Fovea-Sparing Versus Standard Internal Limiting Membrane Peeling for Myopic Traction Maculopathy
Nobuhiko Shiraki N, Wakabayashi T, Ikuno Y, et al. Fovea-Sparing Versus Standard Internal Limiting Membrane Peeling for Myopic Traction Maculopathy: A Study of 102 Consecutive Cases. Ophthalmol Retina. 2020 May 26; S2468-6530(20)30208-6. doi: 10.1016/j.oret.2020.05.016.
Myopic traction maculopathy is a major source of visual impairment in eyes with pathological myopia and affects between 8-34% of pathologic myopes with posterior staphylomas. The spectrum of myopic traction maculopathy can range from vitreomacular traction, retinal thickening, macular retinoschisis (MRS), lamellar macular hole (MH), and foveal retinal detachment (RD). The pathogenesis of myopic traction maculopathy is considered as a result of a thinner and stiffer internal limiting membrane (ILM), traction from the posterior vitreous cortex and due to outward traction from elongation of the eye/staphyloma.
Prior natural history studies of eyes with MRS showed that between 33% to 50% of eyes develop either foveal RD or full-thickness MH (FTMH)) requiring surgical intervention. However, developing a FTMH is a serious complication of vitrectomy for foveal RD. The authors hypothesize peeling of ILM during vitrectomy for repair of foveal RD increases the risk of FTMH post-operatively. This study is aimed at evaluating the safety and efficacy of fovea-sparing ILM peeling to prevent post-operative FTMH for the treatment of foveal RD due to myopic traction maculopathy.
Patient Selection – Forty-five eyes of 45 patients with pathologic myopia (spherical equivalent> -8.00 diopters or axial length > 26.5 mm) underwent vitrectomy with ILM peeling for foveal RD due to myopic traction maculopathy. Foveal RD was confirmed by OCT and patients with preoperative FTMH, myopic CNV, or macular atrophy were excluded. Patients excluded for other ocular comorbidities including history of trauma, diabetic retinopathy or retinal vein occlusion.
Surgical technique – surgeries were completed by 3 surgeons at the Tokyo Medical and Dental University Hospital from Dec 2005 to June 2011
- Complete ILM peeled group: standard 25-gauge PPV with cortical and hyaloid removal. Then ILM was stained with ICG for 30 seconds and ILM was completely peeled. This was completed between Dec 1005 – Sep 2009.
- Fovea-sparing ILM peeled group: after ILM staining with ICG, the ILM was peeled in a circular fashion around the macula without peeling it off the fovea. Then the ILM is trimmed with vitreous cutter and left attached to the fovea. This was completed from Oct 2009 – Jun 2011.
- Fluid-air exchange was performed in all cases, followed by 18% sulfur hexafluoride with prone position for at least 1 week.
Demographics – Of the 45 eyes, 30 had complete ILM peeled and 15 had fovea-sparing ILM peeled. There was no difference between the baseline characteristics of both groups (age, sex, axial length, and pre-operative lens status). The only difference was in duration of follow-up with less overall follow up in the fovea-sparing ILM peeled group.
Anatomic outcomes – Full-thickness MH developed in 5 of the 30 eyes in the complete ILM peeled group and in none of the 15 eyes in the fovea-sparing ILM peeled group. Three of the 5 eyes that developed FTMH developed an RD around the MH. In the rest of the complete ILM peeled group (25 eyes), all had resolution of the foveal RD or MRS. In the fovea-sparing ILM peeled group patients with less than 12 months of follow up had reduction but not resolution of foveal RD/MRS, while patients with greater than 12 months of follow up had resolution of foveal RD/MRS. Post-operative focal retinoschisis was noted near retinal vascular microfolds in both groups equally. There was also a transient increase in MRS at time of gas resorption in about 13% of cases of both groups.
Visual outcomes – There was no difference between the preoperative, postoperative and final BCVA between both groups. However, there was a significant improvement in BCVA between pre- and postoperative BCVA in the fovea-sparing ILM peeled group and this overall improvement was not present in the complete ILM peeled group. None of the fovea-sparing ILM eyes had reduction in BCVA and 4 of the 30 eyes in the compete ILM peeled group had reduction in BCVA (all 4 due to FTMH post-operatively).
Take home points
Fovea-sparing ILM peeling for myopic traction maculopathy with foveal RD can prevent post-operative full-thickness macular hole development. Post-operative residual ILM contracts after 3 months without functional loss. Overall, fovea-sparing ILM peeling has better visual and anatomic outcomes in myopic tractional maculopathy. The main limitations to the study, besides its retrospective nature, is the selection criteria for surgery and the lack of longer follow up in the fovea-sparing ILM peeling group to assess the effects of the remaining ILM.