Abstract
Purpose :
To determine whether the macular region of the retina is displaced after vitrectomy with internal limiting membrane (ILM) peeling in eyes with macular hole (MH) using optical coherence tomography angiography (OCTA) and to identify factors correlated with the displacements.
Methods :
A retrospective, observational case series of 20 eyes of 20 patients with an idiopathic macular hole. OCTA was used to obtain 3 mm × 3 mm en face images before and 2, 4, and 8 weeks after the vitrectomy with ILM peeling. We determined the displacements of the retina relative to the fovea and optic disc. We measured the distance between the center of the optic disc and an identifiable bifurcation of the retinal vessels (51.5 ± 8.1 for an eye) (1), and the angle made by a line between the center of the optic disc and the bifurcation point and a line extending to the center of the fovea. The angle was 0° in the foveal direction and increased in the counterclockwise direction in the left eye and clockwise direction in the right eye (2). We also measured the distance between the fovea and the bifurcation of easily identifiable retinal vessels (3).
Results :
The distance between the optic disc and vessel bifurcations was significantly shorter in all four quadrants throughout the postoperative period (P<0.01). This distance was significantly greater in the temporal quadrant (P<0.01). The distance of the bifurcations was significantly correlated with the preoperative distance from the optic disc (r = - 0.579, P<0.001). The angle was significantly rotated downward in the temporal, superior, and nasal quadrants 2 weeks after the surgery (P <0.01) and a significantly greater downward displacement was observed in the superior quadrant (P<0.01). The change in the angle of bifurcations was significantly correlated with the preoperative angle to the optic disc (- 0.632, P<0.001). The change in the distance in the inner region was significantly greater than that in the outer region in all quadrants. A significant reduction was observed in the mean FAZ area during the follow-up period.
Conclusions :
The retina in the macular region was displaced nasally probably due to movement of the retina toward the optic disc due to a contraction after the ILM removal. There was also a rotation downward by buoyancy from gas tamponade, and centripetal contraction during the process of hole closure.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.