Objective measurement of tonic and dynamic accommodative behavior in Duane retraction syndrome

To compare accommodative function and ocular biometric parameters between patients with Duane retraction syndrome (DRS) and healthy controls.

In this age- and sex-matched case-control study, 44 eyes of 30 DRS patients and 78 eyes of 39 healthy controls underwent comprehensive evaluation. Accommodative amplitude (AA) and pupil dynamics (ΔPD with accommodation) were assessed using the Tonoref III (Nidek), with three consecutive measurements. Biometric parameters (axial length [AL], lens thickness [LT], anterior chamber depth [ACD], central corneal thickness [CCT]) were measured using the Lenstar 900 (Haag-Streit).

Patients and controls were comparable in age (P = 0.305), CCT (P = 0.347), ACD (P = 0.597), LT (P = 0.297), and sex distribution (P = 0.709). DRS patients exhibited more hyperopia (mean spherical equivalent refraction -0.02 ± 1 D vs -0.63 ± 1.1 D [P = 0.019]) and shorter AL (22.57 ± 0.8 mm vs 23.1 ± 1 mm [P = 0.010]). AA showed no intergroup differences (P = 0.393), but DRS patients had a more hyperopic refractive state than controls at both the point of minimum accommodation (0.86 ± 1.2 D vs 0.06 ± 1.4 D [P = 0.006]) and the point of maximum accommodation (-1.8 ± 2.4 D vs -3 ± 2.7 D [P = 0.024]). Pupil parameters (minimum and maximum PD, ΔPD) were similar between groups (P > 0.05).

DRS patients demonstrate similar accommodative amplitude to control patients, although in our patient sample they tended to be more hyperopic than age-matched patients presenting for refractive assessment, and to adopt more hyperopic refractive states during assessment of accommodative performance.