Cystoid macular oedema and changes in retinal thickness after phacoemulsification with optical coherence tomography

Aims To study the incidence of cystoid macular oedema and changes in retinal thickness after phacoemulsification with optical coherence tomography (OCT). Methods In all, 131 eyes of 131 patients were studied at the ophthalmology clinic at Tung Wah Eastern Hospital from September 2001 to October 2002. All the patients had clinical assessment and OCT preoperatively and at weeks 2, 4, and 8 postoperatively. The incidence of postoperative cystoid macular oedema (CMO) was evaluated. The foveal thickness (FT) and central 1 mm retinal thickness ( CT) at different time intervals were analysed. Results Four (3.05%) patients developed CMO after phacoemulsification, which was evident clinically and tomographically. Fluorescein angiogram confirmed leakage in all cases. For other patients, the mean preoperative FT was 189.36 +/- 26.83 mu m. The mean FT, were 175.74 +/- 26.79 mu m, 180.25 +/- 27.13 mu m, 176.58 +/- 26.45 mu m at 2 weeks, 4 weeks, and 8 weeks postoperatively, respectively. The preoperative FT was significantly thicker than those in the postoperative period. The same trend was noted for CT. Conclusion: OCT is useful for detecting and confirming clinical CMO after cataract surgery; however, its use in detecting subtle changes in retinal thickness is limited by the normal variation in retinal thickness. The measurement of retinal thickness with OCT may also be affected by the status of the lens.