Prospective randomized comparative study of macular thickness following phacoemulsification and manual small incision cataract surgery.

PURPOSE

To compare macular thickness following uncomplicated phacoemulsification with foldable acrylic lens and manual small incision cataract surgery (MSICS) with non-foldable polymethyl methacrylate (PMMA) lens implantation.

METHODS

Prospective study was carried out with one eye each of 224 patients with senile cataract randomized into two groups, phacoemulsification and MSICS, by simple 1:1 randomization. Following surgery by either of the two methods, macular thickness was measured by optical coherence tomography (OCT) on the 1st, 7th, 42nd and 180th postoperative day. Main outcome measure was postoperative macular thickness.

RESULTS

On the first postoperative day, central subfield mean thickness (CSMT) in MSICS group was 192.8 +/- 17.9 microm and that in phacoemulsification group was 192.1 +/- 27.4 microm, with no significant difference (p = 0.12). On the 7th day, CSMT in MSICS group (198.9 +/- 21.4 microm) was significantly (p = 0.04) more than that in phacoemulsification group (193.1 +/- 19.3 microm). On the 42nd day, CSMT in MSICS group was 207.8 +/- 26.3 microm and that in phacoemulsification group was 198.3 +/- 23 microm, the difference being significant (p = 0.007). Clinically macular oedema was not diagnosed in any of the patients at any visit. The increase in macular thickness was sub-clinical and did not affect final visual outcome in any patient.

CONCLUSION

In spite of the greater theoretical risk of increased postoperative inflammation following MSICS, there was no evidence of cystoid macular oedema, either clinically or on OCT. However, chance of sub-clinical increase in CSMT was more following MSICS compared to phacoemulsification.