All patients had an optometric evaluation including refraction, best corrected visual acuity, evaluation with PHP Foresee and with the Amsler grid. The sensitivity of the macular evaluation tests The Amsler grid and PHP for each maculopathy was calculated. It is currently the most frequent macular dystrophy, and the second most frequent retinal inherited condition after retinitis pigmentosa. It is estimated 15 million American people are currently affected with AMD. The Amsler grid was presented in as a technique to evaluate the central visual field in patients with macular conditions. However, this test reliability is doubtful, given a possible fixation loss, and the brain adaptation to complete scotoma areas.
|Published (Last):||25 January 2019|
|PDF File Size:||13.99 Mb|
|ePub File Size:||15.3 Mb|
|Price:||Free* [*Free Regsitration Required]|
All patients had an optometric evaluation including refraction, best corrected visual acuity, evaluation with PHP Foresee and with the Amsler grid. The sensitivity of the macular evaluation tests The Amsler grid and PHP for each maculopathy was calculated. It is currently the most frequent macular dystrophy, and the second most frequent retinal inherited condition after retinitis pigmentosa. It is estimated 15 million American people are currently affected with AMD.
The Amsler grid was presented in as a technique to evaluate the central visual field in patients with macular conditions. However, this test reliability is doubtful, given a possible fixation loss, and the brain adaptation to complete scotoma areas. It is a visual field test to qualitatively measure the macular distortion areas in a non-invasive way, on the basis of the hyperacuity characteristic, i.
So far, this technology has been used to assist in the AMD monitoring, to detect changes in the visual function. The results showed that the PHP was more sensitive than the Amsler grid to detect lesions due to AMD, in spite of a high false-positive ratio for healthy subjects.
After signing the informed consent, the patients had an optometric evaluation under photopic lightening conditions: refraction, visual acuity, PHP, and the Amsler grid. The best-corrected, far visual acuity was evaluated using a Bailey-Lovie test. The presence of scotomas was one-eyed evaluated with the best optical compensation, using the Amsler grid with white lines on black background in one-eyed vision, and using the PHP. Before starting the test with the PHP, the patients had to go through a tutorial to avoid the possible effect of test-learning.
The sensitivity and specificity of the Amsler grid and the PHP were calculated, and compared for each condition. Likewise, there was a control group, with no disease, to check the technique reliability in their application. Although the sensitivity and specificity are usually calculated on a validated gold standard, there is no-one to detect scotoma using VA charts, unless using methods like macular perimetry or scanning laser microperimetry.
To achieve the goal of this study, it was essential to choose an objective case of scotoma definition which would allow to stimate the rate of scotoma detection with each method; thus, it was defined that the patient had scotoma when both conditions were present. It was defined the sensitivity and specificity of the methods as scotoma detection and screening technique.
Standard descriptive statistical techniques were used. Descriptions of mean values, proportions, sensitivity and specificity following common formules are exposed. All comparisons were two-tailed and performed assuming an alpha-error of 0. The VA average in all patients was 0. The average time to do the PHP was 4. So, we did the statistical analyses exclusively considering the reliable tests.
However, the results showed no significant differences between the analyses including all the cases irrespective its reliability and the exclusive use of reliable cases. In AMD, due to the waste products accumulated and the possible neovascularization, the affected patients will perceive a distortion in the straight lines, or metamorphopsia.
That is the reason why we decided to compare it with the Amsler grid for this type of condition, given the good results watched in AMD with this technique for the detection of both, distortion and scotomas Figure 1. The sole technician who performed both PHP and Amsler grid test was aware of the diagnosis. This is actually a methodological strength of the study. On the other hand, the unblinding could be considered as a disadvantage; but the possibility of biased data in these tests is so low.
We are aware of the handicap involved in the small sample size of this study, which could be considered as a first pilot one. However, there is a series of relevant findings to be confirmed in future studies with a larger sample size. Regarding the Amsler grid, we must point out that we insisted particularly in the need to do the test carefully, emphasizing its understanding and explanation of the subjective grid perception.
Hence the Amsler grid sensitivity results may have been higher than in previous studies. This problem can be related to other field tests which must be repeated several times until a reliable result is achieved.
However, this does not modify the test sensitivity results. This difference can affect the understanding of the PHP test and the ability to do it. Another PHP disadvantage in comparison with the Amsler grid is the test time, estimated in an average of more than 4 minutes per eye. This means the Amsler grid is a fast, portable, cheap, accessible method, with a reasonable sensitivity and specificity at handling maculopathies. Despite these problems, the PHP allows a qualitative and quantitative monitoring of the scotoma changes in placing and depth, in a more precise way than using the Amsler grid in AMD patients.
This means it is probably a test less appropriate for diseases with photoreceptor loss, and more appropriate for diseases involving retinal degeneration. Acknowledgement This study and data accumulation has been carried out in conformity with all National laws. An informed consent was obtained and the study is in adherence to the tenets of the Declaration of Helsinki. Frequency of ABCA4 mutations in Spanish controls: an insight into the prevalence of autosomal recessive Stargardt disease.
Br J Ophthalmol. Westerfeld C, Mukai S. Semin Ophthalmol. Coco R, Navarro R, editors. Prevalence of age-related maculopathy. The Beaver Dam Eye Study. Ophthalmology, ; Comparison of the original Amsler grid with the modified Amsler grid: result for patients with age-related macular degeneration. Earliest symptoms caused by neovascular membranes in the macula. Arch Ophthalmol. Schuchard RA. Validity and interpretation of Amsler grid reports. Role of the completion phenomenon in the evaluation of Amsler grid results.
Am J Ophthalmol. Replacing the Amsler grid: a new method for monitoring patients with age-related macular degeneration. Results of a multicenter clinical trial to evaluate the preferential hyperacuity perimeter for detection of age-related macular degeneration. Comparison of the original Amsler grid with the preferential hyperacuity perimeter for detecting choroidal neovascularization in age-related macular degeneration. Arq Bras Oftalmol.
Test de la Rejilla de Amsler
It is a convenient eye test that you can use at home to monitor changes in your vision. It helps to detect many problems early, while they may still be treatable, such as retinal detachments and central serous choroidopathy. It is recommended that individuals with macular degeneration test their eyes with the Amsler Grid daily. If any changes are noted, you should contact your optometrist immediately. An Internet connection is not required to use this app. Your privacy is secure because our app does not require any special permissions and does not collect any information.
Test de Amsler: Prueba optométrica
Incluye la nueva rejilla modificada de Amsler. El test consta de 7 rejillas cuadradas y una redonda. Se incluye un manual detallado de cada rejilla, as como el anlisis por separado de cada carta. No hemos pretendido profundizar demasiado en el estudio de la regin macular mediante este test, sino dar sencillas explicaciones de su manejo aportando ejemplos de alteraciones que ilustren y clarifiquen al examinador en su comprensin. No obstante, invitamos a aquellos examinadores interesados en el tema a que realicen un estudio ms detallado mediante la lectura de los diferentes estudios publicados, citados en la bibliografa, de los que parte la creacin de cada una de las cartas que conforman el manual y que a su vez aportan valoraciones clnicas valiosas, as como nuevos mtodos y cartas de evaluacin. Mediante este manual el profesional de la visin puede evaluar el dao funcional producido en un paciente por procesos degenerativos de la retina, coroides, nervio ptico, rbita, caminos visuales y del crtex cerebral.
Admira Visión. Oftalmólogos en Barcelona
Rejilla de Amsler