First Author: A.Dom SPAIN
Co Author(s): C. P T. Ferrer Blasco S. Garc R. Mont
Purpose:
To study the effect of higher order aberrations (HOAs) of idiopathic amblyopic eyes on their visual performance.
Setting:
University of Valencia, Spain.
Methods:
An Adaptive optics visual simulator (crx1, Imagine Eyes, France) was used to simulate the wavefront aberration pattern of normal and idiopathic amblyopic eyes. In order to simulate the aberration pattern of each group, the crx1 was programmed to compensate the eyes wavefront aberrations using the deformable mirror and then, it was programmed to induce the wavefront pattern of amblyopic or normal eye. The Zernikes values were extracted from a previous study published. We analysed the modulation transfer function (MTF) and point spread function (PSF). The visual acuity (VA) was measured for high (100%)-, medium (50%)- and low (10%)-contrast using the Freiburg Visual Acuity Test (FrACT) software. The contrast sensitivity (CS) was measured for 3 spatial frecuencies: 10, 20 and 25 cycles per degree (cpd). All measures were taken for 3- and 5.5-mm pupil. Moreover, the subjects included had clear intraocular media, no known ocular pathology and a pupil size ? 5.5mm in dark conditions, because of no mydriatic eye drop was instilled.
Results:
No statistical significant differences in VA and CS were found between both groups at any contrast, spatial frequency and pupil size (P>0.01). For 3-mm pupil, the mean logMAR VA for 100% contrast level was -0.11±0.04 and -0.06±0.06 (>20/20) for normal and amblyopic eyes, respectively. For a 50%, VA results were about -0.06±0.06 for normal and 0.00±0.05 for amblyopic patterns. For a 10%, VA results for normal pattern were 0.17±0.07 and 0.21±0.06 for amblyopic ones (about 20/32). For 5.5-mm pupil, the mean logMAR VA for 100% contrast level were similar for both groups (about 0.00±0.04, 20/20). At 50%, VA results were about 0.10±0.10 for both normal and amblyopic patterns. For 10%, VA results were about 0.35±0.09 for both groups (about 20/40). For CS results, for 3-mm pupil, at 10 cpd, log CS values for normal and amblyopic patterns were 1.9±0.2 and 1.7±0.1, respectively; at 20 cpd these values changed to 1.2±0.15 and 1.1±0.2 and at 25 cpd were 0.9±0.1 and 0.8±0.2, respectively. For a 5.5-mm pupil, the results were similar between both groups for 10, 20 and 25 cpd, yielding logCS values of 1.4±0.1, 0.9±0.2, and 0.6±0.1, respectively. MTFs and PSFs were comparable for both groups at 3- and 5.5-mm.
Conclusions:
Our VA and CS results, showed no statistical significant differences between normal and amblyopic eyes for any pupil size, contrast level or spatial frequency (P>0.01). These results agree with the optical quality metrics analysed (MTFs and PSFs) being also very similar between both groups. Thus, it does not seem likely that HOAs have a main role in compromising visual performance of idiopathic amblyopic eye and therefore, have not a role in its onset. FINANCIAL DISCLOSURE?: No
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