When choosing a glaucoma operation, be guided by the target intra-ocular pressure (IOP)

In recent years, we have seen a vast expansion of incisional surgical techniques for glaucoma with a wide range of long-term efficacy and safety profiles. The EGS guidelines recommend surgery as soon as medical or laser treatment is deemed unlikely to maintain sight in the glaucomatous eye.

To help us select the best operation for a patient, we need to decide which operation is most likely to achieve the target IOP for that patient. This is the IOP that will slow the rate of visual field deterioration sufficient to maintain the patient’s quality of life (1). The more advanced the glaucoma, the longer the life expectancy, the lower the untreated IOP and the faster the progression; the lower the target IOP should be (2). In these scenarios, target IOP should be as low as 10-12mmHg (3). In experienced hands and in the absence of risk factors for scarring (e.g., previous surgery or ischaemia), trabeculectomy with mitomycin C remains the most likely procedure to achieve these low target pressures (4).

Contributor: Andrew Scott MD FRCOphth MRCSEd FEBO PhD – Moorfields Eye Hospital, United Kingdom

References
1. Sihota R, Angmo D, Ramaswamy D, Dada T. Simplifying target intraocular pressure for different stages of primary open-angle glaucoma and primary angle-closure glaucoma. Indian J Ophthalmol. 2018;66(4):495-505. doi:10.4103/ijo.IJO113017
2. EGS Guidelines, 5th Edition. Fig II.3.2
3. Palmberg P. Evidence-based target pressures: How to choose and achieve them Int Ophthalmol Clin. 2004;44:1–4
4. King AJ, Hudson J, Fernie G, et al. Primary trabeculectomy for advanced glaucoma: pragmatic multicentre randomised controlled trial (TAGS) correction appears in BMJ. 2021 May 25;373:n1337 correction appears in BMJ. 2021 Jun 16;373:n1510. BMJ. 2021;373:n1014. Published 2021 May 12. doi:10.1136/bmj.n1014

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