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Sub-retinal new vessels arising from the choroid are the most dangerous components in disciform maculopathies. The greatest advance made in their treatment has been due to the use of photocoagulation over the last few years, but their destruction by this method is still a very controversial subject. The aim of the present study was to define which lesions should be treated and which should not. Results demonstrated that the use of photocoagulation to destroy new vascular membrane which is very close to the foveola, is possible, and can restore vision or preserve useful visual acuity. The laser can be used very close to the centre of the foveola, even in a part of the central avascular area. A randomized study is now being conducted and should supply statistical evidence as to whether this treatment should or should not be recommanded.

Photocoagulation has proved to be an effective means of treating active presumed histoplasmic maculopathy. Xenon arc and argon laser light sources have proved equally effective when moderately intense, confluent burns are produced, and both are ineffective when mild lesions are produced. The membrane must be destroyed for the treatment to be effective; and, of course, the fovea must be preserved. In treating neovascular nets that are very close to the fovea, the argon laser offers the advantage of being capable of producing a sharper zone of delineation than the xenon arc (Fig. 6). When moderate amounts of subretinal fluid or hemoglobin overlie the neovascular membrane, it is very difficult to achieve the required degree of coagulation. Under these circumstances, it is best first to try to reduce the height of the sensory retinal detachment by means of systemic steroid treatment. If this is not successful, xenon photocoagulation has produced better coagulation effects than the argon laser. Analysis of our data indicates that resultant visual acuity can be correlated with pretreatment visual acuity (Fig. 5), with best results achieved before visual acuity deteriorates beyond the 20/40 level. The closer the edge of the neovascular membrane is to the fovea, the more risky it is to treat. However, these lesions are also those most apt to destroy central vision if left alone. It is encouraging to note that in only 3 of the 16 lesions in which the foveal edge was within 1 degree of the fovea did the visual acuity deteriorate to the 20/200 level, compared to 50 percent deterioration reported in the natural history of this disease [3].

Regadless of the etiology of the disciform lesion in the presumed ocular histoplasmosis syndrome, and regardless of our ignorance as to whether the pathogenetic mechanism relates in part to hypersensitization, or can be explained solely on a mechanistic interpretation (that is, chronic vascular decompensation [9]), the question of therapy can be evaluated independently. However, our knowledge regarding the natural history of these lesions is similarly incomplete and thus, without a controlled study, e cannot compare any of the therapeutic modalities with the natural history. Therefore, we cannot make any definitive statements regarding the value of therapy, let alone compare the different modalities. For these reasons, conclusions as to the results of photocoagulation of the macular lesions in the ocular histoplasmosis syndrome must remain incomplete...

After fluorescein angiography, central visual field testing, and photofield mapping, 94 eyes with senile macular degeneration and foveal choroidal new vessels (distance of 200 micron or less from the center of the foveal avascular zone) were treated with the monochromatic green argon laser. By the end of the follow-up period (average follow-up, 15 months), the new vessels were closed in 88 eyes and visual acuity was stabilized or improved in 70 eyes. These 70 eyes included 68 of 80 eyes with preoperative visual acuities of 20/70 or worse and only two of 14 eyes with preoperative visual acuities of 20/60 or better. Visual acuity was stabilized or improved in 55 of 62 eyes in which the foveal edge of the choroidal new vessels was within the margins of the pretreatment scotoma and in only 15 of 32 eyes with foveal edges extending beyond the scotoma margins.

A 30-year-old man had symptoms and signs consistent with bilateral classic central serous chorioretinopathy. Conventional single-session laser treatments to both eyes stabilized the condition for 9 years. The patient then developed atypical central serous chorioretinopathy consisting of tracts of fluid emanating from the posterior pole and bilateral inferior exudative retinal detachments. Diffuse retinal pigment epithelial disease with recurrent leakage in both maculas was treated with grid laser photocoagulation, which was effective in stabilizing the patient's condition.

Free Running Neodymium-Yttrium Aluminum Garnet (FR Nd-YAG) laser coagulation of the macula was performed in seven human eyes. Follow-up varied from 1 to 15 days. Damage to the outer retinal layers was apparent immediately after exposure whilst that in the inner retinal layers developed subsequently. The choriocapillaris and major choroidal vessels were occluded. Visual acuity changed in an unpredictable way.