Visual symptoms and aberrations PDF Print E-mail
Saturday, 10 December 2005 19:00

Researchers study the relation between the two.

by Matt Young EyeWorld Staff Writer While researchers often discuss higher-order aberrations (HOAs) and whether they lead to visual symptoms, it is also worthwhile to understand which visual symptoms are related to which aberrations. Complete article is available at www.eyeworld.org/article.php?sid=2824

From the article:

Halos were associated with spherical aberration for the scotopic pupil size.
“I find this as well,” Dr. Boxer Wachler said. “The reason is that if you look at the very center of the topography and look towards the periphery, the corneal power gets steeper. If the steeper power transition occurs relatively close to the center of topography – as in higher myopes, and/or smaller laser optical zones – this causes more spherical aberration.”
Glare also was significantly correlated with spherical aberration and total aberration. Starburst was associated with spherical aberration and total aberration for the scotopic pupil size.

The actual peer-reviewed study they are referring to appears to be this one:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15019317&query_hl=3

Ophthalmology. 2004 Mar;111(3):447-53.

Wavefront analysis in post-LASIK eyes and its correlation with visual symptoms, refraction, and topography.

Chalita MR, Chavala S, Xu M, Krueger RR.

The Cole Eye Institute,
Cleveland Clinic Foundation/I32, 9500 Euclid Avenue, Cleveland, OH 44195, USA.

PURPOSE: To evaluate the information assessed with the LADARWave wavefront measurement device and correlate it with visual symptoms, refraction, and corneal topography in previously LASIK-treated eyes.

PARTICIPANTS: One hundred five eyes (58 patients) of individuals who underwent LASIK surgery were evaluated. DESIGN: Retrospective, noncomparative case series.

MAIN OUTCOME MEASURES: Complete ophthalmologic examination, corneal topography, and wavefront measurements were performed. Correlations were made between the examinations and symptoms.

METHODS: Wavefront measurements were assessed with the LADARWave device. Manifest, cycloplegic refraction, and topographic data were compared with wavefront refraction and higher order aberrations. Visual symptoms were correlated to higher order aberrations in 3 different pupil sizes (5-mm, 7-mm, and scotopic pupil size). Pearson's correlation coefficient and generalized estimating equations were used for statistical analysis.

RESULTS: In post-LASIK eyes, wavefront refraction components were poorly correlated to manifest and cycloplegic components. The comparison between manifest, cycloplegic, and wavefront refraction with total amount of higher order aberrations showed no strong correlation. The comparison between topography and manifest, cycloplegic, and wavefront refraction did not show strong correlation. Visual symptoms analysis showed correlation of double vision with total coma and with horizontal coma for the 5-mm and 7-mm pupil size; correlation between starburst and total coma for the 7-mm pupil size; and correlation of double vision with horizontal coma, glare with spherical aberrations and with total aberrations, and starburst with spherical aberrations for the scotopic pupil size. Scotopic pupil size had a positive association with starburst and a negative association with double vision.

CONCLUSIONS: The LADARWave wavefront measurement device is a valuable diagnostic tool in measuring refractive error with ocular aberrations in post-LASIK eyes. A strong correlation between visual symptoms and ocular aberrations, such as monocular diplopia with coma and starburst and glare with spherical aberration, suggest this device is valuable in diagnosing symptomatic LASIK-induced aberrations. Horizontal coma was correlated with double vision, whereas vertical coma was not.