This article discusses the prognostic factors and options in the surgical management of rhegmatogenous retinal detachments associated with macular holes.
Conventional techniques are rarely successful in achieving retinal reattachment and MH closure. In 1982, Gonvers and Machemer first described vitrectomy for MH and RD.1 Other adjunctive manoeuvers include internal limiting membrane (ILM) peeling, epiretinal membrane peeling, laser photocoagulation to the rim of the MH and use of internal tamponades such as gas or silicone oil (SO). Reported success of the surgery also varies considerably in terms of retinal reattachment of MH closure. This article discusses the prognostic factors and options in surgical management.
Reported success rates
In the literature, retinal reattachment ranged from 40% to 93.5% and MH closure ranged from 31% to 100%. We recently reported the success rates in a study with the largest cohort to date and we achieved a success rate of 86% and 53.5% for retinal reattachment and MH closure respectively.2
In a Japanese study, Nakanishi et al.3 analysed 49 eyes which underwent vitrectomy and gas tamponade, and found axial length to be a prognostic factor. Of note, ILM peeling and choice of tamponade gas was not significant.
Lam et al.4 found that ILM peeling, shorter axial length and shorter duration of MH to be important prognostic factors. Our study found increased age and use of C3F8 to be factors predicting anatomic success.
We postulate that in older age, the eyes are more likely to have a complete posterior vitreous detachment, which may be advantageous when trying to relieve epimacular traction during surgery.
The use of scleral buckling
Various authors have described posterior or macular buckling techniques. Posterior episcleral buckling has been shown to have a better outcome than vitrecomy.5 We did not find the use of scleral buckle to be associated with success. However, we perform encirclage buckle with the aim to support the vitreous base and reduce the risk of future peripheral tears in these highly myopic eyes.
The role of ILM peeling
ILM peeling aids in relieving tangential traction and helps in promoting MH closure. The literature is scarce and results conflicting for ILM peeling for MH closure in eyes with MH and RD. Some limitations of previous studies, which precludes meaningful interpretation, include the lack of a comparison group, or the failure to report MH closure.
We found that ILM peeling did not improve either retinal reattachment of MH closure rates, nor did the use of ILM stain. Axial elongation in these highly myopic globes probably diminishes the role of relieving tangential traction through ILM peeling.
Choice of internal tamponade
Available options include sulphur hexafluoride, C3F8 or SO. The use of SO brings with it attendant problems of the need to remove it at a later date, or complications such as glaucoma or corneal decompensation. We found that C3F8 yielded the best results, and therefore propose the use of longer acting gas in these complex detachments.
The poorer efficacy of SO could be due to selection bias whereby the surgeon chooses SO in more complicated detachments. However, it is also possible that C3F8 conforms better to the contour of the staphyloma and its better buoyancy may have contributed to its superior performance.