Search

Purpose To describe the clinical findings of an autosomal dominant macular dystrophy in a family of Mayan Indian ancestry in Belize, Central America, and to determine its molecular genetic relationship with the original North Carolinian family. Methods We performed comprehensive ophthalmic examinations on 56 members of a single family living in Chicago, Illinois, and Belize, Central America. Fundus photography and fluorescein angiography were performed on 17 affected subjects and six affected family members were serially examined over a 12-year period. Blood was collected from 26 individuals, and DNA was extracted for genotyping. Two-point linkage, multipoint linkage, and haplotype analysis was performed. Results In 17 affected individuals, the clinical features were consistent with the diagnosis of North Carolina macular dystrophy. Multipoint linkage analysis generated a peak lod score of 5.6 in the MCDR1 region. The haplotype associated with the disease was, however, different from that of the original North Carolinian family. Conclusions This family has an autosomal dominant macular dystrophy that is clinically indistinguishable from North Carolina macular dystrophy (MCDR1). Our findings indicate that the mutated gene in this Belizean family maps precisely to the same region as that of the North Carolina macular dystrophy (MCDR1) locus. This study provides evidence that MCDR1 occurs in various ethnic groups and that there is no evidence of genetic heterogeneity.

Three patients with geographic choroiditis developed subretinal neovascular membranes associated with subretinal hemorrhage and serous elevation of the retina. Proximity of the membrane to the foveal avascular zone prevented photocoagulation of the neovascular membrane in one patient. Central visual acuity remained 6/60 (20/200) despite systemic corticosteroid therapy. The neovascular membranes in the other two patients were obliterated by argon laser photocoagulation with preservation of central vision. The inflammatory process of geographic choroiditis can disrupt Bruch's membrane, allowing occasional choroidal vascular growth. Concomitant destruction of choroidal vessels may account for rarity of subretinal neovascularization in geographic choroiditis.

The stromal deposits of a failed corneal graft from a patient with primary familial amyloidosis of the cornea stained positively with Congo red and showed green birefringence with polarized light. These deposits contained protein AP but not protein AA, immunoglobulins, light chains, or prealbumin. The amyloid deposits of primary familial amyloidosis of the cornea differ from those in lattice corneal dystrophy which contain both protein AA and protein AP.

Six black patients had fundus lesions diagnostic of the presumed ocular histoplasmosis syndrome. All patients had peripapillary changes or peripheral punched-out chorioretinal lesions, or both. Five of the six had macular subretinal neovascularization, disciform scarring, or an atrophic macular lesion, and one patient had a macular hole; four of five patients tested had a positive histoplasmin skin test. The macular involvement was bilateral in three of the six cases. HLA B-7 was present in one of four patients who had HLA typing. Macular involvement can occur in blacks with the presumed ocular histoplasmosis syndrome.

Of 45 patients with proliferative sickle retinopathy in stages III, IV, and V, nine patients (eight with hemoglobin SC disease, one with sickle cell thalassemia) showed spontaneous regression (autoinfarction) of retinal sea fans. One mechanism involved in autoinfarction of neovascular tissue is progressive, centripetal retraction of the anterior vascular arcade of the peripheral retina. In addition, vitreous traction on feeder vessels may result in sluggish blood flow and occlusion of these vessels, or may tear the sea fan completely away from its feeder vessels. In view of the many incidences of vitreous hemorrhages that occur in patients with proliferative retinopathy, however, we recommend treatment of neovascularization rather than prolonged observation.

Case 1—A 54-year-old black woman was seen in the Department of Ophthalmology of Cook County Hospital because of decreasing vision in each eye. Her past medical history included diabetes mellitus, diagnosed one year previously and controlled with diet only. Family history was unremarkable. The initial eye examination revealed her right vision was decreased to light perception with good projec­ tion and color perception due to a mature cataract. The best corrected vision in the left eye was 20/40. Action of the extraocular muscles was normal. The anterior chamber was of normal depth and clarity in each eye. The right iris showed a semilunar patch of atrophy which was adjacent to the pupil­ lary margin between six and eight o'clock (Fig. 1). The left iris had a similar atrophie patch, horseshoe in shape, located between 12 and two o'clock and extending from the pupillary margin to the collar­ ette (Fig. 2). Grayish pigmentation of the involved