-speed scheimpflug imaging for detecting ectatic corneas. Int J Keratoconus Ectatic Corneal Dis 2016;5:1-5.

39 Salomão M, Hoing-Lima AL, Lopes B, et al. Recent developments in keratoconus diagnosis. Expert Review of Ophthalmol. 2018;13:329-41.

40 Wheeler J, Hauser MA, Afshari NA, Allingham RR, Liu Y. The Genetics of Keratoconus: A Review. Reprod Syst Sex Disord 2012.

41 Bykhovskaya Y, Rabinowitz YS. Update on the genetics of keratoconus. Exp Eye Res 2021;202:108398. https://doi.org/10.1016/j.exer.2020.108398.

42 Bisceglia L, De Bonis P, Pizzicoli C, Fischetti L, Laborante A, Di Perna M, et al. Linkage analysis in keratoconus: Replication of locus 5q21.2 and identification of other suggestive loci. Investig Ophthalmol Vis Sci 2009;50:1081–6. https:// doi. org/10.1167/iovs.08-2382.

43 Bykhovskaya Y, Li X, Taylor KD, Haritunians T, Rotter JI, Rabinowitz YS. Linkage analysis of high-density SNPs confirms keratoconus locus at 5q chromosomal region. Ophthalmic Genet 2016;37:109–10. https://doi.org/10.310 9/13816810.2014.889172.

44 Aknin C, Allart J, Rouland J. Unilateral keratoconus and mirror image in a pair of monozygotic twins. Journal francais d’ophtalmologie 2007;30:899.

45 Stabuc-Silih M, Strazisar M, Ravnik-Glavac M, Hawlina M, Glavac D. Genetics and clinical characteristics of keratoconus. Acta Dermatovenerol Alp Pannonica Adriat 2010;19:3-10.

46 Nowak DM, Gajecka M. The genetics of keratoconus. Middle East Afr J Ophthalmol 2011;18:2-6.

47 Khaled ML, Helwa I, Drewry M, Seremwe M, Estes A, Liu Y. Molecular and Histopathological Changes Associated with Keratoconus. BioMed research international. 2017/03/03 ed2017:7803029.

34 | Jobson Medical Information: The Keratoconus Education Initiative 2023

48 Shetty R, Ghosh A, Lim RR, et al. Elevated expression of matrix metallopro[1]teinase-9 and inflammatory cytokines in keratoconus patients is inhibited by cyclosporine. Invest Ophthalmol Vis Sci 2015;56:738-50.

49 Hashemi H, Asgari S, Panahi P, Mehravaran S, Fotouhi A, Ambrósio R. Corneal ectasia in mothers of Down syndrome children. Scientific Reports 2021;11:1-5.

50 Akoto T, Li JJ, Estes AJ, Karamichos D, Liu Y. The Underlying Relationship between Keratoconus and Down Syndrome. International Journal of Molecular Sciences 2022;23:10796.

51 Regueiro U, López-López M, Varela-Fernández R, Sobrino T, Diez-Feijoo E, Lema I. Immunomodulatory Effect of Human Lactoferrin on Toll-like Receptors 2 Expression as Therapeutic Approach for Keratoconus. International Journal of Molecular Sciences 2022;23:12350.

52 Rabinowitz YS, Rasheed K. KISA% index: a quantitative videokeratography algorithm embodying minimal topographic criteria for diagnosing keratoconus. J Cataract Refract Surg 1999;25:1327-35.

53 Randleman JB, Woodward M, Lynn MJ, Stulting RD. Risk assessment for ectasia after corneal refractive surgery. Ophthalmology 2008;115:37-50.

54 Randleman JB, Trattler WB, Stulting RD. Validation of the Ectasia Risk Score System for preoperative laser in situ keratomileusis screening. American journal of ophthalmology 2008;145:813-8.

55 Reinstein DZ, Archer TJ, Gobbe M. Stability of LASIK in topographically suspect keratoconus confirmed non-keratoconic by Artemis VHF digital ultrasound epithelial thickness mapping: 1-year follow-up. J Refract Surg 2009;25:569-77.

56 Klein SR, Epstein RJ, Randleman JB, Stulting RD. Corneal ectasia after laser in situ keratomileusis in patients without apparent preoperative risk factors. Cornea 2006;25:388-403.

57 Ambrosio R, Jr., Dawson DG, Salomao M, Guerra FP, Caiado AL, Belin MW. Corneal ectasia after LASIK despite low preoperative risk: tomographic and biomechanical findings in the unoperated, stable, fellow eye. Journal of refractive surgery (Thorofare, NJ : 1995) 2010;26:906-11.

58 Malecaze F, Coullet J, Calvas P, Fournie P, Arne JL, Brodaty C. Corneal ectasia after photorefractive keratectomy for low myopia. Ophthalmology 2006;113:742-6.

59 Ambrosio R, Jr., Nogueira LP, Caldas DL, et al. Evaluation of corneal shape and biomechanics before LASIK. International ophthalmology clinics 2011;51:11-38.

60 Lopes BT, Ramos IC, Dawson DG, Belin MW, Ambrosio R, Jr. Detection of ec[1]tatic corneal diseases based on pentacam. Zeitschrift fur medizinische Physik 2016;26:136-42.

61 Ambrosio R, Jr., Valbon BF, Faria-Correia F, Ramos I, Luz A. Scheimp©ug imaging for laser refractive surgery. Curr Opin Ophthalmol 2013;24:310-20.

62 Ambrosio Jr R, Belin M. Enhanced screening for ectasia risk prior to laser laser vision correction. . International Journal of Keratoconus and Ectatic Corneal Diseases 2017;6:23-33.

63 Lopes BT, Ramos IC, Salomao MQ, et al. Enhanced Tomographic Assessment to Detect Corneal Ectasia Based on Artificial Intelligence. American journal of ophthalmology 2018;195:223-32.

64 Ambrósio Jr R, Ramos I, Lopes B, et al. Assessing ectasia susceptibility prior to LASIK: the role of age and residual stromal bed (RSB) in conjunction to Belin-Ambrósio deviation index (BAD-D). Revista Brasileira de Oftalmologia 2014;73:75-80.

65 Flockerzi E, Hafner L, Xanthopoulou K, et al. Reliability analysis of successive Corneal Visualization Scheimpflug Technology measurements in different keratoconus stages. Acta Ophthalmol 2022;100:e83-e90.

66 Flockerzi E, Vinciguerra R, Belin MW, Vinciguerra P, Ambrosio R, Jr., Seitz B. Correlation of the Corvis Biomechanical Factor with tomographic parameters in keratoconus. J Cataract Refract Surg 2022;48:215-21.

67 Flockerzi E, Vinciguerra R, Belin MW, Vinciguerra P, Ambrosio R, Jr., Seitz B. Combined biomechanical and tomographic keratoconus staging: Adding

a biomechanical parameter to the ABCD keratoconus staging system. Acta Ophthalmol 2022;100:e1135-e42.

68 Eliasy A, Chen K-J, Vinciguerra R, et al. Determination of Corneal Biomechanical Behavior in-vivo for Healthy Eyes Using CorVis ST Tonometry: Stress-Strain Index. Frontiers in bioengineering and biotechnology 2019;7.

69 Vinciguerra R, Ambrosio R, Jr., Elsheikh A, et al. Detection of Keratoconus With a New Biomechanical Index. J Refract Surg 2016;32:803-10.

70 Lopes BT, Ramos IdC, Salomão MQ, Canedo ALC, Ambrósio Jr R. Perfil paquimétrico horizontal para a detecção do ceratocone. Rev Bras Oftalmol 2015;74:382-5.

71 Flockerzi E, Hafner L, Xanthopoulou K, et al. Reliability analysis of successive Corneal Visualization Scheimpflug Technology measurements in different keratoconus stages. Acta Ophthalmol 2021.

72 Ambrosio R, Jr., Lopes BT, Faria-Correia F, et al. Integration of Scheimp©ug Based

Corneal Tomography and Biomechanical Assessments for Enhancing Ectasia Detection. J Refract Surg 2017;33:434-43.

73 Ambrosio R, Jr., Correia FF, Lopes B, et al. Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications. Open Ophthalmol J 2017;11:176-93.

74 Kataria P, Padmanabhan P, Gopalakrishnan A, Padmanaban V, Mahadik S, Ambrósio Jr R. Accuracy of Scheimpflug-derived corneal biomechanical and tomographic indices for detecting subclinical and mild keratectasia in a South Asian population. Journal of Cataract & Refractive Surgery 2019;45:328-36.

75 Sedaghat M-R, Momeni-Moghaddam H, Ambrósio Jr R, et al. Diagnostic ability of corneal shape and biomechanical parameters for detecting frank keratoconus. Cornea 2018;37:1025-34.

76 Ferreira-Mendes J, Lopes BT, Faria-Correia F, Salomão MQ, Rodrigues-Barros S, Ambrósio Jr R. Enhanced ectasia detection using corneal tomography and biomechanics. American journal of ophthalmology 2019;197:7-16.

77 Steinberg J, Siebert M, Katz T, et al. Tomographic and Biomechanical Scheimp[1]flug Imaging for Keratoconus Characterization: A Validation of Current Indices. J Refract Surg 2018;34:840-7.

78 Sedaghat MR, Momeni-Moghaddam H, Ambrosio R, Jr., et al. Long-term Eval[1]uation of Corneal Biomechanical Properties After Corneal Cross-linking for Keratoconus: A 4-Year Longitudinal Study. J Refract Surg 2018;34:849-56.

79 Valbon BF, Ambrosio Jr R, Glicéria J, Santos R, Luz A, Alves MR. Unilateral corneal ectasia after Bilateral LASIK: the thick flap counts. International Journal of Keratoconus and Ectatic Corneal Diseases 2013;2:79.

80 Ambrósio Jr R, Lopes B, Amaral J, et al. Ceratocone: Quebra de paradigmas e contradições de uma nova subespecialidade. Revista Brasileira de Oftalmologia 2019;78:81-5.

81 Augustin VA, Son HS, Baur I, Zhao L, Auffarth GU, Khoramnia R. Detecting subclinical keratoconus by biomechanical analysis in tomographically regular keratoconus fellow eyes. European journal of ophthalmology 2021:11206721211063740.

82 Belin M, Duncan J, Ambrósio Jr R, Gomes J. Keratoconus: the ABCD grading system. Int J Kerat Ect Cor Dis 2015;4:55-63.

83 Belin M, Meyer J, Duncan J, Gelman R, Borgstrom M, Ambrosio R. Assessing progression of keratoconus and cross-linking efficacy: the Belin ABCD Progression Display. Int J Kerat Ect Cor Dis 2017;6:1-10.

84 Flockerzi E, Vinciguerra R, Belin MW, Vinciguerra P, Ambrósio Jr R, Seitz B. Correlation of the Corvis Biomechanical Factor CBiF with tomographic param[1]eters in keratoconus. Journal of cataract and refractive surgery 2021.

85 Shen Y, Han T, Jhanji V, et al. Correlation Between Corneal Topographic, Densitometry, and Biomechanical Parameters in Keratoconus Eyes. Transla[1]tional vision science & technology 2019;8:12-.

86 Lopes B, Ramos I, Ambrosio R, Jr. Corneal densitometry in keratoconus. Cornea 2014;33:1282-6.


f 1) Pediatrics and Keratoconus

1 Mukhtar S, Ambati BK. Pediatric keratoconus: a review of the literature. Int Ophthalmol. 2018 Oct;38(5):2257-2266. doi: 10.1007/s10792-017-0699-8. Epub 2017 Aug 29. PMID: 28852910; PMCID: PMC5856649.

2 Leoni-Mesplie, S., et al. Scalability and Severity of Keratoconus in Children. American Journal of Ophthalmology, July 2012: 154(1)56-62.

3 Gordon MO, Steger-May K, Szczotka-Flynn L, Riley C, Joslin CE, Weissman BA, Fink BA, Edrington TB, Olafsson HE, Zadnik K; Clek Study Group. Baseline factors predictive of incident penetrating keratoplasty in keratoconus. Am J Ophthalmol. 2006 Dec;142(6):923-30. doi: 10.1016/j.ajo.2006.07.026. Epub 2006 Sep 1. PMID: 17157577.

4 Al-Mahrouqi H, et al. Retinoscopy as a Screening Tool for Keratoconus. Cornea April 2019; 38(4):442-445.

5 Zadnik K, et al. CLEK Study Group. Collaborative longitudinal evaluation of keratoconus. Between-eye asymmetry in keratoconus. Cornea. 2002; 21:671-679.

6 Bykhovskaya Y, Rabinowitz YS. Update on the genetics of keratoconus. Exp Eye Res. 2021 Jan;202:108398. doi: 10.1016/j.exer.2020.108398. Epub 2020 Dec 13. PMID: 33316263.

7 Caporossi A, et al. Age-related long-term functional results after ribo[1]flavin UV A corneal cross-linking. J Ophthalmol. 2011;2011:608041. doi.org/10.1155/2011/60804

8 Glaukos Announces Positive Phase 3 Trial Results for iLink Epi-on Investiga[1]tional Therapy That Met the Primary Efficacy Endpoint

9 Gaster RN, Margines JB, Li X, Canedo AC, Rabinowitz YS. Results of corneal crosslinking in adolescents with progressive keratoconus: prospective study. J Cataract Refract Surg. 2021 Oct 1;47(10):1333-1337. doi: 10.1097/j. jcrs.0000000000000617. PMID: 33769766.

10 Perez-Straziota C, Gaster RN, Rabinowitz YS. Corneal Cross-Linking for Pediatric Keratcoconus Review. Cornea. 2018 Jun;37(6):802-809. doi: 10.1097/ ICO.0000000000001579. PMID: 29601364; PMCID: PMC5938128.

11 Akkaya Turhan S, Aydın FO, Toker E. Clinical Results of Repeated Corneal Collagen Cross-linking in Progressive Keratoconus. Cornea. 2020 Jan;39(1):84- 87. doi: 10.1097/ICO.0000000000002128. PMID: 31490276.

12 Michaud L, Breton L. Contact Lens Fitting Post-Corneal Cross-linking. Contact Lens Spectrum. 2018 Mar;33:30-34,51.

13 Perez-Straziota C, Gaster RN, Rabinowitz YS. Corneal Cross-Linking for Pediatric Keratcoconus Review. Cornea. 2018 Jun;37:802-809.

14 Olivo-Payne A, et al. Optimal management of pediatric keratoconus: challenges and solutions. Clinical Ophthalmology. 2019;13:1183-1191.

15 Anitha, V. et al. Pediatric Keratoconus – Current perspectives and clinical challenges. Indian J Ophthalmology. 2021 Feb; 69(2): 214-225.

16 Huang C, O’Hara M, Mannis MJ. Primary pediatric keratoplasty: indications and outcomes. Cornea 2009;28(9):1003–8.

17 Asuri MK, Garg P, Gokhle N, Gupta S. Penetrating keratoplasty in children. Cornea 2000;19(2):140–4.

18 Koppen C, Kreps EO, Anthonissen L, Van Hoey M, Dhubhghaill SN, Vermeulen L. Scleral lenses reduce the need for corneal transplants in severe keratoconus. Am J Ophthalmol 2018;185:43–7.

 

f 2) Corneal Crosslinking for Keratoconus and Corneal Ectasia

1 Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-a-induced collagen cross[1]linking for the treatment of keratoconus. Am J Ophthalmol 2003;135:620-7.

2 Brooks NO, Greenstein S, Fry K, Hersh PS. Patient subjective visual function after corneal collagen crosslinking for keratoconus and corneal ectasia. J Cataract Refract Surg 2012;38:615-9.

3 Greenstein SA, Fry KL, Bhatt J, Hersh PS. Natural history of corneal haze after collagen crosslinking for keratoconus and corneal ectasia: Scheimpflug and biomicroscopic analysis. J Cataract Refract Surg 2010;36:2105-14.

4 Greenstein SA, Fry KL, Hersh MJ, Hersh PS. Higher-order aberrations after corneal collagen crosslinking for keratoconus and corneal ectasia. J Cataract Refract Surg 2012;38:292-302.

5 Greenstein SA, Fry KL, Hersh PS. Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results. J Cataract Refract Surg 2011;37:1282-90.

6 Greenstein SA, Fry KL, Hersh PS. In vivo biomechanical changes after corneal collagen cross-linking for keratoconus and corneal ectasia: 1-year analysis of a randomized, controlled, clinical trial. Cornea 2012;31:21-5.

7 Hersh PS, Greenstein SA, Fry KL. Corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results. J Cataract Refract Surg 2011;37:149-60.

8 Wollensak G, Spoerl E, Seiler T. Stress-strain measurements of human and porcine corneas after riboflavin-ultraviolet-A-induced cross-linking. J Cataract Refract Surg 2003;29:1780-5.

9 Sawaguchi S, Yue BY, Chang I, Sugar J, Robin J. Proteoglycan molecules in keratoconus corneas. Invest Ophthalmol Vis Sci 1991;32:1846-53. 10 Hersh PS, Stulting RD, Muller D, Durrie DS, Rajpal RK. U.S. Multicenter Clinical Trial of Corneal Collagen Crosslinking for Treatment of Corneal Ectasia after Refractive Surgery. Ophthalmology 2017;124:1475-84.

11 Hersh PS, Stulting RD, Muller D, Durrie DS, Rajpal RK. United States Multi[1]center Clinical Trial of Corneal Collagen Crosslinking for Keratoconus Treatment. Ophthalmology 2017;124:1259-70.

12 Henriquez MA, Villegas S, Rincon M, Maldonado C, Izquierdo L, Jr. Long-term efficacy and safety after corneal collagen crosslinking in pediatric patients: Three-year follow-up. Eur J Ophthalmol 2018;28:415-8.

13 Mazzotta C, Traversi C, Baiocchi S, et al. Corneal Collagen Cross-Linking With Riboflavin and Ultraviolet A Light for Pediatric Keratoconus: Ten-Year Results. Cornea 2018;37:560-6.

14 Raiskup F, Theuring A, Pillunat LE, Spoerl E. Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: ten-year results. J Cataract Refract Surg 2015;41:41-6.

15 Vinciguerra R, Romano V, Arbabi EM, et al. In Vivo Early Corneal Biomechanical Changes After Corneal Cross-linking in Patients With Progressive Keratoconus. J Refract Surg 2017;33:840-6.

16 Kucumen RB, Sahan B, Yildirim CA, Ciftci F. Evaluation of Corneal Biomechanical Changes After Collagen Crosslinking in Patients with Progressive Keratoconus by Ocular Response Analyzer. Turk J Ophthalmol 2018;48:160-5.

17 Scarcelli G, Pineda R, Yun SH. Brillouin optical microscopy for corneal biomechanics. Invest Ophthalmol Vis Sci 2012;53:185-90.

18 Seiler T, Hafezi F. Corneal cross-linking-induced stromal demarcation line. Cornea 2006;25:1057-9. m19 Greenstein SA, Hersh PS. Characteristics influencing outcomes of corneal collagen crosslinking for keratoconus and ectasia: implications for patient selection. J Cataract Refract Surg 2013;39:1133-40.

20 Stulting RD, Trattler WB, Woolfson JM, Rubinfeld RS. Corneal crosslinking without epithelial removal. J Cataract Refract Surg 2018;44:1363-70.

21 Hersh PS, Lai MJ, Gelles JD, Lesniak SP. Transepithelial corneal crosslinking for keratoconus. J Cataract Refract Surg 2018;44:313-22.

22 Rosenblat E, Hersh PS. Intraoperative corneal thickness change and clinical outcomes after corneal collagen crosslinking. J Cat Refract Surg 2016; 42: 596-605.

23 Alio JL, Shabayek MH, Artola A. Intracorneal ring segments for keratoconus correction: long-term follow-up. J Cataract Refract Surg 2006;32:978-85.

24 Hersh PS, R; Greenstein, S.A. Corneal Collagen Crosslinking and Intracorneal Ring Segments for Keratoconus: A Randomized Study of Concurrent versus Sequential Treatment. Journal of Cataract and Refractive Surgery 2019.

25 Sakla H, Altroudi W, Munoz G, Albarran-Diego C. Simultaneous topography-guided partial photorefractive keratectomy and corneal collagen crosslinking for keratoconus. J Cataract Refract Surg 2014;40:1430-8.

 

Practice Considerations in Managing Keratoconus and Cross-Linking

REFERENCES:

1.Eisenberg JS. First Treatment for Keratoconus Itself. Optometry Times, June 1, 2012.

2.Lindstrom RL et al. J Med Econ 2021;24:410. 3. Godefrooij DA, Gans R, Imhof SM, et al. Acta Ophthalmol 2016; 94:675 678

INDICATIONS

Photrexa Viscous (riboflavin 5’-phosphate in 20% dextran ophthalmic solution) and Photrexa (riboflavin 5’-phos phate ophthalmic solution) are indicated for use with the KXL System in corneal collagen cross-linking for the treatment of progressive keratoconus and corneal ectasia following refractive surgery.

IMPORTANT SAFETY INFORMATION

Corneal collagen cross-linking should not be performed on pregnant women.

Ulcerative keratitis can occur. Patients should be monitored for resolution of epithelial defects. The most common ocular adverse reaction was corneal opacity (haze). Other ocular side e‡ects include punctate keratitis, corneal striae, dry eye, corneal epithelium defect, eye pain, light sensitivity, reduced visual acuity, and blurred vision.

 These are not all of the side effects of the corneal collagen cross-linking treatment. For more information, go to www.livingwithkeratoconus.com to obtain the FDA-approved product labeling.

You are encouraged to report all side effects to the FDA.

Optometry’s Role in the Patient Journey

1. Koller T et al. J Cataract Refract Surg 2009;35:1358. 2. Davidson AE et al. Eye (Lond) 2014;28:189. 3. Tan JCK, et al. Cornea 2019;38:600. 4. Kandel H, et al. Clin Exp Ophthalmol 2022;Epub ahead of print. 5. Lindstrom RL et al. J Med Econ 2021;24:410. 6. American Academy of Ophthalmology Preferred Practice Pattern, Corneal Ectasia, 2018

INDICATIONS

Photrexa Viscous (riboflavin 5’-phosphate in 20% dextran ophthalmic solution) and Photrexa (riboflavin 5’-phos[1]phate ophthalmic solution) are indicated for use with the KXL System in corneal collagen cross-linking for the treatment of progressive keratoconus and corneal ectasia following refractive surgery.

IMPORTANT SAFETY INFORMATION

Corneal collagen cross-linking should not be performed on pregnant women.

Ulcerative keratitis can occur. Patients should be monitored for resolution of epithelial defects. The most common ocular adverse reaction was corneal opacity (haze). Other ocular side e‡ects include punctate keratitis, corneal striae, dry eye, corneal epithelium defect, eye pain, light sensitivity, reduced visual acuity, and blurred vision.

These are not all of the side effects of the corneal collagen cross-linking treatment. For more information, go to www.livingwithkeratoconus.com to obtain the FDA-approved product labeling.

You are encouraged to report all side effects to the FDA.

Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.


g) Surgical Management of Keratoconus

1 Hersh PS, Stulting RD, Muller D, Durrie DS, Rajpal RK, United States Cross[1]linking Study G. United States Multicenter Clinical Trial of Corneal Collagen Crosslinking for Keratoconus Treatment. Ophthalmology 2017;124:1259-70.

2 Greenstein SA, Hersh PS. Corneal Crosslinking for Progressive Keratoconus and Corneal Ectasia: Summary of US Multicenter and Subgroup Clinical Trials. Transl Vis Sci Technol 2021;10:13.

3 Holmes-Higgin DK, Burris TE. Corneal surface topography and associated visual performance with INTACS for myopia: phase III clinical trial results. The INTACS Study Group. Ophthalmology 2000;107:2061-71.

4 Rabinowitz YS. INTACS for keratoconus. Int Ophthalmol Clin 2006;46:91-103.

5 Hersh PS, Issa R, Greenstein SA. Corneal crosslinking and intracorneal ring segments for keratoconus: A randomized study of concurrent versus sequen[1]tial surgery. J Cataract Refract Surg 2019;45:830-9.

6 Greenstein SA, Chung D, Rosato L, Gelles JD, Hersh PS. Corneal higher-order

aberrations after crosslinking and intrastromal corneal ring segments for keratoconus. J Cataract Refract Surg 2020;46:979-85.

7 Nguyen N, Gelles JD, Greenstein SA, Hersh PS. Incidence and associations of intracorneal ring segment explantation. J Cataract Refract Surg 2019;45:153-8.

8 Stulting RD, Fant BS, Group TCS, et al. Results of topography-guided laser in situ keratomileusis custom ablation treatment with a refractive excimer laser. J Cataract Refract Surg 2016;42:11-8.

9 Cheng SM, Tu RX, Li X, et al. Topography-Guided Versus Wavefront-Optimized LASIK for Myopia With and Without Astigmatism: A Meta-analysis. J Refract Surg 2021;37:707-14.

10 Nattis A, Donnenfeld ED, Rosenberg E, Perry HD. Visual and keratometric outcomes of keratoconus patients after sequential corneal crosslinking and topography-guided surface ablation: Early United States experience. J Cataract Refract Surg 2018;44:1003-11.

11 Greenstein SA DI, N, Hersh PS,. Transepithelial Topography Guided PRK for Keratoconus. ASCRS 2021, Las Vegas NV.

12 Kanellopoulos AJ. Ten-Year Outcomes of Progressive Keratoconus Manage[1]ment With the Athens Protocol (Topography-Guided Partial-Refraction PRK Combined With CXL). J Refract Surg 2019;35:478-83.

13 Nattis AS, Rosenberg ED, Donnenfeld ED. One-year visual and astigmatic outcomes of keratoconus patients following sequential crosslinking and topography-guided surface ablation: the TOPOLINK study. J Cataract Refract Surg 2020;46:507-16.

14 Eye Bank Association of America 2019 Data.

15 Shams M, Sharifi A, Akbari Z, Maghsoudlou A, Reza Tajali M. Penetrating Keratoplasty versus Deep Anterior Lamellar Keratoplasty for Keratoconus: A Systematic Review and Meta-analysis. J Ophthalmic Vis Res 2022;17:89-107.

16 Anwar M, Teichmann KD. Deep lamellar keratoplasty: surgical techniques for anterior lamellar keratoplasty with and without baring of Descemet’s mem[1]brane. Cornea 2002;21:374-83.

17 Son HS, Rigi M, Srikumaran D, Eberhart CG, Jun AS, Soiberman US. “Groove and Peel” Deep Anterior Lamellar Keratoplasty: How Deep Can You Go? Cornea 2022.

18 Farid M, Rostov AT. Femtosecond laser deep lamellar keratoplasty. Indian J Ophthalmol 2022;70:3669-72.

19 Ganesh S, Brar S. Femtosecond Intrastromal Lenticular Implantation Combined With Accelerated Collagen Cross-Linking for the Treatment of Keratoco[1]nus--Initial Clinical Result in 6 Eyes. Cornea 2015;34:1331-9.

20 Eshraghi H GS, Gelles J, Hersh P. Cornea Tissue Addition for Keratoconus (CTAK): Clinical Trial of Allogenic Corneal Inlays for Keratoconus. ASCRRS 2021, Las Vegas NV.

21 Rafat M, Jabbarvand M, Sharma N, et al. Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts. Nat Biotechnol 2022.

22 Shah Z, Hussain I, Borroni D, Khan BS, Wahab S, Mahar PS. Bowman’s layer transplantation in advanced keratoconus; 18-months outcomes. Int Ophthal[1]mol 2022;42:1161-73.

23 Panda A, Aggarwal A, Madhavi P, et al. Management of acute corneal hydrops secondary to keratoconus with intracameral injection of sulfur hexafluoride (SF6). Cornea 2007;26:1067-9.

24 Yahia Cherif H, Gueudry J, Afriat M, et al. Efficacy and safety of pre-Descem[1]et’s membrane sutures for the management of acute corneal hydrops in keratoconus. Br J Ophthalmol 2015;99:773-7.

25 Bachmann B, Handel A, Siebelmann S, Matthaei M, Cursiefen C. Mini-De[1]scemet Membrane Endothelial Keratoplasty for the Early Treatment of Acute Corneal Hydrops in Keratoconus. Cornea 2019;38:1043-8.

26 Garcia de Oteyza G, Bregliano G, Sassot I, Quintana L, Rius C, Garcia-Albisua AM. Primary surgical options for acute corneal hydrops: A review. Eur J Ophthalmol 2021:11206721211037833.

27 Fairaq R, Almutlak M, Almazyad E, Badawi AH, Ahad MA. Outcomes and complications of implantable collamer lens for mild to advanced keratoconus. Int Ophthalmol 2021;41:2609-18.

28 Moshirfar M, Ziari M, Ronquillo YC. Cataract surgery considerations in patients with prior history of keratoconus and ectasia. Curr Opin Ophthalmol 2022.

29 Ton Y, Barrett GD, Kleinmann G, Levy A, Assia EI. Toric intraocular lens power calculation in cataract patients with keratoconus. J Cataract Refract Surg 2021;47:1389-97

 

h) Specialty Contact Lenses for Keratoconus

1 Edrington TB, Szczotka LB, Barr JT, et al. Rigid contact lens «tting relationships in keratoconus. Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study Group. Optom Vis Sci 1999;76:692–9.

2 Koppen C, Kreps EO, Anthonissen L, et al. Scleral Lenses Reduce the Need for Corneal Transplants in Severe Keratoconus. Am J Ophthalmol 2017 Nov 15. pii: S0002-9394(17)30453-1. doi: 10.1016/j.ajo.2017.10.022.

3 Rathi VM, Mandathara PS, Dumpati S. Contact lens in keratoconus. In: Indian Jour[1]nal of Ophthalmology. Vol 61. Wolters Kluwer -- Medknow Publications; 2013:410–

4 Jupiter DG, Katz HR. Management of irregular astigmatism with rigid gas permeable contact lenses. CLAO J 2000;26:14–7.

5 Shorter E, Harthan J, Nau CB, Nau A, Barr JT, Hodge DO, Schornack MM. Scleral Lenses in the Management of Corneal Irregularity and Ocular Surface Disease. Eye Contact Lens 2018;44:372–8.

6 Barr JT, Zadnik K, Wilson BS, Edrington TB, Everett DF, Fink BA, Shovlin JP, Weissman BA, Siegmund K, Gordon MO. Factors associated with corneal scar[1]ring in the collaborative longitudinal evaluation of keratoconus (CLEK) study. Cornea 2000;19:501–7.

7 Zadnik K, Barr JT, Steger-May K, Edrington TB, McMahon TT, Gordon MO. Comparison of flat and steep rigid contact lens fitting methods in keratoconus. Optom Vis Sci 2005;82:1014–21.

8 Michaud L, Brazeau D, Corbeil ME, Forcier P, Bernard PJ. Contribution of soft lenses of various powers to the optics of a piggy-back system on regular cor[1]neas. Contact Lens Anterior Eye 2013;36:318–23.

9 Schornack M. Medical indications for scleral lens use in Barnett M, Johns LK. Contemporary Scleral Lenses: Theory and Application. Bentham Science 2017. Chapter 5 135-141. Volume 4 ISBN: 978-1-68108-567-8.

10 Efron N and Pearson RM. Centenary celebration of Fick’s Eine Contactbrille. Archives of ophthalmology. 1988;106(10):1370-7.

11 Pearson RM. Kalt, keratoconus, and the contact lens. Optom Vis Sci. 1989;66(9):643-6.

12 Levit A, Benwell M, Evans BJW. Randomised controlled trial of corneal vs. scleral rigid gas permeable contact lenses for keratoconus and other ectatic corneal disorders. Cont Lens Anterior Eye. 2020 Jan 7. pii: S1367-0484(19)30268-1. doi: 10.1016/j.clae.2019.12.007. [Epub ahead of print]

13 McMonnies CW. The biomechanics of keratoconus and rigid contact lenses. Eye Contact Lens. 2005 Mar;31(2):80-92. doi: 10.1097/01.icl.0000146321.56815.75.

14 Soeters N, Visser ES, Imhof SM, et al. Scleral lens in©uence on corneal curvature and pachymetry in keratoconus patients. Cont Lens Anterior Eye. 2015 Aug;38(4):294-7.

15 Severinsky B, Fadel D, Davelman J, Moulton E. Effect of Scleral Lenses on Corneal Topography in Keratoconus: A Case Series of Cross-Linked Versus Non-Cross-Linked Eyes. Cornea. 2019 Aug;38(8):986-991.

16 Serramito-Blanco M, Carpena-Torres C, Carballo J, et al. Anterior Corneal Cur[1]vature and Aberration Changes After Scleral Lens Wear in Keratoconus Patients With and Without Ring Segments Eye Contact Lens. 2019 Mar;45(2):141-148.

17 Tyagi G, Collins M, Read S, et al. Regional changes in corneal thickness and shape with soft contact lenses. Optom Vis Sci. 2010 Aug;87(8):567-75. doi: 10.1097/OPX.0b013e3181e61b78.

18 Hastings GD, Applegate RA, Nguyen LC, et al. Comparison of wavefront-guided and best conventional scleral lenses after habituation in eyes with corneal ectasia. Optom Vis Sci. 2019; 96: 238–47.

19 Sabesan R, Johns L, Tomashevskaya O, et al. Wavefront-guided scleral lens prosthetic device for keratoconus. Optom Vis Sci 2013; 90: 314–23.

20 Gelles JD, Hillier KE, Krisa S, Greenstein SA, Hersh PS. Lipid Keratopathy Management With Therapeutic Scleral Lens Wear. Eye Contact Lens. 2022 Feb 1;48(2):91-94. doi: 10.1097/ICL.0000000000000866. PMID: 35058420.

21 Chen M, Yoon G. Posterior corneal aberrations and their compensation effects on anterior corneal aberrations in keratoconic eyes. Invest Ophthalmol Vis Sci. 2008; 49: 5645-52.

22 Cressey A, Jacobs DS, Carrasquillo KG. Management of vascularized limbal keratitis with prosthetic replacement of the ocular surface system. Eye Contact Lens. 2012;38:137-140.

23 Koh S, Inoue R, Maeda N, et al. Corneal tomographic changes during corneal rigid gas-permeable contact lens wear in keratoconic eyes. Br J Ophthalmol. 2022 Feb;106(2):197-202. doi: 10.1136/bjophthalmol-2020-317057. Epub 2020 Nov 10.

24 Walker MK, Bergmanson JP, Miller WL, et al. Complications and «tting challenges associated with scleral contact lenses: A review. Cont Lens Anterior Eye. 2016 Apr;39(2):88-96. doi: 10.1016/j.clae.2015.08.003. Epub 2015 Sep 2. PMID: 26341076

25 Romero-Jiménez M, Santodomingo-Rubido J, Wolffsohn JS. Keratoconus: a review. Cont Lens Anterior Eye. 2010;33(4):157-166; quiz 205. doi:10.1016/j.clae.2010.04.006

26 Sharma N, Rao K, Maharana PK, Vajpayee RB. Ocular allergy and keratoconus. Indian J Ophthalmol. 2013;61(8):407-409. doi:10.4103/0301-4738.116063

27 Bawazeer AM, Hodge WG, Lorimer B. Atopy and keratoconus: a multivariate analysis. Br J Ophthalmol. 2000;84(8):834-836. doi:10.1136/bjo.84.8.834

28 Douglas JP, Lowder CY, Lazorik R, et al. Giant papillary conjunctivitis associated with rigid gas permeable contact lenses. CLAO J. 1988 Jul-Sep;14(3):143-7. PMID: 3208429

29 Jupiter D, Karesh J. Ptosis associated with PMMA/rigid gas permeable contact lens wear. CLAO J. 1999 Jul;25(3):159-62. PMID: 10444052

30 Kobashi H, Rong SS. Corneal Collagen Cross-Linking for Keratoconus: Systematic Review. Biomed Res Int. 2017;2017:8145651. doi: 10.1155/2017/8145651. Epub 2017 Jun 11.

31 Kim BZ, Jordan CA, McGhee CN, Patel DV. Natural history of corneal haze after corneal collagen crosslinking in keratoconus using Scheimpflug analysis. J Cataract Refract Surg. 2016 Jul;42(7):1053-9. doi: 10.1016/j.jcrs.2016.04.019. PMID: 27492105.

32 Greenstein SA, Fry KL, Bhatt J, Hersh PS. Natural history of corneal haze after collagen crosslinking for keratoconus and corneal ectasia: Scheimpflug and biomicroscopic analysis. J Cataract Refract Surg. 2010 Dec;36(12):2105-14. doi: 10.1016/j.jcrs.2010.06.067. PMID: 21111314.

33 Koller T, Pajic B, Vinciguerra P, Seiler T. Flattening of the cornea after collagen crosslinking for keratoconus. J Cataract Refract Surg. 2011 Aug;37(8):1488-92. doi: 10.1016/j.jcrs.2011.03.041. PMID: 21782091.

34 Hersh PS, Stulting RD, Muller D, Durrie DS, Rajpal RK; United States Crosslink[1]ing Study Group. United States Multicenter Clinical Trial of Corneal Collagen Crosslinking for Keratoconus Treatment. Ophthalmology. 2017 Sep;124(9):1259-1270. doi: 10.1016/j.ophtha.2017.03.052. Epub 2017 May 7. Erratum in: Ophthal[1]mology. 2017 Dec;124(12 ):1878. PMID: 28495149.

35 Mandathara PS, Kalaiselvan P, Rathi VM, Murthy SI, Taneja M, Sangwan VS. Contact lens fitting after corneal collagen cross-linking. Oman J Ophthalmol. 2019 Oct 11;12(3):177-180. doi: 10.4103/ojo.OJO_43_2018. eCollection 2019 Sep-Dec. PMID: 31902993

36 Visser ES, Soeters N, Tahzib NG. Scleral lens tolerance after corneal cross-link[1]ing for keratoconus. Optom Vis Sci. 2015 Mar;92(3):318-23. doi: 10.1097/OPX.0000000000000515. PMID: 25599340.

37 Nepomuceno RL, Boxer Wachler BS, Weissman BA. Feasibility of contact lens fitting on keratoconus patients with INTACS inserts. Cont Lens Anterior Eye. 2003 Dec;26(4):175-80. doi: 10.1016/S1367-0484(03)00049-3. PMID: 16303515.

38 Bautista-Llamas MJ, Sánchez-González MC, López-Izquierdo I, López-Muñoz A, Gargallo-Martínez B, De-Hita-Cantalejo C, Sánchez-González JM. Complica[1]tions and Explantation Reasons in Intracorneal Ring Segments (ICRS) Implan[1]tation: A Systematic Review. J Refract Surg. 2019 Nov 1;35(11):740-747. doi: 10.3928/1081597X-20191010-02. PMID: 31710377.

39 Nguyen N, Gelles JD, Greenstein SA, Hersh PS. Incidence and associations of intracorneal ring segment explantation. J Cataract Refract Surg. 2019 Feb;45(2):153-158. doi: 10.1016/j.jcrs.2018.09.021. Epub 2018 Nov 30. PMID: 30509748.

40 Kanellopoulos AJ, Vingopoulos F, Sideri AM. Long-Term Stability With the Athens Protocol (Topography-Guided Partial PRK Combined With Cross-Linking) in Pediatric Patients With Keratoconus. Cornea. 2019 Aug;38(8):1049-1057. doi: 10.1097/ICO.0000000000001996. PMID: 31169612.

41 Kanellopoulos AJ. Ten-Year Outcomes of Progressive Keratoconus Management With the Athens Protocol (Topography-Guided Partial-Refraction PRK Combined With CXL). J Refract Surg. 2019 Aug 1;35(8):478-483. doi: 10.3928/1081597X[1]20190627-01. PMID: 31393985.

42 Wietharn BE, Driebe WT Jr. Fitting contact lenses for visual rehabilitation after penetrating keratoplasty. Eye Contact Lens. 2004 Jan;30(1):31-3. doi: 10.1097/01.ICL.0000101488.84455.E6. PMID: 14722466.

43 Schear MJ, Ibrahim K, Winokur J, Busuioc C, Udell I, Steiner A. Treatment Lim[1]itations With PROSE (Prosthetic Replacement of the Ocular Surface Ecosystem): One Centers Experience. Eye Contact Lens. 2019 Sep;45(5):315-317. doi: 10.1097/ ICL.0000000000000610. PMID: 31033605.

44 Kumar M, Shetty R, Khamar P, Vincent SJ. Scleral Lens-Induced Corneal Edema after Penetrating Keratoplasty. Optom Vis Sci. 2020 Sep;97(9):697-702. doi: 10.1097/OPX.0000000000001571. PMID: 32932397.

45 Nguyen LT, Yang D, Vien L. Case Series: Corneal Epithelial Macrocysts in Scleral Contact Lenses Post-penetrating Keratoplasty. Optom Vis Sci. 2018 Jul;95(7):616-620. doi: 10.1097/OPX.0000000000001245. PMID: 29957737


i) Collaborative Care in Keratoconus

1 Hashemi H, Heydarian S, Hooshmand E, et al. The Prevalence and Risk Factors for Kerato[1]conus: A Systematic Review and Meta-Analy[1]sis. Cornea. 2020;39(2):263‐270

2 Chan, E., Chong, E., Lingham, G., Stevenson, L., Sanfillippo, P., Hewitt, A., & Yazar, S. (2020, August 21). Prevalence of keratoconus based on Scheimphlug imaging: The RAINE study. Oph[1]thalmology.

3 Eisenberg, J. (2012, May 31). First treatment for keratoconus itself. Optometry Times


j) Clinical Pearls for Communicating with Keratoconic Patients

1 McMahon J. Patient centred care in keratoconus. Optician. Vol.2016 Issue 4, April 2016.

2 Amiri F, Ghiyasvandian S, Navab E, Zakerimoghadam M. Corneal transplantation: A new view of life. Electron Physician. 2017 Apr 25;9(4):4055-4063.

3 Subasinghe SK, Ogbuehi KC, Dias GJ. Current perspectives on corneal collagen crosslinking (CXL). Graefes Arch Clin Exp Ophthalmol. 2018 Aug;256(8):1363-1384.

4 Najmi H, Mobarki Y, Mania K, Altowairqi B, Basehi M, Mahfouz MS, Elmahdy M. The correlation between keratoconus and eye rubbing: a review. Int J Ophthal[1]mol. 2019 Nov 18;12(11):1775-1781.

5 Lim L, Lim EWL. Current perspectives in the management of keratoconus with contact lenses. Eye (Lond). 2020 Dec;34(12):2175-2196.

6 Castro-Luna, G., & Pérez-Rueda, A. (2020). A predictive model for early diagno[1]sis of keratoconus. BMC ophthalmology, 20(1), 263.

7 Gordon-Shaag, A., Millodot, M., Shneor, E., & Liu, Y. (2015). The genetic and environmental factors for keratoconus. BioMed research international, 2015, 795738.

8 Mannis MJ, Ling JJ, Kyrillos R, Barnett M. Keratoconus and Personality-A Review. Cornea. 2018 Mar;37(3):400-404. doi: 10.1097/ICO.0000000000001479. PMID: 29215397.

9 Mannis MJ, Morrison TL, Zadnik K, et al. Personality trends in keratoconus. An analysis. Arch Ophthalmol. 1987 Jun;105(6):798-800.

10 Yildiz M, Turhan SA, Yargı B, et al. Psychiatric morbidity of patients with keratoconus: A cross-sectional study. J Psychosom Res. 2021 Apr;143:110384.doi: 10.1016/j.jpsychores.2021.110384. Epub 2021 Feb 3. PMID: 33611072.

11 Lim, L., & Lim, E. (2020). Current perspectives in the management of keratoconus with contact lenses. Eye (London, England), 34(12), 2175–2196.

12 Vastardis I, Sagri D, Fili S, et al. Current Trends in Modern Visual Intraocular Lens Enhancement Surgery in Stable Keratoconus: A Synopsis of Do’s, Don’tsand Pitfalls. Ophthalmol Ther. 2019 Oct;8(Suppl 1):33-47. doi: 10.1007/s40123-019-00212-1. Epub 2019 Oct 11. PMID: 31605318; PMCID: PMC6789053.

13 Yahalomi, T., Achiron, A., Hecht, I., et al. Refractive Outcomes of Non-Toric and Toric Intraocular Lenses in Mild, Moderate and Advanced Keratoconus: A Systematic Review and Meta-Analysis. J Clin Med. 2022 Apr 27;11(9):2456. doi: 10.3390/jcm11092456. PMID: 35566583; PMCID: PMC9101494.