Massimo Cesareo

Epidemiology of primary glaucoma: prevalence, incidence, and blinding effects.

Certain general conclusions can be drawn from a series of 56 studies on glaucoma prevalence. Even in the most recently published studies the rate of undiagnosed glaucoma is particularly high. Another fairly constant finding is the discrepancy between the clinical and epidemiologic diagnoses of glaucoma. The prevalence of primary open-angle glaucoma (POAG) has been increasing, and this trend is undoubtedly due at least in part to advances in diagnostic technology. The decreasing prevalence of primary angle-closure glaucoma (PACG) is due to the adoption of more stringent criteria for the diagnosis of this form of glaucoma. Prevalence increases proportionately with age for each racial group. African or African origin populations had the highest POAG prevalence at all ages but the increase in prevalence of POAG is steeper for white populations. PACG is commonest in Asian ethnic groups, with the exception of the Japanese. Low-tension glaucoma (LTG) is quite common in the Japanese population. Over 80% of those with PACG live in Asia, while POAG disproportionately affects those of African derivation. Women are more affected by glaucoma. Very few incidence studies have been completed, because the cost of examining large samples is high. There are only two recent studies conducted on persons of African descent in Barbados (West Indies) and on white inhabitants of Rotterdam (Netherlands). Risk of incident glaucoma was highest among persons classified as having suspect POAG at baseline, followed by those with ocular hypertension. No difference in incidence of POAG between men and women was found. The more recent studies which included routine visual-field testing reveal rates of blinding glaucoma <10% in many countries, including those that are developing.

Prevalence of glaucoma in Ponza, Italy: a comparison with other studies

The purpose of this study was to determine the prevalence of glaucoma in Ponza, Italy. The design was a population-based prevalence survey of residents of Ponza aged 40 years or older. There were 1,296 official residents identified by a house-to-house census, of whom 1,226 were identified as eligible for the study. Of these, 1,034 individuals (449 males and 585 females), or 84.3% of the eligible population, participated in the ophthalmological examination. A two-stage method was adopted to identify cases of glaucoma. All subjects underwent a standardized initial examination. Glaucoma suspects and 50% of non-suspects were referred to a definitive examination which included visual field testing. Patients were defined as glaucoma cases if they presented abnormal visual fields and at least one of the following: high 10P, large or asymmetric cup-to-disc ratio. In addition to typical glaucomatous visual field defects such as paracentral scotoma, nasal step, arcuate scotoma and temporal and/or central islands fields, a visual field defect was identified as a decrease in sensitivity greater than 6 db in at least one location of the central 10 degrees, two locations of the central 20 degrees or three locations of the central 30 degrees. Prevalence rates of 2.51% of Primary Open Angle Glaucoma (1.72%-3.66%, CI 95%), 0.97% of Primary Closed Angle Glaucoma (0.53%-1.77%, CI 95%) and 0.29% of secondary glaucoma were found. Moreover, 2.13% of probable POAG (1.41%-3.20%, CI 95%) and 6.00% of High Intraocular Pressure (4.71%-7.61%, CI 95%) were found. The prevalence rates of POAG found in the Ponza Ophthalmological Survey are consistent with the results of other studies. Minor differences are most likely due to the different criteria adopted in the assessment of glaucomatous visual field damage.

Incidence of blindness and low vision in a sample population ☆: The Priverno Eye Study, Italy

PURPOSE To study the incidence of blindness and low vision over a 7-year period. DESIGN Population-based cohort study. PARTICIPANTS The survivors of the original cohort of 860 persons from Priverno, Italy, aged 45 to 69 years, were reexamined. Of the 760 eligible survivors, 619 (81.4%) had a 7-year follow-up visit. METHODS Baseline and follow-up examinations included the collection of anamnestic and ophthalmologic data by the same observers using the same methods and classification criteria to minimize sources of variability. MAIN OUTCOME MEASURES Best-corrected visual acuity (VA) measured at 4 m by standardized logarithmic chart was expressed as the logarithm of the minimum angle of resolution (logMAR). World Health Organization definitions of blindness and low vision were adopted (respectively, VA > 1.3 logMar and VA > 0.6 to 1.3 logMar in the better eye or in either eye). Participants at risk for visual impairment were those without blindness or low vision in one or both eyes at baseline; participants at risk for one-eye visual impairment were those without blindness or low vision in both eyes at baseline. RESULTS A total of 33 participants were defined as incident cases of visual impairment. The overall incidence figures for blindness, low vision, one-eye blindness, and one-eye low vision were respectively 0.2% (95% confidence interval [CI], 0.0-0.9), 1.3% (95% CI, 0.7-2.6), 1.2% (95% CI, 0.6-2.4), and 2.9% (95% CI, 1.8-4.6). CONCLUSIONS This study provides population-based estimates of the incidence of visual impairment in an adult, free-living European population. With respect to the younger participants, older subjects at baseline were at higher risk for incident visual impairment, the main causes of which were cataract, myopia, and diabetic retinopathy. The incidence of visual impairment in the subgroup aged 55 to 64 years at baseline was significantly higher than that found in Beaver Dam 5-year study and similar to that found in Beaver Dam 10-year Study, when the same definitions were adopted. This difference may be partially explained by social and cultural habits of the female samples, but many other factors may play a role.

Validity and limitations of the Nidek NT-4000 non-contact tonometer: a clinical study

Using Goldmann applanation tonometry (GAT) as a gold standard, we evaluated the accuracy of Nidek NT‐4000 pneumotonometry (NPT) in adults without corneal disease. Bland and Altman analysis of serial intra‐ocular pressures (IOPs) measured with NPT and GAT in 10 healthy subjects revealed that the repeatability coefficients for the two methods were similar. NPT, GAT and ultrasonic pachymetry were then performed in 100 patients. Bland and Altman analysis showed that NPT yielded significantly higher readings than GAT [mean biases for right and left eye measurements were 1.37 mmHg (95% limits of agreement: −3.02–5.76) and 1.17 mmHg (95% limits of agreement: −2.76–5.11) respectively] and was more affected by corneal thickness variations. For detection of IOPs ≥21 mmHg, NPT displayed very high sensitivity (0.90) and good specificity (0.95). NPT may be useful in screening and clinical settings but borderline‐high IOP readings should be confirmed with GAT.

Association between lens opacities and mortality in the Priverno Eye Study

BackgroundLens opacities are associated with a higher risk of death, although there are some discrepancies regarding the specific types of cataract representing risk. The purpose of the present study was to further investigate the relationships between different types of lens opacity and patient survival.MethodsIn 1987, 860 residents of Priverno, Italy, aged 45–69 years underwent an ophthalmologic examination. Based on patient histories and the findings of the slit-lamp examination, each of the 860 patients was classified according to the type of opacity (pure cortical, pure nuclear, pure posterior subcapsular, mixed, and surgical aphakia). The survivors of the original cohort were re-examined in 1994. Death and survival rates were computed by the Kaplan–Meier method. Associations between mortality and significant factors were included in a stepwise Cox proportional-hazards regression model.ResultsForty-four members of the original cohort had died during the 7-year follow-up. Age-adjusted survival curves based on Kaplan–Meier estimates showed significantly lower survival in those whose baseline examinations had revealed pure nuclear opacity (log rank test: P=0.020) and aphakia (log rank test: P<0.001). When adjusted for other mortality risk factors (age, sex, diabetes, cardiovascular diseases), the hazard ratio was 4.32 for pure nuclear opacity (95% CI 1.13–16.4) and 18.3 for aphakia (95% CI 3.21–104.0).ConclusionsThe analysis of the Priverno data seems to confirm an association between lower survival and cataracts, particularly those confined to the lens nucleus and those that had already prompted surgery.

Standard automated perimetry and algorithms for monitoring glaucoma progression

Despite increasingly sophisticated techniques for the computerized analysis of the optic nerve and retinal nerve fiber layer, standard automated perimetry (SAP) is still the primary test for assessing functional damage in glaucoma. Most of the diseases affecting the visual field can be studied analyzing the central visual field with a fixed grid of points set at 6 degrees or at a variable density within central 30 degrees, using a III white target stimulus (program 30/2 or 24/2 Humphrey, G1/G2 or 30/2 Octopus). Although there is lack of a true gold standard for glaucoma, SAP results were the primary endpoint in most of the clinical trials in glaucoma. New thresholding strategies allowed a considerable reduction of examination time without substantial loss of accuracy. Moreover, recent findings on structure-function correlation in glaucoma validate the clinical role of this well-known and widespread method of examination.

Links among glaucoma, neurodegenerative, and vascular diseases of the central nervous system.

Glaucoma is the leading cause of irreversible blindness worldwide. Although the intraocular pressure (IOP) has been considered for long time the key point and the only treatable risk factor of the disease, there are cases in which glaucoma continues to progress despite normal IOP values. Vision loss in glaucoma is related to a selective decrease in the number of retinal ganglion cells by apoptosis that is associated to alterations of the central visual pathways. Interestingly, similar events have been also described in disorders of the central nervous system (CNS), such as Alzheimers disease, Parkinsons disease, Lebers hereditary optic neuropathy, and cerebrovascular diseases. In this review, we discuss recent evidence supporting pathological links between glaucoma and disorders of the CNS.

Association Between Alzheimer's Disease and Glaucoma: A Study Based on Heidelberg Retinal Tomography and Frequency Doubling Technology Perimetry

Aim: To assess the frequency of glaucoma-like alterations in Alzheimers disease (AD) patients using Heidelberg Retinal Tomograph III (HRT-3) and Frequency Doubling Technology (FDT) perimetry. Methods: The study included 51 eyes of 51 AD subjects and 67 eyes of 67 age- and sex-matched controls. Subjects underwent an ophthalmological examination including measurements of intraocular pressure (IOP), Matrix FDT visual field testing, optic nerve head morphology and retinal nerve fiber layer thickness (RNFLt) assessment by slit-lamp biomicroscopy and HRT-3. Results: The frequency of alterations was significantly higher in the AD group (27.5 vs. 7.5%; p = 0.003; OR = 4.69). AD patients showed lower IOP (p = 0.000) despite not significantly different values of central corneal thickness (CCT) between the groups (p = 0.336). Of all the stereometric parameters measured by HRT-3, RNFLt was significantly lower in AD patients (p = 0.013). This group also had significantly worse results in terms of Moorfields Regression Analysis (p = 0.027). Matrix showed significantly worse Mean Deviation (MD) (p = 0.000) and Pattern Standard Deviation (PSD) (p = 0.000) values and more altered Glaucoma Hemifield Test (p = 0.006) in AD patients. Pearsons R correlation test showed that Mini Mental State Examination is directly correlated with MD (R = 0.349; p = 0.034) and inversely correlated with PSD (R = −0.357; p = 0.030). Conclusion: Patients with AD have a higher frequency of glaucoma-like alterations, as detected by the use of HRT-3. These alterations were not associated with elevated IOP or abnormal CCT values.

Visual disability and quality of life in glaucoma patients

Glaucoma is an optic neuropathy that can result in progressive and irreversible vision loss, thereby affecting quality of life (QoL) of patients. Several studies have shown a strong correlation between visual field damage and visual disability in patients with glaucoma, even in the early stages of the disease. Visual impairment due to glaucoma affects normal daily activities required for independent living, such as driving, walking, and reading. There is no generally accepted instrument for assessing quality of life in glaucoma patients; different factors involved in visual disability from the disease are difficult to quantify and not easily standardized. This chapter summarizes recent works from clinical and epidemiological studies, which describe how glaucoma affects the performance of important vision-related activities and QoL.

Evaluation of pupillary response to light in patients with glaucoma: a study using computerized pupillometry

The aim of this study was to evaluate pupillary response to light stimulation in patients with different stages of glaucoma using computerized pupillometry. We conducted a retrospective study on a group of 44 glaucoma patients who had undergone complete ophthalmological examination, visual field test (Humphrey SITA Standard 24-2) and monocular dynamic pupillometry (MonCV3 Metrovision). Eyes were classified into stages of glaucoma according to visual field damage using the Glaucoma Staging System 2. A group of 18 healthy subjects, homogeneous for age and sex with glaucoma patients, was used as a control. The following parameters were considered—latency and duration of contraction and dilatation; initial, minimum, maximum, and mean pupil diameter; amplitude of contraction; contraction and dilatation speed; and percent pupil contraction (PPC). PPC and pupil contraction speed and minimum diameter showed covariate correlation with the stages of glaucoma. The control group significantly differed from the stage 3 group in terms of PPC and from the stage 4 group in terms of minimum diameter. There were significant differences between the stage 5 group and stage 1, 2, 3 and control groups. Ordinal logistic regression showed a correlation between pupil contraction speed, minimum diameter, PPC, initial diameter and the stage of glaucoma. The study showed that glaucoma damage is associated with altered values of pupillary response to light. This event may be the consequence of the progressive loss of retinal ganglion cells and their axons induced by glaucoma.