Faculty Bibliography

Twenty-nine suture removals from 20 eyes (21 patients) on which penetrating keratoplasty had been performed were analyzed in a nonrandomized consecutive study to evaluate the role of computer-assisted corneal topography in selective suture removal to reduce astigmatism. Topographic guidance for suture removal resulted in a net decrease in refractive and keratometric astigmatism in 21 of the 29 cases. The net reduction in astigmatism averaged 1.4, 0.9, and 1.0 diopters when measured by refraction, keratometry, and topography, respectively. The preliminary choice of sutures to be removed on the basis of refraction, keratometry, and inspection was changed in 20 of the 29 cases when information added by the topographic map was considered. Although many variables of suture removal remain unpredictable, computer-assisted corneal topography is a powerful means of describing corneal power after penetrating keratoplasty and is useful as a guide in selective suture removal for reduction of astigmatism

The effects of gas-permeable contact lens wear on the density and morphologic characteristics of corneal endothelial cells were prospectively studied by wide-field specular microscopy in 18 eyes that had undergone keratoplasty at least 14 months previously. Daily-wear rigid gas-permeable lenses were fitted to allow as much movement and tear exchange as possible. There was no evidence of morphologic instability of the endothelial cells during the course of the study, with a mean duration of lens wear of 9.8 months. Although there is concern over adverse effects associated with polymethylmethacrylate contact lens wear, this study suggests that the endothelium of a corneal transplant tolerates rigid gas-permeable lens wear without adverse effect during a limited period of follow-up

We conducted a retrospective study of corneal ulcers that had been managed on the Cornea Service at Wills Eye Hospital in 1988 and 1989. Forty-four percent (51 of 116) of the ulcers were associated with contact lens use. Pseudomonas was the most often isolated organism (25 of 116, 22%) and was most frequently associated with cosmetic soft contact lenses (16 of 25, 64%). Ulcers associated with disposable contact lenses (five cases) were similar to those associated with conventional extended wear myopic lenses (15 cases). Pseudomonas was the predominant organism with both disposable (four of five, 80%) and conventional extended wear lenses (nine of 15, 60%). Staphylococcus aureus (19 cases) and Staphylococcus epidermidis (19 cases) were the next most frequently isolated organisms and usually occurred in ulcers not associated with contact lenses (29 of 38, 76%). Ulcers were treated 3.3 times more often in people using extended wear than in those using daily wear myopic lenses. Disposable contact lenses have not eliminated the problem of corneal ulcers associated with extended wear contact lenses

Contact lenses were fit after traumatic corneal lacerations in 30 eyes (28 patients). Twenty-eight of the eyes (93%) were aphakic. Twenty-two of the 30 eyes (73%) wore the contact lens successfully (average follow-up 22 months). The visual acuity with the contact lens was 20/40 or better in 25 eyes (83%). In 13 eyes (43%) the final contact lens fit was a rigid gas permeable lens, with a daily wear soft contact lens as the final lens in 17 eyes (57%). The eight failures included four patients who were contact lens intolerant, two who had binocular diplopia, and two who lacked motivation. All but one of 12 (92%) small corneal lacerations (less than 3 mm) were successfully fit with contact lenses. Eleven out of the 13 (85%) central large lacerations, but none of the five large peripheral lacerations could be successfully fit with a contact lens. Three of the 30 eyes (10%) developed late retinal detachments. Contact lenses are successful in the majority of patients referred after corneal lacerations, but fitting these patients is challenging and time consuming

We retrospectively review our experience with four patients with Streptococcus pneumoniae scleritis. Two of the patients had been exposed to beta irradiation after pterygium removal 4 and 13 years previously. One patient had a 3-year history of chronic anterior nodular scleritis, and one patient had severe rheumatoid arthritis. All were treated with intensive i.v. and topical fortified antibiotics. In two of the cases, the infection was controlled and visual acuity returned to 20/30 and 20/60. In one patient, infectious scleritis progressed to endophthalmitis. This eye ultimately became phthisical and required enucleation because of chronic pain. In the remaining patient, infectious scleritis led to perforation, which required a corneal-scleral patch graft. This patient had a final visual acuity of counting fingers. An infectious etiology should be suspected in cases of necrotizing scleritis associated with a purulent discharge, and appropriate smears and cultures should be obtained. Infectious scleritis can be caused by streptococcal organisms. Appropriate topical and intravenous antibiotic treatment is effective in some cases

Four patients with contact lens associated Acanthamoeba keratitis were treated at Wills Eye Hospital between 1987 and 1989. Two patients had used daily wear soft contact lenses and two had worn hard contact lenses. All four patients were treated with topical antibiotics (propamidine and neomycin), oral ketoconazole, and varying amounts of topical steroids. Two of these patients received topical clotrimazole. All four patients eventually required surgery for either control of their infection (three cases) or control of secondary disease (glaucoma and cataract). Medical therapy for Acanthamoeba keratitis remains problematic, and therefore prevention of this disease by avoidance of risk factors remains paramount