Specvis: Free and open-source software for visual field examination

Abstract

Visual field impairment affects more than 100 million people globally. However, due to the lack of the access to appropriate ophthalmic healthcare in undeveloped regions as a result of associated costs and expertise this number may be an underestimate. Improved access to affordable diagnostic software designed for visual field examination could slow the progression of diseases, such as glaucoma, allowing for early diagnosis and intervention. We have developed Specvis, a free and open-source application written in Java programming language that can run on any personal computer to meet this requirement (http://www.specvis.pl/). Specvis was tested on glaucomatous, retinitis pigmentosa and stroke patients and the results were compared to results using the Medmont M700 Automated Static Perimeter. The application was also tested for inter-test intrapersonal variability. The results from both validation studies indicated low inter-test intrapersonal variability, and suitable reliability for a fast and simple assessment of visual field impairment. Specvis easily identifies visual field areas of zero sensitivity and allows for evaluation of its levels throughout the visual field. Thus, Specvis is a new, reliable application that can be successfully used for visual field examination and can fill the gap between confrontation and perimetry tests. The main advantages of Specvis over existing methods are its availability (free), affordability (runs on any personal computer), and reliability (comparable to high-cost solutions).

A free and simple computerized screening test for visual field defects

“…A common challenge when validating two visual field tests against each other is that they rarely probe the exact same locations in space (see, for example, Dzwiniel et al ., and Koiava et al ., for other studies that have faced the same challenge). The Esterman test covers an oval space, vertically spanning 30 degrees of visual angle superior, 60 degrees inferior, and horizontally spanning 160 degrees.…”

“…However, most of these run online (e.g., Koiava et al ., and Olsen et al ., ) and thus require a stable Internet connection to work as intended. Other programs, while giving excellent information on the patient's visual field, are harder to complete for the patients or harder to administer for the examiner (e.g., Dzwiniel et al ., ). Test selection and the interpretation of results often require in‐depth knowledge about visual perception, detailed knowledge about visual field assessment techniques, as well as advanced computer skills.…”

“…A number of computerized visual field screening tests already exist (e.g., Dzwiniel, Gola, Wójcik‐Gryciuk & Waleszczyk, ; Koiava et al ., ; Olsen et al ., ). However, most of these run online (e.g., Koiava et al ., and Olsen et al ., ) and thus require a stable Internet connection to work as intended.…”

Personal Computer-Based Visual Field Testing as an Alternative to Standard Automated Perimetry

“…Of these novel ideas, the concept of usage of a personal computer (PC) screen for automated perimetry and as a screening device for visual field defects was given by Dzwiniel et al after an internal validation study in the form of a free and open-source software called Specvis, having the capability to run on almost all types of popular PCs irrespective of its manufacturer or operating system. Although the internal validation revealed that the software can be used as a reliable visual field examination tool, the study was limited by a small sample size including only four glaucoma patients, and comparison to only Medmont M700 Automated Static Perimeter [ 11 ].…”

Current trends for customized biomedical software tools

“…This software could be of potential application by assisting the clinicians in quick evaluation or optimization of the radiotherapy treatment plans. For testing visual field impairment, a free and open-source application (Specvis), written in Java programming language has been developed and tested on glaucomatous, retinitis pigmentosa and stroke patients [ 28 ]. The main advantages of Specvis over existing methods are its free availability, affordability, and reliability in parallel to high-cost solutions.…”