Ocular hypertension after silicone oil filling surgery for high myopia: A case control study

Abstract

Purpose In order to analyze the influence of factors including the length of the eye axis on the occurrence of ocular hypertension (OH) after silicone oil filling. Methods 214 eyes undergoing vitrectomy and silicone oil filling were retrospectively enrolled from 432 eyes of high myopia patients. The time of occurrence of postoperative OH in patients with secondary OH after silicone oil filling was observed and recorded. Various clinical parameters were analysed that basic characteristics, past disease history, other combined surgery, the correlation of the auxiliary examination results (the length of the eye axis, silicone oil entering the anterior chamber, silicone oil emulsification), and the relevance of the silicone oil filling time in the eye. Chi-square test and logistic regression analysis were conducted. Results After high myopia silicone oil is filled, the length of the eye axis (29.21 ± 0.85) mm becomes longer than the actual length (28.31 ± 0.82) mm. 80 cases of postoperative high intraocular pressure occurred cumulatively, with an incidence rate of 37.38%. There was a statistically significant difference in the surgical conditions (scleral cerclage or external pressure, lens eye, the axis of the eye, and emulsified silicone oil) and the filling time of silicone oil in the eye in OH and normal intraocular pressure groups (P < 0.05). The results of logistic regression analysis showed that combined episcleral cerclage/external scleral pressure, aphakic eyes, axial length ≥ 29 mm, silicone oil emulsification, and silicone oil entering the anterior chamber are high myopia patients after silicone oil filling. The OR values​of the risk factors of stress were 3.478, 1.945, 2.461, 5.387, 4.151, respectively. Conclusion The high intraocular pressure after silicone oil filling is related to pupil block, angle obstruction, and humor circulation disorder caused by the forward movement of the crystalline iris septum or the front interface of silicone oil in aphakic eyes.