Researchers in the Netherlands have revealed the Dutch Crosslinking for Keratoconus (DUCK) score may better identify patients with progressive keratoconus. A prospective cohort study demonstrated that the new scoring system, compared with conventional measures of maximum keratometry, could better identify eyes that were properly withheld treatment by 35%. Use of the new clinical scoring system also was associated with an overall reduced rate of crosslinking (CXL) treatment by 23% compared with assessment with maximum keratomatry, without increasing the risk of keratoconus progression.

In addition to keratometry and manifest refraction, the DUCK score also incorporates age, patient-reported quality of vision and objective visual acuity. Researchers compared DUCK scores with maximum keratometry criterion in a longitudinal discovery and validation cohort. The cohort for the scoring system consisted of 504 eyes of 388 patients. Of the cohort, 230 (46%) underwent CXL during follow-up. Among the 273 eyes that did not receive treatment, 59 would have received CXL based keratometry reading. If using the DUCK score, 43 of the nontreated eyes would have been treated. Both keratometry and the DUCK score did not treat 95 eyes, which later appeared to be progressive.

Researchers noted that clinical criteria might not be the sole determinants of disease progression. They still recommend that practitioners apply the DUCK score after addressing extraocular morbidities and eye rubbing. Ultimately, they believe the DUCK score may better select patients who might benefit from CXL and prevent unnecessary treatments, reduce exposure to treatment risks and improve CXL’s cost effectiveness.

Wisse RPL, Simons RWP, van der Vossen MJB, et al. Clinical evaluation and validation of the Dutch Crosslinking for Keratoconus score. JAMA Ophthalmol. March 28, 2019. [Epub ahead of print].