Sir,
We thank Shah et al1 for their interest in the Portsmouth Glaucoma Refinement Scheme.2 The scheme also uses Van Herick grading for anterior chamber depth—all patients with a Van Herick peripheral limbal anterior chamber depth of less than 25% of corneal thickness were referred to the virtual clinic for assessment by an ophthalmologist. Approximately 10% of all of those accepted from the Refinement Scheme virtual clinic to HES (from a total of 11 out of 100 referred to the virtual clinic, from our audit) were due to narrow angles suspected through Van Herick grading. Of these, 25% subsequently required laser peripheral iridotomy, slightly higher than the 17% positive predictive value, for the suggestion of occludable angles by an initial Van Herick test, outlined by Foster.3
The authors declare no conflict of interest.
References
- Shah B, Campbell P, Ford C, Goyal S, Lim KS. Re: The Portsmouth-based refinement scheme: a role for virtual clinics in the future. Eye. 2013;27 (7:892–893. doi: 10.1038/eye.2013.67. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Trikha S, Macgregor C, Jeffery M, Kirwan J. The Portsmouth-based refinement scheme: a role for virtual clinics in the future. Eye. 2012;26:1288–1294. doi: 10.1038/eye.2012.120. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foster P. Advances in the understanding of primary angle-closure as a cause of glaucomatous optic neuropathy. Commun Eye Health. 2001;14 (39:37–39. [PMC free article] [PubMed] [Google Scholar]