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PURPOSE To quantify the effect of a single scleral lens design on visual acuity and ocular higher-order aberrations in eyes with post-LASIK ectasia, keratoconus and pellucid marginal degeneration (PMD) that could not achieve satisfactory vision with spectacles or soft contact lenses. METHODS Forty-six eyes of 28 participants fitted with diagnostic scleral lenses (KeraCare) were analysed, including 19, 15 and 12 eyes with post-LASIK ectasia, keratoconus and PMD, respectively. Corrected distance visual acuity (CDVA) and ocular aberrations were measured prior to lens wear and during lens wear after 60 min of settling. An i-Trace aberrometer was used to determine aberrations over a 4.5 mm diameter pupil. RESULTS Before lens wear, the median (95% confidence interval) values across all groups were: CDVA 0.30 (0.30, 0.40) logMAR, spherical equivalent refraction -2.75 (-5.25, -2.12) D, cylindrical refraction 3.75 (2.50, 5.00) D, higher-order-root-mean-square error (HO-RMS) 0.90 (0.64, 1.03) μm and vertical coma co-efficient C(3,-1) -0.32 (-0.42, -0.12) μm. RMS coma of 0.52 (0.40, 0.74) μm was higher for the keratoconus group than for the other groups (p

INTRODUCTION: Post-laser in situ keratomileusis (LASIK) corneal ectasia is a serious late postoperative complication. Here, we report the ultrastructural features of the post- LASIK cornea of two patients. METHODS: Two normal corneas (age 24 and 37 years old) and two post-LASIK ectaic corneas from two patients (A and B) were studied. The "patient A" (age 27 years) underwent penetrating keratoplasty and "patient B" (age 31 years) underwent deep- anterior lamellar keratoplasty. The excised corneas were processed for light and electron micros- copy. A total of 120 images for three-dimensional (3D) reconstruction were taken by using the software "Recorder" and using a bottom mounted camera "Quemesa" attached to a JOEL 1400 transmission electron microscope. The 3D images were constructed using "Visual Kai" software. RESULTS: In the post-LASIK cornea, the hemidesmosomes, the basement membrane, and Bowman"s layer were abnormal. The stromal lamellae were thin and disorganized. The collagen fibrils (CFs) diameter and interfibrillar spacing had decreased. Aggregated microfibrils were present in the Bowman's layer and all parts of the stroma. A large number of microfilaments were present at the detachment end of the flap and residual stroma. The 3D images showed the presence of collagen microfibrils and proteoglycans (PGs) within the CF of the normal and post- LASIK cornea. The collagen microfibrils and PGs within the CFs had degenerated in the post- LASIK cornea. CONCLUSION: Collagen microfibrils and PGs within the CFs were degenerated, leading to the degeneration of CFs, followed by the disorganization of lamellae in post-LASIK cornea. The CFs diameter and interfibrillar spacing decreased. Microsc. Res. Tech. 00:000-000

Background: To validate Randleman's model of ectasia risk factor scores using a large unbiased sample of unpublished cases. Methods: Data were collected retrospectively on 36 eyes with ectasia post laser in situ keratomileusis treated by two surgeons at Vision Eye Institute. The data were then entered into Randleman's risk factor score system. Data were also collected about posterior maximum elevation (PME) and posterior maximum elevation position (PMEP); and these were compared with a control group of 50 eyes. Results: Of the 36 eyes, 9 (25%) were classified as low risk, 7 (19%) as moderate risk and 20 (56%) as high risk. On average, the most points were scored in the topography and topography was abnormal in 69% of cases. Topography points also correlated the most strongly with the increasing risk scores (P

Scleral lens has a double interest: Thanks to its anterior optically perfect surface without any contact with the cornea nor the limbus, it erases the irregularities of cornea whatever the degree of ectasia. On the other hand, it provides a favorable microenvironment for regeneration of diseased corneal epithelium. We present our short Algerian experience in cases of challenging cornea, typically requiring keratoplasty (expensive, often unavailable and with unpredictable results), fitted with scleral lens: Primary corneal ectasia (stage IV keratoconus, pellucid marginal degeneration, globus), secondary post Lasik ectasia, failure of corneal reshaping surgery (Lasik, PKR, radial keratotomy and intracorneal ring segment implantation), irregular corneal graft and traumatic or post infectious corneal scar. We present the functional outcome and the quality of life of these patients. Therapeutic scleral lenses have a magical result, we illustrate it with trophic ulcer cases of various etiologies, resistant to conventional treatment and who healed very quickly under scleral lens wear alone. Finally, we present our pilot study on total UV filter scleral lens to protect ocular surface of children with Xeroderma Pigmentosum. Commercial interest

Purpose Post-LASIK corneal ectasia is a serious late postoperative complication. After LASIK, the corneal stroma is structurally weakened. Patients with this complication present with an increase in myopia and astigmatism. Here we report the stromal alteration in the post-LASIK cornea. Methods Two Saudi male patients were diagnosed post-LASIK ectasia. Patient 1, had ectasia six years after LASIK in both eyes. Patient 2, had ectasia four years after LASIK in right eye. Both patients had undergone penetrating keratoplasty in the right eye. The corneas were processed for light (LM) and electron microscopy (EM). Results The LASIK flap was detached from the residual stromal bed. The posterior end of the flap which had separated from the stromal bed lacked collagen fibrils and instead contained numerous very fine microfilaments. The proteoglycans were absent. There were large keratocytes containing a large nucleus in the stroma. The stromal lamellae were thin and disorganized. The collagen fibrils were running randomly and their distribution was not uniform. There were aggregates of micro-filaments, which replaced some parts of the Bowman’s layer and stroma. Conclusion The present study showed the disorganisation of the lamellae collagen fibrils. A large number of microfilaments were present at the detachment end of the flap and the residual stroma. Numerous aggregates of micro-fibrils replaced some parts of the Bowman’s layer and stroma. Acknowledgement: Supported by National Plan for Science and Technology, KSU, Riyadh.

Purpose To study the safety and efficacy of a new design of RGP lens namely Rose K irregular cornea (IC) in management of corneas with high degree of irregular astigmatism. Methods The study was made in 66 eyes of 40 patients with irregular astigmatism.The selection criterion was to obtain a sample population with irregular astigmatism that was unlikely to be corrected with spectacles or conventional contact lens.A complete ophthalmologic exploration which included topography was made. All eyes were fitted with Rose K IC after measuring precisely lens parameters according to a special trial set of this design.Refraction, visual acuity before and after fitting,maximum wearing time, contact lens related problems and patient satisfaction were analyzed. Results The studied eyes included eyes with high degree of irregular astigmatism due to keratoconus in 42 eyes (63.6%),corneal injuries in 6 eyes (9.1%), PMD in 12 eyes (18.2%), and post Lasik ectasia in 6 eyes (9.1%).After fitting of the eyes with the RGP lens, there was a significant improvement in the visual acuity (VA)in all fitted eyes. The mean VA improved from 0.16±0.25 to 0.85± 0.13(p