Article can be accessed here
Reflections by: Jay South
Date: Oct 2023
I chose this article for journal club as I had an interesting and long discussion with some of the optometrists recently about the management and treatment of intermittent distance Exos.
As we know it is the most common form of strabismus and the control of the manifest phase can vary throughout the day. The etiology is largely unknown in otherwise neurologically and systemically disease free children and the natural history is not fully understood. From a prospective observational study of 183 children between 3-10 years old by PEDIG we know that the probability of deterioration at 3 years was only 15% which was similar to the retrospective findings of Romanchuk et al, 2006 (JAAPOS). The retrospective study found the angle of strabismus remained stable in 58% of patients aged 5-25 years (19% improved and 23% worsened). Observation is an acceptable method of treatment in patients who have good near control and are not concerned about cosmesis
For patients that are not keen on surgery the options available are:
- Observation
- Part-time patching
- Prisms
- Minus lenses
- Exercises
PEDIG and others have conducted RCTs on the first 4 methods with varying success and no optimal method of treatment. We talked through the prisms, minus lens and vision therapies but they hadn’t considered part-time occlusion and asked why it wasn’t used more as a non-surgical option.
Part time patching is thought to improve the control by eliminating suppression and inducing diplopia thus stimulating motor fusion and preserving binocularity. This in turn reduces the frequency and magnitude of the exodeviation. This paper describes observation versus 6 months of 3 hours daily of patching either one eye or alternating eyes in children aged 3 to 10 years of age.
Advantages of occlusion for IXT
- Reduces risk of deterioration by 5%
- Low cost
- Low risk of harm
Disadvantages of occlusion for IXT
- Having to wear a patch and the psychosocial problems of patching
- Practical challenges of occlusion in pre-school and school aged children
- Additional supervision
- Low gain from treatment
Reflective practice
Like the RCT’s on over minus lens therapy and base in prisms, part-time occlusion did not have a significant effect on the control of IXT versus observation. I used to think that exercises made a small difference in those that were motivated but due to follow up times and poor compliance and limited success I stopped prescribing exercises. Currently I opt to monitor children until there is a deterioration in their binocular function or deviation. Surgery is discussed on deterioration as currently there are no RCT’s that show exercises or ‘vision therapy’ make any difference. Having reviewed the papers on the other methods of treatment for IXT there isn’t strong evidence to suggest a change to my practice.
I would be interested to hear if anyone else does more.
One response to “Comparing part-time patching verses obervation for children with IXT: Oct 2023”
I agree Jay, this is very similar to my findings.
I now discuss with families and use the generalisation 1/3 stable, 1/3 with improve and 1/3 progress and will require surgery. This seems to make it easier for them to understand why we are happy to review. I also do not prescribe over minus lens therapy and base in prisms, part-time occlusion. I make one proviso though if clinically I feel they are stable but family feel progressing and pushing surgery I have suggested do part-time occlusion during ‘bad’ control periods and often this allows us to keep monitoringor longer and not rush early surgery.
Thanks Sally-Anne (Sally)