Partial posterior hyaloidectomy for macular disorders

Abstract

Purpose: To evaluate the effect of partial posterior hyaloidectomy (PPH) in preventing iatrogenic retinal breaks related to the induction of a posterior vitreous detachment (IPVD).

Methods: Fifty-nine patients who necessitated IPVD for an epiretinal membrane or macular hole were included in this prospective, interventional case series. Extensive removal of vitreous gel, close to the retina, was conducted before IPVD under 23 G (gauge)-vitrectomy system. The PPH involved the limited extent of IPVD and limited removal of the outermost vitreous cortex to an area slightly beyond the margin of the temporal major vascular arcade. The incidence of retinal breaks related to the surgery was compared with 57 eyes that had undergone conventional 23-G total vitrectomy accompanied by extensive IPVD using χ(2)-test.

Results: Patients were followed-up for a mean of 14.3 months (6-30 months) after the surgery. The incidence of peripheral retinal breaks after the PPH was 3.4% (2/59 eyes), which was significantly lower than that in the eyes that underwent conventional 23 G vitrectomy (15.8%, 9/57 eyes, P=0.023) for the same disorders that required an IPVD. No patient complained of postoperative floaters, postoperatively.

Conclusions: PPH would be an efficient procedure to prevent iatrogenic peripheral retinal breaks related to an IPVD.

Figure 1

A diagram illustrating the conventional vitrectomy (a) and PPH procedures (b). Each pair of pictures shows the difference in specific techniques between the two surgeries. A1, B1: core vitrectomy; A2, B2: IPVD utilizing a bent needle; A3, B3: vitreous cortex removal; A4, B4: residual vitreous and the extent of posterior vitreous detachment after the surgery. In a PPH procedure, as much of the vitreous gel as possible is removed before the IPVD. Notice the thin residual vitreous cortex after core vitrectomy (B1). After the IPVD, the extent of vitrectomy was restricted to just beyond the margin of the temporal major vascular arcade to avoid peripheral propagation of the PVD. In addition, an attempt to minimize the perpendicular traction to the vitreous base was made by maintaining the position of the vitreous cutter very close to the retinal surface, and by lowering the suction power (B3). Arrows indicate the expected direction of traction force during vitreous cortex removal (A3, B3).

Figure 2

An intraoperative capture image taken during the fluid–air exchange in an eye with MH. It shows the extent of IPVD and removal of vitreous cortex in PPH. White arrows indicate margin of residual vitreous cortex.

Figure 3

Diagrams showing the distribution of retinal breaks from two eyes in the PPH group (top) and from nine eyes in the conventional 23 G-vitrectomy group (bottom).