Retinoschisis
Reviewed by Sofia Rokerya

In this retrospective study the authors evaluate the effect of pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling for lamellar macular hole (LMH) with or without macular retinoschisis in highly myopic eyes. Twenty-one highly myopic patients (22 eyes) with LMH were divided into two groups based on preoperative optical coherence tomography (OCT): the ‘flat group’ had no macular retinoschisis (n=10), and the ‘retinoschisis group’ had macular retinoschisis (n=12). The mean age of all included patients was 61.9±10.5 years (range 35-75 years). The mean AL was 29.55±1.62 mm (range 26.30-33.11mm). The average preoperative refractive error was -12.90± 6.77 dioptre (D), excluding the pseudophakic eyes (range -6.25-25D). The average preoperative logMAR value was 0.61±0.27 (range 0.1-1.0). The mean residual foveal thickness (RFT) was 165.76±53.70μm. Two eyes already had cataract extraction and lens implantation before PPV. There were no significant differences between the flat and retinoschisis groups in gender (p=0.62), age (p=0.29), or lens opacification (p=0.988). All surgeries were performed by one experienced surgeon (LS). To avoid cataract progression, phacoemulsification with simultaneous intraocular lens implantation was performed in 19 phakic eyes (all over the age of 50 years) followed by a conventional three-port, 23-gauge PPV. After posterior vitreous detachment, ILM peeling was successfully performed in all eyes with the help of indocyanine green (0.2 ml of 0.5%). Fluid exchange with air (16 eyes) or 20% perfluoropropane tamponade (six eyes) was performed at the end of the surgery. All patients maintained the prone position for three to seven days after surgery. The average follow-up time was 17.2±12.6 months. Outcomes were based on six-month postoperative best-corrected visual acuity (BCVA), integrity of the ellipsoid zone (EZ), external limiting membrane (ELM), and RFT. Results: The appearance of the macula on OCT was normalised in 19 eyes (86.3%) at the final follow-up visit. Compared to the flat group, the retinoschisis group presented a significantly higher incidence of epiretinal membrane (p=0.046) and lower refractive error (p=0.033), shorter axial length (p=0.0009), better integrity of ELM and EZ (p=0.005 and p=0.005, respectively), and better preoperative and postoperative BCVAs (p=0.015). The authors advocate that PPV is an effective method to achieve high anatomical success, improve postoperative vision and prevent foveal thinning in highly myopic eyes with LMH. In these eyes, the presence of retinoschisis strongly indicates the need for vitrectomy. Limitations: retrospective nature and small sample size.

Retinoschisis: a predictive factor in vitrectomy for lamellar macular holes in highly myopic eyes.
Tao J, Wu H, Chen H, et al.
OPHTHALMOLOGICA
2019;242:208-13.