Improvement of fluctuations of intraocular pressure after cataract surgery in primary angle closure glaucoma patients

Background: Cataract surgery has been shown to reduce intraocular pressure (IOP) in eyes with primary angle closure glaucoma (PACG). In this study, we examined IOP fluctuations and circadian IOP patterns before and after cataract surgery in PACG patients using the contact lens sensor (CLS) Triggerfish®.

Methods: This was a prospective open-label study. Ten consecutive patients with PACG were included. The patients underwent phacoemulsification and intraocular lens implantation (PEA+IOL) surgery. In each eye, IOP fluctuations over 24 h were measured with the CLS before and at three months after the surgery. Changes in corneal curvatures and anatomic parameters of the anterior chamber were measured by anterior segment optical coherence tomography (AS-OCT).

Results: The mean IOP was significantly reduced from 14.7 ± 1.5 mmHg to 11.2 ± 2.2 mmHg at three months after the surgery in PACG patients (P = 0.002). Although the mean range of 24-h IOP fluctuations was not significantly changed after the surgery (P = 0.49), the mean range of IOP fluctuations during the nocturnal period was significantly decreased from 246 ± 61 mVeq to 179 ± 64 mVeq after the surgery (P = 0.02). After the surgery, seven eyes of the ten (70 %) showed the same circadian IOP patterns. AS-OCT showed significant improvements in the anatomic parameters of the anterior chamber after the surgery.

Conclusions: Cataract surgery decreased IOP fluctuations during the nocturnal period in PACG patients. These effects might partly prevent the progression of PACG.