Interlamellar corneal grafts in rats. Effect of histocompatibility.

A technique of interlamellar keratoplasty was employed to evaluate the influence of difference in histocompatibility on the results of corneal transplantation in highly inbred rats. The degree of corneal clarity and vascularity and the incidence of rejection of relatively conpatible ("weak") and incompatible ("strong") allografts were recorded blindly in recipients with normal and vascularized corneas and in recipients sensitized with donor tissue either before or after corneal grafting. In contrast to the well-known effects of histocompatibility on skin and organ allografts, there was no substantial effect whatsoever of histocompatibility on either the severity of corneal allograft reactions orthe incidence of rejection. Consequently, the results of this experimental investigation suggest that tissue typing may have little or no value in clinical keratoplasty.

Osseous choristoma of the choroid simulating a choroidal melanoma. Association with a positive 32P test.

We report the clinical and histopathologic features of an osseous choristoma of the choroid that appeared in a 26-year-old woman. Her diagnostic evaluation included a radioactive phosphorus (32P) uptake test, which was 270% positive and led us to believe that the lesion was an atypical malignant melanoma. The extent of true ossification within this tumor, seen microscopically, explains the false-positive uptake of radioactive phosphorus by this benign tumor; it is well known that bone avidly accumulates radioactive phosphorus. We recommend that all "atypical choroidal melanomas" be studied for the presence of bone, with bone-free roentgenograms, ultrasonography, and possibly, computerized tomographic scans before 32P testing or enucleation. This, to our knowledge, is the second histopathologically proved case of an osseous choristoma of the choroid to be reported in the literature.

Metastatic ciliary body carcinoid tumor.

A 50-year-old man with a history of systemic carcinoid had decreased right eye vision and a darkly pigmented cilio-choroidal mass. Results of ultrasonographic and fluorescein angiographic examinations were consistent with a malignant melanoma. Fine-needle aspiration biopsy of the lesion identified it as a carcinoid metastasis. The patient refused both radiation and enucleation; complete excision with a cyclochoroidectomy was performed. Histopathologic examination showed a carcinoid neoplasm covered by marked hyperplasia of the retinal pigment epithelium that produced the pigmented appearance of the lesion.

The electroretinogram after peripheral retinal ablation in diabetic retinopathy.

The electroretinograms (ERGs) from 14 patients with proliferative diabetic retinopathy were recorded before and after peripheral retinal ablation by photocoagulation. It was expected that the ERG would be reduced in amplitude in proportion to the area of retina destroyed by the treatment. The ablation treatment, carried out in a standard manner in each patient, resulted in a decrease of ERG amplitude that varied from 10 to 95% among the patients, and caused an increase in ERG latency and implicit time in several patients. This suggests a wide variability in the area of retina affected by the treatment, and the possibility of an effect of the procedure on adjacent untreated retina in some diabetic patients.

Correlation of histologic and electroretinographic changes in peripheral retinal ablation in the rhesus monkey.

We studied the effect of peripheral retinal ablation on the electroretinograms of five rhesus monkeys. An ablation procedure analogous to that commonly used in the treatment of diabetic retinopathy was carried out with an argon laser photocoagulator. Quantitative histologic measures showed retinal destruction of about 13% of total retinal area. This was associated with about a 50% reduction in scotopic electroretinographic amplitude.

[Changes in the retina accompanying the Osler syndrome (author's transl)]. / Netzhautveränderungen beim Osler Syndrom.

A histological examination was carried out on the eye of an eleven-year-old patient who, like his brother, was suffering from the lung variety of the Osler syndrome. The examination showed rubeosis of the iris accompanied by secondary glaucoma. One striking feature was extensive proliferous retinopathy presumably caused by chronic lack of oxygen in the arterial blood.

Subretinal nematode. An unusual etiology for uveitis and retinal detachment.

Retinal detachments are usually divided between rhegmatogenous and exudative. Many causes for exudative retinal detachments are described in the literature. Subretinal nematodes are a rare but well-known etiology for severe exudative retinal detachments and endophthalmitis. The case presented represents the first known infestation of human ocular tissue by the nematode Porrocaecum or Hexametra. Described are the presenting symptoms and medical and surgical management, including pars plana vitrectomy, retinotomy, and air-fluid exchange to salvage the eye.

Management of the hypotonous cyclodialysis cleft.

Authoritative experience in the management of hypotonous cyclodialysis clefts is difficult to obtain because of their rarity. In this study, the authors describe nine patients with hypotonous cyclodialyses clefts: six patients were treated successfully with argon laser photocoagulation to the cleft surfaces; in one patient, cleft diathermy was used to seal an incompletely closed cleft after a single argon laser treatment; one patient responded to conservative management; another patient did not require treatment. Four cases followed ocular trauma and five occurred after extracapsular cataract extraction and posterior chamber intraocular lens implantation. In three patients, the anterior chamber was too shallow to permit gonioscopy; sodium hyaluronate (Healon) was used to reform the anterior chamber, to delineate the extent of the cyclodialysis cleft, and to provide maximal access for the argon laser treatment. In another patient, laser cleft consolidation was successful only after fully opening the cleft with sodium hyaluronate. The evolution of the laser photocoagulation technique used by the authors is described. Laser cyclodialysis cleft consolidation can be repeated easily and safely. The authors recommend argon laser photocoagulation as the primary management approach. Intracameral viscoelastic agents are useful adjuncts. The complications of cleft lasering are minor, although a hypertensive episode commonly occurs in the early postoperative period as the cleft closes. Major intraocular surgeries usually can be avoided.