Accommodation As A Modulator Of Vault: Comparative Dynamic Behavior Of Two Posterior Chamber Phakic Iols
Published 2026 - 44th Congress of the ESCRS
Reference: FP19.11 | Type: Free paper | DOI: 10.82333/365r-0s98
Authors: Dr Rodrigo Ernesto Barrera Rodriguez* 1 , Dr Catalina Becerra Revollo 2 , Dr Ernesto Otero 3 , Dr Abel Martinez 4 , Dr Ana Mercedes Garcia 5 , Dr Enrique De la Torre 5 , Dr Gisella Santaella 3
1Cornea,Asociacion Para Evitar la Ceguera,City of Mexico,Mexico;Ocular Ultrasound,Clinica Barraquer,Bogota,Colombia, 2Ocular Ultrasound,Asociacion Para Evitar la Ceguera,City of Mexico,Mexico, 3Cornea,Clinica Barraquer,Bogota,Colombia, 4Cornea,Sociedad de Cirugia Ocular,Bogota,Colombia, 5Cornea,Asociacion Para Evitar la Ceguera,City of Mexico,Mexico
Purpose
To prospectively assess dynamic vault modulation induced by accommodation, defined as the change in vault between the resting crystalline lens configuration and its increased anteroposterior thickness during near fixation, in eyes implanted with two posterior chamber phakic intraocular lens models of distinct material composition
Setting
Department of Cornea and Refractive Surgery, tertiary referral center, Clínica Barraquer, Bogotá, Colombia
Methods
Prospective comparative study including 132 eyes: 97 implanted with Eyecryl (Biotech Healthcare) and 35 with Visian ICL (STAAR Surgical) (mean age 32.8 ± 7.1 years). Under mesopic conditions, vault was measured using ultrasound biomicroscopy (ABSolu, Quantel) by the same examiner during distance (6 m) and near (30 cm) fixation. Three measurements were averaged per condition. The primary outcome was vault change (Δ vault). To minimize bias related to extreme vault values, Δ vault was compared between IOL models in a subgroup of 20 eyes with normal vault (250–600 µm). A two-way mixed ANOVA was performed to assess the effects of fixation condition and IOL model on vault measurements. Post hoc analyses were conducted when appropriate (p < 0.05)
Results
Mean vault decreased from 404 ± 190 µm during distance fixation to 350 ± 192 µm during near fixation, corresponding to a mean Δ vault of 55.6 ± 46.6 µm (p < 0.001). Accommodation-induced vault changes were similar between IOL models (Eyecryl: 56.7 ± 40.8 µm; Visian ICL: 57.3 ± 42.8 µm; p = 0.94). Mixed ANOVA confirmed a significant main effect of fixation condition (p < 0.001) with no significant interaction between IOL model and accommodation (p = 0.94)
Conclusions
Accommodation induces a significant reduction in vault in eyes implanted with posterior chamber phakic IOLs, with a similar magnitude across different IOL models. These findings suggest that accommodative dynamics should be considered when interpreting postoperative vault measurements. In eyes with vault values near the lower limit of normal, accommodative changes may transiently reduce vault to suboptimal levels, potentially increasing the risk of complications such as anterior subcapsular cataract, highlighting the need for careful follow-up. However, factors such as age and refractive status may influence accommodative amplitude and could represent potential sources of bias; therefore, further studies are warranted