Does Surgical Resection of Horizontal Extraocular Muscles Disrupt Ocular Proprioceptors?

Ala Paduca,1 Per O Lundmark,2 J Richard Bruenech2 1Ophthalmology Department, State University of Medicine and Pharmacy Nicolae Testemitanu, Chisinau, Republic of Moldova; 2Department of Optometry, Radiography and Lighting Design, Faculty of Health and Social Sciences, University of South-Eastern Norway, Kongsberg, NorwayCorrespondence: Ala Paduca, PhD Ophthalmology Department, State University of Medicine and Pharmacy Nicolae Testemitanu, bd Stefan cel Mare si Sfant 165, Chisinau, Republic of Moldova, Email ala.paduca@usmf.mdPurpose: It has been promoted that disturbance of ocular proprioception may play a role in the pathogenesis of concomitant strabismus and other types of oculomotor anomalies. The aim of the study was to obtain knowledge about how surgical foreshortening of the myotendinous region potentially affects the proprioceptors that resides in this area of the muscles and to test the hypothesis that avoiding disruption of ocular proprioceptors result in a more favorable long term postoperative result.Patients and Methods: The distal end of the lateral and medial rectus muscles from patients with manifest concomitant strabismus with a deviation of ≥ 15 prism diopters (PD) were collected during strabismus surgery and processed for light microscopy by standard histochemical techniques. Histological analysis served to differentiate between the tissue samples containing pure tendon, versus samples containing the myotendinous junction. Criteria for successful outcome was defined as a residual angle of deviation less than 10 PD. The binocular status of the patient was measured pre- and post-operatively at 6-months of follow-up.Results: Tissue samples from 43 patients (median age 19 years old, range 3– 58 years) were collected during surgery. Twenty-six of the samples contained pure tendon, while 17 contained muscle fibres. The evolution of the post-operative result revealed a moderate reduction in the residual angle of deviation in patient-samples containing pure tendon. In contrast, the residual angle ...