Will Perimetry Be Performed to Monitor Glaucoma in 2025?

Visual field testing has played an essential role in the diagnosis and management of glaucoma for more than a century. Methods to examine the visual field have been refined from early kinetic perimetry to current standard automated perimetry (SAP). Clinicians now use SAP for the diagnosis and management of glaucoma throughout the world. Various testing paradigms and analytic methods have been developed to simplify the diagnosis of glaucoma and the interpretation of progression. Moreover, strategies have been implemented to improve patient experience with visual field testing and to increase reliability. Objective functional tests, such as electroretinography, provide an alternative to subjective visual field testing but are not yet ready for widespread adoption. Standard automated perimetry is being adapted and improved constantly. New devices may allow patients to complete visual field tests at home, which could relieve patients and clinicians from in-office testing and allow for more frequent examinations. Glaucoma detection and progression analysis also are incorporating progressively more information and will be improved as deep learning strategies are applied. Finally, perimetric and structural testing likely will become more closely intertwined as testing platforms and progression analysis incorporate both of these measures. Visual field testing will continue to have an important role in the diagnosis and management of glaucoma.

Trends in use of ancillary glaucoma tests for patients with open-angle glaucoma from 2001 to 2009.

PURPOSE: To assess trends in the use of ancillary diagnostic tests in the evaluation of patients with open-angle glaucoma (OAG) and glaucoma suspects over the past decade. DESIGN: Retrospective, longitudinal cohort analysis. PARTICIPANTS: A total of 169 917 individuals with OAG and 395 721 individuals with suspected glaucoma aged ≥40 years enrolled in a national United States managed care network between 2001 and 2009. METHODS: Claims data were analyzed to assess trends in visual field (VF) testing, fundus photography (FP), and other ocular imaging (OOI) testing for patients with OAG or suspected glaucoma between 2001 and 2009. Repeated-measures logistic regression was performed to identify differences in the odds of undergoing these procedures in 2001, 2005, and 2009 and whether differences exist for patients under the exclusive care of optometrists versus ophthalmologists. MAIN OUTCOME MEASURES: Odds and annual probabilities of undergoing VF testing, FP, and OOI for OAG from 2001 to 2009. RESULTS: For patients with OAG, the odds of undergoing VF testing decreased by 36% from 2001 to 2005, by 12% from 2005 to 2009, and by 44% from 2001 to 2009. By comparison, the odds of having OOI increased by 100% from 2001 to 2005, by 24% from 2005 to 2009, and by 147% from 2001 to 2009. Probabilities of undergoing FP were relatively low (13%-25%) for both provider types and remained fairly steady over the decade. For patients cared for exclusively by optometrists, the probability of VF testing decreased from 66% in 2001 to 44% in 2009. Among those seen exclusively by ophthalmologists, the probability of VF testing decreased from 65% in 2001 to 51% in 2009. The probability of undergoing OOI increased from 26% in 2001 to 47% in 2009 for patients of optometrists and from 30% in 2001 to 46% in 2009 for patients of ophthalmologists. By 2008, patients with OAG receiving care exclusively by optometrists had a higher probability of undergoing OOI than VF testing. CONCLUSIONS: From 2001 to 2009, OOI increased dramatically whereas VF testing declined considerably. Because OOI has not been shown to be as effective at detecting OAG or disease progression compared with VF testing, increased reliance on OOI technology, in lieu of VF testing, may be detrimental to patient care.

A history of perimetry and visual field testing.

Perimetry and visual field testing have been used as clinical ophthalmic diagnostic tools for many years, and this manuscript will provide a brief historical overview of these procedures and the individuals who developed them. Today, we have many different forms of perimetry that are designed to evaluate different locations within the visual pathways and various mechanisms and subsets of mechanisms within the visual system. However, the most widely used method of performing perimetry and visual field testing has not substantially changed for more than 150 years, consisting of detecting a small target superimposed on a uniform background at different locations within the field of view. Although the basic test procedure has remained similar throughout the ages, there have been many advances in test administration, standardization, statistical evaluation, clinical analysis, interpretation, and prediction of outcome based on visual field findings.

Brain Morphometric and Functional Magnetic Resonance Imaging Study on Patients with Visual Field Defects Resulting from Suprasellar Tumors: Preoperative and Postoperative Assessment.

OBJECTIVE: The aim of this study was to investigate the structural and functional changes in the visual cortex in patients with suprasellar tumor with recovery of visual field defects at different times before and after surgical decompression of the optic nerves. METHODS: Twenty-one patients with suprasellar tumor with visual field defects were scanned with structural images and resting-state functional magnetic resonance imaging at 1 week preoperation, 1 week postoperation, and 1 month postoperation. Paired-sample t test was performed on the gray matter volume (GMV) within the occipital cortex, and the significance level was set at false discovery rate (FDR)-adjusted P < 0.05 voxel level to define the region of interest (ROI). One-way analysis of variance was performed on GMV and amplitude of low frequency fluctuation (ALFF) within the ROI. Pearson coefficients were calculated between changes of GMV and ALFF within the ROI and clinical factors. RESULTS: The GMV in the bilateral pericalcarine cortex increased significantly at 1 month postoperation compared with the preoperative period (FDR-adjusted P < 0.05), with correlation to visual field defects. ALFF values in the bilateral pericalcarine cortex at 1 month postoperation were significantly higher than preoperative values. CONCLUSIONS: The postoperative visual improvement can be reflected in the increased GMV and ALFF of the bilateral pericalcarine cortex at 1 month postoperation, which suggests that an experience-dependent plasticity of the visual cortex was induced by an increase in sensory input.

Macular function surveillance revisited.

BACKGROUND: The Amsler grid is a widely used means of evaluating the central 20 degrees diameter visual field. It is a common practice to have patients who are at risk for exudative maculopathy evaluate their macular function daily using the Amsler grid. The goal is to make the patient aware of the earliest symptoms of choroidal neovascularization at a time when therapeutic intervention has the greatest chance for success. There are, however, several important shortcomings of self-monitoring macular function with the Amsler grid, including low sensitivity and low compliance. METHODS: The history of macular function surveillance is reviewed. The following techniques that are either currently available or under development for home self-monitoring of macular function are discussed: Amsler grid, red Amsler grid, threshold Amsler grid, environmental Amsler techniques, entoptic perimetry, preferential hyperacuity perimetry, and Internet-based interventions. CONCLUSION: There is compelling evidence that several currently available technologies are superior to the conventional Amsler grid in detecting the earliest symptoms of macular disease. Threshold Amsler grid, entoptic perimetry, and preferential hyperacuity perimetry each have been found to be more sensitive than the conventional Amsler grid in detecting vision disturbances caused by macular disease. Any one of these diagnostic tests could conceivably be utilized by patients at home for self-monitoring of macular function if the technology were suitably deployed for this purpose, such as over the Internet.

Recent developments in perimetry: test stimuli and procedures.

Automated perimetry has evolved substantially in recent years, in part due to modern computer technology that enables more complex visual stimuli and test procedures to be realised than those incorporated in traditional white-on-white luminance increment perimetry. This paper reviews briefly a number of advances in automated perimetry. The review includes discussion of new test types: frequency doubling technology perimetry, short wavelength automated perimetry, flicker perimetry, high-pass resolution perimetry and rarebit perimetry. Test algorithms applied to perimetry such as zippy estimation of sequential thresholds (ZEST), Swedish interactive thresholding algorithm (SITA), tendency-oriented perimetry (TOP) and multi-sampling supra-threshold perimetry are also discussed.

Improving glaucoma detection using spatially correspondent clusters of damage and by combining standard automated perimetry and optical coherence tomography.

PURPOSE: To improve the detection of glaucoma, techniques for assessing local patterns of damage and for combining structure and function were developed. METHODS: Standard automated perimetry (SAP) and frequency-domain optical coherence tomography (fdOCT) data, consisting of macular retinal ganglion cell plus inner plexiform layer (mRGCPL) as well as macular and optic disc retinal nerve fiber layer (mRNFL and dRNFL) thicknesses, were collected from 52 eyes of 52 healthy controls and 156 eyes of 96 glaucoma suspects and patients. In addition to generating simple global metrics, SAP and fdOCT data were searched for contiguous clusters of abnormal points and converted to a continuous metric (pcc). The pcc metric, along with simpler methods, was used to combine the information from the SAP and fdOCT. The performance of different methods was assessed using the area under receiver operator characteristic curves (AROC scores). RESULTS: The pcc metric performed better than simple global measures for both the fdOCT and SAP. The best combined structure-function metric (mRGCPL&SAP pcc, AROC = 0.868 ± 0.032) was better (statistically significant) than the best metrics for independent measures of structure and function. When SAP was used as part of the inclusion and exclusion criteria, AROC scores increased for all metrics, including the best combined structure-function metric (AROC = 0.975 ± 0.014). CONCLUSIONS: A combined structure-function metric improved the detection of glaucomatous eyes. Overall, the primary sources of value-added for glaucoma detection stem from the continuous cluster search (the pcc), the mRGCPL data, and the combination of structure and function.

[Pulsar perimetry. A review and new results]. / Pulsarperimetrie. Überblick und neue Ergebnisse.

We present a review and update on Pulsar perimetry, which combines temporal frequency, contrast and spatial frequency stimuli. The effects of age, visual acuity, and learning on results are described. Data on threshold fluctuation, signal-to-noise ratio, and the possibility of reducing noise with filtering techniques are provided. We describe its dynamic range and the possibility of compensating for profound defects. Finally, we show the results obtained in normal patients and in those with ocular hypertension or initial glaucoma, as well as an analysis of glaucoma progression.

[Flicker and conventional perimetry in comparison with structural changes in glaucoma]. / Flimmer- und konventionelle Perimetrie im Vergleich zu Strukturveränderungen beim Glaukom.

The selective perimetry with the FDF flicker stimulation has proven to be effective in a sample of 131 eyes in detecting early glaucomatous alterations, frequently without detectable changes in standard automated perimetry (SAP). Probability values may be successfully used as a new ordinal score of abnormality, especially for such marginal changes. Subjects must be thoroughly introduced to this new form of stimulation. The correlation of global perimetric with optic disc parameters is limited but slightly higher for FDF than for SAP. Interpretation thus requires an individual approach. In advanced cases SAP is preferable due to its larger dynamic range offered by the same instrument.

Update on the imaging techniques in the diagnosis of diabetic retinopathy.

Diabetic retinopathy is one of the leading causes of vision loss worldwide. Fluorescein angiogram still plays a primary role in its diagnosis but new non-invasive technologies as optical coherence tomography, fundus autofluorescence and microperimetry are gaining popularity in the last years. Anatomical changes found with these devices have been widely described but their correlation with visual function needs to be assessed and several features have been proposed as indicators of visual prognosis. The aim of this paper is to give a scope of the actual role of these techniques in the evaluation of retinal impairment secondary to diabetes.

Modified visual field trend analysis.

PURPOSE: Visual field trend analysis can be influenced by outlying values that may disproportionately affect estimation of the rate of change. We tested a modified approach to visual field trend analysis to minimize this problem. METHODS: Automated pointwise linear regression (PLR) was used in glaucoma patients with ≥13 SITA-Standard 24-2 VF tests in either eye. In the control group (Group A), conventional PLR using the entire set of VF tests was carried out. In the other 3 groups (study groups), a truncated analysis was done using only the first and last 3 (Group B), first and last 4 (Group C), or first and last 5 (Group D) VF tests. We compared the global slopes (dB/y), number of eyes experiencing significant progression, and significant improvement between groups. RESULTS: Ninety eyes of 90 patients were evaluated. The mean number±SD of VF tests was 15.7±2.6, spanning 7.8±1.7 years. The study groups showed similar global rates of VF change as the control group (Group A=-0.48±0.5, Group B=-0.48±0.6, Group C=-0.48±0.6, Group D=-0.48±0.5 dB/y, P>0.05), and a similar number of eyes reaching a progression endpoint (Group A=53, Group B=52, Group C=49, Group D=53, P>0.05). However, Group B showed fewer eyes presenting VF improvement (false-positives). CONCLUSIONS: The modified VF trend-analysis showed greater specificity than conventional PLR in a population with glaucoma.

Influence of visual field testing frequency on detection of glaucoma progression with trend analyses.

OBJECTIVE: To explore whether increased frequency of visual field testing leads to earlier detection of glaucoma progression with trend analyses. METHODS: The visual fields of 468 eyes (381 patients) from the Advanced Glaucoma Intervention Study with 10 or more reliable visual field tests and 3 or more years of follow-up were studied. Starting at year 1, every other visual field examination was deleted to create a low-frequency data set, and the original group was kept as the high-frequency data set. The proportion of progressing eyes and the time to progression were compared between the 2 data sets with global and pointwise linear regression criteria. RESULTS: The median number of visual field examinations was 20 and 12 for the high- and low-frequency data sets, respectively. Based on primary mean deviation criteria, 204 eyes (43.6%) in the high-frequency data set and 160 eyes (34.2%) in the low-frequency data set progressed (P < .001), whereas 185 eyes (39.5%) in the high-frequency data set and 167 eyes (35.7%) in the low-frequency data set progressed according to pointwise linear regression (P = .02). The high-frequency data set was more likely to detect progression with mean deviation (hazard ratio [HR], 1.69 [95% confidence interval {CI}, 1.36-2.10]) or pointwise linear regression criteria (HR, 1.52 [95% CI, 1.21-1.90]). A similar number of improving eyes were detected with mean deviation criteria (HR, 0.95 [95% CI, 0.58-1.60]), but pointwise linear regression criteria were more likely to detect improvement in the high-frequency data set (HR, 2.27 [95% CI, 1.43-3.62]). The results did not significantly change after censoring data at 5 years. CONCLUSIONS: Increasing the frequency of visual field testing leads to earlier detection of glaucoma progression, especially with global trend analyses. This finding has significant implications for the care of patients with glaucoma.

[Frequency-doubling technology : A new method for determining glaucomatous visual field defects]. / Frequenzverdopplungsperimetrie : Neue Methode zur Untersuchung glaukomatöser Gesichtsfeldausfälle.

Glaucoma is a disease in which death of retinal ganglion cells is associated with loss of visual function. The gold standard for visual field testing has been standard automated perimetry (SAP). However, up to 30-50% of retinal ganglion cells must be lost before a scotoma is detected with SAP. Therefore, investigators have been interested in finding diagnostic techniques that would allow earlier detection of visual field loss than that detected by standard white-on-white perimetry. Frequency-doubling technology (FDT) has been suggested as a promising technique that may detect glaucomatous ganglion cell damage earlier than SAP by targeting a sparsely spaced subsystem of Mgamma retinal ganglion cells where cell damage is less masked by redundancy. The second generation of FDT perimetry, the Matrix FDT, was released with the intention of improving the spatial resolution of visual field defects. In this article we present FDT and discuss data that compare FDT with standard white-on-white perimetry.

Modern trends in perimetry.

In this review of perimetry the subject is treated in two main sections. Part I discusses developments, particularly during the last thirty years, in classical clinical perimetry including the topics of kinetic and static perimetry, the use of multiple stimuli and the role of automation and objective techniques. Part II describes the development of various special techniques designed for more specific information about visual function. These include reference to the importance of controlling target illuminance, the value of spatial and temporal summation in perimetry and the use of coloured targets. The paper concludes by emphasizing the clinical value of routine field screening and the urgent need for standardization in perimetry.