Zoran Georgievski

Victorian orthoptists' performance in the photo evaluation of diabetic retinopathy

Purpose:  The aim of this study was to investigate the effectiveness of orthoptists in detecting various grades of diabetic retinopathy (DR) and retinal pathology not directly associated with diabetes and to identify factors associated with best performance.

The use of distance stereoacuity assessment in determining the effectiveness of minus lenses in intermittent exotropia.

PURPOSE Minus lens treatment has been advocated for intermittent exotropia to prevent progression and has been found to be effective in improving the control of the deviation in the distance. However, the effectiveness of this treatment is difficult to ascertain because of the lack of standardized outcome measures. Distance stereoacuity has been reported to be a reliable assessment of control of intermittent exotropia. In this study, its role as an outcome measure in the efficacy of minus lens treatment was examined by the use of the Frisby-Davis Distance stereotest. METHODS Patients (n = 24) with intermittent exotropia participated. Their distance stereoacuity was tested with the Frisby-Davis Distance stereotest at baseline and with varying minus lens powers (of -1, -2 and -3 D) that were tested randomly, as were the distance binocular visual acuity and angle of deviation. RESULTS Varying minus lens powers had a significant effect on the angle of deviation and binocular visual acuity but not distance stereoacuity. However, both measures of binocularity, distance stereoacuity, and binocular visual acuity tended to diminish with the stronger minus lens power of -3 D. Participants actually demonstrated difficulty in accommodating through the stronger lenses. CONCLUSIONS Distance stereoacuity (and binocular visual acuity) cannot reliably be used to determine the optimum minus lens strength that could be used in these patients to reduce the angle of deviation and regain binocularity in the distance. An additional observation was made that stronger lenses should perhaps be avoided to prevent binocular and visual discomfort.

The base-to-base induced-tropia prism test for detection of amblyopia: a pilot study.

PURPOSE To investigate the accuracy of the base-to-base prism test (BBPT), which entails inducing an esotropia with the use of base-in prisms before each eye, in the diagnosis of amblyopia. METHODS Participants were consecutive patients recruited from a pediatric ophthalmology practice who were able to perform logMAR acuity testing. All participants underwent an orthoptic examination, including logMAR visual acuity testing, and a sensorimotor evaluation. Patients with an interocular difference of 2 or more lines were considered to have amblyopia. Fixation preference was assessed by use of both the vertical fixation test and the BBPT. The agreement between the BBPT and visual acuity was analyzed and compared with the agreement between the vertical fixation test and visual acuity. RESULTS Fifty-one consecutive patients aged 4 to 17 (mean, 9.8 years; SD ± 3.4) were included, of whom 11 were diagnosed with amblyopia. Kappa analysis showed moderate but significant agreement between the BBPT and logMAR (κ = 0.453, p = 0.001), whereas the vertical fixation test demonstrated only a fair agreement (κ = 0.254, p = 0.061). The overall sensitivity for the BBPT was 72.7% (95% confidence interval [95% CI], 43.4%-90.3%) but only 40% for the vertical fixation test (95% CI, 16.8%-69.7%). For the BBPT, specificity was 80% (95% CI, 65.2%-89.5%); for the vertical fixation test, 78% (95% CI, 63.3%-88.0%). CONCLUSIONS The BBPT appears to be more sensitive than the vertical fixation test for detecting amblyopia in our patient population. The 2 tests had similar specificity.

Orthoptists' management of amblyopia - a case-based survey.

Purpose The aim of this study was to investigate the amblyopia treatment trends of Australian orthoptists and to identify variations or consistencies amongst treatment patterns. Methods A questionnaire was distributed to all orthoptists who attended an annual national scientific conference. This questionnaire consisted of four case vignettes of amblyopic patients. Each was presented with a series of multiple-choice questions that orthoptists were required to answer. Results The questionnaire was completed by 46 orthoptists. Large diversity between orthoptists in their treatment application was found. This related mostly to the intensity of occlusion treatment. Conclusion Treatment variability continues to exist between orthoptists. Further investigations evaluating the clinical decision making processes of clinicians in prescribing amblyopia treatment may help us to better understand the determinants that are considered when prescribing treatment. This would be useful in establishing best-practice guidelines.