Comparison of anterior chamber depth measurement methods in phakic and pseudophakic eyes

Abstract

Purpose To compare anterior chamber depth (ACD) measurements in phakic and pseudophakic eyes using a slit-beam photographic technique (IOLMaster, Carl Zeiss Meditec AG) with those obtained with the laboratory prototype version of partial coherence interferometry (PCI) and with conventional applanation ultrasound in phakic eyes. Setting Department of Ophthalmology, Vienna General Hospital, Vienna University, Vienna, Austria. Methods Thirty-three ACDs of 28 patients with age-related cataract were measured preoperatively with a slit-beam photographic technique (IOLMaster) and the prototype version of PCI. In 24 eyes, the ACD was also assessed with applanation ultrasound. In addition, 34 ACDs of 18 pseudophakic patients in a different study population were examined postoperatively with the IOLMaster and PCI. Results The median ACD in the phakic eyes was 3.06 mm (range 1.93 to 3.90 mm) with the IOLMaster, 3.09 mm with PCI (range 1.49 to 4.06 mm), and 2.87 mm (range 2.18 to 3.33 mm) with applanation ultrasound. The precision was 0.005 mm for PCI and 0.015 mm for IOLMaster measurement. The median difference between the IOLMaster and PCI ACD biometry was 0.01 mm ± 0.14 (SD) (range −0.44 to 0.17 mm) ( P = .71). In pseudophakic eyes, the 2 methods showed a median difference of −0.22 mm (range −0.45 to 1.99 mm) ( P > .1) and did not correlate ( r = 0.21; P > .2). Conclusions In phakic eyes, the difference between IOLMaster and PCI measurements was small and not statistically significant. In pseudophakic eyes, the difference was larger and the methods did not correlate.