We read with interest the article by Kekunnaya et al. The authors have conducted an interesting retrospective study and emphasized the importance of cycloplegic refraction prior to surgical management of Duane retraction syndrome (DRS) in patients with high hypermetropia. We would like to make following comments regarding their article.
Cycloplegic refraction should be the primary step in the management of all patients presenting with ocular deviation. It would be disastrous to subject any child to surgery without adequate refractive correction being prescribed for an appropriate duration.
The primary cause of compensatory head posture (CHP) in DRS is limited ocular motility, with the patient adopting a posture to utilize the small field of binocular vision. The authors have not explained how elimination of head posture/torticollis occurs with spectacles. We try to explain this observation. Some children with DRS are initially able to enjoy binocular single vision (BSV) without CHP, despite motility restriction and palpebral fissure abnormality. When (later in life) the accommodative convergence induces an ocular deviation, these children probably compensate for it by adapting a CHP, which due to asymmetrical ocular motility allows them comfortable BSV. Elimination of this deviation by suitable refractive correction corrected the torticollis in these patients, probably with re-centralization of the binocular field. It is interesting to note that non-DRS patients with accommodative esodeviation cannot similarly use compensatory head posture to their advantage for BSV.
In the 2nd case of Table 1, it would be interesting to know the magnitude and age at which refractive correction was prescribed. It is surprising that this child did not develop amblyopia. It would also be more informative if the authors commented about the eventual binocular status rather than simple visual acuity. Binocular functions in patients of DRS have also been controversial, and if the authors have this information about their patients, it would be a useful contribution to literature.
When surgical treatment is being considered, it should also be understood that angle measurements in these children are difficult and often their accuracy is doubtful. Sometimes the diagnosis is also not certain. We would suggest a staged approach for their management with only medial rectus recession with or without posterior fixation being the first step. This may be combined with graded recession of ipsilateral lateral rectus if palpebral fissure abnormality is marked. 2 This would reduce the torticollis and palpebral fissure abnormality and also ensure better binocular development. More aggressive modalities like vertical rectus transposition should be taken up later in life when the measurements and results would be more predictable. The consecutive exotropia in the 2nd and 4th patient could thus be avoided.
1. Kekunnaya R, Velez FG, Pineles SL. Outcomes in patients with esotropic duane retraction syndrome and a partially accommodative component Indian J Ophthalmol. 2013;61:701–4
2. von Noorden GK, Campos ECvon Noorden GK, Campos EC. Special Forms of Strabismus Binocular Vision and Ocular Motility. 19906th ed St. Louis Mosby:459–65
3. Agrawal S, Singh V, Agrawal S. Congenital sixth nerve palsy or Type I Duane syndrome? Oman J Ophthalmol. 2011;4:92–4