The etiology of macular detachment associated with optic nerve pits

Purpose. Up to two-thirds of patients with optic disc pits develop serous macular detachment. There is confusion regarding the etiology of the subretinal fluid in these cases. We present 4 cases of serous macular detachment occurring in association with optic pits, and identify a rhegmatogenous etiology. Methods. We reviewed the records of 4 patients with optic nerve pits and macular detachment. Patients were treated with observation, barricade laser, vitrectomy, and/or gas tamponade. Results. Four patients were noted to have serous macular detachment associated with an optic nerve pit. The duration of follow-up averaged 26 months (range 2 to 60 months). A hole or tear in the diaphanous tissue overlying the optic pit was identified in all 4 patients. None of the patients had a posterior vitreous detachment. Two patients were treated with photocoagulation only, while two underwent pars plana vitrectomy with fluid-gas exchange ± photocoagulation. Pretreatment visual acuity ranged from 20/30 to 6/200. Posttreatment acuity ranged from 20/25 to 20/100, and improved in all treated eyes an average of 3 lines. Conclusions. A tear in the diaphanous tissue overlying the optic nerve pit is responsible for the development of serous macular detachment, and is consistent with findings in similar conditions such as retinal detachment in association with chorioretinal coloboma. These tears may be quite subtle, and careful biomicroscopic examination is required to appreciate them. The treatment of this condition remains controversial. However, because of the relatively poor prognosis, we believe treatment should include the formation of a barricade to fluid movement, and sealing and relief of traction from the hole. The value of laser treatment may be increased by the early identification of a defect in the diaphanous membrane prior to the development of macular detachment. Consideration of prophylactic laser might then reduce the need for later, more invasive measures, and improve the prognosis.