Abstract
Purpose:
Lens exchange surgery is not limited to cases with reduced visual acuity. In refractive lens exchange, typically eyes are treated that do not suffer from visual acuity loss. Also, sometimes patients come in with complaints of quality of vision that may be interpreted as resulting from the condition of the lens, unaccompanied by visual acuity loss. It is however known that straylight may be increased because of lens aging before visual acuity losses occur. This study compares the behavior of straylight in lens exchange surgery between a cataract center, and a refractive surgery center where most surgery is on patients with good visual acuity.
Methods:
In a prospective non-randomized case series of eyes that had either cataract surgery or refractive lens exchange, with a preop acuity of LogMAR 0.1 or better, straylight was compared from pre- to postop. Results were compared to those of a cataract center. Straylight was measured with the Oculus C-Quant, serves as an objective and reliable parameter of visual quality, and is expressed as log(s).
Results:
Visual acuity and straylight were measured before and 3 months after phacoemulsification and IOL implantation surgery. In 136 eyes with logMAR≤0.1, mean preop log(s) was 1.17 ± 0.19 (range 0.83 to 1.72), and mean postop log(s) was 1.12 ± 0.16 (range 0.76 to 1.67). This difference is statistically significant (paired t-test, p<0.0003), but in individual cases the improvement could be much better, with 33 cases improving more than 0.2 log units. The age of 53.5 years was the age at which pseudophakia on average conferred better (lower) straylight levels, compared to the phakic state. Values in the cataract center for preop logMAR≤0.1 were 1.47±0.26 vs 1.23±0.26 (n=31), and for preop logMAR>0.1 1.57±0.27 vs 1.24±0.20 (n=281), but significant age differences existed. In both centers the pre-op log(s) value was highly predictive for positive outcome.
Conclusions:
In eyes with good visual acuity, straylight can improve significantly after lens exchange surgery for the purpose of both cataract surgery and refractive lens exchange. This study suggests that the average age at which pseudophakia benefits straylight, as parameter of visual quality, is 53.5 years, but because interindividual differences are significant, preop straylight assessment is mandatory.
Keywords: 445 cataract •
630 optical properties •
669 quality of life