Subretinal fluid, disrupted ELM line independently predict metamorphopsia
Young patients and cases with involvement of macula must be given special attention, considering metamorphopsia, which can be predicted by the postoperative presence of subretinal fluid (SRF) and disrupted external limiting membrane (ELM) line, suggests a recent study.
After rhegmatogenous retinal detachment (RRD) surgery, high-resolution optical coherence tomography (OCT) is useful in identifying anatomic abnormalities.
A cross-sectional, comparative study was conducted to investigate the prevalence of metamorphopsia after successful RRD surgery and determine the independent predictors of the said vision defect. In total, there were 380 eyes of 357 patients who underwent a successful RRD surgery between 2009 and 2015 included in the study.
Researchers used an Amsler grid to test the presence of metamorphopsia and a high-resolution spectral-domain OCT to scan the foveal microstructure at a follow-up visit. They also reviewed medical records for preoperative and intraoperative factors related to postoperative visual recovery.
The mean follow-up period was 35.1 months. Overall, the prevalence of metamorphopsia was 46.58 percent (177/380), but this number increased to 56.69 (144/254) in macula-off cases.
Based on stepwise logistic regression analysis, the independent predictors for metamorphopsia after surgery were younger age at diagnosis (odds ratio [OR], 0.97; p<0.01), preoperative macula-off status (OR, 3.34; p<0.01), postoperative presence of SRF (OR, 3.58; p=0.01) and disrupted ELM junction (OR, 1.79; p=0.02).
After successful surgeries, the abnormal foveal microstructures primarily included six types: disrupted inner segment/outer segment (133 eyes; 35.00 percent), disrupted ELM (131 eyes; 34.47 percent), epiretinal membrane (44 eyes; 11.58 percent), SRF (26 eyes; 6.84 percent), macular hole (9 eyes; 2.37 percent) and cystoid macular oedema (6 eyes; 1.58 percent).