Assessment of amplitude of accommodation (AA) in Owerri Municipal Council, Southeast, Nigeria

Amplitude of accommodation (AA) was measured in 399 consecutive participants, aged 5 to ≥55 years, in Owerri Municipal Council, Southeast, Nigeria using Donders’ Push-up-to-blur (PUB) technique; and compared with the average AA derived from Hofstetter’s equation. Each participant wore the subjective prescription and the reduced Snellen chart was gradually moved towards the participant until the first sustained blur on the 6/6 (20/20) line was reported. The distance between the test chart and the spectacle plane was recorded as the near point of accommodation (NPA) in centimeters. Dividing 100 by the NPA gave the AA value. The results showed that age and AA were inversely but significantly (p<0.05) correlated, with the 5-14 and ≥55 years age categories having the highest (17.49D) and least (1.60D) AA values respectively. Males had insignificantly (p>0.05) higher mean AA (46.74D) than the age-matched females (45.52D), while students were found to have significantly (p<0.05) higher mean AA (11.23D) than other occupation groups. Among all age groups, the total measured mean AA was observed to be significantly (p<0.05) lower than the calculated average AA derived from Hofstetter’s equation. Therefore, Hofstetter’s equation did not accurately predict the real amplitude of accommodation among various age groups in Owerri Municipal Council, Nigeria.

Keywords:Amplitude of accommodation; Push-up method; Hofstetter’s equation; Nigeria