• Abida Fida Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi
  • Sadia Humayun Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi
  • Iram Fatima Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi
  • Imran Basit Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi
  • Mazhar Ishaq
  • Fida Hussain AFIP Rawalpindi


Background: This study was conducted to evaluate the safety of accelerated corneal collagen crosslinking (CXL) in keratoconus patients on basis of endothelial cell density measurements. Methods: We studied 24 patients (42 eyes) with diagnosed keratoconus who underwent accelerated CXL with 9 Mw/cm2 UVA irradiance for 10minutes. All patients underwent detailed examination and video keratography (VKG) for classification and confirmation of keratoconus. Patients with central corneal thickness (CCT) of ≥400µ were included in the study. Specular microscopy was done to note endothelial cell density (ECD) preoperatively and then at the end of 1st, 4th and 12th weeks’ post-operative period. Results: The study included 24 patients (42 eyes) from October 2016 to June 2017.  Among these 13 were females and 11 males with mean age of 20.15±6.73 years. Eighteen patients underwent the procedure in both eyes while 6 had the procedure in one eye. The pre-operative ECD mean±SD of right eye was 2743.97±542.77/mm2 and left eye was 2763.35±532.57/mm2. The post-operative ECD mean±SD of right and left eyes at the end of 12th post-op weak were 2806.34±520.11/mm2 and 2823.30±628.57/mm2 respectively. The pre and post-op ECD comparison showed p-values at first week post-op are 0.474 and 0.683 for right and left eyes respectively. Similarly, the p-values at 4th and 12 weeks post-op for right eye are 0.266 and 0.280 respectively. The p-values at 4th and 12th weeks for left eye are 0.913 and 0.404 respectively. Conclusion: Accelerated CXL protocols is safe and effective procedure and did not lead to significant change in ECD in our study population in three months post-procedural follow up. However further research is required to determine the effect of high intensity UVA radiation on other ocular structures with larger group of patients and long-term follow up.Keywords: Keratoconus; Prevalence; Epithelium-off corneal crosslinking

Author Biographies

Abida Fida, Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi

Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi

Sadia Humayun, Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi

Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi

Iram Fatima, Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi

Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi

Fida Hussain, AFIP Rawalpindi

Nuclear Medical Centre AFIP Rawalpindi


Goebels S, Eppig T, Seitz B, Langenbucher A. Intraindividual Keratoconus Progression. Klin Monatsbl Augenheilkd 2017;234(8):1010–4.

Jhanji V, Sharma N, Vajpayee RB. Management of keratoconus: current scenario. Br J Ophthalmol 2010;95(8):1044–50.

Rodrigues FD, Santos GC, Gonçalves S, Ferreira CC, Salgado-Borges J. Sequential management of keratoconus treatment. Int J Kerat Ect Cor Dis 2012;1(3):201–4.

Romero-Jiménez M, Santodomingo-Rubido J, Flores-Rodríguez P, González-Méijome JM. Short-term corneal changes with gas-permeable contact lens wear in keratoconus subjects: A comparison of two fitting approaches. J Optom 2015;8(1):48–55.

Gomes JA, Tan D, Rapuano CJ, Belin MW, Ambrósio R Jr, Guell JL, et al. Global consensus on keratoconus and ectatic diseases. Cornea 2015;34(4):359–69.

McCall AS, Kraft S, Edelhauser HF, Kidder GW, Lundquist RR, Bradshaw HE, et al. Mechanisms of corneal tissue cross-linking in response to treatment with topical riboflavin and long-wavelength ultraviolet radiation (UVA). Invest Ophthalmol Vis Sci 2010;51(1):129–38.

Kymionis GD, Grentzelos MA, Kankariya VP, Liakopoulos DA, Portaliou DM, Tsoulnaras KI, et al. Safety of high-intensity corneal collagen crosslinking. J Cataract Refract Surg 2014;40(8):1337–40.

Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-A–induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol 2003;135(5):620–7.

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(1):41–6.

Tsatsos M, MacGregor C, Kopsachilis N, Anderson D. Is accelerated corneal collagen cross-linking for keratoconus the way forward? Yes. Eye (Lond) 2014;28(7):784–5.

Asri D, Touboul D, Fournié P, Malet F, Garra C, Gallois A, et al. Corneal collagen crosslinking in progressive keratoconus: multicenter results from the French National Reference Center for Keratoconus. J Cataract Refract Surg 2011;37(12):2137–43.

Jankov MR 2nd, Hafezi F, Beko M, Ignjatovic Z, Djurovic B, Markovic V, et al. Corneal Cross-linking for the treatment of keratoconus: preliminary results. Arq Bras Oftalmol 2008;71(6):813–8.

Wittig-Silva C, Whiting M, Lamoureux E, Lindsay RG, Sullivan LJ, Snibson GR. A randomized controlled trial of corneal collagen cross-linking in progressive keratoconus: preliminary results. J Refract Surg 2008;24(7):S720–5.

Mazzotta C, Traversi C, Baiocchi S, Sergio P, Caporossi T, Caporossi A. Conservative treatment of keratoconus by riboflavin-uva-induced cross-linking of corneal collagen: qualitative investigation. Eur J Ophthalmol 2006;16(4):530–5.

Raiskup-Wolf F, Hoyer A, Spoerl E, Pillunat LE. Collagen crosslinking with riboflavin and ultraviolet-A light in keratoconus: long-term results. J Cataract Refract Surg 2008;34(5):796–801.

Kymionis GD, Portaliou DM, Diakonis VF, Kounis GA, Panagopoulou SI, Grentzelos MA. Corneal collagen cross-linking with riboflavin and ultraviolet-A irradiation in patients with thin corneas. Am J Ophthalmol 2012;153(1):24–8.

Kymionis GD, Tsoulnaras KI, Liakopoulos DA, Skatharoudi CA, Grentzelos MA, Tsakalis NG. Corneal stromal demarcation line depth following standard and a modified high intensity corneal cross-linking protocol. J Refract Surg 2016;32(4):218–22.

Çınar Y, Cingü AK, Türkcü FM, Çınar T, Yüksel H, Özkurt ZG, et al. Comparison of accelerated and conventional corneal collagen cross-linking for progressive keratoconus. Cutan Ocul Toxicol 2014;33(3):218–22.

Elbaz U, Shen C, Lichtinger A, Zauberman NA, Goldich Y, Chan CC, et al. Accelerated (9-mW/cm2) corneal collagen crosslinking for keratoconus—a 1-year follow-up. Cornea 2014;33(8):769–73.

Ulusoy DM, Göktaş E, Duru N, Özköse A, Ataş M, Yuvacı İ, et al. Accelerated corneal crosslinking for treatment of progressive keratoconus in pediatric patients. Eur J Ophthalmol 2017;27(3):319–25.

Sherif AM. Accelerated versus conventional corneal collagen cross-linking in the treatment of mild keratoconus: a comparative study. Clin Ophthalmol 2014;8:1435–40.

Akbar B, Intisar-ul-Haq R, Ishaq M, Fawad A, Arzoo S, Siddique K. Comparison of transepithelial corneal crosslinking with epithelium-off crosslinking (epithelium-off CXL) in adult Pakistani population with progressive keratoconus. Taiwan J Ophthalmol 2017;7(4):185–90.



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