This retrospective case series evaluated the efficacy of re-operation in patients with persistent or recurrent idiopathic full-thickness macular hole after initial surgery with internal limiting membrane (ILM). All re-operated patients underwent vitrectomy, enlargement of ILM rhexis and gas tamponade. The hole closure rate was significantly lower than in primary surgery, and visual outcomes also did not compare favorably.
Of 491 patients who underwent surgery for full-thickness macular hole at a single-center from January 2004 to November 2007, macular holes in 55 either did not close or reopened during the follow-up period. This produced a primary surgery success rate of 88.8 percent. Of the 25 patients who underwent re-operation and for whom complete follow-up data were available, the overall success rate was 46.7 percent.
In re-operated patients, the surgeons achieved a closure rate of 52 percent for unclosed holes and 25 percent for reopened holes, both of which are significantly lower than the rates achieved in a previous retrospective case series of 532 patients (76 percent and 100 percent, respectively). This difference is probably due to technique. In the other study, ILM peeling was rarely carried out in both initial surgery and re-operation. The authors hypothesize that re-operation is much less likely to succeed in patients whose ILMs have already been peeled; there is little else to do when the posterior hyaloid has been detached and the ILM removed.
The overall visual outcomes were poor compared to those seen in primary surgery. However, when considering each re-operated patient's highest visual acuity at any point during the year following re-operation, there was a significant improvement. It is also notable that the BCVA of patients whose holes did not close did not decrease. Clinically, however, 88 percent of patients did not improve by at least one Snellen line, 8 percent improved by two lines and 4 percent improved by four lines. These poor visual acuity outcomes relative to primary surgery may relate to the added duration of the hole and having to wait for and undergo a second surgery.
It is often difficult to ascertain how long a hole has been present. Furthermore, longer-duration holes tend to be bigger and less likely to close, so the ones that have failed may already be predisposed to worse outcomes. Additionally, after the ILM has been peeled, residual ILM is more adherent. Additional surgical trauma damages retinal pigment epithelium and photoreceptors and is probably an important component of disappointing visual results.
Given that the majority of failed cases were unclosed holes, the authors recommend removing all vitreal traction with ILM peeling. While the causal mechanism of these reopened holes remains unclear, they believe that elevation of the posterior hyaloid and removal of the ILM eliminates centripetal traction and residual vitreous adherence to the retinal surface. Certainly the difficulties of face-down positioning and noncompliance are likely to be important contributors, as well as hole size and presence of the hole for longer than realized.
Ultimately, the decision to proceed with repeat macular hole surgery must be made after careful deliberation with the patient and informing the patient of the benefits, risks and likelihood of hole closure and visual acuity improvement.