ARVO 2010 Expert Video: Diagnostic Approaches to Glaucoma
ARVO 2010 Expert Video: Diagnostic Approaches to Glaucoma
Hello. I'm Jay Katz from Wills Eye Hospital in Philadelphia, Pennsylvania, here at ARVO 2010 in Fort Lauderdale, Florida, and I would like to report on some exciting new research in the area of diagnosis in glaucoma.
Dark room prone test. The first thing I'd like to talk about is an old test, the dark room prone test that we use to try to see if there a marked pressure elevation in narrow angles. Dr. Friedman and coworkers at Wilmer Eye Institute (Baltimore, Maryland) did the dark room prone test not only in patients with narrow angles, but also in people with open angles. They found that the percentage of patients who had an 8-mm increase in intraocular pressure was higher in the group with open angles compared with the group with narrow angles, thus casting doubt on this test as a way of screening for patients at risk for angle-closure glaucoma.
Functional testing. There has also been interest in functional tests, other than visual fields, to understand how patients with glaucoma are affected in their daily lives by limitations of vision. The group at Wills Eye Hospital (Philadelphia, Pennsylvania) has done something called AARV (Assessment of Ability Related to Vision), which is a functional multitask test looking at things like recognizing facial expressions, matching socks, and ability to walk through an obstacle course. These tests take about 3-14 minutes to be completed, and the investigators think that these tests may be a viable way of better understanding the limitations of patients with glaucoma. We have known for years that even though people might qualify as drivers with a driving test, they may be more at risk of having a car accident, and, indeed, there is a study from Japan that showed that patients with glaucoma were more likely to be involved in motor vehicle accidents. That [study] was presented here at the meeting.
Telemetry. The assessment of clinical information can sometimes be done with telemetry, even stereoscopically, and Dr. Damji and coworkers in Edmonton, Alberta, Canada, have presented a pilot series where they interfaced with optometrists in remote areas to get clinical information about glaucoma suspects. They found that the agreement in diagnosis approached 50% in this telemetry project, but only 14% of the patients needed to be referred for further evaluation, thereby sparing the other 86% [of patients] from traveling long distances for glaucoma consultation.
Intraocular pressure measurement. We know that measuring intraocular pressure throughout the day and evening might be a very exciting and important way of understanding glaucoma progression and stability. Technology companies are looking at devices such as contact lenses that are worn continuously for up to 24 hours to give a recording of intraocular pressure through the sensors in the contact lens. De Smedt and colleagues, from Switzerland, presented their results looking at a contact lens in a normal population and showed that they were fairly well tolerated. Also, a group from Spain has started looking at another contact lens system that they have studied in an animal model.
We know that body position may change intraocular pressure, and now [Lai and associates] from Singapore has reported here at ARVO that not only does body position, supine or sitting, [affect intraocular pressure], but it also turns out that if the patient is flat supine, the pressure is 3 mm lower on average than [if the patient is] lateral supine, turned to one side.
Optical coherence tomography (OCT). Imaging technologies such as spectral-domain OCT are gathering a great deal of interest, and there are quite a few papers looking at the use of spectral-domain OCT in helping to diagnose and separate glaucoma from normal patients. Traditionally we have used nerve fiber layer thickness as the primary parameter, but the group from Bascom Palmer Eye Institute (Miami, Florida) has talked about looking at other parameters, [such as] looking at the optic nerve, in particular, and looking at rim area and horizontal rim thickness as good ways of helping to distinguish glaucoma in a normal population.
There is still confusion as to how to best use the technology, because compared with Status-3 (which is the time domain OCT), the spectral-domain OCT seems to be comparable but not superior, thus far, in looking at the different pieces of information. We all suspect that spectral-domain will be a better way of evaluating patients because of the higher resolution of this technology. The group in San Diego, California, Rao and coworkers, has talked about how the stage of disease might influence which parameters are going to be best to look at. For example, if one has a [patient with] early stage glaucoma, looking at the nerve fiber layer may be more important, whereas, if you have a [patient with] more advanced stage -- a moderate or advanced stage of glaucoma -- the macular thickness program may prove to be a better parameter to look at.
Combining technologies. There has been an interest in kind of putting together different technologies, so Dr. Harris and coworkers at Indiana University have looked at blood flow and imaging together and explored the relationship between structure (in terms of the optic nerve and nerve fiber layer), and blood flow and circulation to the structures. There have been other papers presented here at ARVO talking about the definite relationship between an impairment of blood flow or oxygen saturation and areas of structural abnormality in patients with glaucoma, as measured with imaging technology.
Ocular hypertension. There has also been an update here on the Ocular Hypertension Treatment Study (OHTS). Dr.Kass and coworkers, the primary architects of the ocular hypertension treatment study, talked about how patients who were diagnosed as having glaucoma, either by structural confirmation (looking at serial optic discography) or by confirmation of visual field defects, many times, despite treatment, would also have the ["normal"] modality convert to an abnormality, so if [the patient] originally only had a visual field defect but no optic nerve progression was noted, even with treatment some people went on to develop structural change and vice versa. Some people had structural change only, and then went on to have functional deficits later despite treatment.
As an ancillary part of the trial, HRT (Heidelberg retinal tomography) was also done in a segment of the population [in the] OHTS. Zangwill and coworkers commented on the rate of [structural] change [found] by looking at serial assessment of HRT-- there was a 5 times greater rate of [structural] change in the glaucomatous population, in those who developed glaucoma in OHTS, compared with the stable population who did not convert.
There is a great deal of interest in all the imaging modalities as ways of helping to diagnose glaucoma and also to look at progression of glaucoma over time.
Genetics in glaucoma. We are still hearing more and more about the genetics in glaucoma, and [Wirtz and colleagues] from Australia talked about 1 particular gene mutation that they have identified that is present in 6.6% of the primary open-angle glaucoma population [that they] looked at.
I think that there is a great deal of interest in understanding the diagnostic approaches to glaucoma and its many different facets. This proved to be a very exciting meeting for looking at many of these new modalities. Thank you very much.
Overview: Research in Glaucoma Diagnosis
Hello. I'm Jay Katz from Wills Eye Hospital in Philadelphia, Pennsylvania, here at ARVO 2010 in Fort Lauderdale, Florida, and I would like to report on some exciting new research in the area of diagnosis in glaucoma.
Dark room prone test. The first thing I'd like to talk about is an old test, the dark room prone test that we use to try to see if there a marked pressure elevation in narrow angles. Dr. Friedman and coworkers at Wilmer Eye Institute (Baltimore, Maryland) did the dark room prone test not only in patients with narrow angles, but also in people with open angles. They found that the percentage of patients who had an 8-mm increase in intraocular pressure was higher in the group with open angles compared with the group with narrow angles, thus casting doubt on this test as a way of screening for patients at risk for angle-closure glaucoma.
Functional testing. There has also been interest in functional tests, other than visual fields, to understand how patients with glaucoma are affected in their daily lives by limitations of vision. The group at Wills Eye Hospital (Philadelphia, Pennsylvania) has done something called AARV (Assessment of Ability Related to Vision), which is a functional multitask test looking at things like recognizing facial expressions, matching socks, and ability to walk through an obstacle course. These tests take about 3-14 minutes to be completed, and the investigators think that these tests may be a viable way of better understanding the limitations of patients with glaucoma. We have known for years that even though people might qualify as drivers with a driving test, they may be more at risk of having a car accident, and, indeed, there is a study from Japan that showed that patients with glaucoma were more likely to be involved in motor vehicle accidents. That [study] was presented here at the meeting.
Telemetry. The assessment of clinical information can sometimes be done with telemetry, even stereoscopically, and Dr. Damji and coworkers in Edmonton, Alberta, Canada, have presented a pilot series where they interfaced with optometrists in remote areas to get clinical information about glaucoma suspects. They found that the agreement in diagnosis approached 50% in this telemetry project, but only 14% of the patients needed to be referred for further evaluation, thereby sparing the other 86% [of patients] from traveling long distances for glaucoma consultation.
Intraocular pressure measurement. We know that measuring intraocular pressure throughout the day and evening might be a very exciting and important way of understanding glaucoma progression and stability. Technology companies are looking at devices such as contact lenses that are worn continuously for up to 24 hours to give a recording of intraocular pressure through the sensors in the contact lens. De Smedt and colleagues, from Switzerland, presented their results looking at a contact lens in a normal population and showed that they were fairly well tolerated. Also, a group from Spain has started looking at another contact lens system that they have studied in an animal model.
We know that body position may change intraocular pressure, and now [Lai and associates] from Singapore has reported here at ARVO that not only does body position, supine or sitting, [affect intraocular pressure], but it also turns out that if the patient is flat supine, the pressure is 3 mm lower on average than [if the patient is] lateral supine, turned to one side.
Optical coherence tomography (OCT). Imaging technologies such as spectral-domain OCT are gathering a great deal of interest, and there are quite a few papers looking at the use of spectral-domain OCT in helping to diagnose and separate glaucoma from normal patients. Traditionally we have used nerve fiber layer thickness as the primary parameter, but the group from Bascom Palmer Eye Institute (Miami, Florida) has talked about looking at other parameters, [such as] looking at the optic nerve, in particular, and looking at rim area and horizontal rim thickness as good ways of helping to distinguish glaucoma in a normal population.
There is still confusion as to how to best use the technology, because compared with Status-3 (which is the time domain OCT), the spectral-domain OCT seems to be comparable but not superior, thus far, in looking at the different pieces of information. We all suspect that spectral-domain will be a better way of evaluating patients because of the higher resolution of this technology. The group in San Diego, California, Rao and coworkers, has talked about how the stage of disease might influence which parameters are going to be best to look at. For example, if one has a [patient with] early stage glaucoma, looking at the nerve fiber layer may be more important, whereas, if you have a [patient with] more advanced stage -- a moderate or advanced stage of glaucoma -- the macular thickness program may prove to be a better parameter to look at.
Combining technologies. There has been an interest in kind of putting together different technologies, so Dr. Harris and coworkers at Indiana University have looked at blood flow and imaging together and explored the relationship between structure (in terms of the optic nerve and nerve fiber layer), and blood flow and circulation to the structures. There have been other papers presented here at ARVO talking about the definite relationship between an impairment of blood flow or oxygen saturation and areas of structural abnormality in patients with glaucoma, as measured with imaging technology.
Ocular hypertension. There has also been an update here on the Ocular Hypertension Treatment Study (OHTS). Dr.Kass and coworkers, the primary architects of the ocular hypertension treatment study, talked about how patients who were diagnosed as having glaucoma, either by structural confirmation (looking at serial optic discography) or by confirmation of visual field defects, many times, despite treatment, would also have the ["normal"] modality convert to an abnormality, so if [the patient] originally only had a visual field defect but no optic nerve progression was noted, even with treatment some people went on to develop structural change and vice versa. Some people had structural change only, and then went on to have functional deficits later despite treatment.
As an ancillary part of the trial, HRT (Heidelberg retinal tomography) was also done in a segment of the population [in the] OHTS. Zangwill and coworkers commented on the rate of [structural] change [found] by looking at serial assessment of HRT-- there was a 5 times greater rate of [structural] change in the glaucomatous population, in those who developed glaucoma in OHTS, compared with the stable population who did not convert.
There is a great deal of interest in all the imaging modalities as ways of helping to diagnose glaucoma and also to look at progression of glaucoma over time.
Genetics in glaucoma. We are still hearing more and more about the genetics in glaucoma, and [Wirtz and colleagues] from Australia talked about 1 particular gene mutation that they have identified that is present in 6.6% of the primary open-angle glaucoma population [that they] looked at.
I think that there is a great deal of interest in understanding the diagnostic approaches to glaucoma and its many different facets. This proved to be a very exciting meeting for looking at many of these new modalities. Thank you very much.
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