Contrast sensitivity after extracapsular and intracapsular cataract extraction

Contrast sensitivity function after cataract extraction and intraocular len s implantation has been mainly correlated to the type or the material of th e intraocular lens. Our purpose was to identify other possible factors, lik e posterior capsule, to contrast sensitivity alterations after cataract sur gery, comparing patients operated for cataract by techniques that mainly di ffered on the posterior capsule's integrity. The intraocular lens implanted was either a posterior or an anterior chamber one, always monofocal and ma de of PMMA. We measured contrast sensitivity function at four spatial frequ encies in two groups of operated individuals (group A and B) and in one gro up of healthy control individuals. Each group consisted of 42 eyes. Group A comprised eyes with intact, clear posterior capsule and posterior chamber monofocal intraocular lens. Group B comprised eyes with ruptured or removed posterior capsule and anterior chamber monofocal intraocular lens. Control group comprised healthy control eyes. A pair matched design was used to co mpare contrast sensitivity values among the individuals of the three groups . No statistically significant differences in contrast sensitivity values w ere found when group B patients were compared to healthy controls (p>0.05). Patients of group A exhibited contrast sensitivity function impairment at intermediate and high spatial frequencies when compared to patients of grou p B (p<0.05) and to controls (p<0.01). It seems that intact posterior capsu le provides inferior visual function, in spite of relatively good visual ac uity and apparently satisfactory results.