Macular changes after peeling of the internal limiting membrane in macular hole surgery

To report the incidence of macular changes following pars plana vitrectomy with peeling of the internal limiting membrane (ILM) for idiopathic macular hole.

Prospective consecutive series.

In a prospective study 105 eyes of 105 patients underwent vitrectomy for idiopathic macular holes. Surgery consisted of a standard three-port vitrectomy, induction of a posterior hyaloid detachment, removal of epiretinal membranes including the ILM, fluid-air exchange and intraocular gas tamponade (15% hexafluoroethane (C2F6) gas mixture) followed by head-down positioning for at least five days. No adjuvants were used during surgery. In addition to the clinical examination, static microperimetry using a Rodenstock scanning laser ophthalmoscope (SLO-105) was performed pre- and 6 or 12 weeks postoperatively. The stimulus size was 0.2 degrees (Goldmann II), intensities employed were 0 and 12 dB. For all tests, 20-degree fields were used.

Anatomic closure of macular holes was achieved in 92 (87.6%) of 105 patients by one operation. Eight patients underwent a successful second procedure. The closure rate after two operations was 95.2%. Best corrected visual acuity increased from a median of 0.2 (range 0.05 to 0.5) preoperatively to a median of 0.5 (range 0.05 to 1.0) postoperatively. Anatomical macular changes were found in 8 (7.6%) patients: There were two cases of macular edema following secondary cataract extraction and six cases of retinal pigment epithelium changes. Formation of postoperative epiretinal membranes or late reopenings were not noted. Small, mostly asymptomatic paracentral scotomata were seen in 59 (56.2%) of 105 patients.

Anatomical changes of the macula following vitrectomy with removal of the ILM are infrequent. However, paracentral scotomata observed in our series might be caused by a trauma to the nerve fibers during ILM peeling. To achieve reliable results a standardized procedure for microperimetry should be developed.