A Watson1, R Armstrong. 1. Department of Ophthalmology, Royal Newcastle Hospital, Australia.
Abstract
PURPOSE: The purpose of the present study was to determine whether contact and immersion A-scan techniques produce comparable measures of the magnitude of eye axial length. METHOD: A prospective study in which 225 consecutive patients scheduled for cataract surgery in a private day surgery setting had axial lengths measured with an Alcon Ocuscan machine (Alcon Australia, Frenchs Forest, NSW, Australia) using both contact and immersion techniques. Twelve patients had both techniques repeated on a separate occasion. RESULTS: Measurements of eye axial length obtained by the immersion technique averaged 0.1 mm longer than those obtained by the contact technique. A difference in axial length values was confirmed in eyes subjected to repeated measurements. CONCLUSIONS: Both techniques give consistent results, but the difference between axial lengths measured by the two techniques has implications for choice of intra-ocular lens power.
PURPOSE: The purpose of the present study was to determine whether contact and immersion A-scan techniques produce comparable measures of the magnitude of eye axial length. METHOD: A prospective study in which 225 consecutive patients scheduled for cataract surgery in a private day surgery setting had axial lengths measured with an Alcon Ocuscan machine (Alcon Australia, Frenchs Forest, NSW, Australia) using both contact and immersion techniques. Twelve patients had both techniques repeated on a separate occasion. RESULTS: Measurements of eye axial length obtained by the immersion technique averaged 0.1 mm longer than those obtained by the contact technique. A difference in axial length values was confirmed in eyes subjected to repeated measurements. CONCLUSIONS: Both techniques give consistent results, but the difference between axial lengths measured by the two techniques has implications for choice of intra-ocular lens power.