Analysis of risk factors that may be associated with progression from ocular hypertension to primary open angle glaucoma

The Use of ChatGPT to Assist in Diagnosing Glaucoma Based on Clinical Case Reports

INTRODUCTION

The purpose of this study was to evaluate the capabilities of large language models such as Chat Generative Pretrained Transformer (ChatGPT) to diagnose glaucoma based on specific clinical case descriptions with comparison to the performance of senior ophthalmology resident trainees.

METHODS

We selected 11 cases with primary and secondary glaucoma from a publicly accessible online database of case reports. A total of four cases had primary glaucoma including open-angle, juvenile, normal-tension, and angle-closure glaucoma, while seven cases had secondary glaucoma including pseudo-exfoliation, pigment dispersion glaucoma, glaucomatocyclitic crisis, aphakic, neovascular, aqueous misdirection, and inflammatory glaucoma. We input the text of each case detail into ChatGPT and asked for provisional and differential diagnoses. We then presented the details of 11 cases to three senior ophthalmology residents and recorded their provisional and differential diagnoses. We finally evaluated the responses based on the correct diagnoses and evaluated agreements.

RESULTS

The provisional diagnosis based on ChatGPT was correct in eight out of 11 (72.7%) cases and three ophthalmology residents were correct in six (54.5%), eight (72.7%), and eight (72.7%) cases, respectively. The agreement between ChatGPT and the first, second, and third ophthalmology residents were 9, 7, and 7, respectively.

CONCLUSIONS

The accuracy of ChatGPT in diagnosing patients with primary and secondary glaucoma, using specific case examples, was similar or better than senior ophthalmology residents. With further development, ChatGPT may have the potential to be used in clinical care settings, such as primary care offices, for triaging and in eye care clinical practices to provide objective and quick diagnoses of patients with glaucoma.

The eye in migraine: a review of retinal imaging findings in migraine

Migraine is a common headache disorder with neurovascular involvement. Because eyecare practitioners are likely to encounter people with migraine in their everyday practice, it is important to understand how migraine might impact on ocular health. In this narrative review, we provide an update on the latest ophthalmic imaging evidence for retinal involvement in migraine, derived from studies of retinal structure and retinal vascular perfusion using spectral domain and swept source optical coherence tomography (OCT) and OCT angiography. Combined structural OCT evidence from a recent meta-analysis indicates subtle and non-specific thinning of the peripapillary retinal nerve fibre layer (RNFL) in people with migraine, whereas there is little consistent evidence for structural abnormalities of the macular region. Recent advances in OCT angiography technology have also provided an opportunity to visualise microstructural damage and vascular dysregulation in the eyes of people with migraine. However, given that OCT and OCT angiography studies have been exclusively cross-sectional, it is not possible to demonstrate the causal effect of migraine events. Furthermore, the lack of common methodology (different ophthalmic imaging devices and analysis algorithms), and very limited datasets (small samples, heterogenous migraine groups), lead to an inability to make strong conclusions regarding the nature of altered retinal structure and vascular perfusion in migraine. Nevertheless, we discuss the clinical implications of such observations for eyecare practitioners and provide practical advice for the monitoring and management of patients with a history of migraine.

Longitudinal Evaluation of the Structural and Functional Changes Associated with Glaucoma in Myopia

SIGNIFICANCE

This study ascertains that myopia is a risk factor for glaucoma progression among eyes with primary open angle glaucoma. Myopic eyes with primary open angle glaucoma may benefit from measurement and incorporation of axial length information into clinical decision making.

PURPOSE

The purpose of this study was to estimate the rate of change in retinal nerve fiber layer (RNFL) thickness and the rate of change in visual field of glaucoma patients with and without myopia.

METHODS

We conducted a prospective, observational cohort study where we analyzed 245 eyes of 135 glaucoma patients followed for a mean period of 6.08 years. All the subjects had RNFL imaging and standard automated perimetry performed for both eyes in the same visit every 4 months for at least 60 months.

RESULTS

The rate of change of average RNFL thickness and visual field index (VFI) was -0.29 μm/y (95% confidence interval, -1.80 to +1.23 μm/y) and -0.30%/y (95% confidence interval, -2.24 to +1.64%/y), respectively, after adjusting for age, axial length, IOP, baseline RNFL thickness, signal strength, and correlation between fellow eyes. Axial length, as a continuous variable, was not associated with the rates of change of average RNFL thickness and VFI. However, high myopic eyes with axial lengths of ≥26.0 and ≥26.5 mm had an average rate of change of RNFL thickness of 0.15 and 0.16 μm/y faster than eyes with axial lengths of less than 26 and 26.5 mm, respectively. Similarly, myopic eyes with an axial length of ≥26.5 mm were associated with a 0.21%/y faster rate of VFI reduction.

CONCLUSIONS

Both RNFL and visual field progression rates are faster in myopic glaucomatous eyes with an axial length of ≥26.5 mm than in eyes <26.5 mm. However, the small difference that supports high myopia as a risk factor for progression does not indicate the clinical importance or significance of axial length.

Prevalence, incidence, and risk factors of primary open-angle glaucoma - a cohort study based on longitudinal data from a German public health insurance

Background

This study estimates the prevalence and incidence rates of primary open -angle glaucoma (POAG) as well as risk factors based on a dataset from the largest German health insurance company.

Methods

A random sample of 250,000 persons at age 50+ of the Allgemeine Ortskrankenkasse (AOK) from 2010 to 2013 was used. Selected risk factors of POAG incidence were analyzed using multivariate Cox proportional hazard models.

Results

The age-standardized prevalence of POAG at age 50+ in 2010 was 2.79% (95%-CI: 2.72–2.85%). The age-standardized total incidence rate was 0.38 (0.36–0.39) per 100 person-years. Sex differences were significant for total prevalence and total incidence rates, with higher prevalence and incidence rates for women compared to men. The Cox model revealed a strong age effect, a significantly 19% higher incidence for women (p ≤ 0.001), injuries of the eye and orbit (175%, p ≤ 0.001), degeneration of iris and ciliary body (155%, p = 0.022), myopia (155%, p ≤ 0.001), retinal vascular occlusions (134%, p ≤ 0.001), hypertension (13%, p ≤ 0.001) and diabetes mellitus (23%, p ≤ 0.001).

Conclusion

Health claims data are an important data source for estimating POAG occurrence and help overcome the problems of small sample sizes. These results may help to understand the causal pathways of POAG and to develop intervention strategies to increase the awareness of patients and physicians with the aim of reducing POAG incidence.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6935-6) contains supplementary material, which is available to authorized users.

Racioethnic differences in the biomechanical response of the lamina cribrosa

Glaucoma is the second leading cause of irreversible blindness in the world with a higher prevalence in those of African Descent (AD) and Hispanic Ethnicity (HE) than in those of European Descent (ED). The objective of this study was to investigate the pressure dependent biomechanical response of the lamina cribrosa (LC) in normal human donor tissues from these racioethnic backgrounds. Pressure inflation tests were performed on 24 human LCs (n = 9 AD, n = 6 ED, and n = 9 HE) capturing the second harmonic generation (SHG) signal of collagen at 5, 15, 30, and 45 mmHg from an anterior view. A non-rigid image registration technique was utilized to determine the 3D displacement field in each LC from which 3D Green strains were calculated. The peak shear strain in the superior quadrant of the LC in those of ED was significantly higher than in those of AD and HE (p-value = 0.005 & 0.034, respectively) where ED = 0.017 [IQR = 0.012-0.027], AD = 0.0002 [IQR = -0.001-0.007], HE = 0.0016 [IQR = -0.002-0.012]). There were also significant differences in the regional strain heterogeneity in those of AD and HE that were absent in those of ED. This work represents, to our knowledge, the first ex-vivo study identifying significant differences in the biomechanical response of the LC in populations at increased risk of glaucoma. Future work will be necessary to assess if and how these differences play a role in predisposing those of Hispanic Ethnicity and African Descent to the onset and/or progression of primary open angle glaucoma. STATEMENT OF SIGNIFICANCE: Glaucoma is the second leading cause of irreversible blindness in the world and occurs more frequently in those of African Descent and Hispanic Ethnicity than in those of European Descent. To date, there has been no ex-vivo study quantifying differences in the biomechanical response of the non-glaucomatous lamina cribrosa (LC) across these racioethnic backgrounds. In this work we report, for the first time, differences in the pressure dependent biomechanical response of LC across different racioethnic groups as quantified using nonlinear optical microscopy. This study lays the foundation for future work investigating if and how these differences may play a role in predisposing those at increased risk to the onset and/or progression of primary open angle glaucoma.

Cyclodestructive procedures for refractory glaucoma

BACKGROUND

Cyclodestructive procedures are often used in patients with refractory glaucoma who have failed to achieve lower intraocular pressure (IOP) from filtration procedures and maximal medical therapy. Destruction of the ciliary body helps to lower IOP by reducing aqueous humor formation. Of the many types of cyclodestructive procedures, laser cyclophotocoagulation (CPC) has become the most common surgical method for reducing aqueous inflow. Options for CPC are wide-ranging: they can be performed using a neodymium:yttrium-aluminum-garnet (Nd:YAG) or diode laser and laser energy can be delivered by either the contact or non-contact method. Another cyclodestructive procedure is endoscopic cyclophotocoagulation (ECP), which the ophthalmologist can use selectively to target the ciliary epithelium and ablate ciliary body tissue. There is debate regarding which cyclodestructive method is best and how they compare to other glaucoma surgeries.

OBJECTIVES

To assess the relative effectiveness and safety of cyclodestructive procedures compared with other procedures in people with refractory glaucoma of any type and to assess the relative effectiveness and safety of individual cyclodestructive procedures compared with each other.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 9); Ovid MEDLINE; Embase.com; PubMed; LILACS BIREME; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 21 September 2018.

SELECTION CRITERIA

We included randomized controlled trials or quasi-randomized trials in which participants underwent a secondary procedure for refractory glaucoma. We included trials with any laser type, route of administration, and laser settings. The primary comparison was any cyclodestructive procedure versus another glaucoma treatment, and the secondary comparisons were individual cyclodestructive procedures versus another cyclodestructive procedure.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the titles and abstracts from the database searches, and after retrieving the full-text reports of those that were potentially relevant, classified the full-text articles as included or excluded. Two review authors independently extracted data from the included studies and assessed the risk of bias. Discrepancies were resolved by discussion or by consultation with a third review author when necessary.

MAIN RESULTS

We included five trials reporting data for 330 eyes (326 participants). One study to had a low risk of bias for most domains and the other studies had an overall unclear risk of bias. This review includes four different comparisons: 1) ECP versus Ahmed implant, 2) micropulse CPC versus continuous-wave CPC; 3) CPC with a diode versus Nd:YAG laser; and 4) CPC with an Nd:YAG laser emitting 8J versus 4J.No study reported data for our primary outcome, change from baseline in pain severity as reported by the participant or change in number of pain medications.For our primary comparison, we included one trial that compared ECP with the Ahmed implant. At 12-month follow-up, the mean difference (MD) in IOPs between groups was -1.14 mmHg (95% confidence interval (CI) -4.21 to 1.93; 58 participants; low-certainty evidence (LCE)). At 24 months postintervention, we found very LCE suggesting that visual acuity may be better among participants in the ECP group than in the Ahmed implant group (MD -0.24 logMAR, 95% CI -0.52 to 0.04; 54 participants), and the difference in the mean number of glaucoma medications used by participants in each group was unclear (MD -0.50, 95% CI -1.17 to 0.17; 54 participants; very LCE). Reported adverse events in the ECP group (34 participants) were one case each of hypotony, phthisis bulbi, retinal detachment, and choroidal detachment; in the Ahmed implant group (34 participants) there was one case of endophthalmitis, two cases of retinal detachment, and six cases of choroidal detachment.Three types of comparisons from four included studies provided data for our secondary comparisons. In the study that compared micropulse with continuous-wave CPC, median IOP was reported to be similar between the two groups at all time points. At 18 months postintervention, the median number of IOP-lowering medications was reduced from two to one in both groups. One participant in the micropulse and two in the continuous group exhibited worsened visual acuity. One case of prolonged inflammation was seen in the micropulse group (23 participants). Seven cases of prolonged inflammation, five cases of hypotony, and one case of phthisis bulbi were seen in the continuous group (23 participants).Two studies compared CPC using a semiconductor diode versus an Nd:YAG laser. At 12 months postintervention, the MD in IOP was 1.02 mmHg (95% CI -1.49 to 3.53) in one study (LCE). The second study did not report mean IOP beyond three months of follow-up. Neither study reported the mean change in best-corrected visual acuity or number of glaucoma medications. Both studies reported hypotony as an adverse event in three participants in each study.One study compared different energy settings of the same Nd:YAG laser. At 12-month follow-up, visual acuity was unchanged or improved in 21 of 33 participants in the 8J group and 20 of 27 participants in the 4J group (risk ratio 0.86, 95% CI 0.61 to 1.21; very LCE). More participants in the 8J group reduced the number of medications taken compared with the 4J group (RR 1.49, 95% CI 0.76 to 2.91; 50 participants; very low-certainty evidence). The presence of fibrin or hyphema were seen in five participants who received 8J and none who received 4J. There was a severe anterior chamber reaction in 11 of 26 (42%) participants who received 8J of energy and 2 of 21 (10%) participants who received 4J of energy.

AUTHORS' CONCLUSIONS

Evidence from five studies included in this review was inconclusive as to whether cyclodestructive procedures for refractory glaucoma result in better outcomes and fewer complications than other glaucoma treatments, and whether one type of cyclodestructive procedure is better than another. The most commonly reported adverse events across all five studies were hypotony and phthisis bulbi. Large, well-designed randomized controlled trials are needed. Patient-reported outcomes such as pain and quality of life should be considered as primary outcomes or important secondary outcomes of future trials.

Migraine as a risk factor for primary open angle glaucoma: A systematic review and meta-analysis

Migraine is increasingly being reported as a risk factor for primary open angle glaucoma (POAG). However, studies aimed to investigate this association yielded conflicting results. To assess the consistency of the data on the topic, we performed a systematic review and meta-analysis. A systematic literature search from Embase, Web of Science, and PubMed was performed to identify relevant studies on the relationship between migraine and POAG. Random effects models were used to estimate the pooled relative risks (RRs) with 95% confidence intervals (95% CIs) in this meta-analysis. A total of 11 studies meeting the inclusion criteria were included in this meta-analysis. Our findings showed an RR of developing POAG of 1.24 (95% CI = 1.12-1.37) in migraine patients. No evidence of significant heterogeneity was detected across studies (P = .071; I = 41.7%). This association was not modified by the glaucoma type of the included patients. A significant association was observed in case-control design studies, but not in cohort design studies. Little evidence of publication bias was found. The findings of this meta-analysis suggest that migraine can significantly increase the risk of the development of POAG. However, the cohort study design failed to identify this association. Whether migraines can significantly increase the risk of developing POAG is still controversial.

Long-term evaluation of ocular hypertension with primary angle closure and primary open angles

PURPOSE

To evaluate the long-term course of primary angle-closure ocular hypertension and primary open-angle ocular hypertension and possible risk factors for progression to glaucoma.

METHODS

A total of 109 eyes of 109 ocular hypertension (OHT) patients with a minimum follow-up period of 5 years having complete ocular/medical records were evaluated. They were classified into primary angle closure or primary open angle based on gonioscopy at baseline. Baseline and review data of Humphrey field analyser, HFA, and Heidelberg retinal tomography, HRT, were recorded. Guided progression analysis (GPA) and univariate Cox regression were used for time to event analysis in identifying progression to glaucoma.

RESULTS

Over a mean follow-up of 12.18 ± 4.8 years, progression to glaucoma was 17.43% (19 eyes), out of whom 5.5% (6 eyes) showed ≥ 3 loci on GPA. Sub-classifying them, progression to primary angle-closure glaucoma was 19.72%, and that of primary open-angle glaucoma was 13.16%. The mean time to progression was 9.34 ± 3.6 years. Significant risk factors included small disc area (≤ 1.99 sq.mm on HRT), requirement of ≥ 2 drugs to maintain target IOP and those engaged in activities yielding a Valsalva effect in daily life. Coronary artery disease (CAD) and systemic use of steroids were associated with increased severity.

CONCLUSION

Overall progression of OHT to glaucoma was 17.43% over a mean of 9 years, with target IOP of ≤ 18 mm Hg. Patients with smaller discs, CAD, exercising Valsalva type activities and using ≥ 2 glaucoma medications or systemic steroids should be closely monitored.

Is normal-tension glaucoma a risk factor for stroke?-A 10-year follow-up study

OBJECTIVES

To investigate whether patients with normal-tension glaucoma (NTG) have a higher incidence of stroke.

DESIGN

A population-based retrospective cohort study based on data from the Taiwan National Health Insurance Research Database (NHIRD) from January 1, 2001, to December 31, 2010.

METHODS

Data were retrospectively collected from the NHIRD. A total of 245 (20.1%) patients with a history of stroke at the time of glaucoma diagnosis were excluded, and 1,218 patients with NTG who were 20 years of age and older were identified. Patients' age, gender and pre-existing comorbidities, including hypertension, diabetes, congestive heart failure, ischemic heart disease, atrial fibrillation and disorders of lipid metabolism, were recorded. The propensity score method with a 1:5 matching ratio was used to minimize selection bias. Cox regression with robust variance estimation was used to estimate the hazard ratio (HR) of developing stroke between the NTG and control groups.

RESULTS

After adjusting for patient age, gender, and pre-existing comorbidities, the HR was 6.34, indicating that the incidence of stroke was significantly higher in patients with NTG than in controls. Furthermore, a higher risk of stroke was also found in most subgroups with the above-mentioned comorbidities.

CONCLUSION

NTG is a significant risk factor for subsequent stroke in most of the described comorbidity subgroups. Early interventions for stroke prevention should be provided to newly diagnosed patients with NTG.

Glaucoma history and risk factors

Apart from the risk of developing glaucoma there is also the risk that it is not detected and irreversible loss of vision ensues. Some studies of methods of glaucoma diagnosis have examined the results of instrument-based examinations with great if not complete reliance on objective findings in arriving at a diagnosis. The very valuable advances in glaucoma detection instrument technologies, and apparent increasing dependence on them, may have led to reduced consideration of information available from a patient history in those studies. Dependence on objective evidence of glaucomatous pathology may reduce the possibility of detecting glaucoma suspects or patients at risk for becoming glaucoma suspects. A valid positive family history of glaucoma is very valuable information. However, negative family histories can often be unreliable due to large numbers of glaucoma cases being undiagnosed. No evidence of family history is appropriate rather than no family history. In addition the unreliability of a negative family history is increased when patients with glaucoma fail to inform their family members. A finding of no family history can only be stated as no known family history. In examining the potential diagnostic contribution from a patient history, this review considers, age, frailty, race, type and degree of refractive error, systemic hyper- and hypotension, vasospasm, migraine, pigmentary dispersion syndrome, pseudoexfoliation syndrome, obstructive sleep apnea syndrome, diabetes, medication interactions and side effects, the degree of exposure to intraocular and intracranial pressure elevations and fluctuations, smoking, and symptoms in addition to genetics and family history of the disease.

Topical medication instillation techniques for glaucoma

BACKGROUND

Glaucoma is a leading cause of irreversible blindness worldwide and the second most common cause of blindness after cataracts. The primary treatment for glaucoma aims to lower intraocular pressure (IOP) with the use of topical medicines. Topical medication instillation techniques, such as eyelid closure and nasolacrimal occlusion when instilling drops, have been proposed as potential methods to increase ocular absorption and decrease systemic absorption of the drops.

OBJECTIVES

To investigate the effectiveness of topical medication instillation techniques compared with usual care or another method of instillation of topical medication in the management of glaucoma or ocular hypertension.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 12), MEDLINE Ovid (1946 to 8 December 2016), Embase Ovid (1947 to 8 December 2016), PubMed (1948 to 8 December 2016), LILACS (Latin American and Caribbean Health Sciences Literature Database) (1982 to 8 December 2016), International Pharmaceutical Abstracts Database (1970 to 8 December 2016), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (last searched 13 May 2013), ClinicalTrials.gov (www.clinicaltrials.gov) (searched 8 December 2016) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en) (searched 8 December 2016). We did not use any date or language restrictions in the electronic searches for trials.

SELECTION CRITERIA

We included randomized controlled trials which had compared any topical medication instillation technique with usual care or a different method of instillation of topical medication.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened records from the searches for eligibility, assessed the risk of bias, and extracted data. We followed methods recommended by Cochrane.

MAIN RESULTS

We identified two trials (122 eyes of 61 participants) that had evaluated a topical medication instillation technique. We also identified two ongoing trials. Both included trials used a within-person design and administered prostaglandin monotherapy for glaucoma or ocular hypertension. Because the trials evaluated different instillation techniques and assessed different outcomes, we performed no meta-analysis.One trial, conducted in the US, evaluated the effect of eyelid closure (one and three minutes) versus no eyelid closure on lowering IOP. At one to two weeks' follow-up, reduction in IOP was similar in the eyelid closure group and the no eyelid closure group (mean difference (MD) -0.33 mmHg, 95% confidence interval (CI) -0.8 to 1.5; 51 participants; moderate-certainty evidence).The second trial, conducted in Italy, evaluated the effect of using an absorbent cloth to wipe excess fluid after instillation (fluid removal) versus not using an absorbent cloth (no removal) on reducing dermatologic adverse events. At four months' follow-up, eyelashes were shorter among eyes in the fluid removal group compared with the no fluid removal group (MD -1.70 mm, 95% CI -3.46 to 0.06; 10 participants; low-certainty evidence). Fewer eyes showed skin hyperpigmentation in the eyelid region towards the nose in the fluid removal group compared with the no removal group (RR 0.07, 95% CI 0.01 to 0.84; 10 participants; low-certainty evidence); however, the difference was uncertain in the eyelid region towards the temples (RR 0.44, 95% CI 0.07 to 2.66; 10 participants; low-certainty evidence). The effect hypertrichosis (excessive hair growth) was uncertain between groups (RR 1.00, 95% CI 0.17 to 5.98; 10 participants; low-certainty evidence).Neither trial reported other outcomes specified for this review, including the proportion of participants with IOP less than 21 mmHg; participant-reported outcomes related to the ease, convenience, and comfort of instillation techniques; physiologic measurements of systemic absorption; escalation of therapy; mean change in visual fields; optic nerve progression; mean change in best-corrected visual acuity; proportion in whom glaucoma developed; quality of life outcomes; or cost-effectiveness outcomes. Neither trial reported data at follow-up times of more than four months.

AUTHORS' CONCLUSIONS

Evidence to evaluate the effectiveness of topical medication instillation techniques for treatment of glaucoma is lacking. It is unclear what, if any, effects instillation techniques have on topical medical therapy for glaucoma.

Comprasion of ICare rebound tonometer and Goldmann applanation tonometer in high myopia

Purpose. To compare intraocular pressure (IOP) measurements with the Goldmann applanation tonometer (GAT) and the ICare rebound tonometer (RBT) in high myopic eyes. Patients and Methods. This randomized prospective study included 40 eyes of 40 patients with high myopia. All patients' central corneal thickness (CCT), anterior chamber depth (ACD), axial length (AXL), keratometry, and refractive measurements were recorded and followed by IOP measurement with RBT and GAT. Results. The average CCT, AXL, and ACD were determined to be 514.65 ± 32 μm, 27.65 ± 2.22 mm, and 3.25 ± 0.51 mm, respectively. Mean K was 43.27 ± 1.4 D and mean spherical equivalent was −11.31 ± 4.30 D. The mean IOP values obtained by RBT and GAT were 17.18 ± 3.72 mmHg and 16.48 ± 3.19 mmHg, respectively. The deviations of RBT readings from corrected GAT values were highly correlated with CCT values (r = 0.588, P = 0.0001). The mean corrected GAT reading was 17.49 ± 3.01 mmHg. Linear regression analysis showed that a CCT change of 10 μm resulted in an RBT reading deviation of 0.57 mmHg. The Bland-Altman scatter-plot and McNemar test showed a clinically good level of agreement between the two tonometers. Conclusion. This study found a good agreement level between the two tonometers in high myopic patients and that RBT measurements are influenced by CCT variations.

High-risk populations for vision loss and eye care underutilization: a review of the literature and ideas on moving forward

Much work has been done to highlight and understand the significant disparities in the use of eye care services, but they continue to exist. We review the existing literature on utilization in high-risk populations to provide a context for understanding what "high-risk" means, to understand the utilization patterns among high-risk populations, and to highlight barriers to appropriate eye care utilization. We also discuss potential approaches to reduce these disparities.

Comparison of newly diagnosed ocular hypertension and open-angle glaucoma: ocular variables, risk factors, and disease severity

Purpose. To describe the distribution of ocular variables, risk factors, and disease severity in newly diagnosed ocular hypertension (OH) or open-angle glaucoma (OAG). Methods. Eligible subjects underwent a complete history and examination. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) obtained from multiple logistic regression models were used to compare OAG to OH and advanced to early/moderate OAG. Results. 405 subjects were enrolled: 292 (72.1%) with OAG and 113 (27.9%) with OH. 51.7% had early, 27.1% moderate, and 20.9% advanced OAG. The OR for OAG versus OH was 8.19 (P < 0.0001) for disc notch, 5.36 (P < 0.0001) for abnormal visual field, 1.45 (P = 0.001) for worsening mean deviation, 1.91 (P < 0.0001) for increased cupping, 1.03 for increased age (P = 0.030), and 0.36 (P = 0.010) for smoking. Conclusions. Increased age was a risk for OAG, and smoking decreased the risk of OAG compared to OH. Almost half of the OAG subjects had moderate/advanced disease at diagnosis.

[Is myopia a risk factor for glaucoma?]

Controversy exists in the literature concerning the role of axial myopia as a risk factor for primary open-angle glaucoma. Epidemiologic evidence suggests that moderate and especially high myopia with a refractive error exceeding -6D is a risk factor for the development and the progression of glaucomatous optic neuropathy, with a twofold to threefold increased risk of glaucoma compared with that of nonmyopic subjects. This risk has been proven to be independent of other glaucoma risk factors and intraocular pressure (IOP). Myopic eyes have slightly although probably not clinically relevant, higher IOPs than emmetropic or hyperopic eyes. Selection bias could account for some of the reported association between glaucoma and myopia given that myopic subjects are likely to consult their ophthalmologist more frequently and glaucoma is underdiagnosed in myopic patients due to the great variability of their optic disc morphology, especially in high myopia, and the difficulty to interpret their visual field. The weakness of the fibroglial matrix of the nerve fibers at the optic disc together with the structural alterations in the lamina cribrosa and choroid, could contribute to the high susceptibility of the optic disc to IOP fluctuations and to increasing the risk of glaucomatous neuropathy, especially in high myopic eyes. Special attention will be given to patients with mild myopia who present with both elevated IOP levels and a positive family history. On the other hand, high myopic subjects should be screened for glaucoma at closer intervals. Moreover, after appropriate adjustments for deviations in central corneal thickness have been made, IOP greater than 17 mmHg must already be regarded as critical and initiation of medical treatment considered.

Increased intraocular pressure on the first postoperative day following resident-performed cataract surgery

PURPOSE

The aim of this study was to investigate the incidence of intraocular pressure (IOP) elevation after resident-performed cataract surgery and to determine variables, which influence postoperative day 1 (POD1) IOP.

METHODS

In all, 1111 consecutive cataract surgeries performed only by training residents between 1 July 2001 and 30 June 2006 were included. Elevated IOP was defined as ≥23 mm Hg. Surgeries were classified according to the presence of POD1-IOP elevation. Fisher's exact test and Student t-test were used to compare both groups. Multivariate analyses using generalized estimating equations were performed to investigate predictor variables associated with POD1-IOP elevation.

RESULTS

The average preoperative IOP was 16.0±3.2 mm Hg and the average POD1-IOP was 19.3±7.1 mm Hg, reflecting a significant increase in IOP (P<0.001, paired t-test). The incidence of POD1-IOP elevation ≥23 mm Hg was 22.0% (244/1111). Presence of glaucoma and ocular hypertension, higher preoperative IOP, and longer axial length were frequently encountered variables in the POD1-IOP elevation group (all P<0.05). Using a multivariate analysis, presence of glaucoma (P=0.004, OR=2.38; 95% confidence interval (95% CI)=1.31-4.30), presence of ocular hypertension (P=0.003, OR=6.09; 95% CI=1.81-20.47), higher preoperative IOP (P<0.001, OR=3.73; 95% CI=1.92-7.25), and longer axial length (P=0.01, OR=1.15; 95% CI=1.03-1.29) were significant predictive factors for POD1-IOP elevation.

CONCLUSIONS

IOP elevation on the first postoperative day following resident-performed cataract surgery occurred frequently (22.0%). Increased early postoperative IOP was associated with presence of glaucoma and ocular hypertension, higher preoperative IOP, and longer axial length.

Association between intraocular pressure variation and glaucoma progression: data from a United States chart review

PURPOSE

To evaluate whether greater intraocular pressure (IOP) variation between visits was associated with higher likelihood of glaucoma progression.

DESIGN

Cohort study.

METHODS

A five-year minimum of data (June 1, 1990 through January 22, 2002) was collected on 151 patients (302 eyes) from 12 United States specialty centers. A post hoc analysis of visual field (VF) progression, glaucoma medication, intraocular pressure (IOP), and other ocular data was conducted for two nonmutually exclusive cohorts based on retrospective data abstracted well after actual patient visits. Mean IOP and standard deviations (SD) were calculated before treatment (medication or surgery) or progression, whichever occurred first, and before progression regardless of treatment. IOP variables were assessed in a univariate fashion; Cox proportional hazards models evaluated glaucoma progression as an outcome measure and IOP SD as a main predictor, controlling for covariates.

RESULTS

In cohort 1 (55 patients; 84 eyes), mean age was 63 years (range, 37 to 85 years), 58% were female, and 19% of eyes underwent VF progression. In cohort 2 (129 patients; 251 eyes), mean age was 66 years (range, 19 to 88 years), 55% were female, and 27% of eyes underwent VF progression. Mean IOP was 16.5 mm Hg (IOP SD, 2.0 mm Hg), and 16.4 mm Hg (IOP SD, 2.7 mm Hg) in cohorts 1 and 2, respectively. Controlling for age, mean IOP, VF stage, and other covariates, each unit increase in IOP SD resulted in a 4.2 times and 5.5 times higher risk of glaucoma progression for cohort 1 (95% confidence interval [CI], 1.3 to 12.9) and cohort 2 (95% CI, 3.4 to 9.1), respectively.

CONCLUSIONS

IOP variability is an important predictor of glaucoma progression; SD is a convenient measure of variability to assess glaucoma progression risk.

The influence of corneal properties on rebound tonometry

PURPOSE

To determine the influence of corneal thickness, corneal hysteresis (CH), and corneal resistance factor (CRF) on intraocular pressure (IOP) measurements obtained using the iCARE rebound tonometer.

DESIGN

Cross-sectional study.

PARTICIPANTS

One hundred twenty-five eyes of 125 normal healthy subjects.

METHODS

Intraocular pressure was determined in all subjects using the iCARE at both central and temporal corneal regions. Corneal thickness at these 2 regions was determined by ultrasonic pachymetry. Corneal hysteresis and corneal resistance factor were measured using an ocular response analyzer. Goldmann applanation tonometry (GAT) was also performed on all eyes.

MAIN OUTCOME MEASURES

Intraocular pressure, corneal thickness, corneal hysteresis, and corneal resistance factor.

RESULTS

Although the peripheral cornea was significantly thicker than the central cornea, IOPs obtained by the iCARE at the 2 regions were similar and significantly higher than GAT measurements. There were an overestimation at higher IOPs and an underestimation at lower IOPs relative to GAT measurements. Multiple regression analysis showed a significant correlation between the iCARE and CH (partial correlation r = -0.67, P<0.01) and CRF (partial correlation r = 0.82, P<0.01). The correlation between the iCARE and central corneal thickness was not significant.

CONCLUSIONS

Rebound tonometry is affected by corneal properties including CH and CRF but not corneal thickness.

Risk Factors and Open-angle Glaucoma: Classification and Application

Decades of epidemiologic research into open-angle glaucoma have elucidated several risk factors related in some way to the disease. As more and more risk factors are identified, however, assessing their individual and collective contributions in a particular patient is becoming increasingly complicated. To help organize our knowledge of risk in glaucoma we first review some concepts of risk and then propose a scheme that places known risk factors into categories (state of the individual, ocular anatomy and physiology, signs of disease, non-glaucoma medications, and personal behaviors) and also indicates how each factor interacts with disease (incidence, prevalence, progression, therapy.) We also describe methods for using risk factors in clinical practice and describe ways that a large and complex body of knowledge can be applied to individual patients.

Self-reported glaucoma in Canada: findings from population-based surveys, 1994-2003

BACKGROUND

To provide population estimates and 10-year trends in the self-reported prevalence of glaucoma in Canada, including age and sex profiles, frequency of contact with eye specialists, and associated chronic medical conditions.

METHODS

Analyses were based on cross-sectional, self-reported data for ages >or=20 years from 5 national surveys: the 1994-95, 1996-97, and 1998-99 National Population Health Survey (minimum sample size [n] = 33 153) and the 2000-01 and 2002-03 Canadian Community Health Survey (min n = 113 212). Prevalence estimates were derived from descriptive analyses; multivariate logistic regression analyses examined the association of income, education, and chronic medical conditions with the likelihood of reporting glaucoma.

RESULTS

In 2002-03, an estimated 409,000 Canadians had glaucoma, including 2.7% of those >or=40 years and 11% of those >or=80 years. Overall, the prevalence of self-reported glaucoma increased from 1.1% in 1994-95 to 1.8% in 2002-03 (p < 0.01). Significant increases in age-specific prevalences over time were also observed in 4 of 6 age groups. In total, 14% of respondents with glaucoma reported no recent contact with an eye specialist. Arthritis (and other rheumatic conditions), high blood pressure, migraines, and diabetes were associated with glaucoma.

INTERPRETATION

Our review suggests glaucoma is at least as prevalent in Canada as in other Western nations. It is most common in the over-80 age group and appears to be associated with other medical conditions.

Vascular risk factors in glaucoma: the results of a national survey

BACKGROUND

The role of vascular risk factors in glaucoma is still being debated. To assess the importance of vascular risk factors in patients with primary open-angle glaucoma (POAG), data from the medical history of 2,879 POAG patients and 973 age-matched controls were collected and analyzed.

METHODS

DESIGN

observational survey.

SETTING

35 Italian academic centers.

STUDY POPULATION

POAG patients and age-matched controls. In order to reduce bias consecutive patients were included.

OBSERVATION PROCEDURES

data concerning vascular risk factors were collected for all patients with a detailed questionnaire. A complete ophthalmological examination with assessment of intraocular pressure (IOP), visual field, optic disc, and systemic blood pressure was performed.

MAIN OUTCOME MEASURES

the ESH-ESC (European Society of Hypertension-European Society of Cardiology) guidelines were used to calculate the level of cardiovascular risk. Crude and adjusted estimates of the odds ratios (OR) were calculated for all cardiovascular risk factors in POAG and controls.

RESULTS

The study included 2,879 POAG patients and 973 controls. POAG cases had a significantly higher systolic and diastolic blood pressure (p = 0.001) and systolic perfusion pressure (p = 0.02) as compared with controls. Also mean IOP was significantly higher in the POAG group (p = 0.01), while diastolic perfusion pressure was not significantly different in the two groups. Myopia was more prevalent in the POAG group (23 vs 18%, p = 0.005) as well as a positive family history for glaucoma (26 vs 12%, p = 0.004). POAG patients tended to have a higher cardiovascular risk than controls: 63% of glaucoma cases vs 55% of controls (OR: 1.38, p = 0.005) had a "high" or "very high" cardiovascular risk.

CONCLUSIONS

The level of cardiovascular risk was significantly higher in glaucoma patients than in controls.

Comparison of ICare Tonometer with Goldmann Applanation Tonometer in Glaucoma Patients

PURPOSE

To compare the intraocular pressure (IOP) readings taken with the new ICare tonometer and with the Goldmann applanation tonometer (GAT) and to evaluate the influence of central corneal thickness (CCT) on the IOP measurements.

PATIENTS AND METHODS

One eye of 178 consecutive patients with primary open-angle glaucoma underwent ultrasonic CCT measurement, followed by IOP evaluation with the GAT and with the ICare tonometer. The deviation of ICare readings from GAT values, corrected according to the Doughty and Zaman formula, was calculated and correlated to CCT by a linear regression model. The agreement between the 2 devices was assessed by use of the Bland-Altman method.

RESULTS

The average CCT was 552+/-39 mum. The mean IOP and the mean corrected IOP with GAT were 19.4+/-5.4 mm Hg, and 18.5+/-5.7 mm Hg, respectively. The mean ICare IOP reading was 18.4+/-5.2 mm Hg. The deviations of ICare readings from corrected GAT values were highly correlated with CCT values (r=0.63, P<0.01). Linear regression analysis showed that a CCT change of 10 mum resulted in an ICare reading deviation of 0.7 mm Hg. The Bland-Altman scatter-plot showed a reasonable agreement between the 2 tonometers.

CONCLUSIONS

The ICare tonometer can be useful in a routine clinical setting. The IOP readings are quite in accordance with those obtained by GAT. The measurements seemed to be influenced by CCT variations, and thus pachymetry should always be taken into consideration.

Predictive factors for glaucomatous visual field progression in the Advanced Glaucoma Intervention Study

PURPOSE

To investigate the risk factors associated with visual field (VF) progression in the Advanced Glaucoma Intervention Study (AGIS) with pointwise linear regression (PLR) analysis of serial VFs.

DESIGN

Prospective, multicenter, randomized clinical trial.

PARTICIPANTS

Five hundred nine eyes of 401 patients from the AGIS with a baseline VF score of <or=16, >or=7 VF examinations, and >or=3 years of follow-up were selected.

MAIN OUTCOME MEASURE

Visual field progression.

METHODS

This is a cohort study of patients enrolled in a prospective randomized clinical trial (AGIS). Worsening of a test location on PLR analysis was defined as a change of threshold sensitivity of >or=1.00 decibels a year, with P<or=0.01. Visual field progression was defined as worsening of at least 2 test locations within a Glaucoma Hemifield Test cluster with PLR analysis. Multivariate logistic regression was used to determine risk factors associated with VF worsening. Intraocular pressure (IOP) fluctuation was defined as standard deviation of the IOP at all visits after the initial surgery.

RESULTS

The mean (+/- standard deviation) follow-up time and baseline AGIS score were 7.4 (+/-1.7) years and 7.7 (+/-4.4), respectively. Visual field progression was detected with PLR analysis in 151 eyes (30%). Older age at the initial intervention (P = 0.0012; odds ratio [OR], 1.30; 95% confidence interval [CI], 1.11-1.50), larger IOP fluctuation (P = 0.0013; OR, 1.31; 95% CI, 1.12-1.54), increasing number of glaucoma interventions (P = 0.01; OR, 1.74; 95% CI, 1.14-2.64), and longer follow-up (P = 0.02; OR, 1.19; 95% CI, 1.03-1.38) were associated with increased odds of VF progression. When regression analyses were repeated in eyes with and without a history of cataract extraction, IOP fluctuation was the only variable to be consistently associated with VF progression.

CONCLUSION

Both increasing age and greater IOP fluctuation increase the odds of VF progression by 30% (for each 5-year increment in age and 1-mmHg increase in IOP fluctuation). The higher risk conferred by IOP fluctuation was consistently observed in eyes with and without a history of cataract extraction.

An evidence-based assessment of risk factors for the progression of ocular hypertension and glaucoma

PURPOSE

To critically review the existing literature concerning risk factors for progression of ocular hypertension and glaucoma to assist in assigning levels of risk for individual patients.

DESIGN

Evidence-based review.

METHODS

A panel of physicians specializing in treatment of glaucoma patients was convened to critically analyze published population-based studies of ocular hypertension and glaucoma progression. The strength of evidence in support of reported risk factors was weighed.

RESULTS

Many putative risk factors for progression of ocular hypertension or glaucoma have been reported in the literature. The risk factors most strongly supported by evidence are higher intraocular pressure (IOP), greater cup-to-disk ratio, thinner central corneal measurement, and older age. Black race does not appear to be an independent risk factor, although black individuals tend to have thinner corneas, greater cup-to-disk ratios, and higher IOP, which increase their risk. The limited number of studies in which other suspected risk factors are reported prevents drawing firm conclusions about their importance at this time.

CONCLUSIONS

Only a subset of patients with ocular hypertension will eventually develop glaucoma. Decisions regarding the implementation and extent of therapy for ocular hypertension can be difficult and require an understanding of the relative importance of risk factors for progression. This review discusses the strength of evidence supporting reported risk factors and may be useful in assessing the risk for progression of individual patients.

Self-tonometry with the Ocuton S: evaluation of accuracy in glaucoma patients

BACKGROUND

To compare two methods of measuring intraocular pressure (IOP) and to evaluate whether repeated measurements taken with the Ocuton S applanation self-tonometer can improve reliability.

METHODS

Ocuton S and Goldmann applanation tonometry (GAT), and corneal thickness measurements taken with the Orbscan topography system, were successfully performed in 64 of 68 glaucoma patients.

RESULTS

The median IOPs were 15.5 mmHg using GAT, and 16 mmHg using the first self-taken Ocuton S measurement (n = 64). The differences between the median of the GAT measurements and the first Ocuton S measurement, and the medians of the three and six separate Ocuton S measurements were within 3 mmHg in 52%, 59% and 67% of cases, respectively. The mean corneal thickness of all evaluated eyes was 545.3 microm. There was no effect of corneal thickness on the accuracy of either of the two devices (p > 0.05).

CONCLUSION

Repeated measurements can improve the reliability of the Ocuton S. However, even with repeated measurements only every second patient succeeds in obtaining reliable measurements.