Incidence of Pseudophakic Cystoid Macular Oedema Post-Cataract Surgery in Illawarra Shoalhaven Local Health District, Australia

Abstract

Background: Post-operatively, cataract surgery is associated with pseudophakic cystoid macular oedema (PCMO) causing vision disturbances. The presence of comorbidities may increase the incidence of PCMO post-cataract surgery.

Objective: This observational study aimed to assess the incidence of PCMO in Australia (Illawarra region) and identify risk factors for developing PCMO.

Methods: Retrospective analysis was performed on data from patients who underwent uncomplicated phacoemulsification and intraocular lens implantation between 1st March and June 30, 2016. Demographics, comorbidities, central subfield thickness (CST), visual acuity, and intraocular pressure (IOP) were collected preoperatively, day 1, and weeks 2, 4, and 6 post-operatively. Statistical analysis was performed using SPSS v.27.0 and GraphPad Prism v.9.0. The median and 95% confidence intervals were used to describe data. Logistic regression and χ² tests were used to describe the associations. We followed the Declaration of Helsinki guidelines.

Results: Fifty right and 35 left cataract eyes were operated on (58.8% were females; average age 72.8 ± 8.146 years). Total PCMO incidence was 10.6%, and true PCMO incidence (removing PCMO risk factors) was 4.2% at week 6 post-operatively. CST was slightly increased between pre- and post-cataract surgery at week 4 (p = 0.002) and week 6 (p < 0.0001; median = 259 μm, 264 μm, and 263 μm, respectively). IOP was found to be decreased (p < 0.0001) compared to day 1 (median = 17 mm Hg) and week 6 (median = 13 mm Hg). The probability of developing PCMO (odds ratio [OR] = 3) and vitreomacular traction (OR = 2.9) was higher in diabetic patients compared to non-diabetic patients and in patients >65 years old (OR = 1.5).

Conclusion: The true incidence of PCMO was found to be the greatest at 2-4 weeks post-operatively. Patients with diabetes or advanced age (>65 years) are at an elevated risk of developing PCMO after cataract surgery. The treatment regimens for the comorbid populations, especially diabetic patients, remain limited, and future efforts should target pharmaceutical management for these groups.

Keywords: Cataract; Comorbidities; Pseudophakic cystoid macular oedema.

Fig. 1

Retinal OCT 6 weeks following cataract surgery illustrating macula with perifoveal cysts and localized foveal oedema indicative of PCMO.

Fig. 2

aCST pre- and post-cataract surgery.bIOP pre- and post-cataract surgery.cCorneal thickness post-cataract surgery.

Fig. 3

Snellen BCVA values at week 2, week 4, and week 6 post-cataract surgery.