[Clinical observation of highly myopic eyes with retinoschisis after phacoemulsification]

To evaluate the changes of the retinal thickness in the highly myopic eyes with retinoschisis after phacoemulsification by optical coherence tomography (OCT) and to analyze their postoperative visual acuity.

It was a retrospective case series study. This study included 25 (35 eyes) highly myopic patients with retinoschisis. One week, 1 and 3 months after phacoemulsification, the best corrected visual acuity (BCVA) was measured and OCT was performed to evaluate the central foveal thickness (CFT) as well as the maximum neurosensory thickness (MNT). These 35 eyes were divided into low and high accumulated energy complex parameter (AECP) groups, and ≤ 28.00 mm, > 28.00 and ≤ 30.00 mm, > 30.00 mm groups according to the axial length respectively. Variance analysis of data obtained from repeated measurement, Wilcoxon rank sum test, linear correlation and one-way ANOVA were used to analyze the data.

According to the location of schisis, the 35 eyes were classified as foveal schisis (20 eyes) and nonfoveal schisis (15 eyes). Among the 35 eyes, there were 30 eyes with outer retinoschisis and 5 with compound schisis. The mean BCVA (logMAR) preoperatively and 1 week, 1 and 3 months postoperatively was 0.23 ± 0.24, 0.59 ± 0.38, 0.57 ± 0.38 and 0.60 ± 0.36 respectively (F = 31.15, P = 0.000). CFT preoperatively and 1 week, 1 and 3 months postoperatively was (255.46 ± 197.57) µm, (256.80 ± 199.88) µm, (274.37 ± 246.87) µm, and (268.60 ± 238.41) µm (F = 0.99, P = 0.420); while MNT was (473.31 ± 175.52) µm, (477.71 ± 188.71) µm, (486.60 ± 229.17) µm and (482.63 ± 208.82) µm respectively (F = 0.26, P = 0.857). BCVA in eyes with foveoschisis and in eyes with nonfoveal schisis was statistically significantly different at 1 week, 1 and 3 months postoperatively (Z = -0.580, P = 0.048; Z = -2.147, P = 0.030 and Z = -2.099, P = 0.034). BCVA (0.43 ± 0.28) was inversely correlated with CFT (497.42 ± 281.49) µm in the eyes with foveoschisis unaccompanied with a macular lamellar hole at 3 months postoperatively (r = -0.667, P = 0.018). There were no significant differences in the changes of the thickness of the retina between the groups with different AECP or among the groups with different axial lengths (Z = -0.314 - 1.290, P = 0.192−0.741 and F = 0.15−0.62, P = 0.545−0.859).

Cataract surgery has no significant effect on thickness of the retina in the highly myopic eyes with retinoschisis. The patients with retinoschisis could achieve good visual recovery after phacoemulsification. Postoperative visual acuity is related to the location and degree of retinoschisis. Besides, patients with non-foveal schisis could obtain better visual acuity than those with foveoschisis. Further investigation on the development of retinoschisis and the complications after surgery is required.