26 October 2012

Stickler Disease Prophylaxis that Worked

The day I first drafted this post about 2 years ago, I had examined a 12 year old with very likely Stickler Disease.  No genetic testing was ever performed, since it costs $3000 and they have public aid.  The Father had bilateral RDs and is blind  The son arrived with a ugly RD that had failed and I reattached with poor vision.  The contralateral eye I did nice laser 5-8 rows 360 degrees and a few months later there was a new tremendous vitreous floater.  Since the lad will not allow me to measure his pressure in the office I did an EUA.  I found a giant retinal tear anterior to the laser.  The vision is excellent and the retina securely attached.

The previous month another patient was examined by a colleague EUA and he found a retinal break without detachment in the eye with prophylaxis he added laser.

The vitreous is very abnormal and its separation causes retinal breaks.

Prophylaxis seems to work in my experience.  However, I hear reports of frequent failures and these are my hypotheses:

  1. The prophylaxis is not targeted correctly to the pathology.  For example, it encircle the lattice but not the vitreous base.   In stickler disease the major pathology is giant retinal tear and not lattice associated breaks.  The lattice can be quite anomalous (termed perivascular).  The perivascular lattice may not even carry the increased risk for RD of typical circumferential lattice.  Attention to the vitreous base and periphery is the most likely correct targets for the stickler prophylaxis
  2. The prophylaxis is the wrong pattern. Perhaps it is performed using a contact lens and slit-lamp rather than an indirect delivery
Now when I say prophylaxis works, I mean it reduces the rate of RD from around 50% to around 10 %.  I have 2 failures in about 75 patients which is lower, but really you need survival curve data.  In the past, I did scleral buckle and cryotherapy.  However, when I describe the difference in relative pain most will opt for laser treatment.

A common side effect of the laser is extended dilation and loss of accommodation because of treatment of the long post cillary nerve,  it has always improved.  I recently did cryothrapy treatment along the horizontal and laser elsewhere, but it made little difference.

Clearly, if your surgeon has had no experience or poor experience (bad outcomes) with Stickler Prophylaxis then it may not be the way to go and frequent exams may be better.  In young kids who may not complain parents should test the vision of each eye on a monthly basis.  When a detachment occurs more decisions are required.  Scleral Buckle, Vitrectomy or both, etc.  If virectomy is done the special attention needs to be given the anomalous vitreous.

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