Author: Sonia Gholami, Rotterdam Ophthalmic Institute
In one study (Marsack et al., 2004), it has been shown that the visual Strehl ratio (VSR) metric accounts for 81% of the variance in high-contrast logMAR visual acuity (VA) which makes this metric a strong predictor of visual performance in normal eyes. We have applied this method and investigated the correlation between the VA and the VSR of cataract eyes. The VSR versus visual acuity (logMAR VA) plot shows a very similar relationship for both groups (Fig. 1).
We furthered the study to computing lenticular VSR by subtracting the corneal Zernike coefficients from the ocular ones (see post on 2.2.2015). A rather high correlation with visual acuity (Fig. 2), convinced us to apply this method on a group of cataract eyes which are listed by the ophthalmologists to be operated on. This will help us to find out whether the lenticular VSR is a factor which is considered unconsciously in making decision for cataract surgery.
Figure 1 : Ocular VSR vs. logMAR VA in cataract and non-cataract eyes
Figure 2: Lenticular VSR vs. logMAR VA in cataract eyes