The Progression Of Keratoconus Despite Aging

Keratoconus (KCN) is a progressive corneal ectasia that typically manifests in adolescence and progresses gradually, often leading to significant visual impairment. While progression generally slows by the third decade of life, its course beyond this period remains less well defined. This study investigates the potential for continued disease progression in patients diagnosed with KCN at age 35 or older.

Data was collected from the eye clinic at Johns Hopkins Aramco Healthcare (JHAH). Keratoconus patients aged 35 years or older and that had not undergone any corneal procedures were identified. Patients who had two cornea clinic visits with a minimum of one year and a maximum of two years apart and had a Pentacam imaging performed during the visits were included.

A retrospective analysis was conducted on patients aged ≥35 years with a confirmed diagnosis of keratoconus. Patients with a history of corneal collagen cross-linking, intracorneal ring segment implantation, or excimer laser treatment were excluded. Hard contact lens users were analyzed separately. Corneal tomography was assessed using Pentacam imaging, comparing two scans taken at least one year apart (maximum two years). Disease progression was evaluated based on established criteria, including changes in keratometric (K) readings and corneal thinning. Statistical analysis was performed separately for non-contact lens users and contact lens users.

The study included both eyes of 121 participants (72.73% male, 90.91% Saudi). None reported a family history of KCN, allergies, or habitual eye rubbing. Contact lens use was noted in 33.06%. Root mean square (RMS) progression was found in 43.28% (OD) and 54.29% (OS), while KMax progression was observed in 11.11% (OD) and 17.02% (OS). Among non-contact lens users, Wilcoxon test results showed that median differences were RMS: -0.01 (IQR = 0.16, p = 0.857), K1: 0.05 (IQR = 0.50, p = 0.006), and KMax: -0.10 (IQR = 1.00, p = 0.138). Staging progression showed 7 (stage A), 11 (stage B), and 8 (stage C) in OD, while OS had 8 (stage A), 6 (stage B), and 6 (stage D). Despite being over 35, many patients still exhibited KCN progression.

Keratoconus remains a progressive disease beyond the age of 35, albeit at a slower pace. While disease progression may stabilize in some individuals, continued monitoring is warranted. Regular long-term follow-up, including corneal tomography, is recommended to detect progression and assess the need for intervention, such as corneal collagen cross-linking.