Vitrectomy for epiretinal membranes with good visual acuity

Abstract

Purpose: To evaluate the visual results of vitrectomy for epiretinal membrane in eyes with a preoperative visual acuity of 20/50 or better.

Methods: The visual results and complications were analyzed following vitrectomy for idiopathic epiretinal membranes and epiretinal membranes secondary to retinal tears. This study was a retrospective, consecutive case series of 40 eyes of 40 patients treated by a single surgeon.

Results: The mean preoperative visual acuity was 20/50 +2 (range, 20/30 +1 to 20/50 -3). The mean visual acuity improved to 20/40 +2 (P = .02) by the final examination at a mean of 2.4 years following surgery. The status of the lens at the final examination was correlated with the visual results of surgery. Twenty-one eyes were phakic preoperatively, and 14 of these eyes had cataracts removed by the final examination. The mean preoperative visual acuity in seven eyes that were still phakic at the final examination was 20/50, and this decreased to 20/50 -2 (P = .82). The mean preoperative visual acuity was 20/50 +2 in 33 eyes that were pseudophakic by the final examination, and this improved to 20/32 -2 (P = .005). The visual acuity improved by 2 or more Snellen lines in only one in seven eyes (14%) that were still phakic on the final examination and in 14 of 33 eyes (42.4%) that were pseudophakic by the final examination. There were no serious surgical complications.

Conclusions: Vitrectomy for epiretinal membranes is beneficial in eyes with relatively good preoperative visual acuities, but cataract surgery is necessary in phakic eyes to achieve long-term visual acuity improvement.

Figure 1

Comparison of visual acuity data for all eyes and eyes that were phakic and pseudophakic preoperatively. Visual acuity remained unchanged for the entire group at 3 months but improved by the final examination (P = .02). Visual acuity improved in pseudophakic eyes at 3 months and at the final examination (P = .002). Visual acuity decreased in phakic eyes at 3 months and improved marginally by the final examination primarily due to visually significant cataracts remaining in some phakic eyes.

Figure 2

Visual acuity change in Snellen lines based on preoperative lens status. Visual acuities improved a mean of 1 line in all eyes. Phakic eyes had a smaller gain of 0.6 line, and pseudophakic eyes improved 1.4 lines.

Figure 3

Visual acuity results based on preoperative lens status. Eyes that were phakic on the preoperative examination were more likely to lose 2 or more lines of acuity (0.2 logMAR units), and eyes that were pseudophakic were somewhat more likely to gain 2 or more lines between the preoperative and final examination.

Figure 4

Mean visual acuity based on postoperative status of lens. The mean visual acuity remained essentially unchanged between the preoperative and 3-month examination in all eyes and eyes that were pseudophakic by the final examination. The visual acuity improved a little at 3 months in eyes that were phakic by the final examination. Visual acuities improved significantly in all eyes (P = .02) and eyes that were pseudophakic by the final examination (P = .005). Visual acuities deteriorated slightly in eyes that remained phakic at the final examination (P = .82), primarily because of visually significant cataracts.

Figure 5

Visual acuity change based on final lens status. Visual acuities deteriorated .28 line in eyes that were phakic on the final examination and improved a mean of 1.26 lines in eyes that were pseudophakic by the final examination.

Figure 6

Visual acuity results based on final lens status. Eyes that were phakic by the final examination were much more likely to lose 2 or more lines of visual acuity by the final examination. Eyes that were pseudophakic by the final examination were much more likely to gain 2 or more Snellen lines.