Welcome to question of the day #29

Eyetools question of the day #29

Microtropia is a fully adapted strabismus and does not give rise to symptoms unless other conditions have been superimposed. Patients tend to present late when reduced vision is detected at a school check.

Management consists, initially, of correcting the refractive error. This is particularly important if the patient is under 5 years of age and has anisometropia. Vision therapy for microtropia is very seldom successful, although it is possible to treat the amblyopia and eccentric fixation in the usual way.

Full refractive correction and total full-time occlusion of the fixing eye for children under 5 years old, may result in total resolution of the deviation and complete restoration of normal visual acuity and gross stereopsis. For patients older than eight, the hyperopic prescription can be reduced and deep anomalous correspondence will maintain a small angle.

Ill-health in older children (5 to 10 years) may cause the microtropia to break down into a larger deviation, or if monofixational heterophoria is decompensated and giving rise to symptoms, orthoptic treatment for these conditions may be appropriate to restore the microtropia to its compensated and fully adapted state.

Microtropic patients can also have inadequate vergence and accommodative skills for their visual requirements at school or work. Prisms and added lenses do not seem to help for these symptomatic patients, possibly due to prism adaptation. Vision therapy in these cases can be successful.