Glaucoma

Glaucoma

World Glaucoma Day, 6 March 2008: tackling the glaucoma pandemic

Chronic angle-closure with glaucomatous damage: Long-term clinical course in a north american population and comparison with an asian population

Glaucoma and Intravitreal Steroids

To estimate the effect of reducing intraocular pressure (IOP) on: (i) the incidence of primary open-angle glaucoma (POAG) in patients with ocular hypertension (OH), and (ii) the progression of glaucoma. A meta-analysis of relevant randomized controlled trials was conducted. A literature search was performed to identify trials with: a randomized comparison of IOP-lowering intervention versus placebo or no treatment; visual field loss or optic disc changes as outcome; and follow-up >6 months. A pooled relative risk (RR) was calculated by a random effects model. Risk reduction of glaucoma conversion per mmHg of IOP reduction was quantified in a meta-regression model. We identified nine OH and one POAG trials. A meta-analysis of OH trials gives a pooled RR of 0.61 [95% confidence interval (CI) 0.45-0.83]. A meta-regression shows a decrease of the RR of glaucoma conversion by 14% with each mmHg extra IOP reduction (P = 0.045). No meta-analysis of POAG trials was performed because only one study has been identified. There is sufficient evidence that OH therapy reduces the risk of conversion to glaucoma. This risk reduction increases with greater IOP reduction.

The Glaucoma Guidelines of the Swedish Ophthalmological Society

This Issue At A Glance

Reply.

Incidence of Glaucomatous Visual Field Loss: A Ten-Year Follow-up from the Rotterdam Study

© 2007 Scientific Communications International Limited Correspondence: Dr George Lambrou, Athens Institute of Ophthalmology, Agias Barbaras 61, Halandri 15231, Athens, Greece. Tel: (30 210) 722 2722; Fax: (30 210) 722 2747; E-mail: gnlambrou@hotmail.com, george@lambrou.eu We have all heard many times that “Glaucoma is the second most common treatable cause of blindness worldwide”. Glaucoma is a significant public health concern, being the leading cause of irreversible blindness and consistently ranking among the leading causes of blindness in virtually every nation. In developing countries, cataract is the leading cause of blindness. In developed countries, the leading cause of blindness is age-related macular degeneration (AMD). However, there is a fundamental difference between these 2 diseases and glaucoma; their high rank as causes of blindness is due to structural reasons that are hard to address (limited access to surgical infrastructure for cataract and lack of an effective preventive treatment for AMD), whereas in the case of glaucoma, the main reason is low awareness of the disease and its implications. Indeed, it is estimated that only 50% of those affected with glaucoma in developed nations are aware that they have the disease, while as many as 90% or more of people with glaucoma in underdeveloped countries are unaware of having the disease or have even heard of glaucoma. Despite our better understanding of risk factors for glaucoma, we have yet to see an improvement in these numbers. Worse, although glaucoma occurs in all age groups, it is more common in older adults, and with an ageing population, estimates of glaucoma prevalence are increasing. It has been predicted that by 2020, 79.6 million people worldwide will have glaucoma, 11.2 million of whom will be bilaterally blind, up from the current 4.5 million. Recent years have seen considerable progress in the diagnosis and treatment of glaucoma. Technological advances in optic nerve and retinal nerve fibre layer imaging and visual field testing make it possible to diagnose glaucoma at earlier stages, when treatment has a better prognosis. Medical treatment is available and effective for controlling glaucoma for most patients, while for those who have uncontrolled disease, laser and surgical interventions are often successful. Optic nerve and visual field damage are irreversible. As damage progresses gradually, often unnoticed by the patient, early detection and treatment are of paramount importance to prevent blindness. For individuals with known risk factors for glaucoma, particularly elevated intraocular pressure, increasing age, African descent, family history of glaucoma, vasospasm, low blood pressure, and high myopia, the importance of routine examinations cannot be understated. Also, despite strong evidence that lowering intraocular pressure can delay the onset and progression of glaucoma, reported rates of non-compliance with glaucoma therapy range from 5% to as high as 80%. This high variability results from different definitions for non-compliance and the way it is measured.

© 2007 Scientific Communications International Limited Correspondence: Dr George Lambrou, Athens Institute of Ophthalmology, Agias Barbaras 61, Halandri 15231, Athens, Greece. Tel: (30 210) 722 2722; Fax: (30 210) 722 2747; E-mail: gnlambrou@hotmail.com, george@lambrou.eu We have all heard many times that “Glaucoma is the second most common treatable cause of blindness worldwide”. Glaucoma is a significant public health concern, being the leading cause of irreversible blindness and consistently ranking among the leading causes of blindness in virtually every nation. In developing countries, cataract is the leading cause of blindness. In developed countries, the leading cause of blindness is age-related macular degeneration (AMD). However, there is a fundamental difference between these 2 diseases and glaucoma; their high rank as causes of blindness is due to structural reasons that are hard to address (limited access to surgical infrastructure for cataract and lack of an effective preventive treatment for AMD), whereas in the case of glaucoma, the main reason is low awareness of the disease and its implications. Indeed, it is estimated that only 50% of those affected with glaucoma in developed nations are aware that they have the disease, while as many as 90% or more of people with glaucoma in underdeveloped countries are unaware of having the disease or have even heard of glaucoma. Despite our better understanding of risk factors for glaucoma, we have yet to see an improvement in these numbers. Worse, although glaucoma occurs in all age groups, it is more common in older adults, and with an ageing population, estimates of glaucoma prevalence are increasing. It has been predicted that by 2020, 79.6 million people worldwide will have glaucoma, 11.2 million of whom will be bilaterally blind, up from the current 4.5 million. Recent years have seen considerable progress in the diagnosis and treatment of glaucoma. Technological advances in optic nerve and retinal nerve fibre layer imaging and visual field testing make it possible to diagnose glaucoma at earlier stages, when treatment has a better prognosis. Medical treatment is available and effective for controlling glaucoma for most patients, while for those who have uncontrolled disease, laser and surgical interventions are often successful. Optic nerve and visual field damage are irreversible. As damage progresses gradually, often unnoticed by the patient, early detection and treatment are of paramount importance to prevent blindness. For individuals with known risk factors for glaucoma, particularly elevated intraocular pressure, increasing age, African descent, family history of glaucoma, vasospasm, low blood pressure, and high myopia, the importance of routine examinations cannot be understated. Also, despite strong evidence that lowering intraocular pressure can delay the onset and progression of glaucoma, reported rates of non-compliance with glaucoma therapy range from 5% to as high as 80%. This high variability results from different definitions for non-compliance and the way it is measured.

Author reply

To verify whether there was a significant correlation between central corneal thickness (CCT) and visual field damage in patients with primary open angle glaucoma (POAG). A total of 99 eyes with POAG were consecutively recruited. Patients were classified as glaucomatous based on visual field and optic nerve head damage. All underwent applanation tonometry, Humphrey perimetry, and measurement of CCT with ultrasonic pachymetry. Based on CCT value, the sample was split at the mode in two groups (group 1<535 microm, n=49; group 2>or=535 microm, n=50). Entire cohort: mean CCT 554 microm+/-45.03; mean deviation (MD) -6.68 dB+/-7.32; pattern standard deviation (PSD) 5.33+/-3.75; intraocular pressure (IOP) 17.91+/-4.16 mmHg with treatment. Group 1: CCT was 504.8 microm+/-30.8; MD -9.01 dB+/-8.72; PSD 6.38+/-3.99; IOP 18.02 mmHg+/-4.66. Group 2: mean CCT 574.6 microm+/-35.03; MD -4.39 dB+/-4.70; PSD 4.25+/-3.19; IOP 17.79 mmHg+/-3.57. A significant difference was found between the two groups for both MD and PSD. Linear regression analysis showed a significant correlation between CCT and PSD (P<0.001). Our data show that patients with a thinner cornea had a worse MD and PSD. As a thinner CCT causes an underestimation of the true IOP, there may be a delay in the diagnosis of POAG or an inadequate estimate of the clinical course despite apparently desirable IOP applanation readings.

European Glaucoma Prevention Study

Intraocular pressure (IOP) elevation and post-keratoplasty glaucoma occur commonly after penetrating keratoplasty (PK), but also after Descemet stripping endothelial keratoplasty (DSEK). In this study, we evaluated the risk after Descemet membrane endothelial keratoplasty (DMEK) to develop IOP elevation and post-DMEK glaucoma. The 12-month incidence of IOP elevation and post-DMEK glaucoma was analyzed retrospectively in the first 117 consecutive eyes that underwent DMEK between September 2011 and December 2012 at the Universitätsmedizin-Charité, Berlin. IOP elevation was defined as IOP ≥ 22 mmHg, or ≥10 mmHg from preoperative baseline. The assessment included the pre-operative history of corneal disease and glaucoma. Furthermore, the response to anti-glaucoma treatment, the graft failure, the IOP, the visual acuity, and the endothelial cell count were evaluated. The 12-month incidence of IOP elevation was 12.10 % [95 % confidence interval (CI): 0.94 %, 18.37 %], post-DMEK glaucoma 2.7 % (95 % CI: -0.44 %, 5.84 %). The most frequent cause remained steroid-induced IOP elevation, with an 12-month incidence of 8.0 % (95 % CI: 7.95 %, 8.05 %). In all cases, IOP elevation was treated effectively by tapering down steroid medication and initiating or increasing anti-glaucoma medication. The incidence of postoperative postoperative pupillary block IOP elevation was 15.40 % (95 % CI: 8.93 %, 21.87 %). The number of eyes with iridocorneal contacts after surgery was low (4.2 %). Only the preoperative increased IOP is a significant risk factor for IOP elevation (p = 0.005). Visual acuity improved significantly after surgery (p < 0.001), and clear grafts were achieved in all eyes. Mean endothelial cell count did not differ between patients with and without IOP elevation. Incidence of IOP elevation and post-keratoplasty glaucoma after DMEK were low, but regular IOP measurements, especially in eyes with pre-existing glaucoma and bullous keratopathy, are necessary. Steroid-induced IOP elevation was the most frequent reason, and could be treated effectively by tapering down steroid medication or changing the steroid drug. Development of peripheral anterior synechiae after DMEK occured rarely. Therefore, the risk for IOP elevation and especially post-DMEK keratoplasty was reduced compared to PK and DSEK. In all cases, successful management by medical treatment was possible, and resulted in good visual acuity.