Glaucoma Medical Treatment
Medical Treatment of Open-angle Glaucoma in 2011 Gábor Holló
Professor and Head, Glaucoma and Perimetry Unit, Department of Ophthalmology, Semmelweis University, Budapest
Abstract
Treatment possibilities for open-angle glaucoma have improved considerably in recent years. Fixed-dose combination eye drops and preservative-free preparations are used increasingly in routine clinical practice, and may reduce the frequency and severity of the medication-related ocular surface problems. Despite this progress, our knowledge of several aspects of the use of combined medication is suboptimal and in many cases treatment intensification or surgery is not introduced in time. To improve the quality of glaucoma care it is useful to review the problematic aspects of treatment.
Keywords
Open-angle glaucoma, glaucoma progression, glaucoma medical therapy, glaucoma combination therapy, benzalkonium chloride, ophthalmic preservatives, generic glaucoma medications
Disclosure: Gábor Holló is a consultant for Alcon, Allergan, MSD, Pfizer and Santen. Received: 12 August 2011 Accepted: 18 October 2011 Citation: European Ophthalmic Review, 2011;5(2):123–6 Correspondence: Gábor Holló, Department of Ophthalmology, Semmelweis University, Budapest, Hungary. E:
hg@szem1.sote.hu
Why Treat Open-angle Glaucoma?
The goal of glaucoma treatment is to prevent any further, glaucoma-related decline of visual functions (e.g., deterioration of the visual field) and not to keep intraocular pressure (IOP) under a certain artificial value (e.g., 21 mmHg).1–4
Thus, both an understanding
of the basics of the pathophysiology of glaucoma and the application of evidence-based clinical knowledge on glaucoma treatment are essential to set an appropriate individual treatment and to modify (strengthen) it when early, but established, disease progression (functional, structural or both) occurs. Therefore, no simple instruction on the treatment of the total glaucoma spectrum can be given. In this brief review, the most important new aspects of glaucoma treatment are summarised. However, they cannot be applied usefully without an appropriate basic science, diagnostic and pharmacology background, which is not included in the current review.
Diagnosis of Open-angle Glaucoma Although details of glaucoma diagnostics are not a part of this article, this is the first important step on the way to long-term treatment success.3,4
General Principles of Treatment
Currently, treatment of open-angle glaucoma is based on a sufficiently powerful decrease of IOP.1,4
Although several laboratory results and
some clinical studies are published on the potential benefits of increased ocular perfusion or neuroprotection in open-angle glaucoma, the number of evidence-based clinical trials on these is minimal in this field5
(e.g., primary, pseudoexfoliative and pigment) show considerably different clinical characteristics and IOP reduction under the same treatment, the general treatment principles are the same for all open-angle glaucomas.4
and no glaucoma medication is approved for an effect not related to IOP. Several herbal supplements have been tried as supportive therapy, but no benefits of these agents have been proved scientifically for glaucoma.1
Central cornea thickness (CCT) should not be used for mathematical correction of the measured tonometric IOP value, but the eyes should be divided into three groups:6
In those parts of the world where angle-closure glaucoma is not particularly common, ophthalmologists frequently miss the appropriate classification of the anterior chamber angle. As a consequence, many chronic, painless angle-closure glaucoma cases are misclassified as open-angle glaucoma eyes and are treated accordingly (ineffectively). Eyes with appositional angle closure or a high risk for angle closure need to be identified with van Herick’s technique and then gonioscopy. In such cases, preventive neodymium-doped yttrium–aluminium–garnet laser iridotomy should be made, and then the anatomical condition should be re-investigated. Only when occlusion of the anterior chamber angle is excluded can the case be considered as open-angle glaucoma and treated accordingly. Although the various types of open-angle glaucoma
© TOUCH BRIEFINGS 2011 • •
low CCT (true IOP is probably higher than the measured IOP and the risk for progression is increased);
average CCT (the measured IOP represents the true IOP); and • high CCT (true IOP is probably lower than the measured IOP value).
In ocular hypertension, when no structural and functional damage can be detected but IOP is clinically elevated significantly based on several repeated measurements, the goal of treatment is to reduce the increased IOP-related risk to the average risk level (i.e., the typical normal IOP range).4
The IOP-related risk should be assessed by diurnal
When functional and/or structural glaucomatous damage is verified, risk factors for open-angle glaucoma (verified glaucoma in closest blood relatives, race, age, myopia) need to be investigated.4
123
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76