Modified Bagolini striated glass test: clinical applications of starlight test in binocular visual field screening

Rapid, accurate, multifunctional and self-assisted vision assessment and screening with interactive desktop autostereoscopy

Background

This study aimed to develop an interactive vision screening tool based on desktop autostereoscopy and evaluate its feasibility for testing visual acuity, colour vision, stereo vision and binocular balance clinically.

Methods

An interactive desktop autostereoscopy vision test was developed making it remarkably convenient for individuals to undergo multiple visual function assessments in a single test. With this rapid screening process, an individual's visual acuity, colour vision, stereo vision and binocular balance can be assessed within several minutes. A total of 155 healthy subjects were enrolled to compare the clinical repeatability, accuracy, inter-visit variability, likeability and efficiency between the autostereoscopy and traditional method.

Results

In the repeatability test, the visual acuity measured with autostereoscopy was 0.045±0.018 and 0.035±0.018 (P=0.702) for the first and second tests, respectively. The mean logarithm of the Minimum Angle of Resolution (logMAR) visual acuities measured with the Early Treatment Diabetic Retinopathy Study (EDTRS) chart and autostereoscopy test were 0.04±0.02 and 0.05±0.02, respectively, which were not significantly different (P=0.849). The correlation between these two kinds of tests was statistically significant (Spearman correlation coefficient =0.829, P<0.001). The results for colour vision, stereo vision, and binocular vision are presented, and the effectiveness of the autostereoscopic method is supported with qualitative data comparing its results with those of the traditional methods. In the likeability test, the EDTRS chart and autostereoscopy test had scores of 2.21±0.53 and 3.04±0.07, while the traditional and autostereoscopy tests for colour vision, stereo vision, and binocular vision had scores of 2.02±0.59 and 3.36±0.93, respectively (P<0.001). Regarding visual fatigue, the mean scores were 0.69±0.04 and 0.42±0.04 (P<0.001) with the EDTRS chart and autostereoscopy test, respectively. Regarding work efficiency, the average testing times per person was 59.65±0.66 and 48.92±0.86 s (P<0.001) with the EDTRS chart and autostereoscopy test, respectively.

Conclusions

The autostereoscopy test was conclusively shown to be valid, efficient and repeatable for the measurement of visual acuity, colour vision, stereo vision, and binocular vision, and the process was subjectively well-liked and comfortable.

Why can't my child see 3D television?

A child encountering difficulty in watching three-dimensional (3D) stereoscopic displays could have an underlying ocular disorder. It is therefore valuable to understand the differential diagnoses and so conduct an appropriate clinical assessment to address concerns about poor 3D vision.

Retinitis pigmentosa: visual function and multidisciplinary management

Retinitis pigmentosa (RP) is a leading cause of blindness and visual disability in younger people. Optometrists have a major role in detecting RP and in reducing the visual disability associated with RP. This review summarises the literature relating to visual function in people with RP, with particular attention given to night-blindness, visual acuity decrease and visual field contraction. The range of low vision aids available for people with RP is reviewed and suggestions given on aids that have been found to be most successful. Most importantly, this review overviews the range of services available to people with RP and emphasises how optometrists need to work with a network of professionals to ensure the best possible visual outcomes for people with RP. Particular mention is made of current findings relating to orientation and mobility training, driving, sensory substitution and adaptive technology. The modern optometrist needs to be aware of the multiple needs of people with RP and have the ability to link them with the professionals best able to help them.

Loss of stereopsis with optic chiasmal lesions and stereoscopic tests as a differential test

OBJECTIVE

To identify and characterize the loss of stereopsis observed in patients with lesions of the optic chiasm.

STUDY DESIGN

Cross-sectional study.

PARTICIPANTS

Forty-three patients who had good visual acuity with orthophoria and without strabismologic histories were divided into two groups. Group 1 consisted of 13 patients with lesions involving the optic chiasm (regardless of their visual field loss) diagnosed by magnetic resonance imaging findings. Group 2 (control group) consisted of 30 patients who had large absolute visual field defects as a result of other causes, including 11 intracranial disorders other than optic chiasmal lesions, 11 cases of open-angle glaucoma, and 8 patients with lesions of the retina.

METHODS

The stereoacuity and visual field in each case in group 1 (before and after surgery) and group 2 were assessed, and the results were compared.

MAIN OUTCOME MEASURES

Stereoacuity was assessed by the Titmus stereo test (normal value for circle, 6/9; 80 seconds of arc) and by Lang-stereotest (normal value for circle, 3/3; 350 seconds of arc). Visual field was evaluated by Goldmann and Humphrey perimetry (conventional perimetry), the starlight test (binocular visual field test), and scanning laser ophthalmoscopic microperimetry (microperimetry).

RESULTS

Before surgery, 11 of 13 cases (85%) in group 1 failed stereo tests, and after surgery, 5 of 13 cases (38%) in group 1 failed stereo tests. Before surgery, four patients who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis; after surgery, one patient who failed stereo tests showed no absolute scotoma by Humphrey or Goldmann analysis. However, starlight testing showed complete bitemporal hemianopsia only under binocular conditions, and microperimetry demonstrated a relative bitemporal hemianopsia at the fixating point. No patient failed in the Titmus circle test, but one patient in group 2 failed the Lang test (3%). The patients with chiasmal lesions significantly lost the ability of stereopsis compared with other diseases (group 1 [before or after surgery] vs. group 2, P < 0.001, Fisher's exact test). Conventional perimetry was unable to measure scotomas within 3 degrees of the fixation point, which is the key area for acute foveal stereopsis, because of an attached observational mirror.

CONCLUSIONS

The difficulty with stereopsis in patients with lesions of the optic chiasm is most likely caused by the compression of the decussating optic nerve fibers resulting in the loss of an overlapping visual field at the fixation point. Stereo tests were demonstrated to be simple and effective adjunctive tests for suspected chiasmal compression.

Screening models for glaucoma

For social and economic reasons, glaucoma screening is a useful and necessary task, with possible benefits for individuals and the health care system arising from the early diagnosis and early therapy of patients with glaucoma. Early treatment of patients with glaucoma decreases the probability that those patients will become blind and lowers the direct and indirect costs for patients with glaucoma. Most of the reported studies dealing with glaucoma screening used only one parameter (eg, intraocular pressure) to detect and to discriminate glaucoma patients from healthy subjects. Glaucoma screening devices might be combined to obtain the best specificity and sensitivity. Because the diagnosis of glaucoma is very closely associated with a morphologic change in the optic nerve head, one screening parameter should be the morphology of the papilla. To increase specificity and sensitivity, a combination of morphologic and functional testing might be useful. In this review, we report the context of glaucoma screening in terms of health economics, the testing quality of devices for functional and morphologic screening, and the results of a pilot study.