Myopic foveoschisis: Vitrectomy beneficial before macular hole development

Detecting a macular hole or photoreceptor detachment is critical for obtaining good surgical results in patients with myopicfoveoschisis. Patients with the foveal detachment type seem to benefit the most from vitrectomy. Spectral-domain opticalcoherence tomography (SD-OCT) and fundus autofluorescence (FAF) are valuable for managing these patients, said Yasushi Ikuno,MD, Osaka University Medical School, Osaka, Japan.

Dr. Ikuno and colleagues classified patients with myopic foveoschisis based on the foveal status: the foveal schisis type hasphotoreceptors still attached to the retinal pigment epithelium (RPE), the foveal detachment type is characterized by afoveal detachment from the RPE, and the macular hole type has a full-thickness retinal defect at the fovea.

"The natural course of foveoschisis is quite poor and about half of the patients develop a macular hole or retinal detachmentwithin 3 to 4 years," Dr. Ikuno said.

He explained that he and his colleagues apply triamcinolone and peel the vitreous cortex that adheres to the retina. Theyperform indocyanine green-internal limiting membrane peeling followed by fluid-air exchange.

The results for each subtype following vitrectomy indicated that the foveal detachment type had the most favorable outcome,with about 80% of patients having an improvement in visual acuity. About 50% of patients with the foveal schisis type had avisual improvement, and only 30% of those with the macular hole type had an improvement in vision and 30% had a decrease inthe visual acuity.

Dr. Ikuno said that to achieve the best visual results, a vitrectomy must be performed in the earlier stages. Once thepatient has developed a macular hole it is too late for a vitrectomy to be beneficial. Only two of eight patients with amacular hole had improved vision; the vision remained unchanged or worsened in the remaining six patients.

When the investigators compared the results between the patients with the foveal schisis type and the foveal detachment type,the outcomes indicated that vitrectomy was more beneficial for the patients with the foveal detachment type.

"When treating the foveal schisis type, surgeons can wait until a detachment occurs because the surgical effect is limited,"Dr. Ikuno said. "For the foveal detachment type, surgery can be performed as soon as possible before a macular hole develops.For patients with the macular hole type, the surgical effects of surgery are limited. However, surgery is still meaningful interms of preventing an extensive retinal detachment that can lead to blindness. Detecting a macular hole is critical topredicting the surgical results."

Dr. Ikuno recommended using SD-OCT and FAF as new techniques to manage myopic foveoschisis. SD-OCT isable to detect macular holes that previously were undetectable and FAF can show the photoreceptor status.