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A Reproducible Computerized Method for Quantitation of Capillary Density using Nailfold Capillaroscopy
Published on: October 27, 2015
A new computer assisted objective method for quantifying vascular changes of the bulbar conjunctivae
C G Owen1, F W Fitzke, E G Woodward
1Applied Vision Research Centre, City University, London, UK.
Summary
A new computer software method accurately quantifies conjunctival vasculature, showing significant changes in rigid gas permeable contact lens wearers. This technique offers a simple, inexpensive way to assess ocular surface vascularity.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Medical Imaging
Background:
- The conjunctival vasculature is a dynamic structure providing valuable quantitative information about the ocular environment and diseases.
- Assessing conjunctival vascularity is crucial for understanding ocular health, particularly in contact lens wearers.
- Existing methods for evaluating conjunctival hyperaemia may lack sensitivity and statistical significance.
Purpose of the Study:
- To develop and validate a novel computer software method for quantifying conjunctival vascular surface area from photographs.
- To assess the repeatability and sensitivity of the new quantification technique.
- To compare the computer-assisted method with subjective grading of conjunctival hyperaemia in contact lens wearers.
Main Methods:
- A novel computer software method was employed to quantify the conjunctival plexus on the scleral background, measuring vascular surface area from optimized photographic images.
- The repeatability of the technique was evaluated on 20 subjects (20 eyes) over two separate occasions.
- The method's sensitivity was assessed by comparing conjunctival vasculature in soft contact lens (SCL) and rigid gas permeable contact lens (RGPCL) wearers with subjective hyperaemia grading.
Main Results:
- The developed software method demonstrated high repeatability with maximum 95% confidence limits for repeatability at +8.58/-3.95% and for consecutive estimates between +/- 6.54%.
- The new method detected statistically significant increases in conjunctival hyperaemia in RGPCL wearers.
- Subjective grading also detected hyperaemia but did not reach statistical significance, highlighting the sensitivity of the new technique.
Conclusions:
- The novel computer software method provides a simple, inexpensive, and sensitive tool for quantifying conjunctival vascularity.
- This technique is valuable for assessing ocular surface changes in varied ocular environments and disease states.
- Further investigation into conjunctival vasculature as a source of quantitative information is warranted.
