Background: Visual loss in eyes with full-thickness macular holes has been thought to be due to the absence of retinal function in the area of neurosensory defect as well as loss or reduction of retinal function in the surrounding area of neurosensory retinal detachment. With the advent of surgical techniques to treat macular holes, it is increasingly important to better characterize this visual dysfunction.
Methods: Thirty eyes of 30 patients with full-thickness idiopathic macular holes were evaluated with microperimetry using the scanning laser ophthalmoscope to detect and quantitate absolute and relative scotomata within the central 40 degrees of visual field. A log 2 scale of test stimulus intensities was established. Results of microperimetry were compared with best-corrected visual acuities as measured on the logarithmic Early Treatment of Diabetic Retinopathy Study chart as well as duration of symptoms.
Results: All 30 eyes showed an absolute scotoma in the area of neurosensory defect as well as surrounding relative scotomata in the area of neurosensory detachment. Best-corrected visual acuity was correlated with the size of the absolute and relative scotomata (P < 0.002). The sizes of the scotomata were correlated with the duration of symptoms of the macular holes (P < 0.05).
Conclusion: Microperimetry using the scanning laser ophthalmoscope demonstrates that the visual loss associated with macular holes is related to the reduction of retinal function in the area of the surrounding neurosensory detachment as well as the absence of retinal function in the area of neurosensory defect. The size of the scotomata, determined by microperimetry, is correlated with the patient's visual acuity as well as the duration of symptoms of the macular hole.