A prospective, multi-center clinical trial involving Chinese patients with irregular corneas has demonstrated that a four-zone scleral lens design delivers excellent visual rehabilitation while maintaining a favorable short-term safety profile. The study, published in Eye Discovery, represents one of the largest prospective investigations of scleral lens wear in a Chinese population to date.
Although scleral lenses are well established for managing irregular corneas worldwide, most published evidence comes from non-Asian populations. Anatomical differences – including smaller palpebral apertures, greater eyelid tension, and variations in scleral shape – may influence lens fitting and performance, highlighting the need for population-specific clinical data.
The prospective, open-label study enrolled 138 adults aged 18–65 years across five Chinese centers. Participants had irregular corneas caused by keratoconus, secondary ectasia, corneal transplantation, or corneal scarring, and were fitted with a four-zone scleral lens before being followed for three months. Of those enrolled, 131 completed the study, providing data from 201 treated eyes. Keratoconus accounted for nearly 88% of cases, reflecting its dominance as an indication for scleral lens fitting.
At one month, 97.7% of participants achieved the study's predefined criterion for successful visual rehabilitation – an improvement of at least 0.20 logMAR compared with spectacle correction. Across all treated eyes, 98.5% gained two or more lines of vision with scleral lenses, with a median improvement of 0.30 logMAR. Patients with poorer baseline vision experienced the greatest gains, suggesting the lenses provide particular benefit in more advanced corneal disease. Importantly, these improvements remained stable throughout the three-month follow-up.
Fitting efficiency was another notable outcome. Investigators required an average of just 1.5 lenses per eye to achieve an optimal fit, despite allowing extensive customization of lens parameters. While nearly half of eyes required at least one refit during follow-up, only 5% needed two refits, suggesting the fitting approach was both practical and efficient in routine clinical practice.
Patient-reported outcomes were equally encouraging. By three months, almost three-quarters of participants wore their lenses for at least eight hours per day, while more than 80% wore them on five or more days each week. Around 90% rated both comfort and vision highly, with only a single participant reporting intolerable discomfort, which resolved after retraining in lens application and removal.
Safety findings were reassuring. No serious adverse events occurred during the study, and investigators observed no cases of corneal infection, infiltrates, or new corneal neovascularization. Although small statistically significant changes in corneal curvature and thickness were detected, these were considered clinically negligible, while endothelial cell density and intraocular pressure remained stable over the study period.
The study authors acknowledge that the three-month follow-up limits conclusions regarding long-term safety and that the absence of a comparator lens group precludes direct comparisons with other specialty lens modalities. Nevertheless, the findings provide robust evidence that scleral lenses can deliver predictable, effective, and well-tolerated visual rehabilitation for Chinese patients with irregular corneas, supporting their broader adoption as scleral lens use continues to expand across mainland China.
