Table 5

12-month workload estimates for cataract surgery in Theni population (≥40 years) in hypothetical scenarios based on goals of reducing cataract burden

ScenarioGoalCurrent utilisation %
Additional utilisation to achieve goal %
Overlap between current and additional utilisation %
Net utilisation %
Number of persons to be treated
(E=D×population of 540 078)
Estimated CSR based on 2021 projected population of 1.319 million
1Meet current demand3.10003.116 74212 689
2Meet current demand and eliminate present burden of PVABE<3/603.100.340.203.2417 51713 276
3Meet current demand and eliminate present burden of PVABE<6/603.100.640.413.3318 00113 643
4Meet current demand and eliminate 1/5th of present burden of PVABE<6/123.101.981.633.4618 66714 148
  • Column A: Based on last row of table 4.

  • Column B: Based on last row of table 2. In particular, the 1.98 in scenario four is obtained as 1/5×(1.51+7.77+0.30+0.34).

  • Column C: Of the 221 study participants who obtained cataract surgery in the last 12 months (table 4), data on PVABE was available for 149. Of these, 14 (0.20% of 7127) had PVA<3/60, 29 (0.41% of 7127) had PVA<6/60, and 116 (1.63% of 7127) had PVA<6/12, where 7127 is the study sample size.

  • Column D: Since participants in column C are included in both columns A and B, we remove the duplication by subtracting.

  • Column E: Theni district population (≥40 years) is projected to grow to 540 078 in 2021 from the 2011 level of 425 376. This is done by applying the 10-year growth rate of 26.96% of Tamil Nadu population (≥40 years) obtained from

  • Column F: Theni district population for 2021 based on 10-year Tamil Nadu population growth rate of 5.9% applied to 2011 population of 1 245 899.

  • PVABE, presenting visual acuity in the better eye.