Imaging modalities in keratoconus.

Diagnosis of keratoconus has greatly improved from simple clinical diagnosis with the advent of better diagnostic devices like corneal topographers based on placido disc, elevation based topographers and lately optical coherence tomography (OCT). These instruments are quite sensitive to pick up early keratoconus, which could help refractive surgeons to avoid serious complications like ectasia following keratorefractive surgeries. Each of these instruments has their advantages and disadvantages; in spite of that each one of them has its own place in the clinical practice. Currently, placido disc based topographers are the most commonly used topographers all over the world. There are many different companies making such devices, which follow the different techniques and color for the display. Due to these differences they are not directly comparable to each other. Various quantitative indices based on these topographers have been suggested and validated by different authors to aid in the diagnosis and quantification of keratoconus. OCT with its higher resolution and deeper penetration has created its place in the diagnostic armamentarium for keratoconus.

Clinical outcome of autologous cultivated limbal epithelium transplantation.

PURPOSE: To report the clinical outcome of autologous cultivated limbal epithelial transplantation. METHODS: Eighty-six patients' records and their clinical photographs were reviewed for demographics, primary etiology, type of limbal transplantation, ocular surface stability, visual acuity, final outcome and possible factors affecting outcome and complications. RESULTS: Eighty-eight eyes of 86 patients with limbal stem cell deficiency (LSCD) underwent autologous cultivated limbal epithelium transplantation between March 2001 and May 2003, with a mean follow-up of 18.3 months. The etiology of LSCD was alkali burns in 64% patients. Sixty-one eyes had total LSCD. Thirty-two of the 88 eyes had undergone amniotic membrane transplantation and 10 eyes had previously undergone limbal transplantation with unfavorable outcome. Nineteen eyes underwent penetrating keratoplasty, of which 11 grafts survived at the final follow-up. Finally, 57 eyes (73.1%, 95% CI: 63.3-82.9) had a successful outcome with a stable ocular surface without conjunctivalization, 21 eyes (26.9%, 95%CI: 17.1-36.7) were considered failures and 10 patients were lost to follow-up. CONCLUSION: LSCD can be successfully treated by autologous cultivated limbal epithelium transplantation in majority of the cases.

Amniotic membrane transplantation for reconstruction of corneal epithelial surface in cases of partial limbal stem cell deficiency.

PURPOSE: To assess the efficacy of amniotic membrane for treatment of partial limbal stem cell deficiency (LSCD). METHODS: Medical records of four patients with partial LSCD who underwent pannus resection and amniotic membrane transplantation (AMT) were reviewed for ocular surface stability and improvement in visual acuity. Clinico-histopathological correlation was done with the resected pannus tissue. RESULTS: All the eyes exhibited stable corneal epithelial surface by an average of 7 weeks postoperatively with improvement in subjective symptoms. Best corrected visual acuity improved from preoperative (range: 6/9p-6/120) to postoperative (range: 6/6p-6/15) by an average of 4.5 lines on Snellen visual acuity charts. Histopathological examination of excised tissue showed features of conjunctivalisation. CONCLUSION: Amniotic membrane transplantation appears to be an effective means of reconstructing the corneal epithelial surface and for visual rehabilitation of patients with partial limbal stem cell deficiency. It may be considered as an alternative primary procedure to limbal transplantation in these cases.