Tip of the Month
Publishing date: March 2017
The Science behind the Tip
We were taught that visual field loss from glaucoma is irreversible and that our interventions could at best, preserve the remaining vision.
However, recent studies have revealed that visual field improvement may occur in the short-term after trabeculectomy (1,2). In addition, a study investigating visual field changes by pointwise linear regression analysis in patients who had undergone trabeculectomy, has shown that 30% of the points in the visual field that were tested had improved five years after surgical intervention (3). These results need to be interpreted with caution, as the patients studied had moderately advanced glaucoma (average MD - 7.2dB.)
This finding is supported by previous studies of optic disc morphology after trabeculectomy that have shown reversibility of structural parameters. This is well recognised in children with congenital glaucoma, but also has been shown in adults (average MD - 9.49 dB) (4).
Contributor: Alain M Bron - France
1) Wright TM, Goharian I, Gardiner SK et al. Short-term enhancement of visual field sensitivity in glaucomatous eyes following surgical intraocular pressure reduction. Am J Ophthalmol 2015; 159:378-85.
2) Musch DC, Gillespie BW, Palmberg PF et al. Visual field improvement in the Collaborative Initial Glaucoma Treatment Study. Am J Opthalmol 2014; 158: 96-104.
3) Caprioli J, de Leon JM, Azarbod P et al Trabeculectomy can improve long-term visual function in glaucoma. Ophthalmology 2016; 123: 117-28.
4) Kotecha A, Siriwardena D, Fitzke FW et al Optic disc changes following trabeculectomy : longitudinal and localisation of change. Br J Opthalmol 2001; 85: 956-61.
Tip Reviewer: Roger Hitchings
Tip Editors: John Salmon and Gordana Sunaric Mégevand