Purpose: To design formulas for predicting postoperative vaults in vertical implantable collamer lens (ICL) implantation and to achieve more precise predictions using machine learning models. Design: Retrospective, observational study. Setting: Eye Clinic Tokyo Methods: We retrospectively reviewed the medical records of 720 eyes in 408 patients who underwent vertical ICL implantation. The data included age, sex, refractions, anterior segment biometric data, and surgical records. We designed 3 formulas (named V1 to V3 formulas) using multiple linear regression analysis and tested 4 machine learning models. Results: Predicted vaults by V1 to V3 formulas were 444.17 ± 93.83 μm, 444.08 ± 98.64 μm, and 444.27 ± 108.81 μm, with a mean absolute error of 127.97 ± 107.92 μm, 126.41 ± 105.86 μm, and 122.90 ± 103.00 μm, respectively. There were no significant differences in error among the V1 to V3 formulas, despite the fact that the V1 and V2 formulas referred to limited parameters (3 and 4, respectively) and the V3 formula referred to all 12 parameters. 2 of 4 machine learning models—Extreme Gradient Boosting and Random Forest Regressor—showed better performance in predicted vaults: 444.52 ± 120.51 μm and 446.00 ± 102.55 μm, and mean absolute error: 118.31 ± 100.55 μm and 118.63 ± 99.34 μm, respectively. Conclusions: This is the first study to design V1 to V3 formulas for vertical ICL implantation. The V1 and V2 formulas exhibited good performance despite the limited parameters. In addition, 2 of the 4 machine learning models predicted more precise results.

To report the clinical course of pupillary block by fibrin in the central hole of an implantable collamer lens (ICL). A 24 year old male with high myopia and astigmatism underwent EVO ICL (V5; STAAR Surgical, Monrovia, CA) implantation. The surgery was completed without any complications. The following day, the patient complained of blurry vision in the right eye and headache. The decimal uncorrected distance visual acuity was 1.5 in both eyes. Slit-lamp examination of the right eye revealed fibrin in the central hole of the ICL with a few cells in the anterior chamber. The intraocular pressure (IOP) and vault were increased to 33 mmHg and 1396 μm, respectively. A single shot of the Nd:YAG laser swept away the fibrin, and the reopening of the central hole was confirmed through the aqueous humor flow. The pupillary block was completely relieved 30 min later and the IOP and vault recovered to the normal range. One week postoperatively, the inflammatory reaction disappeared with topical eye drops including steroids. The uncorrected distance visual acuity was 1.5 in both eyes one year postoperatively. Ophthalmic examinations revealed unremarkable findings. We diagnosed the cause of the inflammatory reaction in the right eye as TASS because of the lack of severe pain in the eye, early occurrence, and favorable response to steroid therapy. Pupillary block by fibrin in the central hole may rarely occur following ICL implantation. In such cases, direct fibrin removal using Nd:YAG laser may be an effective treatment.

Background: Recessive dystrophic epidermolysis bullosa (RDEB) is a rare inherited disorder characterized by extreme epithelial fragility and progressive cicatrization, frequently leading to severe ocular surface disease and early visual impairment. Surgical interventions such as ocular surface reconstruction (OSR) in childhood are often delayed because of anesthetic risks and concerns regarding recurrence. Consequently, the effectiveness of OSR, including amniotic membrane transplantation (AMT), and its impact on visual development remain poorly documented. Methods: We report a case series of two pediatric patients (three eyes) with genetically confirmed RDEB who underwent single-step OSR using AMT. Clinical outcomes, long-term visual acuity, perioperative management, and histopathological findings were evaluated. Results: Ocular manifestations included corneal epithelial damage, symblepharon, and pseudopterygium extending over the cornea. One patient underwent symblepharon lysis, superficial keratectomy, and AMT onto the bare sclera in the right eye at age 4 and in the left eye at age 8, both under intubated general anesthesia. The other patient underwent the same procedure in the right eye at age 6. Best spectacle-corrected visual acuity improved from ≤20/300 to 20/30 in all eyes, and pupillary zone clarity was maintained during the follow-up period (up to 6 years). Histopathology confirmed pseudopterygium with squamous metaplasia, goblet cell loss, and fibrovascular stroma. Safe general anesthesia was achieved through meticulous multidisciplinary perioperative planning involving anesthesiologists, dermatologists, and pediatricians. No systemic complications related to anesthesia or perioperative management were observed. Conclusions: Single-step OSR with on-lay AMT can restore and preserve visual function in pediatric RDEB. Early surgical intervention may prevent profound amblyopia and provide durable ocular surface stability. A multidisciplinary approach enables safe general anesthesia and perioperative management.