Amsler grid test for detection of advanced glaucoma in Ethiopia

Caronia Glaucoma Card Versus Amsler Grid for Monitoring Patients With Advanced Glaucoma

PRCIS

Caronia Glaucoma Card (CGC) design incorporates a vertical and horizontal line and seven concentric circles corresponding to 1 o arc at normal reading distance. The study showed that the CGC is preferred by study patients compared to Amsler Grid and can detect central scotomas.

PURPOSE

Evaluate patient acceptance and efficacy of the Caronia Glaucoma Card (CGC) in monitoring patients with severe glaucoma.

METHODS

A retrospective study of consecutive patients with severe glaucoma who agreed to monitor their visual function. Patients were given a two-sided sheet of paper. An Amsler grid was printed on one side, and a CGC was printed on the other side. The patient was given verbal and written instructions on how to perform each test. They were asked to use either one or both tests to monitor their visual function on a weekly basis. Upon return, they were asked which test they preferred and if they appreciated or noticed any change in their scotoma. Patient comments were recorded.

RESULTS

Sixty-seven patients were given the test card whose reported past ocular history consisted solely of severe glaucoma. Seventeen patients were eventually excluded. Fourteen patients had 1 eye that fulfilled the inclusion criteria for the study, while the other eye was excluded. Eighty-six eyes of fifty patients satisfied the inclusion criteria and were enrolled in the study. Thirty of the patients were male (60%) and 20 were female (40%). The average age was 71.8 +/- 10.7 years. They all carried a diagnosis of severe glaucoma. When asked the question which test design they preferred to use, 30 patients preferred the CGC (60%), while 8 patients preferred the Amsler grid (16%). Twelve patients found no difference between the 2 test designs (24%). [χ 2 (2, 50)=16.480, ρ=0.000]. Five patients noticed a change in their scotoma while using the card (5.8%, 5 of 86 eyes). All were exclusively using the CGC.

CONCLUSION

The CGC is a convenient and inexpensive tool that was able to detect a change in scotoma. It may be helpful to add to the armamentarium to monitor glaucoma and its possible progression in patients with advanced disease.

Analysis of the Effectiveness of Metaheuristic Methods on Bayesian Optimization in the Classification of Visual Field Defects

Bayesian optimization (BO) is commonly used to optimize the hyperparameters of transfer learning models to improve the model's performance significantly. In BO, the acquisition functions direct the hyperparameter space exploration during the optimization. However, the computational cost of evaluating the acquisition function and updating the surrogate model can become prohibitively expensive due to increasing dimensionality, making it more challenging to achieve the global optimum, particularly in image classification tasks. Therefore, this study investigates and analyses the effect of incorporating metaheuristic methods into BO to improve the performance of acquisition functions in transfer learning. By incorporating four different metaheuristic methods, namely Particle Swarm Optimization (PSO), Artificial Bee Colony (ABC) Optimization, Harris Hawks Optimization, and Sailfish Optimization (SFO), the performance of acquisition function, Expected Improvement (EI), was observed in the VGGNet models for visual field defect multi-class classification. Other than EI, comparative observations were also conducted using different acquisition functions, such as Probability Improvement (PI), Upper Confidence Bound (UCB), and Lower Confidence Bound (LCB). The analysis demonstrates that SFO significantly enhanced BO optimization by increasing mean accuracy by 9.6% for VGG-16 and 27.54% for VGG-19. As a result, the best validation accuracy obtained for VGG-16 and VGG-19 is 98.6% and 98.34%, respectively.

Amsler Grid Versus 10-2 Test in Primary Open Angle Glaucoma

Background

Glaucoma is the leading cause of global irreversible blindness. The goal of management in glaucoma lies in its early detection and treatment to prevent further optic neuropathy. Available equipment for early glaucoma detection is not cost-effective or readily available in resource-scarce settings such as Nigeria. Thus, there is a need for a simple cost-effective tool to detect glaucomatous central visual field (CVF) defects in all the stages of glaucoma within the community in resource scarce-settings.

Aims and Objectives

The aim of this article is to determine the validity of the Amsler grid in detecting central glaucomatous visual field defects in primary open angle glaucoma (POAG).

Materials and Methods

This was a cross-sectional study of follow-up glaucoma patients at a secondary eye care hospital in Nigeria. All patients had detailed ophthalmic examination in addition to 24-2 and 10-2 CVF tests and Amsler grid test. POAG was classified using the Hodapp-Parrish-Anderson criteria into mild, moderate, and severe on 24-2 CVF. The diagnostic validity of the Amsler grid was calculated using the 10-2 CVF as a reference standard. Regression analyses were performed between the Amsler grid scotoma area and 10-2 CVF parameters [mean deviation (MD), scotoma extent (SE), and scotoma mean depth (SMD)].

Results

A total of 150 eyes of 150 patients were enrolled. The sensitivity, specificity, and positive predictive value and negative predictive value of the Amsler grid compared with the 10-2 CVF was 49.5%, 95.9%, 96.2%, and 47.9%, respectively, with an area under curve of 0.7. Sensitivity increased with increasing severity (P < 0.001) from 20.0%, 31.0%, and 76.6% in mild, moderate, and severe POAG, respectively. The Amsler grid scotoma area had the strongest relationship with the 10-2 MD, followed by 10-2 SE and 10-2 SMD with a quadratic R2 of 0.579, 0.370, and 0.307, respectively.

Conclusion

The Amsler grid has a low sensitivity in mild-to-moderate POAG. However, it may serve as an adjunctive tool in resource-scarce settings for detection of severe POAG in the community by primary eye care providers.

USAGE OF DIGITAL D CHART TEST AS A MODIFICATION OF AMSLER GRID IN OPHTHALMOLOGY AND OPTOMETRY

AIMS

Metamorphopsia is important symptom of macular disease. The most common simple detection method of metamorphopsia is Amsler grid. Usually it is used monocularly with best correction for near. Patient should evaluate grid deformation a describe position of the deformity. This method is based on qualitative principle. For quantitative evaluation we can use Software D Chart (Thomson Software Solution). This instrument enables evaluate degree and position of the metamorphopsia in central visual field. Our goal was to establish M-score values in group of young healthy subjects without correction (M-score natural), with cylindrical spectacle lens (M-score SL) and in group of patients with age related degeneration (M-score ARMD).

OBJECTS AND METHODS

We had 33 probands divided into 2 samples. The first sample contains 15 young probands with average age 23 years without any eye pathology. The second sample contains 18 patients with ARMD (7 with dry form and 11 with wet form). In our study we used software D Chart (Thomson Software Solution). This software was use in Acer PC with touchable screen. We note total M-score in right eye of all probands. Level for statistic evaluation was set on p = 0.05.

RESULTS

Natural M-score values for young probands was: median 0, minimum 0, maximum 2.3. With cylindrical lens we got these values: median 25.2, minimum 3.6, maximum 41.6. In second sample with probands suffer from ARMD we got these values: median 0.8, minimum 0, maximum 29.4. Wilcoxon non-parametric test was used for statistical evaluation. We proved statistically significant difference between all variables. M-score natural vs. M-score SL showed p &lt; 0.001, M-score natural vs. M-score ARMD showed p = 0.04 and M-score SL vs. M-score ARMD showed p &lt; 0.001.

CONCLUSION

Our study showed statistically significant differences between variable M-score natural, M-score SL and M-score ARMD. We found that printed Amsler grid as well as its digital modification D Chart are suitable for determining metamorphopsia in central visual field. The main advantage of D Chart is quantitative evaluation of the test with M-score and digital registration of retinal changes during patient´s follow up.