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Graham W. Lyles, Kenneth L. Cohen, Diana Lam; Comparison Of Anterior Chamber Depth In Phakic And Pseudophakic Eyes As Measured By The Visante And Iolmaster. Invest. Ophthalmol. Vis. Sci. 2011;52(14):6244.
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© ARVO (1962-2015); The Authors (2016-present)
Comparison of preop anterior chamber depth measurement (ACD) in phakic eyes, Haigis formula predicted postop ACD, and postop ACD measurement in pseudophakic eyes using photographic image analysis (IOLMasterTM) (IOL) and anterior segment optical coherence tomography (OCT) (VisanteTM) (Carl Zeiss Meditec, Dublin, CA).
57 eyes of 45 subjects for cataract extraction dilated with phenylepherine (2.5%) and tropicamide (1%). 30 minutes later, ACD measured with IOLM and OCT. Predicted postop ACD calculted using Haigis formula using OCT (hOCT) and IOLM (hIOLM). All eyes underwent uncomplicated bimanual phacoemulsification by the same attending surgeon with placement of a 1-piece IOL (ZCB00, AMO) in the capsular bag. 1 month after surgery following dilation ACD measurements were repeated in the pseudophakic eyes with OCT (OCT2) and IOLM (IOLM2).
The preop ACD with IOLM (mean (SD)) was 3.31mm (0.38) and with OCT was 3.30mm (0.37). Haigis predicted hOCT was 5.36mm (0.32) and with hIOLM was 5.36mm (0.31). Postop ACD was 4.83mm (0.31) with OCT2 and 4.05mm (0.97) with IOLM2. Pearson correlation coefficients were calculated (Table 1). Using a mixed model, the 4 types of measurements were compared and IOLM2 had a significantly different mean from the others (p <0.001). A Bland-Altman assessment for agreement found 95% limits of agreement of -0.5mm and 1.12mm for hOCT and OCT2, and -0.57mm and 3.02mm for hIOLM and IOLM2.
Four studies of pseudophakic IOLMaster measurements found ACD means ranging from 3.84-4.65mm. This is in agreement with IOLM2 of the current study. To our knowledge there are no other available studies comparing pseudophakic ACD measurements using OCT and IOLMaster. hIOLM and hOCT were highly correlated, while hIOLM and IOLM2 were not. IOLM2 was significantly lower than hIOLM, hOCT, and OCT2. For a given predicted ACD, IOLM2 would be expeted to be 0.78mm lower than OCT2. hIOLM appears to over predict for low values and under predict for high values.
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