A critical reevaluation of current glaucoma management: International Glaucoma Think Tank, July 27-29, 2006, Taormina, Sicily

Frontloading visual field tests detect earlier mean deviation progression when applied to real-world-derived early-stage glaucoma data

PURPOSE

To examine the diagnostic accuracy of performing two (frontloaded) versus one (clinical standard) visual field (VF) test per visit for detecting the progression of early glaucoma in data derived from clinical populations.

METHODS

A computer simulation model was used to follow the VFs of 10,000 glaucoma patients (derived from two cohorts: Heijl et al., Swedish cohort; and Chauhan et al., Canadian Glaucoma Study [CGS]) over a 10-year period to identify patients whose mean deviation (MD) progression was detected. Core data (baseline MD and progression rates) were extracted from two studies in clinical cohorts of glaucoma, which were modulated using SITA-Faster variability characteristics from previous work. Additional variables included follow-up intervals (six-monthly or yearly) and rates of perimetric data loss for any reason (0%, 15% and 30%). The main outcome measures were the proportions of progressors detected.

RESULTS

When the Swedish cohort was reviewed six-monthly, the frontloaded strategy detected more progressors compared to the non-frontloaded method up to years 8, 9 and 10 of follow-up for 0%, 15% and 30% data loss conditions. The time required to detect 50% of cases was 1.0-1.5 years less for frontloading compared to non-frontloading. At 4 years, frontloading increased detection by 26.7%, 28.7% and 32.4% for 0%, 15% and 30% data loss conditions, respectively. Where both techniques detected progression, frontloading detected progressors earlier compared to the non-frontloaded strategy (78.5%-81.5% and by 1.0-1.3 years when reviewed six-monthly; 81%-82.9% and by 1.2-2.1 years when reviewed yearly). Accordingly, these patients had less severe MD scores (six-monthly review: 0.63-1.67 dB 'saved'; yearly review: 1.10-2.87 dB). The differences increased with higher rates of data loss. Similar tendencies were noted when applied to the CGS cohort.

CONCLUSIONS

Frontloaded VFs applied to clinical distributions of MD and progression led to earlier detection of early glaucoma progression.

A Novel Think Tank Program to Promote Innovation and Strategic Planning in Ophthalmic Surgery

Background

Continuous quality improvement is a pillar of all surgical groups. Innovation is a critical aspect to continuously improve, but traditional staff retreats have several disadvantages which limit their utility in identifying needs and developing innovative solutions. To address these challenges, we designed the novel Think Tank Program to spur innovation and strategic planning for an academic ophthalmology department including the Kellogg Eye Center 6 operating rooms.

Methods

The Think Tank program is a structured seven-phase program for faculty in small teams to identify, innovate, and implement meaningful change. Participants brainstormed problems and possible solutions to those problems, formed teams, acquired data, and implemented meaningful change in clinical care, research, education, and administration.

Results

The program generated 19 novel proposals and significant faculty engagement and discussion in improving the department. A case example of improving the operating room (OR) utilization resulted in improved OR utilization from 63.8% to 74.6% over a 3 month period before and after implementation. It also resulted in a reduction of cancelled or rescheduled surgeries within 2 weeks or surgery from 29.8% to 15.2%. This resulted in an estimated positive financial margin of over $141,000 to the institution in addition to improvement in patient, surgeon, and staff satisfaction with the quality of care.

Conclusions

Engaged faculty, critical data analysis, and value proposition analysis with data-driven metrics and accountability can result in a significant increase in OR utilization and reduction in surgical cancellations. Think Tank serves as a model transformative program to assist practices and institutions to best fulfill their mission while actively engaging and retaining their members.

Classification and Statistical Trend Analysis in Detecting Glaucomatous Visual Field Progression

Aim

To evaluate the agreement between different methods in detection of glaucomatous visual field progression using two classification-based methods and four statistical approaches based on trend analysis.

Methods

This is a retrospective and longitudinal study. Twenty Caucasian patients (mean age 73.8 ± 13.43 years) with open-angle glaucoma were recruited in the study. Each visual field was assessed by Humphrey Field Analyzer, program SITA standard 30-2 or 24-2 (Carl Zeiss Meditec, Inc., Dublin, CA). Full threshold strategy was also accepted for baseline tests. Progression was analyzed by using Hodapp-Parrish-Anderson classification and the Advanced Glaucoma Intervention Study visual field defect score. For the statistical analysis, linear regression (r ²) was calculated for mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI), and when it was significant, each series of visual field was considered progressive. We also used Progressor to look for a significant progression of each visual field series. The agreement between methods, based on statistical analysis and classification, was evaluated using a weighted kappa statistic.

Results

Thirty-eight visual field series were analyzed. The mean follow-up time was 6.2 ± 1.53 years (mean ± standard deviation). At baseline, the mean MD was -7.34 ± 7.18 dB; at the end of the follow-up, the mean MD was -9.25 ± 8.65 dB; this difference was statistically significant (p < 0.001). The agreement to detect progression was fair between all methods based on statistical analysis and classification except for PSD r ². A substantial agreement (κ = 0.698 ± 0.126) was found between MD r ² and VFI r ². With the use of all the statistical analysis, there was a better time-saving.

Conclusions

The best agreement to detect progression was found between MD r ² and VFI r ². VFI r ² showed the best agreement with all the other methods. GPA2 can help ophthalmologists to detect glaucoma progression and to help in treatment decisions. PSD r ² was the worse method to detect progression.

Effects of different sleeping positions on intraocular pressure in secondary open-angle glaucoma and glaucoma suspect patients

Purpose

The aim of this study was to investigate the effects of different recumbent sleeping positions of the head and body on intraocular pressure (IOP) in secondary open-angle glaucoma and glaucoma suspect patients, specifically pigmentary dispersion (PD) as measured using the ICare rebound tonometer.

Patients and methods

A total of 44 eyes of 24 patients with PD were selected in this study. The IOP of 44 eyes was measured in the initial seated position, in the 4 recumbent positions, and again in the sitting position between each of the recumbent positions.

Results

The IOP of the right eyes and left eyes was higher in each of the 4 recumbent positions compared to its initial sitting position (all P<0.001). Dependent (D) vs nondependent (ND) comparisons failed to show a significant difference. All lateral vs prone comparisons showed a higher average IOP in the prone position than in the lateral position regardless of D vs ND status. The range of recumbent IOP changes was -4 to +17 mmHg or -17% to +142%. A total of 64% had at least a ≥33% IOP increase with 43% having a ≥50% increase.

Conclusion

Lateral and prone sleeping positions usually do result in significant elevations of IOP in PD patients. Dependency status did not make a difference. A significantly larger IOP increase was seen in the prone position than in the lateral position. The presence of 3 clinical variables (disk hemorrhage [DH], notches, and BV changes) might increase the chances of developing a large recumbent increase in IOP. These patients and possibly all PD syndrome (PDS) or PD glaucoma (PDG) patients should consider sleeping in a bed that allows a head elevation of 30°.

Detectability of Visual Field Defects in Glaucoma With High-resolution Perimetry

PURPOSE

To extrapolate the optimal test point resolution for assessment of glaucomatous visual field (VF) defects including subtle functional defects, we performed high-resolution perimetry with the 0.5 degrees test point resolution.

SUBJECTS AND METHODS

Subjects were 11 eyes of 11 normal volunteers and 16 eyes of 16 glaucomatous patients. Octopus 900 custom test was used to measure 61 points with the test point resolution of 0.5 degrees on the temporal meridian of 45 degrees within the eccentricity of 30 degrees. In the glaucoma cases, VF profiles were extracted in 17 patterns of the test point resolutions that ranged from 0.5 to 8.5 degrees and the mean defect (MD), square root of loss variance (sLV), and maximum sensitivity loss (Max loss) were calculated. The influence of the test point resolution on MD, sLV, and Max loss was examined. In addition, the test range from the fixation point to the eccentricity of 30 degrees was divided into 3 zones. Similarly, each zone was investigated if the test point resolution exerted influence on the MD, sLV, and Max loss.

RESULTS

Our glaucoma cases did not show any significant differences in MD and sLV regardless of the resolution. Max loss showed significant difference at resolution ≥1.0 degree. MD and sLV did not show significant differences by the change of resolution in each zone. Max loss showed significant differences at resolution ≥1.5 degrees within the central 10 degrees.

CONCLUSIONS

To detect subtle VF defects within the eccentricity of 10 degrees, high-resolution perimetry with the test point resolution of <1.5 degrees is necessary.

Macular retinal and nerve fiber layer thickness in early glaucoma: clinical correlations

Purpose:

Previous studies have evaluated macular retinal thickness (RT) and nerve fiber layer thickness (RNFLT) changes in early glaucoma using elaborate optical coherence tomography (OCT) scanning protocols.

Materials and Methods:

This study examines RT and RNFLT using standard scanning protocols in early glaucoma. In this prospective, nonrandomized case series, 95 eyes of 95 patients were evaluated, including 29 nonglaucomatous subjects (control group), 34 glaucoma suspects, and 32 early manifest glaucoma patients. RT and RNFLT were measured using scanning fast macular thickness map and Fast RNFLT (3.4) protocols on a 1.70 mm radius around the macular center (respectively) in all four quadrants. The fast RNFLT (3.4) protocol was transposed on the macula from the peri-papillary area. Data were statistically analyzed for differences between groups, and for correlations between parameters. P<0.5 was statistically significant.

Results:

Both early manifest glaucoma patients and glaucoma suspects had significantly lower RT than controls in all quadrants. RNFLT differences in all quadrants were not statistically significant (P>0.05). RT was significantly inversely correlated with axial length in early manifest glaucoma patients and glaucoma suspects but not in controls.

Conclusions:

The finding that RT was significantly lower in early manifest glaucoma patients and glaucoma suspects indicates that the transposition of the OCT fast RNFL thickness (3.4) protocol from the peri-papillary area to the peri-macular area can be used for early glaucoma diagnosis. Intraretinal changes in early glaucoma, likely precede nerve fiber changes.

Assessing the Importance of IOP Variables in Glaucoma Using a Modified Delphi Process

PURPOSE

To assess the degree of consensus among glaucoma experts on the measurement, characterization, and potential implications of intraocular pressure (IOP) and its fluctuation for glaucoma treatment.

METHODS

A multinational panel of 9 glaucoma experts used a modified Delphi process to rate the level of agreement with 72 statements characterizing methods of measuring IOP, the importance of IOP reduction, and clinical implications of changes in IOP over time. After receiving a literature review, panelists rated each statement on a 9-point Likert scale. A panel meeting was held to discuss the ratings followed by a second round of independent ratings. Consensus and nonconsensus regarding the panel's agreement with each statement were determined using a binomially distributed statistical definition.

RESULTS

The panel found consensus in 46% of 81 statements, nonconsensus in 6%, and indeterminate status in 48%. Categories having the highest proportion of statements with consensus were importance of IOP reduction (4/4 statements), importance of long-term IOP fluctuation and reduction (6/9), and impact of medication on short-term and long-term IOP fluctuation (6/10 for each). Indeterminate statements were distributed unevenly with 74% of statements related to IOP measurement rated indeterminate compared with 38% related to the clinical implications of short-term and long-term IOP fluctuation.

CONCLUSIONS

A modified Delphi process was useful in identifying areas of consensus regarding IOP measurement and importance of IOP fluctuation among glaucoma experts. Concurrently, the need for additional investigations assessing the role of IOP changes in glaucoma management is highlighted by the indeterminate and nonconsensus ratings.

OPA1 increases the risk of normal but not high tension glaucoma

BACKGROUND

Primary open angle glaucoma is a progressive optic neuropathy characterised by the selective loss of retinal ganglion cells, pathological optic disc cupping and visual field defects. The OPA1 gene encodes an inner mitochondrial membrane protein crucial for normal mitochondrial function, and pathogenic mutations cause autosomal dominant optic atrophy by specifically targeting retinal ganglion cells. This raises the distinct possibility that more subtle genetic variations in OPA1 could alter the risk of developing glaucoma.

METHODS

137 patients with primary open angle glaucoma (67 patients with high-tension glaucoma (HTG), 70 patients with normal-tension glaucoma (NTG)) and 75 controls from the North East of England were studied. Three single-nucleotide polymorphisms in intron 8 (IVS8+4c-->t and IVS8+32t-->c) and exon 4 (c.473A-->G) of the OPA1 gene were genotyped in the study group. In addition, the entire OPA1 coding region was sequenced in 24 individuals with the CT/TT compound genotype using standard BigDye chemistries.

RESULTS

There was no difference in either allele or genotype frequency for the IVS8+32t-->c single-nucleotide polymorphisms between patients and controls, but there was a significant association between the T allele at IVS8+4c-->t and the risk of developing NTG (OR=2.04, 95% CI=1.10 to 3.81, p=0.004), but not HTG. Logistic regression analysis also confirmed a strong association between the CT/TT compound genotype at IVS8+4 and IVS8+32 with NTG (OR=29.75, 95% CI=3.83 to 231.21, p=0.001).

CONCLUSIONS

The CT/TT compound genotype at IVS8+4 and IVS8+32 is a strong genetic risk determinant for NTG but not HTG.

A critical discussion of the rates of progression and causes of optic nerve damage in glaucoma: International Glaucoma Think Tank II: July 25-26, 2008, Florence, Italy

The International Glaucoma Think Tank II brought together glaucoma clinicians and researchers from all over the world to discuss current practices in glaucoma diagnosis and management, and the neurobiology of glaucoma. The meeting focused on several themes, including rates of deterioration in glaucoma patients, mechanisms of optic nerve damage, and implications for treatment. Issues such as how to measure and integrate progression information into clinical practice, screening protocols, or trials were discussed, as were promising new technologies and limitations of currently available measurement tools. Clinical applications for genetic testing were considered. Study of the neurobiology of glaucoma continues to inform our understanding of underlying degenerative processes, as well as to introduce possibilities for early detection or prevention. Many questions regarding glaucoma pathophysiology and best treatment practices remain unanswered, but with continued research and discussion, we will advance our understanding of this disease and ensure that patients receive optimal care.

Unpredictability of glaucoma progression

BACKGROUND

Glaucoma is a chronic, progressive ocular neuropathy that leads to the loss of retinal ganglion cells and varying degrees of visual impairment or blindness.

MANAGEMENT

There are three major factors to consider in the management of patients with glaucoma. First, extensive damage to retinal ganglion cells often can occur before the appearance of any functional deficits is detected by perimetry. Second, the rate of glaucoma progression varies considerably among different patients and even for the same patient at different times. Third, the lack of correspondence between structural and functional change may reflect the limitations of current assays in measuring each. Given the variability of disease progression, early detection and continued vigilance of both structure and function in the form of regular patient monitoring are essential.

CONCLUSION

This review presents six case histories that demonstrate the differing rates of progression that may be observed in the clinic and the importance of early detection and treatment in controlling the disease. In addition, major lessons from randomised clinical trials are summarised, including the likelihood of progression from diagnosed ocular hypertension to the development of glaucoma, the risks of progression of established glaucoma and the effectiveness of therapy.

Progression: things we need to remember but often forget to think about

Detecting progression, and estimating the rate of change, are among the most important challenges in the care of patients with glaucoma. With rapidly developing technology, there is a need to rethink what we mean to measure, why we measure it, and how we think about these measurements and how they relate to the disease. This article outlines, informally, a small number of issues that may be important to clinicians and researchers alike but are not often discussed in the literature. It is intended to be useful as a highly selective minireview of recent work and a stimulus for future research. It is organized under three main headings that sum up the main message of each section.

Primary open angle glaucoma: an overview on medical therapy

The purpose of this review is to discuss the topics relevant to the use of intraocular pressure-lowering strategies, which remains the first line in the management of glaucoma. Estimates of blindness from glaucoma and identification of risk factors remain of interest for all ophthalmologists. New functional tests offer promise for better detection and more accurate diagnosis of glaucoma. We finally discuss the impact of various glaucoma therapies, the principles of monotherapy and fixed combinations, which offer benefits of convenience, cost, and safety.