Delayed CXL due to COVID-19 restrictions led to high rate of keratoconus progression
Patients with keratoconus who had corneal cross-linking treatment delayed due to re-prioritization of services following the COVID-19 outbreak experienced further progression of the disease with loss of visual acuity lines.
“The results of our study clearly demonstrate that delays in cross-linking treatment ... had important implications for both patient’s vision and limiting therapeutic options available for patients with keratoconus,” the authors wrote.
As hospitals reshaped activities to face the COVID-19 pandemic, the Royal College of Ophthalmologists in the United Kingdom issued guidelines for re-prioritization of services within ophthalmology departments. Patients with keratoconus were classified as low risk, and recommendations were made to delay CXL treatment by 3 to 4 months in rapidly progressing cases or eyes with very thin corneas and by more than 4 months in less severe cases.
A study carried out at the Royal Liverpool University Hospital evaluated keratoconus progression in 46 eyes of 34 patients who were delayed for CXL treatment by approximately 3 months due to the COVID-19 pandemic. The average time between being put on the wait list for CXL and having the procedure done was 182 ± 65 days.
According to the Belin ABCD staging system, 70% of eyes showed progression. An increase in maximum keratometry by more than 1.5 D was reported in 30% of patients, and 17% had a decrease in corneal thickness of at least 20 µm. On average, one line of visual acuity was lost from baseline.
“This is of utmost importance, as keratoconic eyes in which visual acuity cannot be corrected with glasses or contact lenses may need a cornea transplant — an intervention with significant risks and complications,” the authors wrote.
They also expressed concern about delaying the treatment in thin corneas because further thinning could make the cornea ineligible for CXL.
Predictive factors for progression were a higher baseline maximum keratometry and atopy. These factors, according to the authors, should be considered when assessing a patient’s risk of progression and the urgency of treatment.
“Our study shows that delayed CXL had a significant impact on progression, and this was a red flag that led us to reconsider CXL as a priority, deferrable by no more than 6 weeks from the diagnosis of progressing keratoconus,” Vito Romano, MD, one of the study authors, told Healio/OSN. “As soon as we were allowed to resume normal services, we restarted CXL treatment on a tight schedule and organized extra sessions to catch up with the backlog of patients. Over the following waves of the pandemic, we have never halted treatment and treat patients within 6 weeks. In bilateral cases, we perform immediate sequential CXL, which reduces costs, waiting lists and the risk of progression of the second eye.”