James A. Cameron

Risk Factors for Intraoperative Complications in 1000 Extracapsular Cataract Cases

A prospective study of the risk factors in extracapsular surgery was carried out between October 1984 and April 1986. One thousand extracapsular cataract extractions were performed by seven physicians. Decreasing pupil size was the only statistically significant risk factor for vitreous loss (P = 0.0002). Zonular breaks occurred more commonly with pseudoexfoliation syndrome (PX) (P less than 0.0001), with decreasing pupil size (P less than 0.0001), and with one surgeon who used the Simcoe aspirating needle (Storz) exclusively (P = 0.0001). It is acknowledged that it is very difficult to standardize what constitutes a small zonular break; hence, the increase in zonular breaks recorded by this surgeon may have been due only to his using less stringent criteria than the others. Capsule breaks had no significant risk factors at the 0.01 level. High myopia, advanced cataract, glaucoma, advanced age, and diabetes mellitus were not found to be risk factors for vitreous loss, zonular breaks, or capsular breaks.

Shield Ulcers and Plaques of the Cornea in Vernal Keratoconjunctivitis

BACKGROUND Shield-shaped corneal ulcers and plaques are serious sight-threatening corneal manifestations of vernal keratoconjunctivitis. There are few reports describing the management of these patients and their outcomes. METHODS The clinical presentation, treatment, and outcome of 66 shield ulcers and/or plaques in 55 eyes of 41 patients with vernal keratoconjunctivitis were studied in this retrospective study of patients treated at King Khaled Eye Specialist Hospital during an 11-year period. RESULTS Patients with shield ulcers where the base of the ulcer was transparent usually had rapid re-epithelialization and an excellent visual outcome with medical treatment alone. Patients with shield ulcers and visible plaque formation had delayed re-epithelialization when receiving only medical treatment. Complications of delayed re-epithelialization consisted of bacterial keratitis in five eyes, amblyopia in one eye, and strabismus in one patient. CONCLUSIONS Patients with shield ulcers and/or plaques that do not re-epithelialize once active vernal keratoconjunctivitis has been controlled should have surgical intervention. In this series, a simple scraping of the base and margins of the ulcer with removal of the inflammatory material (i.e., the plaque) resulted in rapid re-epithelialization in 20 of 23 ulcers and plaques. An algorithm for treating shield ulcers and/or plaques is presented based on the experience at this institution.

Corneal Ectasia in Vernal Keratoconjunctivitis

The type of corneal ectasia, the presence of breaks in Descemets membrane, and the success with contact lens wear or penetrating keratoplasty were studied in 61 patients with corneal ectasia and vernal keratoconjunctivitis. There were 53 patients with keratoconus, 5 with pellucid marginal corneal degeneration, 2 with keratoglobus, and 1 with superior corneal thinning. The high rate of hydrops and the corneal ectasia itself may be related to excessive eye rubbing. Success with contact lens wear or penetrating keratoplasty in vernal keratoconjunctivitis patients with keratoconus is less than in patients with keratoconus alone.

Results of lamellar crescentic resection for pellucid marginal corneal degeneration.

Five eyes in four patients with pellucid marginal corneal degeneration were treated by lamellar crescentic resection of the thinned area inferiorly. Normal-thickness stroma was then reapposed to normal-thickness stroma with multiple interrupted 10-0 polypropylene sutures. If excessive central corneal steepening along a vertical meridian was present three months after surgery, selected sutures were cut and removed depending on the slit-lamp appearance, keratometry reading, and photokeratograph pattern. Improvement of visual acuity to 20/40 or better was obtained in four of the five eyes with a follow-up of 27 to 40 months (mean, 31.8 months). Early loosening of sutures resulted in a recurrence of corneal thinning and astigmatism in one eye. Pannus developed inferiorly in all five eyes.

Epikeratoplasty for Keratoglobus Associated with Blue Sclera

Patients with keratoglobus and blue sclera as part of a generalized connective tissue disorder are at a high risk of developing corneal perforations either spontaneously or after mild trauma. Six patients (6 eyes) between the ages of 2 and 16 years of age (mean, 7.5 years) with keratoglobus, blue sclera, hypermobile joints, and consanguineous parents were treated by epikeratoplasty, using commercially prepared 12.5-mm lenticules. Surgery was performed for tectonic support and/or visual improvement and was successful in five of six patients with a follow-up period of 11 to 27 months (mean, 21 months). One lenticule was removed because the epithelium did not heal. Peripheral interface opacities occurred in three patients.

EXCIMER LASER PHOTOTHERAPEUTIC KERATECTOMY FOR SHIELD ULCERS AND CORNEAL PLAQUES IN VERNAL KERATOCONJUNCTIVITIS

BACKGROUND Shield-shaped corneal ulcers and corneal plaques in vernal keratoconjunctivitis are associated with delayed epithelial healing, as well as the risks of infectious keratitis and sterile stromal ulceration. Significant visual impairment due to scarring and irregular astigmatism may result from central corneal lesions. METHODS Three eyes with central corneal lesions resulting from vernal keratoconjunctivitis were treated by excimer laser after active vernal keratoconjunctivitis was controlled and inflammatory plaque overlying the shield ulcers was removed. RESULTS All three eyes showed rapid reepithelialization within 1 week. Spectacle-corrected visual acuity of 20/30 or better was obtained in each eye. CONCLUSIONS In selected patients, excimer laser phototherapeutic keratectomy may be a useful adjunct in the treatment of shield-shaped corneal ulcers and plaques in vernal keratoconjunctivitis.

Squamous Cell Carcinoma of the Cornea

We treated two patients with primary squamous cell carcinoma of the cornea without involvement of the corneoscleral limbus. Superficial keratectomy and cryotherapy in one patient and penetrating keratoplasty in the other patient resulted in no recurrence of the tumor after 46 and nine months, respectively. Actinic damage and late manifestation caused by poor vision in both eyes of both patients may have been the risk factors for development of this tumor.

Wessely-type immune ring following phototherapeutic keratectomy

Abstract Immune rings following photorefractive keratectomy (PRK) have been reported but have not been described in detail. This case report describes an immune ring after phototherapeutic keratectomy (PTK) in a patient with long‐standing superficial corneal scars. A dense white ring formed in the peripheral cornea on the fourth day following surgery. The patient was treated with antibiotics until negative cultures were reported 48 hours later. A biopsy was taken and examined by light microscopy using hematoxylin‐eosin and Mason’s trichrome staining. The stroma showed focal keratocyte depopulation with nuclear fragments, occasional polymorphonuclear leucocytes, and an active fibroblastic reaction. No lymphocytes or plasma cells were seen. Clinically, the immune ring faded slowly and was still apparent 9 months after the PTK. Studies of similar cases are required to clarify the mechanisms responsible for this phenomenon.

Pyogenic Granulomas of the Cornea

BACKGROUND Pyogenic granulomas are vascular inflammatory lesions that represent an aberrant wound healing response. They typically arise from mucous membranes or skin. Pyogenic granulomas primarily involving the cornea have been rarely reported. METHODS Between January 1983 and July 1994, 14 patients with histologically proven pyogenic granulomas of the cornea were treated. RESULTS The precipitating event was a persistent epithelial defect in nine patients. Ocular surface disease was present in all patients. Predisposing conditions included indolent corneal ulceration, cry eye syndrome, trachoma, trichiasis, alkali burn, multiple topical drug use, previous orbital irradiation, and ocular cicatricial pemphigoid. CONCLUSIONS Ophthalmologists should be aware that pyogenic granulomas may involve the cornea and include this entry in the differential diagnosis of tumors involving the limbus or cornea. The typical clinical appearance, rapid growth, minimal staining with rose bengal dye, response to topical steroids, and associated ocular surface disease help to distinguish this lesion from a neoplastic epithelial tumor of the conjunctiva or cornea.