ObjectiveTo observe the changes of retinal microstructure in lamellar macular hole (LMH) after vitrectomy.MethodsA retrospective clinical observational study. Forty patients (41 eyes) with LMH and received vitrectomy in Ophthalmology Department of Peking University People’s Hospital from January 2014 to September 2018 were included in this study. Among them, 14 patients (15 eyes) were males and 26 patients (26 eyes) were females, with an average age of 67.8±8.6 years. There were 37 eyes with a lens and 4 eyes with an IOL. There were 29 eyes with LMH of tractional type, 7 eyes of degenerative type, and 5 eyes of mixed type. All patients underwent BCVA and OCT examinations. The BCVA examination was performed using the international standard visual acuity chart, which was converted into logMAR visual acuity. The average logMAR BCVA was 0.57±0.27; the mean macular retinal thickness (CRT) was 192.3±108.9 μm, the mean macular thickness (MRT) was 427.5±110.2 μm. Among the 29 eyes of tractional type, there were 17 eyes with retinal cavity, 8 eyes with macular retinoschisis, and 3 eyes with incomplete ellipsoid zone. Among the 7 eyes of degenerative type, there were 5 eyes with lamellar hole-associated epiretinal proliferation (LHEP), 5 eyes with retinal cavity, and 5 eyes with incomplete ellipsoid zone. Among the 5 eyes of mixed type, 2 eyes with LHEP, 1 eye with macular epiretinal membrane, and 4 eyes with incomplete ellipsoid zone. The average follow-up time after surgery was 12.8±5.2 months. Among them, 10 eyes were followed up for equal or greater than 24 months. After the surgery, the same equipment and method before the surgery were used for relevant examination. The changes of BCVA, CRT, and MRT before and after surgery were observed. Continuous variables were compared by t test.ResultsAt the last follow-up, the mean logMAR BCVA was 0.37±0.26. Compared with before surgery, the difference was statistically significant (t=5.98, P＜0.01). The mean CRT and MRT were (245.2±90.8) and (347.0±46.7) μm, respectively. Compared with before surgery, the differences were statistically significant (t=-2.49, -5.24; P＜0.05, ＜0.01). CRT and MRT changed greatly within 6 months after surgery, and then tended to be gentle. Among the 3 eyes with incomplete ellipsoid zone of tractional type before surgery, ellipsoid zone recovered in 2 eyes and partially recovered in 1 eye. Among the 17 eyes with retinal cavity and 8 eyes with macular retinoschisis before surgery, there were still 4 eyes with retinal cavity, but all the retinoschisis were disappeared. Among the 5 eyes with retinal cavity of degenerative type before surgery, there were still 2 eyes with retinal cavity and all the eyes with incomplete ellipsoid zone. Among 10 eyes with a follow-up time of equal or greater than 24 months, the macular ganglion cell complex partially atrophied in 6 eyes, and the nerve fiber layer separated in 2 eyes. There was no full-thickness macular hole after surgery.ConclusionFor most LMH patients, vitrectomy can effectively improve the visual acuity and promote the recovery of retinal microstructure.