Augmented surgical amounts for intermittent exotropia to prevent recurrence
We read with interest article by Arda, et al. We put forth following observations:
- The study did not mention about detail age subgroup. How many children were below 4 years age? Indication of surgery in the patients below 4 years of age? Is there any amblyopia or fusion loss with augmented surgical amounts in X (T) in this age?
There is a controversy about surgical management in X (T) in children <4 years because these children have intermittent fusion and excellent stereopsis. Previous studies advocated early surgery to prevent the development of sensory changes. However, they do caution in visually immature children a slight under correction should be attempted to prevent the occurrence of monofixation syndrome from consecutive esotropia. A study comparing surgery performed at various ages showed a significant increase in amblyopia, loss of stereopsis when a consecutive esotropia occurred in children under 4 years of age. Also reoperation rates, risk of developing amblyopia and loss of fusion were, greater in younger age group. Thus, it is believed that surgery in this age group is reserved in whom rapid loss of control is documented.
- In one case of consecutive esotropia, the study had not mentioned the age of the patient. Was it <4 years of age?
- In this study, all cases of X (T) (10–45 PD) were managed surgically. Not all intermittent exotropia are progressive. In some cases, the deviation may remain stable for many years, and in few cases, it may even improve. In a series of 48 patients (6–22 years) with unoperated X (T) observed for average 11.7 years, 65% show improvement, the majority of the patients were with deviations <20 PD. Von Noorden found of 51 untreated patients (5–10 years), 75% showed progression, 9% did not change and 16% improved without therapy, on average follow-up period of 3.5 years. Was there any role of observation in some patients they had included (<20 PD)? Unless there is a definitive evidence of existing defective binocular vision, deterioration of control of X (T), surgery should be precede by several months of observation. Were such criteria followed?
- Visual acuity details, refractive error and amblyopia were not mentioned in this study, as variability in subnormal vision can affect the stereo acuity and motor fusion
- In three cases of recurrence exotropia, what was initial surgical amount of LR recession? Was the exotropia for near or for distance?
1. Arda H, Atalay HT, Orge FH. Augmented surgical amounts for intermittent exotropia to prevent recurrence Indian J Ophthalmol. 2014;62:1056–9
2. Raab EC. Management of intermittent exotropia: For surgery Am Orthopt J. 1998;48:25–9
3. Edelman PM, Murphree AL, Brown MH, Wright KW. Consecutive esodeviation. Then what? Am Orthopt J. 1988;38:111–6
4. Hiles DA, Davies GT, Costenbader FD. Long-term observations on unoperated intermittent exotropia Arch Ophthalmol. 1968;80:436–42
© 2015 Indian Journal of Ophthalmology | Published by Wolters Kluwer – Medknow
5. Von Noorden GK. Exodeviations Binocular Vision and Ocular Motility. 19966th ed United States of America Mosby:359