This is a multi-centre, open-label, parallel-group randomized controlled trial with the following objectives: Firstly, the investigators aim to evaluate the efficacy of web-based visual and perceptual training therapy on visual function in children with postoperative congenital ectopia lentis. Secondly, the investigators target to investigate the in stereoacuity, quality of life scores, and treatment compliance following visual and perceptual training intervention. Thirdly, to explore the safety profile of visual and perceptual training therapy software in this specific patient population. Lastly, this study aims to provide evidence-based recommendations for visual rehabilitation training strategies in children with postoperative congenital ectopia lentis in the Chinese population.

Congenital ectopia lentis (CEL) is a hereditary ocular disorder caused by hypoplasia or dysfunction of the lens zonules, and is one of the major etiologies of congenital visual impairment in children and adolescents. Most patients with CEL are children within the critical period of visual development (0-12 years old). Sustained abnormal visual input due to congenital developmental anomalies severely interferes with the normal connection between retinal photoreceptors and the visual center, resulting in severe visual damage. At present, surgery is the main treatment for patients with severe CEL. However, clinical practice has shown that even after standardized surgical intervention and routine postoperative visual rehabilitation training, 36.8% of affected eyes still fail to achieve normal visual levels corresponding to their age. In addition, patients with CEL who undergo IOL scleral fixation often develop a certain degree of astigmatism due to postoperative tilt or decentration of the IOL, which further compromises the improvement of visual function.

In recent years, digital visual perceptual training (HVT), as a novel technique for amblyopia intervention, has attracted considerable attention. Studies have demonstrated that, compared with traditional refractive correction and occlusion therapy, visual perceptual training is characterized by faster visual acuity improvement, higher compliance, and the ability to enhance binocular visual function. Furthermore, as a form of visual perceptual training software, web-based visual perceptual training allows patients to complete training at home through gamified tasks. Meanwhile, training plans can be adjusted according to patients' conditions and progress, enabling personalized treatment regimens. This helps improve treatment compliance and patient experience, and facilitates remote management by hospitals. Notably, the meridional perceptual learning module in visual perceptual training can more effectively improve uncorrected visual function in patients with astigmatism. Nevertheless, no studies to date have focused on the efficacy of visual perceptual training in improving visual function in this specific population of patients with CEL.

This study intends to evaluate the efficacy and safety of visual perceptual training on postoperative visual function in patients with CEL, so as to provide evidence for formulating postoperative visual rehabilitation training strategies for these patients.

Inclusion Criteria

1. Aged 4-12 years, with no gender restriction;
2. Diagnosed with congenital ectopia lentis;
3. Underwent bilateral lensectomy combined with IOL scleral fixation, and within 1 month ± 1 week after the second-eye surgery;
4. Best-corrected visual acuity (BCVA) of unilateral or bilateral eyes is no worse than 20/200 but below the normal level for the corresponding age: for 4-year-old children, BCVA ≤ 20/40; for children aged 5 years and above, BCVA ≤ 20/30;
5. Written informed consent signed by the patient and their parents or legal guardians.

Exclusion Criteria

1. History of ocular trauma or previous ocular surgery other than the study-related procedure;
2. Unable to cooperate with treatment, examinations, and follow-up assessments;
3. Complicated with recurrent lens dislocation, severe cataract (dense, axial, opacity diameter >3 mm and affecting central vision), secondary glaucoma, corneal endothelial decompensation, retinal detachment, or other conditions requiring urgent surgical intervention;
4. Presence of diplopia in either eye;
5. Known history of neurological disorders (e.g., photosensitive epilepsy);
6. Participation in other clinical trials within the postoperative period that may affect the outcomes of the present study;
7. Use of topical or systemic medications that may cause visual impairment, or other vision therapies other than refractive correction in the past 3 months (e.g., atropine penalization, occlusion therapy, digital therapy, Bangerter filters, optical suppression, VR training, etc.).

Study protocol and results will be published in a peer-reviewed journal.

Data will be available on December 2030 for 10 years.

Data are available upon reasonable request by contacting with the corresponding author.

This study employs an open-label design without participant or investigator blinding, but with assessor blinding implemented. To reduce bias under non-blinded conditions, trial-related personnel involved in participant screening remain blinded, and clinical staff conducting regular ophthalmological examinations and data analysts are kept blinded to treatment allocation.