Abstract
Purpose: :
To describe a new automated method to objectively quantify conjunctival injection in clinical slit lamp photographs.
Methods: :
We developed a computer-assisted system that calculates conjunctival redness using a centesimal (0 to 100) scale. The software quantifies conjunctival redness in clinical images based on a mathematical algorithm and allows for standardization of photographs acquired with different slit lamps or recorded in different digital formats. The system utilizes the widely available image platform ImageJ, can be installed on any computer and does not require training in ophthalmology.Two physicians evaluated and scored conjunctival redness in a set of clinical photographs using two non-automated, ordinal classification systems that compare photographs to standards (Efron and VBR scales). In a masked fashion, a third investigator scored the same set of clinical photographs using our newly developed CRI computer-assisted system. Finally, we analyzed the correlation between the CRI and the Efron and VBR scores.
Results: :
We analyzed 102 digital images of patients with ocular surface disease and different degrees of conjunctival hyperemia. There was good agreement between the clinical observers' scores for both, Efron (intra-class coefficient=0.86, P<0.001) and VBR (intra-class coefficient=0.85, P<0.001) scales. There was a statistically significant correlation between the CRI and the Efron (observer 1: R=0.83, P<0.001; observer 2: R=0.82, P<0.001) and VBR (observer 1: R=0.93, P<0.001; observer 2: R=0.86, P<0.001) scales.
Conclusions: :
The CRI provides an automated continuous scale for evaluating conjunctival/ocular injection in an objective manner. This system may be used for evaluating ocular redness in a variety of clinical conditions and clinical trials.
Keywords: conjunctiva • cornea: clinical science • cornea: tears/tear film/dry eye