We appreciate the comments of Seshubabu Gosala and Sriramachandra Murthy Manchikanty on our article regarding the use of inverted internal limiting membrane (ILM) insertion technique to treat macular hole (MH)-associated retinal detachment in high myopia.
Visual acuity examination, contrast sensitivity test, microperimetry, visual field test, and even multifocal electroretinography are all tests useful for evaluation of visual function. Improvement of microperimetry results has been shown in previous papers after macular hole closure. However, in our series, all cases have associated retinal detachment before surgery; it is impractical to compare the microperimetry before and after surgery. Nonetheless, it is a good suggestion to do this examination after surgery for the 2 groups, with or without ILM insertion. In our study, the study group had a significantly higher macular hole closure rate, but did not show a better visual acuity compared with the control. Perhaps detailed microperimetry examinations of the 2 groups may shed some light on the functional outcome of our technique. As for the visual field test, our techniques differ from the conventional vitrectomy only by the ILM insertion or lack thereof; those factors that may possibly affect peripheral visual field were present in both the study and the control group. In addition, since those highly myopic patients often suffer from chorioretinal atrophic patches and have a higher chance of preexisting glaucoma, it is more difficult to use this test to evaluate the influence of surgery on the visual field.
It was our goal to use ILM within the hole to act as a bridge to promote glial cell proliferation. Since we peeled the ILM to the edge of the hole, and removed the other part of the ILM within the arcade, we believe the tangential traction outside the hole was almost completely removed. For the ILM left within the hole, further glial traction would only pull the edge of the original macular hole further centripetally and bring the neuroretinal tissue closer. Furthermore, the additional tissue within the hole may add to the total retinal tissue in the posterior pole, which in turn may act as a reserve to withstand further traction from eye wall out-bulging. Therefore, we do not think our techniques would enhance the recurrence of the macular hole.
We did not measure retinal nerve fiber layer in this paper. OCT is only used for evaluation of the closure of the macular hole, and it was not necessary to use a single kind of OCT machine to perform this evaluation.