DEC 02, 2014
Glaucoma, Pediatric Ophth/Strabismus
This retrospective study found that cupping reversal in pediatric glaucoma may not predict improved optic nerve head health and deserves further investigation.
The authors investigated optic nerve head (ONH) cupping reversal and associated OCT and Humphrey visual field changes in 28 children who achieve sustained, substantial IOP reduction after glaucoma surgery for juvenile open-angle or primary congenital glaucoma.
ONH cupping reversal was common, occurring in more than half of the patients. While most eyes with OCT imaging of the RNFL both before and after IOP reduction demonstrated stable average peripapillary RNFL, a minority showed continued RNFL loss whether or not ONH cupping reversal occurred. In addition, in a small subset of the eyes that did show cupping reversal after surgery, the postoperative “healthy” appearance of the ONH belied a low RNFL revealed by OCT imaging.
They write that these results suggest ONH cupping before treatment in pediatric glaucoma is attributable to true nerve fiber layer axonal damage rather than simply a change in the optic nerve compliance. This lends further evidence to support the theory of glial tissue proliferation as the pathophysiology behind improved appearance in ONH cupping after a substantial decrease in IOP.
However, reversal of cupping may still be partially explained by the compliance of the lamina cribrosa in infants and young children, but the new rim tissue that develops and appears to “reverse the cup” seems unlikely, at least in some cases, to be the return of truly healthy, functional tissue.
They conclude that these findings lend further support to the complexity of assessing optic nerve health in pediatric glaucoma by its clinical appearance alone. Newer imaging technologies, such as handheld supine SD-OCT, and additional study will shed further light on the phenomenon of optic nerve cupping reversal and ultimately improve the understanding of overall vision preservation in pediatric glaucoma.