PURPOSE: To investigate the serial changes of accommodation and spherical aberration in eyes with accommodative spasm. METHODS: Four patients with accommodative spasm and ten healthy subjects were studied. The ocular refractive power (spherical equivalent) and spherical aberration were measured serially with an open-field, binocular Hartmann-Shack wavefront aberrometer. Patients and subjects wore full-correction lenses and were instructed to fixate a target set at 50 cm from the eye. The time-average of the refractive power, spherical aberration, and fluctuations of accommodation analyzed by the fast Fourier transform (FFT) of the two groups were compared. RESULTS: The average ± standard deviation refractive power in the patients was significantly more negative than that in the healthy subject (-3.12 ± 1.06 vs. -1.49 ± 0.17 D). The integrated intensity of the FFT from 1 to 4 Hz was significantly higher in the patients than in the healthy subjects. The spherical aberration in patients was more negative than that in the healthy subjects (-0.033 ± 0.048 μm vs. 0.002 ± 0.027 μm). CONCLUSIONS: Eyes with accommodative spasm are characterized by a lead of accommodation with greater fluctuations and negative spherical aberrations. Excessive accommodation can be measured objectively in such eyes with a binocular wavefront aberrometer without cycloplegics.
PURPOSE: To investigate the serial changes of accommodation and spherical aberration in eyes with accommodative spasm. METHODS: Four patients with accommodative spasm and ten healthy subjects were studied. The ocular refractive power (spherical equivalent) and spherical aberration were measured serially with an open-field, binocular Hartmann-Shack wavefront aberrometer. Patients and subjects wore full-correction lenses and were instructed to fixate a target set at 50 cm from the eye. The time-average of the refractive power, spherical aberration, and fluctuations of accommodation analyzed by the fast Fourier transform (FFT) of the two groups were compared. RESULTS: The average ± standard deviation refractive power in the patients was significantly more negative than that in the healthy subject (-3.12 ± 1.06 vs. -1.49 ± 0.17 D). The integrated intensity of the FFT from 1 to 4 Hz was significantly higher in the patients than in the healthy subjects. The spherical aberration in patients was more negative than that in the healthy subjects (-0.033 ± 0.048 μm vs. 0.002 ± 0.027 μm). CONCLUSIONS: Eyes with accommodative spasm are characterized by a lead of accommodation with greater fluctuations and negative spherical aberrations. Excessive accommodation can be measured objectively in such eyes with a binocular wavefront aberrometer without cycloplegics.