María Amparo Díez Ajenjo

Refractive changes in nuclear, cortical and posterior subcapsular cataracts. Effect of the type and grade

PURPOSE To determine the effect of main morphological types and grades of age-related cataracts on refractive error. METHODS We measured 276 subjects with optical compensation prior to the development of cataract. We evaluated 224 eyes with nuclear cataract, 125 with cortical cataract, and 103 with posterior subcapsular (PSC) cataract classified with LOCSIII. We measured visual acuity (VA) with their spectacles and best-corrected visual acuity (BCVA) with chart in decimal scale to obtain the optimal compensation with cataract. We evaluated the differences between compensations. RESULTS A significant myopic shift was observed in nuclear cataract from low to mild grade (p=0.031), the same as for PSC cataract from mild to advanced grade (p=0.025). No significant changes were found for cortical cataract (p=0.462). Regarding astigmatism, we observed power changes in cortical cataract from low to mild grade (p=0.03) and axis changes in PSC from low to mild grade (p=0.02) and in nuclear cataract from mild to advanced grade (p=0.02). CONCLUSIONS Cataract produces changes in patients compensation which depend on severity and type of cataract. For nuclear and PSC cataract, we observed that the higher the grade of severity, the greater the myopic shift. Power astigmatic changes were found in cortical cataract and axis changes in PSC and nuclear cataract.

Contrast sensitivity perimetry tests along the cardinal directions in color space: correlation with the properties of the neural mechanisms mediating detection of spatio-temporal patterns

It is well-known the advantages of measuring chromatic and achromatic contrast sensitivity for detecting pathologies. But these measurements are rarely used in clinical practice, due the complexity of the measurements and the examinator specialization. In fact, there is not a complete characterization of the response of the visual pathways to achromatic and chromatic spatio-temporal frequency stimuli. We have designed a new experimental device that facilitates these measurements and allow us to characterize the visual response in healthy patients. In this paper, we evaluated the responses of the visual pathways in healthy patients.

Visual fields in a chloroquine treatment

The ATD multichannel perimeter was built thanks to the support of the Spanish Ministerio de Ciencia y Tecnologia (Grants DPI2000-0116-P4-02 and PTR 1995-0909-OP), in collaboration with Industrius De Optica SA (San Cugat del Valles, Spain).