Anatomical and visual outcomes of fovea-sparing internal limiting membrane peeling with or without inverted flap technique for myopic foveoschisis

Abstract

Background: Vitrectomy and peeling of the internal limiting membrane (ILM) was an effective therapeutic approach for myopic foveoschisis with progressive visual loss. This study investigated the anatomical and visual outcomes of fovea-sparing ILM peeling with or without the inverted flap technique for patients with symptomatic myopic foveoschisis (MF).

Methods: We retrospectively reviewed the clinical data of patients with MF. Vitrectomy with fovea-sparing ILM peeling and air tamponade was performed in all patients. The primary outcome measures included best-corrected visual acuity (BCVA), mean macular thickness (MMT), and central foveal thickness (CFT). Depending on whether an inverted ILM flap technique was utilized, further subgroup comparisons between the inverted flap group and the non-inverted flap group were conducted.

Results: Twenty-six eyes of 22 patients were included. Fifteen eyes were underwent fovea-sparing ILM peeling without inverted ILM flap and 11 of the 26 eyes were treated with fovea-sparing ILM peeling and an inverted ILM flap technique. In the mean follow-up period of 10.74 ± 4.58 months, a significant improvement in BCVA was observed from 0.97 ± 0.45 logMAR to 0.58 ± 0.51 logMAR (P < 0.01), during which the BCVA of 20 eyes (76.92%) improved and remained stable in 5 eyes (19.23%). Moreover, a positive correlation was also found between the preoperative BCVA and the postoperative BCVA (r = 0.50, P = 0.01). At the last visit, the final MMT decreased from 492.69 ± 209.62 μm to 234.73 ± 86.09 μm, and the CFT reduced from 296.08 ± 209.22 μm to 138.31 ± 73.92 μm (all P < 0.01). A subgroup analysis found no significant differences in BCVA, MMT, or CFT between the inverted and non-inverted flap groups (all P > 0.05).

Conclusion: Fovea-sparing ILM peeling with or without inverted flap technique resulted in favorable visual and anatomical outcomes for the treatment of MF. An important factor affecting the postoperative visual outcome was the preoperative visual acuity. Our study found no significant difference between the presence and absence of the inverted ILM flap.

Keywords: Fovea-sparing; Internal limiting membrane; Myopic foveoschisis; Vitrectomy.

Fig. 1

Schematic diagrams of fovea-sparing internal limiting membrane (ILM) peeling with and without inverted flap. A In the cases without inverted ILM flap, several sits of ILM tissue at the edge of the reserved area (bold dotted line) were ripped carefully at about one disc diameter away from the fovea, by the retrobulbar injection needle with a hook. B To precede along with the boundary of the reserved area. When the peeled ILM flap deviated from the boundary, to start ILM peeling from a new ripped site was available. C To get the ILM of posterior pole peeled off in the center preserved manner (dotted line circle). D In the cases with the inverted flap, an additional area about one disc diameter above the fovea was prepared when ripping the reserved boundary (bold dotted line). E After removing the ILM around the reservation area, the above additional ILM was peeled and inverted towards to the foveal zone. F The ILM forceps covered the prepared ILM flap onto the fovea area

Fig. 2

OCT images of the patients who underwent fovea-sparing internal limiting membrane (ILM) peeling with and without inverted ILM flap. A Preoperative OCT scan indicated severe foveal detachment (FD) in a fifty years-old female, who had received fovea-sparing ILM peeling with an inverted ILM flap. B Five months after the surgery, the FD got complete recovery and the best-corrected visual acuity (BCVA) improved from 1.30 logMAR to 0.40 logMAR. C Preoperative OCT scan showed foveoschisis and inner retinal structure disorder in a fifty -two-year-old female, who had received fovea-sparing ILM peeling without inverted ILM flap. D Six months later, the degree of foveoschisis reduced and the morphology of the retina got improved, with the BCVA improved from 1.00 logMAR to 0.05 logMAR

Fig. 3

OCT images of two patients who developed full-thickness macular hole postoperatively (A-D) Sixty-six years-old female with an axial length of 26.97 mm had received fovea-sparing internal limiting membrane (ILM) peeling with inverted ILM flap. The preoperative best-corrected visual acuity (BCVA) was 0.52 logMAR and stable at the last visit. (Panel A) The preoperative scan indicated obvious epimacular membrane traction, ellipsoid line disruption (white triangle) and thin bridge of tissue in the inner retina layer (white arrow). (Panel B) A full-thickness macular hole (MH) was discovered one week after surgery with a diameter of 151 μm. (Panel C) The MH was enlarged, and the ILM flap was still covering the surface of the MH one month after surgery. (Panel D) The MH closed automatically about four months after the surgery without further surgical treatment. (E-H) Forty-four-year-old female with an axial length of 27.70 mm had received fovea-sparing ILM peeling without inverted ILM flap. The postoperative BCVA decreased from 0.60 logMAR to 1.85 logMAR. (Panel E) The preoperative scan showed a serve ellipsoid line disruption (white triangle). (Panel F) The degree of foveoschisis was relieved at four days after surgery. (Panel G) A full-thickness MH with diameter of 425 μm was discovered ten days after surgery. (Panel H) The MH was closed with ILM tissue insertion three months after the second surgery, which including ILM inserted, inverted ILM flap and air tamponade three months after the primary surgery