Abstract
Abstract: :
Purpose: Preoperative visual acuity is the most important factor in indicating surgical treatment for cases with idiopathic epiretinal macular membrane (ERM). However, It would be of use if objective indexes predict the surgical outcome. To estimate the postoperative visual acuity, optical coherent tomography (OCT) and multifocal ERG (mfERG) were applied preoperatively. Methods: Our subjects were 40 patients (mean 64.8 ± S.D. 5.7 years old) who underwent the surgical treatment for ERM (36 older patients without significant cataract: prophylactic phacoemulsification+intraocular lens implantation and vitrectomy including ERM peeling, 4 younger patients: vitrectmy without phacoemulsification). Before the surgery, macular thickness (MT) was measured with OCT and the amplitude of macular ERG (AMERG) was extracted from mfERG (VERISTM) in each patient. The preoperative corrected visual acuity (PreVA) was also included in analysis. These indexed are compared to the postoperative visual acuity (PostVA), i.e. the best-corrected visual acuity obtained after the surgery. PreVA and PostVA were assessed in logMAR. Results: PreVA was strongly correlated positively to PostVA (p < 0.001). MT was correlated to PreVA (p < 0.05), however, not to PostVA. AMERG was correlated to neither PreVA nor PostVA. We combined the MT and AMERG. We divided MT by AMERG in each patient, and then multiplied by the mean AMERG (555nV) recorded from our control group (105 subjects, 57.0 ± 10.0 years old, without any visual abnormality). We temporarily name the obtain value, "corrected MT". In cases with AMERG smaller than control, corrected MT was enlarged from MT. Corrected MT was correlated negatively to PostVA (p = 0.005). Conclusion: It is still controversial in the reason of visual reduction with ERM. As case stands, morphological index of macular (MT) and function index (AMERG) were both not expedient enough to predict the outcome of surgery for ERM. However, our corrected MT obtained from the combination of both of them, may reflect the latent visual acuity covered underneath ERM.
Keywords: 460 macula/fovea • 353 clinical (human) or epidemiologic studies: outcomes/complications • 393 electrophysiology: clinical