Prevalence of optical coherence tomography-diagnosed postoperative cystoid macular oedema in patients following uncomplicated phaco-emulsification cataract surgery

Abstract

Background: Postoperative cystoid macular oedema is a complication of uneventful cataract surgery. Whereas improved surgical techniques have decreased the incidence of cystoid macular oedema, it remains a cause of unfavourable visual outcome following surgery. Fundus fluorescein angiography has been the 'gold standard' for diagnosing subclinical cystoid macular oedema; however, non-invasive cross-sectional imaging of the retina with optical coherence tomography may be equally effective at detecting the condition and offers the ability to quantify and repeat results over time.

Design: Prospective pre-post case series of patients undergoing routine phaco-emulsification surgery.

Participants: Eighty consecutive patients (100 eyes) with cataracts and an age range of 40 to 90 years (mean 76.18).

Methods: Macular thickness of participants was determined using time-domain optical coherence tomography preoperatively and after surgery at 1 day, 1 week, 4 weeks and 6 months. Optical coherence tomography was used to diagnose postoperative cystoid macular oedema.

Main outcome measures: Presence of cysts at the macula, identified by optical coherence tomography, in addition to foveal and macular thickness (µm).

Results: Cystoid macular oedema was present in 5% of eyes. Macular thickness increased after surgery and central foveal thickness increased by almost 7% but returned to preoperative levels after 6 months. Findings also indicate that patients who developed postoperative cystoid macular oedema had significantly thicker central foveal thickness of approximately 5% compared with those that did not.

Conclusions: Optical coherence tomography is a useful, non-invasive diagnostic tool in determining subclinical cystoid macular oedema in uncomplicated cataract surgery patients and detects the presence of retinal thickening and intra-retinal cysts very soon after surgery, thereby facilitating earlier diagnosis and treatment of postoperative cystoid macular oedema.