Among people aged ≥ 50 years, the most important causes of blindness in Birbhum, West Bangal were Cataract untreated (70.2%), Cataract surgery complication (14.9%) and Non trachomatous corneal opacity (4.3%). However the most important causes of visual impairment were Cataract untreated (73.8%) and Uncorrected refracted error (15.3%). Most important cause of early visual impairment was uncorrected refracted error (66.4%).
Out of all causes of blindness, 72.3% causes were treatable, 4.3% causes were unavoidable and 23.4% were preventable. Among causes of visual impairment (PVA better eye <6/18), 2.2% were unavoidable, 7.8% were preventable and 90% causes were treatable. For moderate severe visual impairment (PVA better eye <6/18-3/60), 92% treatable, 6.1% preventable and 1.9% unavoidable.
Presenting visual acuity < 3/60 in better eye
Presenting visual acuity < 6/60 – 3/60 in better eye
Presenting visual acuity < 6/18 – 6/60 in better eye
Presenting visual acuity < 6/12 – 6/18 in better eye
Presenting visual acuity <6/18-3/60 in better eye
Presenting visual acuity < 6/18 in better eye
A person with impairment of visual functioning even after treatment and/or standard refractive correction, and a visual acuity of less than 6/18 to light perception, or a visual field of less than 10 degree from the point of fixation.
Cataract Surgical Coverage (Person) indicates how many persons received cataract surgery (one or both eyes) among all who were bilaterally pinhole blind due to cataract.
The numerator includes persons with one operated and one pinhole blind eye and persons with bilateral (pseudo) aphakia. The denominator includes the numerator, plus persons bilaterally pinhole blind due to cataract. Besides this, the indicator can also be calculated separately for PinVA <6/60 and <6/18.
Cataract Surgical Coverage (Eye) measures the proportions of eyes pinhole blind due to cataract, which have been operated so far.
The numerator includes all (pseudo) aphakic eyes. The denominator includes the numerator, plus eyes pinhole blind due to cataract. Besides this, the indicator can also be calculated separately for PinVA <6/60 and <6/18.
| Blindness | SVI | MVI | EVI | MSVI | VI | FLV |
|
|---|---|---|---|---|---|---|---|
| Uncorrected refractive error | 0.0 | 1.5 | 19.9 | 66.4 | 17.0 | 15.3 | 0.0 |
| Aphakia un-corrected | 2.1 | 0.0 | 0.9 | 0.0 | 0.7 | 0.9 | 0.0 |
| Cataract untreated | 70.2 | 84.7 | 72.3 | 29.4 | 74.3 | 73.8 | 0.0 |
| Cataract surgery complication | 14.9 | 9.2 | 4.0 | 3.6 | 4.9 | 5.9 | 47.5 |
| Trachomatous corneal opacity | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Non trachomatous corneal opacity | 4.3 | 0.0 | 0.9 | 0.3 | 0.7 | 1.1 | 9.5 |
| Phthisis | 2.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 0.0 |
| Glaucoma | 2.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 4.8 |
| Diabetic retinopathy | 0.0 | 0.0 | 0.6 | 0.0 | 0.5 | 0.4 | 4.8 |
| Age related macular degeneration | 0.0 | 1.5 | 0.0 | 0.3 | 0.2 | 0.2 | 4.8 |
| Other posterior segment disorders | 4.3 | 3.1 | 1.4 | 0.0 | 1.7 | 2.0 | 28.6 |
| Globe/ CNS abnormalities | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |