Evaluating Natural Progression of Keratoconus in Relation to Age, Gender, and Disease Severity at Presentation

To investigate the natural progression of keratoconus (KC) with respect to age, gender, and disease severity at presentation.

This study analyzed 949 eyes from 503 patients with KC followed at Eskişehir Osmangazi University and Istanbul University-Cerrahpaşa between 2009 and 2023. Patients with ≥1 year of follow-up with ≥3 Pentacam (Oculus, Inc) scans spaced ≥3 months apart were eligible. Progression was identified using Belin ABCD Progression Display using 2 baseline visits. Progression rates were analyzed according to age groups (≤18, >18 to ≤24, >24 to ≤30, >30 to <35, and ≥35 years), and KC severity was categorized based on the Topographic Keratoconus Classification (TKC) as subclinical, early-stage (TKC 1-2) and advanced-stage (TKC 3-4). Median time-to-progression (M-TTP) for progressive eyes was calculated with reference to the first presentation.

Keratoconus progression rates declined significantly with age ( P < 0.001); however, 44.3% of patients aged ≥35 years still showed progression, with the highest rate in those ≤18 years (86.4%). In patients ≥35 years, advanced-stage disease (TKC 3 and 4) markedly increased progression risk (OR: 10.5 [ P = 0.03], 20.0 [ P = 0.008], respectively). The shortest time-to-progression occurred in patients aged ≤18 years (M-TTP: 8.6 and 5.8 months in TKC 1-2 and 3-4, respectively), whereas in those ≥35 years, advanced-stage disease progressed significantly earlier than early-stage (M-TTP: 18.9 vs. 38.2 months).

Although progression typically slows with age, 44% of patients ≥35 years still progressed. The shorter time-to-progression in younger individuals and in older patients with advanced disease at presentation highlight the need for close monitoring in both groups.