Abstract | PURPOSE: To investigate the influence of pupil diameter on the relation between induced changes in ocular higher-order wavefront aberrations and changes in contrast sensitivity by conventional laser in situ keratomileusis ( LASIK) for myopia. METHODS: In 215 eyes of 117 patients (age, 33.2 +/- 8.3 years) undergoing LASIK for myopia of -1.25 to -13.5 D (-5.28 +/- 2.55 D), ocular wavefront aberrations and contrast sensitivity function were determined before and 1 month after surgery. Preoperative photopic pupil diameter was measured with a digital camera. Ocular higher-order aberrations were measured for a 4-mm pupil with a Hartmann-Shack wavefront analyzer. The root-mean-square (RMS) of the third- and fourth-order Zernike coefficients was used to represent coma- and spherical-like aberration, respectively. From the contrast-sensitivity data, the area under the log contrast sensitivity function (AULCSF) was calculated. RESULTS: One hundred five eyes had a photopic pupil diameter of 4 mm or larger, and the remaining 110 had a photopic pupil diameter smaller than 4 mm. There were no statistically significant differences in the background clinical data between these two groups. In the eyes with a photopic pupil diameter of 4 mm or larger, the changes in third-order comalike aberrations did not correlate with the changes in AULCSF (Pearson correlation coefficient, r = -0.037, P = 0.723) and 10% low-contrast visual acuity (r = 0.125, P = 0.224), but fourth-order spherical-like aberrations correlated significantly with the changes in AULCSF (r = -0.229, P = 0.024) and 10% low-contrast visual acuity (r = 0.221, P = 0.038). In the eyes with photopic pupil size smaller than 4 mm, there were significant correlations between the changes in comalike aberrations and the changes in AULCSF (r = -0.487, P < 0.001) and 10% low-contrast visual acuity (r = 0.310, P = 0.003), but spherical-like aberrations showed no correlation with the changes in AULCSF (r = -0.078, P = 0.485) and 10% low-contrast visual acuity (r = 0.208, P = 0.158). CONCLUSIONS: In eyes with larger photopic pupil diameter, increases in spherical-like aberration dominantly affect contrast sensitivity, whereas in eyes with smaller pupil size, changes in coma-like aberration exert greater influence on visual performance.
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Authors | Tetsuro Oshika, Tadatoshi Tokunaga, Tomokazu Samejima, Kazunori Miyata, Keisuke Kawana, Yuichi Kaji |
Journal | Investigative ophthalmology & visual science
(Invest Ophthalmol Vis Sci)
Vol. 47
Issue 4
Pg. 1334-8
(Apr 2006)
ISSN: 0146-0404 [Print] United States |
PMID | 16565365
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Topics |
- Adolescent
- Adult
- Contrast Sensitivity
(physiology)
- Cornea
(physiology)
- Female
- Humans
- Iris
(anatomy & histology)
- Keratomileusis, Laser In Situ
- Male
- Middle Aged
- Myopia
(physiopathology, surgery)
- Pupil
(physiology)
- Refraction, Ocular
(physiology)
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