Intracameral pressure during capsulorhexis in cataract surgery using cohesive versus dispersive ophthalmic viscosurgical devices: a randomised trial.

Abstract

ObjectiveTo study the properties of different ophthalmic viscosurgical devices (OVDs) with respect to their ability to create and maintain high intraocular pressure (IOP) during the creation of a continuous curvilinear capsulorhexis (CCC) by comparing the drop in IOP before and after creation of the CCC.

Methods and analysis: The study included 174 eyes in four groups using two different OVDs (hyaluronic acid (HA) and hydroxypropylmethylcellulose (HPMC)) and two different instruments (utrata forceps (UF) and 26G cystotome (RN)). IOP was measured using rebound tonometry with sterilised probes immediately before the beginning of the CCC and immediately afterwards during cataract surgery.

Results: The drop in IOP during capsulorhexis was measured at 52.1±10.7 mm Hg with the combination HA/RN, 62.4±11.5 mm Hg with HA/UF, 60.5±10.0 mm Hg with HPMC/RN and 68.7±14.1 mm Hg with HPMC/UF. The variance in IOP reduction between HA and HPMC did not reach statistical significance (p=0.100).

Conclusion: The lack of a noticeable difference in IOP levels, despite the use of different OVDs with unique properties, indicates that IOP may not be the main factor influencing the notable differences in tactile feedback perceived by surgeons during capsulorhexis procedures conducted with varying OVDs. To elucidate these sensations, additional characteristics such as viscosity, elasticity, pseudoplasticity and cohesion will have to be explored.