Abstract
Purpose:
Humphrey Visual Field (HVF) is patient response dependent. Learning curve associated with HVF, adds to cost and burden of health care services, especially relevant in developing countries. Computers are now accessible to most individuals if not all. Hence, computer software simulating HVF was developed and glaucoma suspects undergoing their first HVF were subjected to it. Effect of software was assessed on patient performance of HVF by analyzing reliability indices.
Methods:
Prospective randomized case control study conducted in patients attending outpatient department of tertiary care centre, between age group of 18 to 60 years and suspected with glaucoma. Suspects underwent HVF (SITA Standard), those with False Positive (FP) or False Negative (FN) error greater than 15% were included in study. Patients were divided into 2 groups of 30 each. Group 1 subjected to computer based simulator after a period of one hour to eliminate any fatigue, followed by HVF after 1 week. Group 2 was subjected to HVF only after 1 week. Novel computer software was developed using Visual Basic, which simulates HVF by displaying white spots, of varying sizes, at variable intervals, at positions randomly generated over black screen. Reliability indices (FP and FN) were tabulated for groups and mean of indices were compared.
Results:
Both groups were comparable at baseline. Group 1 showed significant improvement in both reliability indices, FP (p=0.001) and FN (p=0.001, Wilcoxon signed rank test). Whereas there was no significant change in reliability indices for group 2, FP (p=0.138) and FN (p=0.069). On first HVF, FP for group 1 and 2 were 14.53 + 4.05 and 14.33 + 3.35 respectively (p=0.81, Mann Whitney U test). FN for group 1 and 2 were 15.07 + 3.03 and 14.67 + 4.41 respectively (p=0.93). On second HVF, FP for group 1 and 2 were 8.73 + 4.46 and 13.47 + 3.90 respectively (p = 0.004). FN for group 1 and 2 were 9.00 + 4.22 and 13.40 + 4.43 respectively (p=0.01).
Conclusions:
Patients subjected to computer simulator showed significant improvement in reliability indices on second HVF as compared to other group. Therefore, computer simulator improves patient performance of HVF. Further, in practical terms, this may decrease learning curve associated with HVF. With ease of access to computers, the simulator may be cheaply distributed and used more widely, saving cost and time to healthcare services.
Keywords: 758 visual fields •
642 perimetry •
465 clinical (human) or epidemiologic studies: systems/equipment/techniques