Anterior segment variations with age and accommodation demonstrated by slit-lamp-adapted optical coherence tomography.

ABSTRACT

OBJECTIVE: To investigate anterior segment variations with age and accommodation by slit-lamp-adapted optical coherence tomography (SL-OCT) and determine a safe central vault distance between the implantable contact lens (ICL) and the crystalline lens to avoid contact cataract formation. DESIGN: Evaluation of diagnostic test or technology. PARTICIPANTS: Eighty-six patients (126 eyes) under regular review from the Optometry Clinic and Outpatient Department in Zhongshan Ophthalmic Center. METHODS: Patients underwent anterior segment measurements, such as anterior chamber depth (ACD), anterior chamber width (ACW), crystalline lens rise (CLR), and pupil diameter (PD), with the SL-OCT system manufactured by Heidelberg Engineering GmbH, Heidelberg, Germany. Data were analyzed with SPSS software (version 16.0, SPSS, Inc., Chicago, IL). MAIN OUTCOME MEASURES: Anterior segment parameters and their variations with age and accommodation. RESULTS: The internal vertical ACW (V-ACW) was anatomically larger than the internal horizontal ACW (H-ACW). With age, the ACD decreased approximately 17 µm per year. Forward movement of the crystalline lens' anterior pole decreased approximately 11 µm per year. During physiologic accommodation, the variation in ACD was -24 µm per diopter and the alterations in CLR were 28 µm per diopter. According to our data, a safe lens vault after phakic intraocular lens implantation should be more than 300 µm to reduce complications. CONCLUSIONS: Slit-lamp-adapted optical coherence tomography is a user-friendly instrument for evaluating the anterior segment, especially for accurate anterior chamber biometry, and may offer guidance on minimizing touch and cataract formation after phakic intraocular lens implantation.