Macular Edema after an Uncomplicated Cataract Surgery

Overview

Purpose:
To characterize the macular thickness changes after an uncomplicated cataract surgery measured by means of optical coherence tomography (OCT), to specify the incidence of cystoid macular edema (CME), and to attempt to establish a correlation between the retinal thickening after an operation and possible risk factors for its development.

Patients and methods:
This study comprised 100 patients (64 women and 36 men) with the mean age of 70 (70.08 ± 9.37 [SD] years; range, 44–85 years). All patients an underwent uneventful phacoemulsification, which was followed by in the bag intraocular lens implantation. The real phacoemulsification time and the duration of the entire surgical procedure were recorded. The operated eye was set into the study group; the contralateral, non operated eyes formed a control group. The patients were clinically assessed with Stratus OCT examination preoperatively, and on day 1, in week 1, and in months 1, 2, 3 and 6 postoperatively. Foveal (central area 1mm in diameter), inner macular (ring area between 1mm and 3mm in diameter), outer macular (ring area between 3mm and 6mm in diameter) thickness and macular volume were analyzed.

Results:
An increase in retinal thickness and macular volume after the cataract surgery reached the maximum in months 1 and 2 in all examined areas. Since month 3 on, there was a progressive decrease of abnormal retinal thickness and macular volume. An increase in retinal thickness was proved to be most prominent in the inner macular area. An increase in macular volume and retinal thickness in inner and outer macular area were statistically significant in months 1, 2 and 3 (Student t-test, p < 0.001; [p=0.01 for the data in month 3]), while an increase in retinal thickness in foveal area was statistically significant in months 1 and 2 (Student ttest, p < 0.05). Six months after the surgery, the difference was not statistically significant in any of the examined areas. Three patients (3 %) developed CME after the phacoemulsification, but in one patient (1 %) only the clinical CME with some degree of a visual loss 1 month after the surgery (BCVA= 0.5) was diagnosed. There was a positive statistical correlation between the real phacoemulsification time and the increase in macular volume and retinal thickness in fovea and inner macular area in week one, and in months one and two after the surgery (Spearman’s correlation test, p<0.05). A positive statistical correlation was also found between the overall duration of the surgical procedure and the increase in macular volume and retinal thickness in all areas one month after the surgery (Spearman’s correlation test, p<0.05).

Conclusion:
The results indicate that changes in retinal thickness in macular area must be taken into account even after an uncomplicated cataract surgery. The increase in retinal thickness and macular volume reached the maximum in months 1 and 2 and tends to decrease since month 3 on. There is a positive statistical correlation between the retinal thickness increase and the real phacoemulsification time as well as between the retinal thickness increase and the overall duration of the surgical procedure. The incidence of CME was 3 %, but clinically significant CME was detected in 1 % of the cases only. Topical application of non-steroid, anti-inflammatory drugs can be important to effectively prevent the CME development after an uneventful cataract surgery.

Key words:
Cystoid macular edema, optical coherent tomography, cataract surgery, phacoemulsification