In a recent study published in Cornea, investigators analyzed interocular progression indicators in patients with untreated keratoconus (KC).
Give me some background first.
KC is a progressive eye disease that occurs when the cornea thins and bulges into a cone shape. The exact cause is unknown but there are several risk factors.
Symptoms may include:
- Mild blurring of the vision
- Straight lines appear bent or wavy
- Increased sensitivity to light and glare
- Eye redness
- Eye swelling
Now, talk about the study.
Researchers conducted a multicenter, longitudinal observational study that utilized real-world data (RWD) collected from the Save Sight Keratoconus Registry (SSKR).
Patient data from June 2000 to September 2022 was examined and analyzed for the following parameters:
- Patient age
- Sex
- Ocular history
- Visual acuity (VA)
- K2
- Max-K
- Thinnest corneal thickness pachymetry (TCT)
Who was included in the study?
Included were 2,171 patients (4,342 untreated eyes) with KC comprised of:
- 32% females with a mean age of 27.6 years
- 10.5 standard deviation (SD), range 12–70
Findings?
- 333 patients showed progression of either Max-K, TCT, or both
- 1,838 patients demonstrated stable parameters
- A younger baseline age was the only predictor of progression in TCT
- Hazard ratio (HR) 0.97 per year older; 95% confidence interval (CI) 0.95-0.99, P = 0.001
Tell me more.
Factors associated with a higher incidence of progression in Max-K included:
- Younger baseline age
- HR 0.96 per year older; 95% CI 0.95-0.98, P < 0.0001
- Higher baseline inter-eye asymmetry in Max-K
- HR 1.02 per higher diopter; 95% CI 1.00-1.04, P = 0.04
Limitations?
This research used RWD, which may have caused bias.
Additionally, the study did not utilize a standardized follow-up protocol.
- Why this matters: There were variations in monitoring regimens among the patients.
Go on …
The authors stated that the threshold used for statistical significance in the study (0.05) was conservative.
Furthermore, there was some degree of heterogeneity due to utilizing the same topographer, which may have influenced the findings.
For a full review of findings, see the study.
Expert opinion?
The authors stated that, “Interocular asymmetry in Max-K at baseline could be used as part of an algorithm for determining the risk of keratoconus progression.”
Take home.
The study found that age may be the most significant predictor of corneal thinning and Max-K progression.