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Clemente Paz Filgueira, Roberto F. Sanchez, Luis A. Issolio, Meritxell Vilaseca, Jaume Pujol, Elisa M. Colombo; Objective Discrimination Between Operable And Non-operable Cataracts. Invest. Ophthalmol. Vis. Sci. 2012;53(14):6630.
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To obtain a limit value in terms of the Objective Scatter Index (OSI), which is based on double-pass retinal images, in order to discriminate between operable and non-operable cataracts. To compare the obtained OSI values with subjective assessments made by a group of ophthalmologists in patients with different grades of cataracts.
Forty-five eyes from 24 patients (from 50 to 70 years old) with posterior subcapsular cataracts (PSC), nuclear cataracts (NC), and cortical cataracts (CC) were included in the study. They did not report any ocular alteration other than the cataract itself and their BSCVA was higher than 0.6. Cataracts were classified according to the LOCS III classification system which consists of the direct observation of the crystalline lens through the slit-lamp (Chylack et al. Arc Ophthalmol 1993). From this subjective analysis made by three different ophthalmologists it was established whether the cataract should be scheduled for surgery or not. Subjects were also analyzed by means of the double-pass instrument (OQAS, Visiometrics SL, Spain), which provides an objective assessment of the intraocular scattering by means of the OSI parameter (Artal el al. Plos 2011).
Twenty-two of the eyes measured (49%) had a PSC cataract, 20 (44%) a NC, and 3 (7%) corresponded to CC. According to the subjective procedure 13 (29%) of the examined eyes showed a severity in their cataract grade that made it operable according to the ophthalmologist criteria. Mean OSI for non-operable cataracts was of 1.30±0.9 (±SD) while for operable cataracts it was of 3.33±1.62. These values were significantly different (p<0.001). We identified a critical OSI value of 1.80 separating both conditions from the intersection of weighted distributions, which could be used to split the early cataract group from the surgery susceptible group. That value corresponds to the early cataracts category previously established in the literature (Artal el al. Plos 2011).
We evaluated the feasibility of using the OSI to discriminate between operable and non-operable cataracts. Results showed that the OSI values obtained in operable cataracts (according to the medical criteria) are distinguishable from those obtained in cataracts that have not been considered for surgery. Therefore this objective parameter may help in taking an objective decision about the convenience of scheduling the cataract surgery.
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