Light coagulation in presumed histoplasmic choroiditis. Controlled clinical study

Follow-up study of presumed ocular histoplasmosis syndrome

One hundred and sixty-two patients with presumed ocular histoplasmosis syndrome were evaluated. New macular scars not present on initial angiogram developed in 9% of eyes. The risk of developing a symptomatic macular lesion in eyes with asymptomatic macular scars was 23%. In eyes with peripapillary scarring, 3.8% developed a peripapillary neovascular membrane. Follow-up was 5.5 years. When the neovascular membrane was touching or outside the foveal avascular zone, the difference between photocoagulated and control eyes was not statistically significant. When only adequately photocoagulated eyes (20) were compared with control eyes (40), the difference was statistically significant (P = 0.04).

Peripapillary neovascular membranes in presumed ocular histoplasmosis

We studied 39 eyes with ocular histoplasmosis and peripapillary neovascular membranes for an average of 12 months. On the basis of clinical findings, 19 were selected for treatment with photocoagulation. Of the treated eyes, 12 (63%) had a visual result of 6/12 (20/40) or better. Of the 20 untreated eyes, six were clinically untreatable and 14 were electively followed up. All but one of the eyes electively followed up had a good visual result. Proximity of the neovascular membrane to the fovea was the most important prognostic factor in determining visual outcome. All eyes with membranes less than 1/4 disk diameter from the fovea lost central vision. All membranes greater than one disk diameter had excellent results. The indications for treatment were prolonged serous or hemorrhagic detachment of the fovea, documented progression of the membrane, and possibly, loss of central vision in the fellow eye from peripapillary disease. Residual and recurrent neovascularization were significant treatment complications.

Results of argon laser photocoagulation in presumed ocular histoplasmosis

We performed argon laser photocoagulation on 31 eyes of 30 patients with presumed ocular histoplasmosis. Nineteen of 25 eyes (76%) with neovascular membranes 0.25 disk diameter or further from the fovea had 6/12 (20/40) or better vision after an average follow-up period of 20 months. Twenty-two of these eyes (88%) had the same or improved visual acuity during this period. When compared to a similar group of untreated eyes, the apparent advantage of photocoagulation in preserving visual acuity was not statistically significant.

Follow-up study in eyes with choroidal neovascularization caused by presumed ocular histoplasmosis

Sixty-four eyes of 60 patients with ocular histoplasmosis, and choroidal neovascularization documented by fluorescein angiography, and not treated with photocoagulation, were followed for an average of 29 months. The primary determinant of visual outcome was the proximity of the neovascular membrane to the fovea. Sixty-four percent of eyes with membranes 0.25 disk diameter or greater from the fovea had a final visual acuity of 6/12 (20/40) or better, and 71% of such eyes maintained or improved initial visual acuity. All eyes with subfoveal neovascularization had a poor visual result. Other factors related to visual prognosis included initial visual acuity, size of the neovascular membrane, size of sensory retinal detachment, and presence of hemorrhage.

Subretinal neovascularization developing after prophylactic argon laser photocoagulation of atrophic macular scars

Two patients who had lost central vision in one eye due to a histoplasmic disciform macular scar received prophylactic argon laser photocoagulation to one or more atrophic lesions (histo spots) in the second macula in an effort to reduce the risk of developing active neovascularization in the second eye. Despite this prophylactic treatment, both patients developed a choroidal neovascular membrane from the photocoagulation scar.

Photocoagulation of active and inactive lesions of presumed ocular histoplasmosis

Argon laser photocoagulation was employed in 27 eyes with presumed ocular histoplasmosis. Thirteen eyes with active macular lesions had stable or improved visual results (72%).