This was a cross sectional study undertaken between March 2016 to March 2018 at St.Paul’s Hospital Millennium Medical College(SPHMMC), Addis Ababa, Ethiopia. This study was done primarily to determine the validity of amsler grid test for identifying central field defect in patients with advanced glaucoma in Ethiopia. A recent Hospital based study in USA showed high sensitivity and specificity of the black on white (BOW) test to detect central vision loss from moderate to severe glaucoma. There is scarcity of data on the use of amsler grid test for detection of glaucoma. It is a valuable test due to the low cost, ease of administration, short testing and process time, and ease of understanding and performance for the patient and no need of maintenance. It is used to detect and monitor central field defects for macular diseases. It is a high contrast supra-threshold test. The amsler grid was designed specifically to analyze VF defects in the central 10 degrees surrounding fixation. This limits their utilization in community setting. However, the equipment needed for such perimetry is expensive, requires expertise for interpretation and is not easily available in the developing countries like Ethiopia. Various studies have also shown that the sensitivity increases up to 96.6% in those eyes with mean deviation (MD) of less than -8 dB. The performance of frequency doubling technology (FDT) perimetry has been evaluated extensively in population based glaucoma prevalence surveys where the sensitivity and specificity values for detecting definite glaucoma was reported to be 55.6% and 92.7%, respectively. The sensitivity and specificity of automated white on white perimetry has been reported to be 70% and 67%, respectively. If patients can be diagnosed in advanced stage, while they still have the central vision intact and treated, it has multiple benefits in terms of personal, social and economic factors and is likely to maintain a reasonable quality of life. driving and walking outside) and the relative emphasis of these priorities changed with increasing VF loss, with concerns for central vision increasing, whereas those for outdoor mobility decreased. reading) have been given the greatest importance, followed by mobility outside the home (i.e. Tasks involving central and near vision (i.e. Central vision is more important for patients than peripheral VF loss and visual acuity is strongly related to VF sensitivity in the central area of the 10–2 VF.
Detecting glaucoma at this stage is of utmost importance since aggressive treatment can prevent blindness.
In advanced stage the remaining central island of vision is in imminent danger of loss, particularly in SSA settings where detection and treatment are far from optimal. Early in the disease process, patients with glaucoma are asymptomatic and central vision and the central visual field (VF) is typically intact. Clinic based studies in Africa have shown that 60%–76% of patients with glaucoma present in advanced stage of the disease or unilateral blindness.Įarly detection is important to reduce the risk of advanced glaucomatous disease and loss of quality of life and productivity. Glaucoma is the leading cause of irreversible blindness worldwide, and the second cause of blindness (after cataract) from various conditions in Sub-Saharan Africa (SSA).
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