RESUMO
BACKGROUND: The aim of the study was to evaluate the predictive value of grating acuity as measured by the TAC Test (TACT) at the age of 6 months corrected age and to compare grating and recognition acuities in eyes with and without ROP residua at an age of three to seven years. PATIENTS AND METHODS: The development of visual acuity between 6 months and 3 - 7 years (4.5 years median) was evaluated in 87 eyes of 44 premature children born between the 24 th and 36 th week of gestation, with a birthweight ranging from 550 to 2580 g. Thirteen eyes reached threshold: ROP disease and underwent cryocoagulation. Grating acuity was measured with the TACT at 6 months corrected age and every half year up to three to seven years (median 4.5 years). Recognition acuity was measured with the Sheridan-Gardiner Test (SGT) at 4.5 years (median). TACT-results at 6 months corrected age and 3 - 7 years were compared for the group of patients with normal posterior pole and patients with ROP residua. Furthermore, SGT scores and TACT scores were compared at the 4.5 years follow-up. A visual acuity of >/= 0.1 (3 cy/ degrees ) and >/= 0.4 (13 cy/ degrees ) was considered favourable at the age of 6 months corrected age and 3 - 7 years, respectively. RESULTS: The TACT scores ranged from < 0.03 to 0.2 (< 1.0 to 6.5 cy/ degrees ) at 6 months and from < 0.05 to 2.0 (< 1.6 to 57 cy/ degrees ) at 3 - 7 years. In 77 % of cases the TACT scores at 6 months had predictive value for the further TACT scores and in 78 % for the optotype acuity. There was no difference between eyes with normal posterior pole and eyes with ROP residua concerning the predictive value of non favourable optotype acuity. CONCLUSIONS: Testing grating acuity at 6 months corrected age allows to roughly predict both grating and recognition acuities at the age of 3 - 7 years. No difference between patients with normal posterior pole and patients with ROP residua was found.