Assessment of Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer Changes following Cataract Surgery in Patients with Pseudoexfoliation Glaucoma

Comparison of changes in retinal nerve fiber layer thickness and intraocular pressure between glaucoma and non-glaucoma patients after phacoemulsification

Objective

To compare the changes in Retinal Nerve Fiber Layer (RNFL) thickness and Intraocular Pressure (IOP) after phacoemulsification in patients with glaucoma versus without glaucoma.

Methods

This was a quasi-experimental study, done at Lahore General Hospital, from January 2021 to December 2021. Patients with senile cataract were divided into two groups. One group included 40 patients, with ≥40 years of age and diagnosed with primary open angle glaucoma compared with a second group of 40 age-matched controls without glaucoma, undergoing phacoemulsification and Intraocular Lens Implantation (IOL). Goldman Applanation Tonometer (GAT) and Spectral Domain Optical Coherence Tomography (SD-OCT) were used to record IOP and RNFL thickness, before surgery, at one week and one month after surgery. The results were compared with baseline readings and also between the two groups.

Results

A total of 80 patients were included in the study. Mean age was 60.3±7.9 years with male to female ratio of 1:1. Mean change in RNFL thickness in glaucomatous eyes group and non-glaucomatous Eyes group from pre-operative baseline was 11.33±4.30μm and 4.08±2.59μm respectively after one month (p-value<0.001). Difference of mean change in RNFL thickness from baseline was statistically significant between both groups (p< 0.001). Difference of mean change in IOP from baseline at four weeks was statistically significant in the individual groups but between both groups was statistically insignificant (p= 0.234).

Conclusion

Phacoemulsification results in increase in RNFL thickness and decrease in IOP, which are good prognostic factors in control of glaucoma. However, a mean change of IOP of 1mmHg in glaucoma patient does not affect management of glaucoma.

Predictors of intraocular pressure change after cataract surgery in patients with pseudoexfoliation glaucoma and in nonglaucomatous patients

Background/Aim. The cataract surgery in eyes with and without glaucoma results in the sustained intraocular pressure (IOP) reduction but it is still unknown which glaucomatous patients will achieve clinically significant reduction. The preoperative IOP and some ocular biometric parameters have been shown as potential predictors of the postoperative IOP reduction. The aim of our prospective intervention study was to evaluate that relationship in medically controlled patients with the pseudoexfoliation glaucoma (PXG) and in the nonglaucomatous patients. Methods. Thirty-one PXG patients (31 eyes) and 31 nonglaucomatous patients (31 eyes), all with clinically significant cataract, were enrolled. The preoperative IOP, anterior chamber depth (ACD), axial length (AL), lens thickness (LT), lens position (LP) [LP = ACD + 0.5 LT], relative lens position (RLP) [RLP = LP / AL] and the pressure-to-depth ratio (PD ratio) [PD ratio = preoperative IOP/preoperative ACD] were evaluated as potential predictors of the IOP change in the 6th postoperative month. Results. In the 6th postoperative month, in the PXG group, the IOP reduction was -3.23 ? 3.41 mmHg (-17.67 ? 16.86%) from the preoperative value of 16.27 ? 3.08 mmHg and in the control group, the reduction was -2.26 ? 1.71 mmHg (-15.06 ? 10.93%) from the preoperative value of 14.53 ? 2.04 mmHg. In the PXG group, the significant predictors of the absolute and the percentage IOP reduction were the preoperative IOP, AL, and PD ratio. In the same group, RLP was shown as a significant predictor of absolute change in the IOP in multi-variate analysis, and the percentage IOP change in both the univariate and the multivariate analyses. In the control group, the preoperative IOP and the PD ratio were the only significant parameters that could predict absolute change in the postoperative IOP. Conclusion. The cataract surgery leads to the IOP reduction both in the PXG and nonglaucomatous eye. Predictors monitored in this study are widely available and simply calculable parameters that can be potentially used in managing glaucoma.