Rhexis effect on IOL positioning is weak

Oliver Findl, MD, MBA, reports that with modern IOLs, rhexis size and shape has minimal influence on postop IOL positioning, a finding that may undermine the argument for femtosecond laser-assisted cataract surgery.

Dr. Findl, of the Vienna Institute for Research in Ocular Surgery in Austria, reported his findings at the 2013 Congress of the European Society of Cataract & Refractive Surgeons.

He and his team considered all surgeries performed by nine surgeons of varying ability, from trainees to experienced, over a 47-day period. Surgeons implanted a range of modern acrylic IOLs in 635 eyes. They took a picture of each eye at one hour postop to evaluate the rhexis and categorized it among three groups: a perfect rhexis  (controls) was defined as 4.5 mm to 5.5 mm in diameter;  eccentric, >5.5 mm; smaller, < 4.5 mm.

They took pictures again at three months, as well as Purkinje meter readings to analyze decentration and tilt and AC master readings.

They found no difference in axial position or anterior chamber depth among the three rhexis groups, from one hour to three months postop.   

“There was slightly more decentration in the eccentric group compared to controls, .08mm, but this is not likely clinically relevant,” Dr. Findl said. “With modern lenses you get little decentration. The rhexis effect is weak.”