They acknowledged limitations in their study. Cataract develops slowly, they pointed out, so the date of diagnosis in the medical records may not correspond to its actual onset. And diabetic patients receive regular eye checks from the hospital eye service, but a general practitioner’s record of early cataract by an optometrist may not be reported to the general practitioner.
However, they argued that the dataset they used is well-established as reliable. “In conclusion,” they wrote, “this large observational study demonstrates that incidence rates of cataract diagnosis in patients with diabetes are higher than among diabetic-free patients, particularly at younger age.”