Sub-Tenon injection of 2% lidocaine prevents intra-operative floppy iris syndrome (IFIS) in male patients taking oral α-adrenergic antagonists.

Purpose:   To compare 2% sub-Tenon and 1% intra-cameral lidocaine for cataract surgery in relation to the incidence and severity of IFIS. Prospective randomized clinical study.

Methods:   From 81 eligible, we included 71 men aged from 59 to 90 years (mean 76.5 ± 6.8) undergoing routine cataract surgery and taking oral α-adrenergic antagonists, for urological reasons, for more than 1 year. Following randomization 34 men, aged from 62 to 90 years (mean 77.4 ± 8.1) received sub-Tenon injection of 2.5 ml of 2% lidocaine and the remaining 37 men aged from 59 to 89 years (mean 75.2 ± 7.2) received 1% preservative free intra-cameral lidocaine. Outcome measures were the incidence of IFIS, severity of intra-operative pupillary constriction and iris prolapse.

Results:   Intra-operative floppy iris syndrome (IFIS) was noted in 3 of 34 patients (8.8%) receiving sub-Tenon lidocaine and in 18 of 37 patients (48.6%) receiving intra-cameral lidocaine (p = 0.00). Severe IFIS was observed only in 3 of 37 patients (8.1%) receiving intra-cameral lidocaine. Pupil diameter at the end of surgery was 4.37 ± 1.07 mm in the sub-Tenon lidocaine group and 4.02 ± 1.06 mm in the intra-cameral lidocaine group (p = 0.00). Iris prolapse was noted in two cases in the sub-Tenon lidocaine group and in 10 cases in the intra-cameral lidocaine group (p = 0.00). Twenty-five patients were receiving tamsulosin. The incidence of IFIS in tamsulosin subgroup was 76.9% (10 of 13 patients) in the intra-cameral lidocaine group and 16.6% (2 of 12 patients) in the sub-Tenon lidocaine group (p = 0.00).

Conclusion:   Sub-Tenon lidocaine reduces significantly the incidence of IFIS in patients taking oral α-adrenergic inhibitors as compared with intra-cameral lidocaine.