Primary open angle glaucoma: an overview on medical therapy
Introduction
Glaucoma is nowadays defined as a progressive optic neuropathy (Gupta and Weinreb, 1997) with a typical associated visual field loss, and it is one of the leading causes of preventable blindness in developed countries.
It is estimated that glaucoma approximately causes the 10% of all blindness (Quigley, 1996).
Since life expectancy is increasing, all the efforts need to be focused on maintaining the quality of patient's life, and alleviating the social and economic burden of glaucoma.
Glaucoma treatment has been available for more than a century. Nevertheless, due to the unproven efficacy of glaucoma therapy and also to the additional treatment modalities, which have expanded the available options, there is a considerable controversy within the glaucoma researchers community concerning how the open angle glaucoma should be treated, and, particularly, which weapons should be employed.
Glaucoma prevention consists in identifying the risk factors associated with the optic neuropathy and attempting to treat those factors for which a therapy exists. For decades intraocular pressure (IOP) has been considered the only risk factor associated with glaucoma and for this reason the goal of many therapeutic options is to treat it. Having the researchers recognized the existence of other treatable risk factors, new therapeutic options should include blood flow, neuroprotection, and genetically based agents.
This work aims to provide an overview on the medical treatment, especially referring to three matters:
- •
When to treat
- •
Whom to treat
- •
How to treat
Section snippets
When to treat
This is the first step in glaucoma treatment, and this item is directly linked to the current opinions about the early glaucoma diagnosis or high-risk ocular hypertension.
Affirmed that, since glaucoma is a slowly progressing disease, someone believes that an early diagnosis and a consequently early treatment may not be essential.
A definition of early glaucoma is needed, in order to guide physicians in their diagnostic and therapeutical decisions. Early glaucoma is a silent condition, without
Whom to treat
In prescribing initial medical therapy for glaucoma or ocular hypertension, a number of factors have to be considered. It was thought that treatment should begin if it is deemed necessary to preserve the quality of life, but that initiation should be considered on an individual base. According to this, discovering and treating people at risk of visual function's loss with an individualized management is preferable.
As recommended in the OHTS (Caprioli and Garway-Heath, 2007), not all
How to treat
A medical treatment is considered effective when the mean effect produced by that drug is similar to published average effect on general population and this effect should be higher than the ones found by tonometry, that are affected by errors and variations (EGS, 2003).
IOP lowering is the most effective therapeutical approach to avoid function loss, because a high IOP is the main risk factor for glaucomatous damage onset. Normal IOP level is a statistical outcome, based on population
Fixed combinations
In glaucoma therapy, we know that both doctors and patients overestimate the adherence and that doctors are poor judges of who is and who is not compliant.
When adding a second drug, a physicians need to consider the possible impact on the patient's adherence to the first drug. The treatment's adherence seems to be of a 75% maximum in most of the studies. With the addition of another therapy, irrespective of the size, frequency of administration, and type of adjunctive therapy medication, the
References (22)
- et al.
Beta-blocker eyedrops and nocturnal arterial hypotension
Am. J. Ophthalmol.
(1999) - et al.
Changing paradigms in the medical treatment of glaucoma
Surv. Ophthalmol.
(2002) - et al.
The safety and efficacy of travoprost 0.004%/timolol 0.5% fixed combination ophthalmic solution
Am. J. Ophthalmol.
(2005) - et al.
A critical reevaluation of current glaucoma management
Ophthalmology
(2007) - European Glaucoma Society (2003). Terminology and guidelines for glaucoma, 2nd edn., Dogma Ed, Savona,...
- et al.
Fixed combination of topical glaucoma medications
Curr. Opin. Ophthalmol.
(2004) 12-week study comparing the fixed combination of brimonidine and timolol with concomitant use of the individual components in patients with glaucoma and ocular hypertension
Eur. J. Ophthalmol.
(2005)- et al.
New definitions of glaucoma
Curr. Opin. Ophthalmol.
(1997) - et al.
Reduction of intraocular pressure and glaucoma progression : results from the Early Manifest Glaucoma Trial
Arch. Ophthalmol.
(2002) A double masked, randomized, parallel comparison of a fixed combination of bimatoprost 0.03%/timolol 0.5% with non-fixed combination use in patients with glaucoma or ocular hypertension
Eur. J. Ophthalmol.
(2007)
A three-month, multicenter, double-masked, study of the safety and efficacy of travoprost 0.004%/timolol 0.5% ophthalmic solution compared to travoprost 0.004% ophthalmic solution and timolol 0.5% dosed concomitantly in subjects with open-angle glaucoma or ocular hypertension
J. Glaucoma
Cited by (5)
Dietary Polyunsaturated Fatty Acids, Intraocular Pressure, and Glaucoma
2014, Handbook of Nutrition, Diet and the EyePrescribing pattern and adverse events of drugs used in patients with primary open-angle glaucoma (POAG) attending a tertiary care hospital: Retrospective study
2017, National Journal of Physiology, Pharmacy and PharmacologyPrimary open-angle glaucoma: Clinical update
2011, Journal of Gerontological NursingIntraocular pressure-lowering effect of auricular acupressure in patients with glaucoma: A prospective, single-blinded, randomized controlled trial
2010, Journal of Alternative and Complementary Medicine