The cornea is the thin, transparent, and avascular connective tissue that lines the front of the eye. As the most anterior surface and a major refractive component of the eye, it allows light transmission to the rest of the eye. Corneal transparency is a general indicator of corneal health. Diseases and some corneal treatments can alter the clarity of the cornea. Assessment of corneal haze in healthy and diseased eyes will aid in the understanding of how diseases progress and the impact of treatment outcomes. Such information will be informative and useful in a clinical setting to assist disease prognosis for the best possible outcome for patients. The iris camera is a specialised device that employs near-infrared light to capture multiple images in seconds which can be analysed to generate a quantitative (objective) estimate of corneal haze. The objective of this project was to investigate corneal haze and its impact on corneal clarity by evaluating changes that take place in health and disease. Specialised algorithms were used to analyse images from an iris camera. Firstly, we assessed changes in corneal transparency over time in a corneal disease with no treatment and compared outcomes with healthy individuals. Corneal diseases and treatments associated with haze were identified, and 163 participants were enrolled and followed up through treatment. We found that corneal clarity changes between patients with the corneal disease (keratoconus) and healthy participants were significantly different. When we compared the outcomes between the two groups, we found that corneal clarity in the healthy participants remained the same with no change while clarity in patients with keratoconus deteriorated. When we compared the outcome of corneal cross-linking on corneal clarity in patients with keratoconus over a certain period, we discovered that the haze level changed (declined) over time, suggesting an improvement. Likewise, in advanced keratoconus, penetrating keratoplasty (PK) improves vision as the last resort when all other remedies prove ineffective against disease progression. The corneal clarity outcomes post-PK again showed improvement, with an observed decline in the haze over time. The corneal response to several treatment methods and disease progression are dependent on a host of factors and will affect corneal clarity differently. With its image analysis software, the iris camera provides an objective means of monitoring corneal clarity in health, disease and assessing treatment modalities.
|Date of Award||31 Dec 2022|
- The University of Manchester
|Supervisor||Tariq Aslam (Supervisor)|