C.B. Nau

Automated assessment of keratocyte density in clinical confocal microscopy of the corneal stroma.

Cell density in the corneal stroma is typically determined by counting the number of bright objects, presumably keratocyte nuclei, in images from clinical confocal microscopy. We present a program that identifies bright objects and counts those that most likely represent cells. Selection variables were determined from 125 normal corneas with cell densities that had been assessed manually. The program was tested on 17 corneas of patients before and at several intervals to 5 years after laser in situ keratomileusis (LASIK) surgery. In these corneas, which showed a decrease in cell density after surgery, the program identified cells as well as human observers did.

Visual and physiological outcomes of scleral lens wear

PURPOSE To describe patient-specific outcomes of scleral lens wear utilizing a variety of lens designs across multiple practice settings as reported in an international practitioner survey. METHODS An electronic survey was administered to eye care providers who prescribe scleral lenses in which they were asked to describe their most recently examined established scleral lens patient. Data was collected on patient characteristics, lens designs, wearing schedules, care products, and visual and physiological outcomes of lens wear. Descriptive analysis of data was performed. RESULTS A total of 292 responses were received. Participants represented 26 countries. The most commonly reported indication for scleral lens wear was corneal irregularity (87%) followed by ocular surface disease (8%), refractive error (4%) and 1% with multiple indications. Visual acuity improved from 0.4 ± 0.4 (mean ± SD) to 0.1 ± 0.2 in eyes with corneal irregularity (p < 0.001), from 0.3 ± 0.3 to 0.1 ± 0.3 in eyes with ocular surface disease (p < 0.001), and from 0.1 ± 0.1 to 0.0± [0.1] in eye with refractive error (p = 0.01). Prior to scleral lens wear, corneal staining was present in 55% of patients; staining was present in only 35% of patients following scleral lens wear. The number of topical ophthalmic drops needed decreased from 1.7 ± 0.9 to 0.8 ± 0.8 in patients with corneal irregularity (p < 0.001) and from 3.5 ± 1.7 to 1.1 ± 1.0 in patients with ocular surface disease (p < 0.001). The number of drops used by patients with refractive error remained stable, with these patients using an average of 2.0 ± 1.0 drops prior to scleral lens wear and 1.7 ± 1.5 drops following scleral lens wear. CONCLUSIONS Patients with corneal irregularity experienced the greatest improvement in visual acuity, but patients with ocular surface disease and refractive error also achieved better visual acuity with scleral lenses. Ocular surface condition improved in patients with both corneal irregularity and ocular surface disease; patients with ocular surface disease experienced the most dramatic improvement. Patients who wore scleral lenses to correct uncomplicated refractive error did not experience an improvement in signs or symptoms of ocular surface disease.