Comparison of Ziemer LDV Z8 femtosecond laser pretreatment of cataract and conventional phacoemulsification in primary angle closure disease (PACD).

Abstract

Purpose: Determine if FLACS in PACD is safe and if predicted IOP rise would lead to long-term sequelae.

Setting: Singapore National Eye Centre.

Design: Prospective randomised control study.

Methods: Subjects with stable PACD and pre-existing LPIs were randomised to FLACS, or conventional phacoemulsification (control). The former underwent pre-treatment using the Ziemer LDVZ8 docking system. Supine IOP was measured at 4 time-points using an applanation tonometer - prior to speculum insertion, with speculum in-situ, with suction on, and 1 minute after suction off. The control group had IOP measured at the first 2 time points. HVF and OCT RNFL measurements were performed preoperatively, 6- and 12-months post-operatively.

Results: 57 eyes successfully treated. In both groups, mean IOP prior to and after speculum placement was similar. In the FLACS group, mean IOP during suction was 78.67mmHg (SD 12.07) and 1 minute post release of suction was 16.92mmHg (SD 3.68). Mean preoperative VF mean deviation (MD) for both groups was similar, -5.07 ± 3.17 SD in the FLACS group and -5.68 ± 4.77 in the control group, with improvement in both at 1 year, to -4.15 ± 5.49 and -2.25 ± 6.08 respectively. In the FLACS group, the average RNFL thickness pre- and post-operatively was 73.2 ± 25.1 SD and 87.9 ± 9.9 SD. In the controls, the average RNFL thickness pre- and post-operatively was 81.9 ± 21.4 SD and 81.5 ± 20.8 SD.

Conclusions: The transient increase in IOP induced by FLACS did not increase glaucomatous damage in PACD eyes after 1 year.