Does ethnic origin influence the incidence or severity of keratoconus?

PURPOSE: Keratoconus affects all races, yet very little information exists as to the relative frequency in patients of different ethnic origin. We aimed to establish the incidence and severity of keratoconus in Asian and white patients. METHODS: The hospital records of the ophthalmology department of a large Midlands hospital with a catchment population of approximately 900,000 (87% white, 11% Asian, 2% other) were examined retrospectively for the 10 year period from 1989 to 1998. RESULTS: For the age group 10-44 years the prevalence of keratoconus in Asians and whites was 229 and 57 per 100,000 respectively, a relative prevalence of 4 to 1. The incidence of keratoconus in the same age group was 19.6 and 4.5 per 100,000 per year respectively, a relative incidence of 4.4 to 1. Asians were significantly younger at presentation compared with whites (mean 22.3 +/- 6.5 vs 26.5 +/- 8.5 years, p < 0.0001). A first corneal graft was carried out on 14% of the Asian and 15% of the white patients. Of those having grafts, Asians were significantly younger than white patients at the time of diagnosis (mean 19.1 +/- 4.8 vs 25.7 +/- 7.3 years, p = 0.005) and at operation (mean 21.4 +/- 5.0 vs 28.7 +/- 7.7 years, p = 0.004). The interval from diagnosis to operation, though shorter for Asians, was not significantly different (mean 1.8 +/- 1.4 vs 2.5 +/- 1.7 years, p = 0.2). CONCLUSION: The results show previously unrecognised racial differences in the hospital presentation of keratoconus in the UK. Compared with white patients, Asians have a fourfold increase in incidence, are younger at presentation and require corneal grafting at an earlier age.

In situ degradation of 11/0 polyester (mersilene) suture material following cataract surgery.

Two hundred and ten patients (231 eyes) had their cataract sections closed with 11/0 polyester suture material over a 4 year period. Their case sheets were assessed to determine the number of eyes from which sutures had been removed prior to discharge, and for what reasons these sutures were removed. Ninety-seven patients (107 eyes) with sutures left in situ were further assessed to determine whether they were suffering from any suture-related symptoms and examined to determine the degree of clinical biodegradation experienced by the sutures. Six of these sutures were removed for electron microscopic examination. Of the 231 eyes initially included, 61 sutures (26.4%) had been removed prior to discharge. None of the 107 sutures examined showed evidence of clinical biodegradation; this was confirmed by electron microscopic analysis which showed only minimal erosion of sutures even after 48 months in situ.

Retrobulbar phenol injection in blind painful eyes.

Retrobulbar phenol injection was used as a neurolytic to manage blind chronically painful eyes in ten patients. The cause of the blind painful eye was absolute glaucoma in eight of the ten eyes. We used 1.5mL of 1:15 (6.7%) aqueous phenol solution in each case. None of the patients experienced any pain from the injection. Seven patients obtained complete pain relief after the procedure, and one patient had some improvement. We found a range of duration of pain relief of 4.5 to 48 months (mean, 15 months), which compares favorably with retrobulbar alcohol injection. We believe retrobulbar phenol injection is preferable to alcohol. It has the advantage of being less painful during injection because of its local anesthetic properties.

Lamellar keratoplasty with lyophilized tissue for treatment of corneal scarring.

BACKGROUND: A pilot study was carried out in Pakistan to assess the feasibility of the use of lathed freeze-dried corneal tissue in the treatment of corneal scarring. METHOD: Six eyes underwent lamellar keratoplasty and were followed up for 18 months. RESULTS: Visual improvement was obtained in every eye. In one eye, the procedure was complicated by delayed epithelialization of the graft, but in the remaining five patients, the grafts epithelialized rapidly. CONCLUSIONS: The use of freeze-dried donor tissue simplifies storage and distribution of corneas and may offer the best hope of treatment in developing countries for patients with corneal scarring.

Medical management of ocular malakoplakia.

A 14-year-old girl had a granulomatous conjunctival lesion, proven histologically to be malakoplakia. This is the first reported case of malakoplakia arising from conjunctiva, although three others have involved the ocular adnexa. Malakoplakia is a rare disease often associated with immunodeficiency and is characterized by the presence of intracellular inclusions and organisms due to deficient intracellular bacteriolysis. Medical management is difficult because an effective antibacterial agent requires three properties: activity against the organism involved, good intracellular penetration, and the capacity to maintain its effectiveness in the intracellular milieu. Escherichia coli was isolated from a biopsy specimen and from conjunctival swabs. Treatment with systemic ciprofloxacin, which has good intracellular penetration and activity, led to rapid resolution of the lesion. This is the first report concerning the successful use of this drug to treat malakoplakia of any organ.

Experimental epikeratophakia using tissue lathed at room temperature.

This report presents for the first time the results of carrying out epikeratophakia with tissue lathed at room temperature. Using an experimental model of epikeratophakia in the rabbit, we evaluated tissue handling techniques for the preparation of donor lenticules. Details of the technique are described and the in-vivo and histopathological findings reported.

Post-measles corneal ulceration in children in northern Nigeria: the role of vitamin A, malnutrition and measles.

This work was prompted by the observation that corneal ulceration was apparently more common in young children in the guinea savannah area of northern Nigeria than in children in the tropical rainforest areas of southern Nigeria, where the intake of vitamin A, as the provitamin in red palm oil, is higher. Since corneal ulceration was usually seen in association with measles, a study was carried out to clarify the relationship between nutritional status, measles infection and vitamin A status in young children. The concentration of total retinol was measured in the plasma of well-nourished and malnourished children under three years of age, with or without a clinical record of recent measles. One hundred and twenty children were studied of whom 17 had corneal lesions. Malnutrition and measles were both found to depress the plasma concentrations of retinol and albumin. Measles depressed retinol levels (-20 to -30%) more than did malnutrition (-4 to -12%) while malnutrition had a greater depressing effect on albumin concentration (-23 to -30%) than did measles (-11 to -23%). The results support the hypothesis that corneal ulceration found in association with measles in northern Nigeria, although clinically similar to xerophthalmia, is not simply mediated through an effect of measles on the concentrations of vitamin A in plasma.

Corneal ulceration following measles in Nigerian children.

Acute corneal ulceration in malnourished children is the commonest cause of childhood blindness in Northern Nigeria and usually develops after measles. Other severe diseases in malnourished children rarely precipitate corneal ulceration. A survey in a school for blind children showed that 69% of the children were blind from corneal disease, and a survey of children with corneal scars showed that at least 42% were caused by ulceration after measles. The clinical appearance of the active ulcers was very varied. The serum retinol-binding protein and prealbumin levels in children with corneal ulcers following measles were below normal, but a group of malnourished children without eye complaints following measles were found to have even lower levels. Thus a specific deficiency of vitamin A does not appear to be the primary cause of these ulcers, though it may be a contributory one. A specific measles keratitis and secondary herpes simplex infectious may be local factors contributing to this ulceration, and there is nearly always a background of protein calorie malnutrition. Racial factors may also be of some significance.

Vernal eye disease in Northern Nigeria.

An analysis of 108 cases of vernal eye disease observed in Northern Nigeria. Although the bulbar and tarsal forms usually coexisted, the disease was predominantly bulbar in young children and predominantly palpebral in older patients. Chacteristic pigmentary conjunctival changes were particularly marked in young children. Corneal involvement occurred mostly in those patients with the palpebral form of the disease. The risk of permanent visual impairment in untreated cases appears to be slight.

The surgical treatment of open-angle glaucoma in Nigerians.

The results of trabeculectomy and sclerectomy procedures for open-angle glaucoma in African Negroes are compared. Trabeculectomy produced fewer long-term complications, but otherwise there was little difference in their results. Excision of Tenon's capsule and the use of local corticosteroids postoperatively are probably significant in preventing failure of aqueous drainage from subconjunctival fibrosis.

Surgical correction of trachomatous cicatricial entropion.

A modified version of Wies's operation for the correction of cicatricial entropion is described, the most important modification being a different plane for the incision through the eyelid. The possible complications and their prevention are discussed.

Superior oblique tendon sheath syndrome.

Clinical examination of 15 patients with the superior oblique tendon sheath syndrome showed that 12 of them had some evidence of stenosing tenosynovitis.