Corneo-pterygium total area measurements utilising image analysis method

Hilmi, Mohd Radzi and Mohd. Kamal, Khairidzan and Che Azemin, Mohd Zulfaezal and Ariffin, Azrin Esmady (2019) Corneo-pterygium total area measurements utilising image analysis method. Journal of Optometry, 12 (4). pp. 272-277. ISSN 1888-4296 E-ISSN 1989-1342

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Abstract

Purpose: To describe an objective method to accurately quantify corneo-pterygium total area (CPTA) by utilising image analysis method and to evaluate its association with corneal astigma- tism (CA). Methods: 120 primary pterygium participants were selected from patients who visited an oph- thalmology clinic. We adopted image analysis software in calculating the size of invading pterygium to the cornea. The marking of the calculated area was done manually, and the total area size was measured in pixel. The computed area is defined as the area from the apex of pterygium to the limbal-corneal border. Then, from the pixel, it was transformed into a per- centage (%), which represents the CPTA relative to the entire corneal surface area. Intra- and inter-observer reliability testing were performed by repeating the tracing process twice with a different sequence of images at least one (1) month apart. Intraclass correlation (ICC) and scatter plot were used to describe the reliability of measurement. Results: The overall mean (N = 120) of CPTA was 45.26 ± 13.51% (CI: 42.38-48.36). Reliability for region of interest (ROI) demarcation of CPTA were excellent with intra and inter-agreement of 0.995 (95% CI, 0.994-0.998; P < 0.001) and 0.994 (95% CI, 0.992-0.997; P < 0.001) respectively. The new method was positively associated with corneal astigmatism (P < 0.01). This method was able to predict 37% of the variance in CA compared to 21% using standard method. Conclusions: Image analysis method is useful, reliable and practical in the clinical setting to objectively quantify actual pterygium size, shapes and its effects on the anterior corneal curvature.

Item Type:	Article (Journal)
Additional Information:	7746/72277
Uncontrolled Keywords:	Pterygium; Corneo-pterygium; Total area; Image analysis; Corneal Astigmatism
Subjects:	R Medicine > RE Ophthalmology
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Allied Health Sciences Kulliyyah of Allied Health Sciences > Department of Optometry and Visual Science Kulliyyah of Medicine Kulliyyah of Medicine > Department of Ophthalmology
Depositing User:	Dr Mohd Radzi Hilmi
Date Deposited:	17 May 2019 14:52
Last Modified:	26 Nov 2019 17:34
URI:	http://irep.iium.edu.my/id/eprint/72277

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