APR 08, 2015
This prospective study found that modern cataract surgery appears to reduce pupil size by around 10% in mesopic and photopic conditions and reduce centroid shift.
Forty patients (40 eyes) were imaged using Placido topography combined with pupillometryto determine pupil size and corneal vertex location before and 1 month after cataract surgery.
The researchers found that pupil diameter underwent a statistically significant relative reduction of -9.8% for photopic pupils and -9.1% for mesopic pupils, suggesting that a preop pupil diameter of 5.5 mm decreases to 5.0 mm as an indirect result of cataract surgery. The authors say their findings provide more evidence that it is safe to use an IOL with a 6.0 mm optic zone diameter instead of one with a larger zone.
Also, there was a reduction in the centroid shift in all eyes from a mean of 0.12 mm preoperatively to 0.05 mm postoperatively, the result of a reduced postop temporal difference between the corneal vertex and pupil center. They say the study’s results may be used clinically to assess visual performance after cataract surgery and may be relevant for IOL design.