Vault changes after cyclopentolate instillation in eyes with posterior chamber phakic intraocular lens

Abstract

posterior chamber phakic intraocular lens (pioL) implantation is a common option for correcting moderate-to-high ocular refractive defects. Because this pIOL is implanted on ciliary sulcus, the distance between the back surface of the pIOL and the anterior surface of the crystalline lens, that it is known as vault, should be measured in different conditions to ensure the technique's safety. Cyclopentolate is a drug that dilates the pupil and relaxes accommodation (cycloplegia). It is often used for different ocular examinations and for other medical purposes. However, there is no evidence of the effect of this drug on vault. This study quantified central vault changes associated with cyclopentolate instillation. We measured the vault under normal conditions (pre-cycloplegic instillation) and after instilling cyclopentolate on 39 eyes of 39 patients with implanted pIOL. Our results suggest that cyclopentolate instillation may induce changes to vault in eyes with implanted pIOL. These changes seem safe and are mainly associated with vault under normal conditions, but also with anterior chamber depth, pupillary diameter and pIOL size. Visian Implantable Collamer Lens (ICL, STAAR Surgical) is a foldable posterior chamber phakic intraocular lens (pIOL) designed to correct moderate-to-high myopia 1. The latest models have a central hole that allows better aqueous humour exchange between the anterior and posterior chambers without the need for iridotomy 2. These models present safe and efficacious results as previous models with no hole 3,4. The central vault is defined as the distance between the back surface of the ICL and the anterior surface of the crystalline lens. An appropriate vault has been suggested to be between 250 and 750 µm 5. An insufficient vault may induce anterior subcapsular cataract due to the contact between the ICL and the anterior lens capsule 1,6,7. Excessive vaulting can cause angle closure, pupillary blockage or pigmentary dispersion syndrome, which can increase intraocular pressure and, thus, the risk of glaucoma 8-11. Therefore, it is important to measure this distance to ensure the technique's safety. Changes in anterior segment structures appear during accommodation, such as reduced anterior chamber depth (ACD), inducing proximity between the anterior surface of the crystalline lens and the cornea with appearance of synkinetic myosis 12. The ICL is implanted in the ciliary sulcus. Given its location, dynamic interactions take place between the pIOL and the surrounding structures. Some authors have studied these effects on the vault by accommodative stimulus 13-17 , instillation of pilocarpine for pharmacologically-induced accommodation 13,18 , light-induced pupil constriction 15,17,19 and mydriasis. 20 However, no studies have quantified the cycloplegic effect on the central vault. Cyclopentolate is a drug that dilates the pupil and relaxes accommodation. Preoperative and postoperative evaluations of post-cyclopentolate instillation (by cycloplegic eyedrops) are necessary with patients who ...

Evaluation of the Anterior Chamber Angle by Anterior Segment Optical Coherence Tomography After Implantable Phakic Contact Lens Implantation in Myopic Eyes.

“…This agreed on other studies on IPCL as Bianchi GR et al 2019 and Bianchi GR et al 2019 (14,15) . AS-OCT was used for angle evaluation with ICL as Singh R et al 2020 who implanted ICL in 32 eyes with 3 months follow-up and resulted in stable angle narrowing in the follow-up period and Gargallo-Martinez, B et al 2020 who studded vault of ICL by OCT (16,17) .…”

Evaluation of the anterior chamber angle by anterior segment optical coherence tomography after implantable phakic contact lens implantation in myopic eyes

“…A study conducted by Wan et al [ 16 , 17 ] on 82 myopic eyes implanted with Visian ICL used 3 instruments: AS-OCT, Oculus Pentacam and UBM for assessment of ACD and central vault for 3 months. They demonstrated that AS-OCT measurements were higher while Pentacam measurements were lower than UBM measurements.…”

Anterior segment structure changes caused by different luminance light after implantable collamer lens surgery

“…When the eye exposed to light, the pupil will constrict. When the PD changes, the vault will change accordingly [ 5 – 9 ]. The safety vault should take into consideration of the change with the light.…”