Prevalence Of Normal Tension Glaucoma Research Articles

Prevalence of Normal-Tension Glaucoma in Patients With Primary Aldosteronism

PurposeTo investigate patients with primary aldosteronism (PA) and the prevalence of normal-tension glaucoma (NTG). DesignCross-sectional study. MethodsNewly diagnosed PA patients were evaluated in this cross-sectional study, with ophthalmic examinations such as intraocular pressure (IOP) measurements by a Goldmann applanation tonometer, central corneal thickness (CCT), slit-lamp biomicroscopic examination, gonioscopy, ophthalmoscopy, fundus photography, visual field test with a Humphrey Field Analyzer 24-2 SITA Standard program, and optical coherence tomography (OCT) of the peripapillary retinal nerve fiber layer (RNFL), performed in each of the subjects. Optic disc appearance, perimetric results, OCT results, and other ocular findings were all used for determining the glaucoma diagnosis. The primary outcome was shown the prevalence of NTG in patients with PA. ResultsNTG prevalence in the 212 PA patients was 11.8% (95% confidence interval [CI], 4.7%-20.7%). As compared to the hypertensive patients without PA, the hypertensive patients with PA exhibited a significantly increased NTG prevalence (odds ratio; 4.019, 95% CI, 1.223-13.205; P = .022). Increased NTG prevalence was associated with age, ranging from 8.8% (95% CI, 2.1%-15.6%) for those aged 40 to 49 years, to 37.5% (95% CI, 13.8%-61.2%) for those aged 70 years and older. In 72 hypertensive patients without PA, who were used as the controls, NTG prevalence was 5.2%, with a 95% CI ranging from 0.5% to 14.4%. ConclusionsThere was an 11.8% prevalence of NTG in PA patients, with these patients at an elevated risk of NTG, which was not mediated by blood pressure.

Asian Race and Primary Open-Angle Glaucoma: Where Do We Stand?

Primary open-angle glaucoma (POAG) is an optic neuropathy characterized by irreversible retinal ganglion cell damage and visual field loss. The global POAG prevalence is estimated to be 3.05%, and near term is expected to significantly rise, especially within aging Asian populations. Primary angle-closure glaucoma disproportionately affects Asians, with up to four times greater prevalence of normal-tension glaucoma reported compared with high-tension glaucoma. Estimates for overall POAG prevalence in Asian populations vary, with Chinese and Indian populations representing the majority of future cases. Structural characteristics associated with glaucoma progression including the optic nerve head, retina, and cornea are distinct in Asians, serving as intermediates between African and European descent populations. Patterns in IOP suggest some similarities between races, with a significant inverse relationship between age and IOP only in Asian populations. Genetic differences have been suggested to play a role in these differences, however, a clear genetic pattern is yet to be established. POAG pathogenesis differs between Asians and other ethnicities, and it may differ within the broad classification of the Asian race. Greater awareness and further research are needed to improve treatment plans and outcomes for the increasingly high prevalence of normal tension glaucoma within aging Asian populations.

Prevalence of Normal Tension Glaucoma (NTG) in Peshawar

Aim: Prevalence of Open angle glaucoma with normal intraocular pressure in Peshawar Methodology: It is a cross sectional study. It is done at Physiology Department, Khyber Medical College, Peshawar in collaboration with Ophthalmology deptt. Khyber Teaching Hospital, Peshawar Study period: six months Sample size: 394 cases attended the department of Ophthalmology, Khyber Teaching Hospital Peshawar. Out of 394 patients, 100 patients were included in this study. Results: There were 33(33%) males and 67(67%) females in the study. There were 27(27%) patients lying in the age range of 35-45 years, 46(46%) were in 46-55 years and 27 (27%) patients of 56-65 years. The mean age of patients was 51.21±8.12. All patients were with normal tension glaucoma. There were 29(29%) cases who had a positive family history of glaucoma. The “mean IOP” of the eye on the right side was 17.15±1.78mmHg and the “mean IOP” of the eye on the left side was 17.30±1.94mmHg. Conclusion: Prevalence of normal tension glaucoma (NTG) was 25.4% in Peshawar and its surroundings. Most of the patients were elderly females and 29 (29%) cases had a positive family history of glaucoma. Keywords: Open angle glaucoma, normal tension glaucoma, prevalence

Prevalence of Open Angle Glaucoma in Patients with Obstructive Sleep Apnea

Background: obstructive sleep apnea seems to have multi-organ harmful effects. Its association with glaucoma was previously reported. However, the debate exists around prevalence of glaucoma and the pathophysiology explains its association with obstructive sleep apnea is not fully known. Objective: the present study was designed to estimate the incidence of normal tension glaucoma among patients with obstructive sleep apnea. Patients and Methods: sixty patients with obstructive sleep apnea and another age and sex matched 60controls were included. Five patients in the study group refused to complete the study and only 55 patients constitute the study group.Allparticipants underwent polysomnographic and ophthalmologic (measurement of intraocular pressure and fundus examination) studies. Data was collected, documented and statistically analyzed. Results: both study and control groups were comparable regarding patients’ demographic and associated chronic medical disease. The prevalence of normal tension glaucoma in patients with obstructive sleep apnea was 27.3% and it was 3.3% in control subjects. Cup disk ratio and oxygen desaturation index were significantly increased, while oxygen saturation significantly decreased in patients with obstructive sleep apnea. In addition, obstructive sleep apnea index (measure of severity) was proportionately correlated with intraocular pressure, oxygen desaturation index, cup to disk ratio and negatively correlated with oxygen saturation. Conclusion: open angle glaucoma significantly increased in obstructive sleep apnea and significantly associated with disease severity.

Prevalence of Open Angle Glaucoma in Patients with Obstructive Sleep Apnea

Background: obstructive sleep apnea seems to have multi-organ harmful effects. Its association with glaucoma was previously reported. However, the debate exists around prevalence of glaucoma and the pathophysiology explains its association with obstructive sleep apnea is not fully known. Objective: the present study was designed to estimate the incidence of normal tension glaucoma among patients with obstructive sleep apnea. Patients and Methods: sixty patients with obstructive sleep apnea and another age and sex matched 60controls were included. Five patients in the study group refused to complete the study and only 55 patients constitute the study group.Allparticipants underwent polysomnographic and ophthalmologic (measurement of intraocular pressure and fundus examination) studies. Data was collected, documented and statistically analyzed. Results: both study and control groups were comparable regarding patients’ demographic and associated chronic medical disease. The prevalence of normal tension glaucoma in patients with obstructive sleep apnea was 27.3% and it was 3.3% in control subjects. Cup disk ratio and oxygen desaturation index were significantly increased, while oxygen saturation significantly decreased in patients with obstructive sleep apnea. In addition, obstructive sleep apnea index (measure of severity) was proportionately correlated with intraocular pressure, oxygen desaturation index, cup to disk ratio and negatively correlated with oxygen saturation. Conclusion: open angle glaucoma significantly increased in obstructive sleep apnea and significantly associated with disease severity.

Continuous 24-Hour Intraocular Pressure-Related Changes in Patients with Obstructive Sleep Apnea with and without Normotensive Glaucoma

Importance: Obstructive apneas during sleep can affect the intraocular pressure fluctuation over 24 hours. Background: Several studies found an increased prevalence of normal-tension glaucoma (NTG) in patients with obstructive sleep apneas (OSA). Design: Prospective exploratory study conducted in academic setting. Participants: Three patients diagnosed with OSA and 3 with OSA and NTG. Methods: Ambulatory blood pressure monitoring (ABPM), overnight respiratory polygraphy and IOP-related changes monitoring in an eye by a contact lens sensor (CLS) over a 24-hour period. Main outcome measure: We analyzed the effect of apneas on the CLS reading. Wake to sleep slope (W/S) and sleep to wake slope (S/W) were tested. Results: An 11% increase in the mean (95% CI) overnight CLS outputs, from 185.2 (125.4-273.8) mVeq to 205.1 (192.4-219.3) mVeq, was associated with the occurrence of apneas lasted 120 s (p=0.001). We found no correlation between ABPM and IOP or ABPM and apneas' duration. The W/S slopes were similar between the two groups (P=0.41), while the S/W slopes in the NTG patients differ considerably from patients without NTG (P=0.03), with a far less steep slope in the first group. Conclusions and Relevance: Obstructive apneas during sleep could affect IOP-related changes in a cumulative way. The smoother W/S and S/W slopes in NTG reveal a sort of inertia that could make some eyes more susceptible to damage following exposure to apneas.

Glaucoma in Atomic Bomb Survivors

Radiation has been associated with increases in noncancerous diseases. An effect of low-dose radiation on the prevalence of clinically detected glaucoma has not been previously reported. We therefore investigated the prevalence of glaucoma in A-bomb survivors and its possible association with radiation dose. A total of 1,589 people who participated in the clinical examination program for A-bomb survivors at the Radiation Effects Research Foundation (RERF) between October 2006 and September 2008 and who had reconstructed radiation doses, were recruited into this cross-sectional screening study. The prevalence of glaucoma and its dose-response relationship to A-bomb radiation were measured. Each subject underwent an initial screening consisting of an interview and ophthalmological examination. Questionable cases with any indication of ocular disease, including glaucoma, were referred to local hospitals for more comprehensive evaluation. A diagnosis of glaucoma was made based on specific optic disc appearance, perimetric results and other ocular findings. Of 1,589 eligible people, we detected 284 (17.9%) cases of glaucoma overall, including 36 (2.3%) cases of primary open-angle glaucoma with intraocular pressure levels greater than 21 mmHg, 226 (14.2%) cases of normal-tension glaucoma and 25 (1.6%) cases of primary angle-closure glaucoma. Seven glaucoma risk factors were examined as potential confounders but only two needed to be included in the final model. Binary regression using a generalized estimating equation method, with adjustment for gender, age, city, cataract surgery or diabetes mellitus, revealed an odds ratio at 1 Gy of 1.31 (95% confidence interval 1.11-1.53, P = 0.001) in the case of normal-tension glaucoma, but no association for other types of glaucoma. The prevalence of normal-tension glaucoma may increase with A-bomb radiation dose, but uncertainties associated with nonparticipation (59% participation) suggest caution in the interpretation of these results until they are confirmed by other studies.

Detection of Glaucoma in a Cohort of Chinese Subjects with Systemic Hypertension

Purpose. To determine the presence and type of glaucoma in a cohort of adult Chinese subjects with systemic hypertension. Methods. This prospective cohort study included 200 hypertensive Chinese adults aged >40 years old who underwent screening via frequency doubling technology (FDT) perimetry and intraocular pressure (IOP) measurement by noncontact tonometry (NCT) in a general outpatient clinic. Those with IOP > 21 mmHg and/or visual field (VF) defects on FDT were referred for complete ophthalmological examination. The diagnosis of glaucoma was based on an abnormal VF on Humphrey Field Analyzer (HFA) by Hodapp-Parrish-Anderson's criteria and an increased vertical cup-disc ratio (VCDR). Results. The mean age of the subjects was 64.66 ± 9.47 years, and the male:female ratio was 92 : 108. All patients were hypertensive with a mean blood pressure (BP) of 131.1 ± 15.1/76.6 ± 11.1 mmHg whilst on systemic antihypertensive medication. Of the 111 patients that had an abnormal initial screening, 14 (7.9%) were confirmed to have glaucoma with the highest prevalence of normal tension glaucoma (NTG) (6.2%), followed by primary angle closure glaucoma (PACG) (1.1%) and primary open angle glaucoma (POAG) (0.5%). The positive predictive value of FDT perimetry was 71%. Conclusion. Nearly 8% of the adults with systemic hypertension had glaucoma, and NTG was the most prevalent type.

Normal Tension Glaucoma in Patients With Obstructive Sleep Apnea/Hypopnea Syndrome

To determine the prevalence of normal tension glaucoma (NTG) in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) and further investigate whether the severity of OSAHS would increase the risk of glaucoma. Two hundred fifty-six participants were consecutively admitted for polysomnographic exam to diagnose OSAHS. All participants, then underwent a complete ophthalmologic evaluation, including best-corrected visual acuity, intraocular pressure, slit lamp biomicroscopy, gonioscopy, fundoscopy, automated visual field (VF), and retinal nerve fiber layer (RNFL) evaluation. A total of 247 participants were enrolled in the study. Two hundred nine patients were OSAHS and 38 participants were classified as the normal group. Among the OSAHS patients, NTG was found in 12 patients with a prevalence of 5.7%, which was higher than that in the normal group (P=0.003). In the NTG patients, 1 was in the mild, 3 were in the moderate, and 8 were in the severe OSAHS group. There was no glaucoma patient in the normal group. The prevalence of NTG in moderate/severe OSAHS patients was 7.1%, significantly higher (P=0.033) than that in normal/mild OSAHS patients. The mean saturation of oxygen and lowest saturation of oxygen correlated with the average thickness of RNFL in the OSAHS patients. Patients with OSAHS had a high prevalence of NTG, especially in patients with moderate and severe OSAHS. The severity of OSAHS inversely correlated with retinal nerve fiber layer thickness. Clinicians need to consider the possibility of glaucoma in patients with moderate and severe OSAHS.

Interleukin-1 attenuates normal tension glaucoma-like retinal degeneration in EAAC1-deficient mice

Glaucoma, one of the leading causes of irreversible blindness, is characterized by progressive degeneration of retinal ganglion cells (RGCs) and optic nerves. Although glaucoma is often associated with elevated intraocular pressure, recent studies have shown a relatively high prevalence of normal tension glaucoma (NTG) in glaucoma patient populations. In the mammalian retina, glutamate/aspartate transporter (GLAST) is localized to Müller glial cells, whereas excitatory amino acid carrier 1 (EAAC1) is expressed in neural cells, including RGCs. Since the loss of GLAST or EAAC1 leads to retinal degeneration similar to that seen in NTG, we examined the effects of interleukin-1 (IL-1) on RGC death in GLAST- and EAAC1-deficient mice. IL-1 promoted increased glutamate uptake in Müller cells by suppressing intracellular Na+ accumulation, which is necessary to counteract Na+-glutamate cotransport. The observed trends for the glutamate uptake increase in the wild-type (WT), GLAST- and EAAC1-deficient mice were similar; however, the baseline glutamate uptake and intracellular Na+ concentration in the GLAST-deficient mice were significantly lower than those in the wild-type mice. Consistently, pretreatment with IL-1 exhibited no beneficial effects on glutamate-induced RGC degeneration in the GLAST-deficient mice. In contrast, IL-1 significantly increased glutamate uptake by Müller cells and the number of surviving RGCs in the wild-type and EAAC1-deficient mice. Our findings suggest that the use of IL-1 for enhancing the function of glutamate transporters may be useful for neuroprotection in retinal degenerative disorders including NTG.

Long axial length as risk factor for normal tension glaucoma

The high prevalence of normal tension glaucoma (NTG) in the Japanese requires special screening tests other than measurements of only the intraocular pressure (IOP). This study was carried out to determine whether there is a significant association between the axial length of the eye and the presence of NTG. We reviewed the medical records of all patients who were scheduled to undergo cataract surgery alone or combined with glaucoma surgery at the same time. There were 87 patients with NTG, 137 with POAG, and 978 non-glaucomatous control cases. The axial length, IOP, curvature of the anterior corneal surface, age, and gender were determined at the time of the operation. If both eyes had surgery, data from only the right eyes were analyzed. An association of these parameters with NTG and POAG was analyzed by logistic regression analysis. The three groups were analyzed for differences in the axial length using the Kruskal-Wallis test followed by the Mann-Whitney U test. The axial length was significantly associated with NTG (odds = 1.24, P = 0.002) and POAG (odds = 1.28, P = 0.001). The incidence of either POAG or NTG was significantly higher in patients with axial lengths >or=25.0 mm (odds = 2.29, P < 0.001, Fisher's exact test). The age at the time of cataract surgery was weakly but significantly correlated negatively with the axial length (r = -0.24, P < 0.001, Pearson's correlation coefficient test). Men had significantly longer axial lengths than women. Long axial lengths can be considered a risk factor for NTG and POAG, and patients with long axial lengths need to be carefully examined for glaucoma.

Investigation of visual disorders of subacute myelo‐optico‐neuropathy (SMON) patients 32 years after onset: Questionnaire‐based survey and ophthalmological examination

An investigation of subacute myelo‐optico‐neuropathy (SMON) patients (20 male and 132 female, aged 31–93 years) was conducted in December 1998 using a self‐administered questionnaire. Following this survey, ophthalmological examinations were performed on 33 patients between 1998 and 2000. The questionnaire‐based survey revealed that the prevalence of patients with cataracts was 52.0%, and those with glaucoma was 9.4%. By dividing the patients into two groups, according to the levels of visual disturbances at the time of onset of SMON, we found that the prevalence of glaucoma was higher in the group with visual disturbances than in the group with normal vision. However, the prevalence of cataracts, optico‐neuritis and fundus hemorrhage was not considerably different between the two groups. Ophthalmological examinations (e.g. intraocular pressure test, visual field test, slit lamp microscopy test, funduscopic examination) revealed that 63.6% of patients had cataracts, and 12.1% had glaucoma (9.1% for normal tension glaucoma). The ophthalmological examination revealed that the prevalence of normal tension glaucoma in the SMON patients tended to be higher than in other surveys in the general population of Japan. SMON patients need follow‐up ophthalmological examinations, especially for glaucoma, on a nationwide scale.

Prevalence of Normal Tension Glaucoma in Obstructive Sleep Apnea Syndrome Patients

To explore the prevalence of normal tension glaucoma (NTG) among patients with obstructive sleep apnea syndrome (OSAS) and to examine OSAS as a risk factor of NTG. Fifty-one consecutive white patients with OSAS were compared with 40 healthy subjects. All the study subjects underwent blood gas analysis, polysomnography, oxyhemoglobin saturation, and an ophthalmologic examination including visual field, visually evoked potential (VEP), and pattern electroretinography (PERG) and disc analysis with the Heidelberg Retina Tomograph II. Three of 51 OSAS patients (5.9%) had NTG. No patient in the control group had OSAS or NTG. The severity of OSAS correlated with intraocular pressure, the mean deviation of the visual field, the cup/disk ratio and the mean of the retinal nerve fiber layer thickness (P<0.01 to 0.001). Apnea hypopnea index and intraocular pressure were significantly greater in OSAS patients with abnormal VEP and PERG, compared to those with normal PERG and VEP. The present study suggests that the prevalence of NTG in our OSAS patients is higher than expected in a white population of the same age and that OSAS may be an important risk factor for NTG. Our data underline the importance of taking an accurate sleep history from patients with NTG and referring patients with sleep disturbance for polysomnography.

Can the prevalence of open‐angle glaucoma be estimated from a retrospective clinical material? A study on the west coast of Iceland

To explore the possibility of estimating the prevalence of open-angle glaucoma (OAG) on the west coast of Iceland using a clinical retrospective material, and to compare that estimate with the results from a recent prospective Icelandic study. The compulsory ophthalmological examination for the prescription of eye glasses in combination with information obtained from Statistics Iceland were used to establish the prevalence of glaucoma in Akranes and to estimate the minimum prevalence for the greater west coast area. A recent prospective study from Iceland was used as reference. In all, 79% of 1443 Akranes inhabitants aged 50 years or more had visited the eye clinic at least once between 1996 and 2001. The prevalence of OAG was 4.8% (95% CI 3.6-6.1). The minimum prevalence for the west coast was 3.8% (95% CI 3.2-4.4). The prevalence increased with age (p < 0.001). The overall prevalence was similar to that of recently published prospective data but the prevalence of normal tension glaucoma (NTG) was lower. The results from the two studies are similar in many respects, which indicates that retrospective data may supply meaningful information on glaucoma prevalence. Important sources of error are the selection and attendance of patients, screening methods and diagnostic criteria. If routine examination does not include fundus photography and/or perimetry, the prevalence of NTG will be underestimated.

Open-angle glaucoma associated with Graves disease

PURPOSE: To estimate the prevalence of open-angle glaucoma, including normal-tension glaucoma, in association with Graves disease. METHODS: In a prospective study, a complete ophthalmic examination including applanation tonometry, exophthalmometry, automated static threshold perimetry, and computed tomography of the orbit was performed in 104 consecutive Japanese patients with Graves disease (age range, 11 to 86 years; mean, 42 years; 80 women, 24 men). Ocular hypertension was defined as an intraocular pressure greater than 21 mm Hg on at least two occasions during the period of follow-up. RESULTS: Of the 104 patients, 14 (13%) exhibited typical glaucomatous visual field defects in automatic static threshold perimetry in the absence of compressive optic neuropathy. The intraocular pressure in seven of the 14 patients was consistently less than 21 mm Hg during the follow-up period. Thus, these patients were diagnosed as having normal-tension glaucoma. Of the 104 patients, 23 (22%) were diagnosed as having ocular hypertension. CONCLUSIONS: The prevalence of normal-tension glaucoma as well as open-angle glaucoma and ocular hypertension was significantly higher among patients with Graves disease than in the general population.

Prevalence of Normal-Tension Glaucoma and Primary Open-Angle Glaucoma in Patients With Collagen Diseases

Purpose: To investigate the prevalence of normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG) in patients with collagen diseases and determine whether an immunocompromised condition is present in a subset of glaucoma patients. Methods: Three glaucoma specialists prospectively examined patients with collagen diseases. The diagnostic process included applanation tonometry, slit-lamp examination, gonioscopy, direct ophthalmoscopy, and automated static perimetry. Twenty-four–hour intraocular pressure monitoring was done when necessary. Using the results of a population-based survey conducted in Japan, we calculated an expected number of cases of NTG and POAG, and compared these with the actual number of cases. Results: Of the 153 patients with collagen diseases examined, we found 6 patients with NTG and 2 patients with POAG. Of these 8 patients, 2 with progressive systemic sclerosis (PSS), one with NTG, and the other, POAG, had a history of being on systemic steroidal therapy. The prevalence of NTG and POAG was significantly higher in women patients having collagen diseases as compared with normal women ( P = .027). Conclusion: Women patients with collagen diseases are highly susceptible to NTG and POAG.