MOTILITY AND BINOCULAR FUNCTION AFTER RAD IAL EPISCLERAL BUCKLE FOR RETINAL-DETACHMENT

Background The incidence of motility disturbances induced by episklera l buckle operations for retinal detachment has been reported to range between 7 and 77%. We anticipated a relation between the buckle size a nd the incidence and extent of motility disturbances. Patients and met hods We examined 45 patients 2 to 4 years after successful retinal det achment surgery with a radial buckle. The buckle diameter was 3-11 mm. Patients were examined for diplopia and heterophoria in the primary p osition and in 20 degrees secondary and tertiary gaze deviations. Ster eopsis was determined using the TNO plates. Refractive error and visua l acuity were also measured. Results Heterophoria measurements in the various directions of gaze revealed a hypermotility in 22/45 cases. A hypomotility was encountered only in one of the 45 cases. In 40 of the 45 cases the field of binocular single vision had a radius of at leas t 20 degrees. 39 of the 45 patients had stereopsis (after macular deta chment 17/22, without macular detachment 22/23). 7/32 patients with a buckle of greater than or equal to 5 mm reported on diplopia, but none of the 13 patients with a buckle of less than or equal to 4 mm. Heter otropia in the primary position was found in one of the 45 cases. He h ad three buckles, a 10.5 mm buckle under the superior rectus muscle of one eye and a 4 and 7.5 mm buckle under the inferior oblique and rect us muscles of the other eye. The resulting vertical deviation was succ esfully treated with prisms. Motility disturbances in the upper field of gaze were found in 2 of 45 cases with buckles of 5 and 7.5 mm. Dipl opia was not permanent in these cases. Discussion Hypermotility toward s the position of the buckle may be explained by a deviation of the ad jacent rectus muscles, after sharp preparation and shrinkage of the in termuscular septum. Conclusion Since motility disturbances were encoun tered only with buckles of greater than or equal to 5 mm, small buckle s (less than or equal to 4 mm) should be applied whenever possible.