Impact of Cataract Severity on Measurement Acquisition with the Lenstar LS 900 Biometer in a Tertiary Care Centre

Shivam Manu Gupta, Manmeet Singh, Manoj Gupta, Ruminder Kaur, Ruchi Singh
Author(s)
1Fellow in IOL and Cataract Surgery, Department of Ophthalmology, Sankara Academy of Vision, Sankara Eye Hospital, Ludhiana, India. 2Chief Medical Officer, Cataract, Cornea and Refractive Surgeon, Department of Ophthalmology, Sankara Academy of Vision, Sankara Eye Hospital, Ludhiana, India. 3Cataract, Cornea and Refractive Surgeon, Department of Ophthalmology, Sankara Academy of Vision, Sankara Eye Hospital, Ludhiana, India. 4Vitreo-Retina Consultant, Department of Ophthalmology, Sankara Academy of Vision, Sankara Eye Hospital, Ludhiana, India. 5Cataract and IOL Consultant, Department of Ophthalmology, Sankara Academy of Vision, Sankara Eye Hospital, Ludhiana, India

Abstract

Background: Accurate ocular biometry is essential for precise intraocular lens power calculation. Increasing cataract density may reduce optical signal transmission and cause measurement failure with the Lenstar LS 900 biometer. This study evaluated the effect of cataract severity and morphology on Lenstar measurement acquisition. Material and Methods: This prospective observational study included 120 eyes of patients aged ≥40 years with cataract, evaluated over a period of 3 months from June to August 2026. Cataract severity was graded using LOCS III. Optical biometry was performed using the Lenstar LS 900 after pupillary dilation. Successful acquisition was defined by a reproducible retinal pigment epithelium peak with valid axial length and keratometry measurements. Ultrasound A-scan was used when optical acquisition failed. Results: Successful Lenstar acquisition was achieved in 101 eyes (84.2%), while 19 eyes (15.8%) had acquisition failure. Failure increased with increasing cataract severity, with higher LOCS III scores observed in failed acquisitions. Posterior subcapsular and mature cataracts showed the highest frequency of acquisition failure. Ultrasound A-scan provided an alternative for eyes with unsuccessful optical acquisition. Conclusion: Mature/very dense and posterior subcapsular cataracts showed the highest failure rates of optical biometry acquisition. Ultrasound A-scan remains a useful alternative when reliable optical biometry cannot be obtained.

Keywords: Lenstar LS 900; Optical biometry; Cataract severity; LOCS III; Measurement failure; Ultrasound A-scan.

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