Photocoagulation of active and inactive lesions of presumed ocular histoplasmosis

Treatment of macular subretinal neovascularization with the red-light krypton laser in presumed ocular histoplasmosis syndrome

A patient with presumed ocular histoplasmosis and decreased visual acuity in one eye had subretinal neovascularization and retinal hemorrhage in the macular area. Argon-laser treatment to eradicate the subretinal neovascular membrane was contraindicated because of the proximity of the hemorrhagic lesion to the fovea. We used a red-light krypton laser (647 nm) because the light is not absorbed by the hemoglobin in the retinal hemorrhage or by the macular luteal pigment (xanthophyll), and because it is transmitted into the choroid, allowing treatment within the macular zone with less damage to the internal retinal elements. After treatment, the subretinal neovascular membrane completely disappeared and the macular hemorrhage cleared. To the best of our knowledge, this is the first time that a histoplasmic macular subretinal neovascular membrane has been treated with the red-light krypton laser.

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.

Choroidal neovascularization associated with choroidal nevi

We observed choroidal neovascularization with associated macular detachment in three cases of benign choroidal nevi. Successful obliteration of the neovascular membranes was performed with argon laser photocoagulation with maintenance of good central visual acuity.

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.

Laser applications in medicine and biology: a bibliography

This bibliography covers the period from 1963 through 1974; 916 references are classified under 23 subject headings. The references are arranged chronologically.

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.