OGS PRESIDENT'S MESSAGE

We live in exciting times. I say this not just because of the upcoming Olympics, or the grace and style that was Spain in Euro2008, the extraordinary Wimbledon final (Spain again), or the way in which Tiger Woods won the US Open. Not even at the thought of cracking open that last bottle of 2002 claret, sipping a favourite malt, or the prospect of new Coldplay music. I say this because we live in an exciting time of discovery in the world of glaucoma. Our understanding of the basic mechanisms of the disease is increasing exponentially, we have imaging techniques with a resolution that could not have been imagined a decade ago, new perimetric techniques for early detection and better progression analysis, and stand with the promise of clinically useful functional imaging. Although our clinical armamentarium has not changed dramatically, there is an inevitable momentum that will fundamentally change our approach to the disease and its management. But, in any time of discovery there is always confusion. The question is whether such confusion serves to destroy morale and lower confidence, or whether it is seen as a challenge that can lead to better patient care. The next question to be considered is how best we can learn and apply this new information?

We can meet: 1. In October the OGS holds its 7th annual meeting with a lineup of speakers as good as can be found anywhere, including the 2008 honoree Dr. Robert Ritch (see http://www.optometricglaucomasociety.org for details). This year's meeting boasts several innovations. There is a half day joint meeting with the Glaucoma Progression Scholars, and the first joint meeting with the American Academy of Optometry.

2. In July 2009 the 3rd World Glaucoma Congress will be held in Boston and all optometrists are encouraged to attend and will be welcomed. The OGS will be holding a special meeting on the first day of the congress. Having attended the first two WGCs in Vienna and Singapore I can highly recommend this meeting and look forward to seeing many of you there.

We can read: 1. The recent special glaucoma issue of Optometry and Vision Science (OVS) is truly exceptional. Under the guidance of guest editor Brad Fortune, the authors and articles are of the highest quality. We owe OVS Editor Tony Adams a debt of gratitude for nurturing the glaucoma special issues we have all come to enjoy. Let the tradition continue!

2. Very soon the latest edition of the OGS Glaucoma Handbook will be distributed through Review of Optometry. With Murray Fingeret as Editor it is always a pleasurable read as well as being topical and relevant.

3. The outstanding OGS E-Journal. Amazingly this is the 10th edition and is as informative and entertaining as ever. Great job Paul Spry and team.

We can practice: As informed clinicians we can make a difference. We can diagnose early and manage our patients with care, compassion and knowledge.

Exciting times indeed!

John Flanagan PhD, MCOptom, FAAO
President, Optometric Glaucoma Society
jgflanag@quark.uwaterloo.ca

Difficult questions need informed answers

What do you say when a patient asks, "Will my glaucoma make me go blind?" Providing an appropriate answer to this question is absolutely critical because no matter what you reply, there will be an inevitable impact on the individuals perception of their own health. A negatively phrased answer may disproportionately reduce their perceived quality of life. A positively phrased answer could fail to provide sufficient impetus for the patient to regard glaucoma seriously, and undermine his/her motivation to adhere to the treatment and follow-up plan. An effective strategy for handling this question may be to provide and discuss information about prognosis. Useful information for this purpose was presented at this year's Annual meeting of the Association for Research in Vision and Ophthalmology (ARVO) by Heijl et al. These authors reported that the rate of progressive visual field decline, quantified using Mean Deviation, in a large cohort of treated patient with chronic open angle glaucoma followed over ~10 years was -1.2dB/year. On average, reaching blindness would take 35 years. However, the spread of progression rates was negatively skewed such that more patients progressed slowly. Extrapolation from this evidence about the relationship between proportion and rates implied that 17% of patients took ≤20 years to reach blindness, whilst 4.8% of patients took ≤12 years. This information will, without doubt, allow a patient to understand the timescale of glaucoma and therefore their prognosis, especially because the power of this study’s findings lies in the lack of selection bias. Unlike clinical trials, this study included data from all patients receiving glaucoma care, with the only drawback to generalisability being that the study population was almost exclusively white and up to one third had pseudoexfoliative glaucoma and such individuals may be more likely to exhibit higher progression rates than primary open angle glaucoma and normal tension glaucoma.

Other information likely to assist patient’s understanding of the potential impact of glaucoma on their life is how and when it may affect their driving ability. This issue of the E-journal reviews recent publications on glaucoma and driving.

One final consideration is that visual field testing appears unlikely to inform us about the relationship between glaucoma and the many visual functions involved in daily life. This subject was explored at ARVO, and highlights are featured in our ARVO review.

Paul GD Spry, PhD, BSc, MCOptom DipGlauc
Editor-in-Chief
paul.spry@uhbristol.nhs.uk

Doctor-patient communication and adherence to glaucoma medication recommendations
In the most recent paper to report results from the ongoing Glaucoma Adherence and Persistency Study (GAPS), David Friedman and colleagues (1) have identified eight variables that were each associated independently with poorer patient adherence to prescribed topical glaucoma medication: 1) hearing all of what you know about glaucoma from your doctor (compared with some or nothing); 2) not believing that reduced vision is a risk of not taking medication as recommended; 3) having a problem paying for medications; 4) difficulty while traveling or away from home; 5) not acknowledging stinging and burning; 6) being non-white; 7) receiving samples; and 8) not receiving a phone call visit reminder.

These findings are important for all eye care professionals to consider because they reveal several potentially modifiable barriers to effective glaucoma therapy and highlight elements of effective doctor-patient communication that are essential to overcoming these barriers. The authors elaborate on the first variable in part by describing three modes of patient learning: those patients who learned all they know about their disease and treatment from their physician were characterized as doctor-dependent learners; those who learned most but not all were described as collaborative learners; and those who learned not much or nothing from their physicians were characterized as independent learners. The authors found that doctor-dependent learners had significantly lower adherence than either the collaborative learners or the independent learners. Though this may seem counter-intuitive at first glance, it speaks to the heart of effective doctor-patient communication. For example, doctor-dependent learners were less likely than the others to report that their physician asked if they had any questions or if they understood what they had been told. They also had the lowest confidence (of the three groups) in their knowledge about glaucoma.

The second variable regarding a patient's concern for vision loss also relates to effective doctor-patient communication. As compared with the 86% of patients who believed that not taking their medications as recommended placed them at risk for reduced vision, the 14% of patients who did not believe this exhibited poorer adherence. These patients who were not concerned that poor adherence put them at risk for vision loss also did not believe they would be at risk for optic nerve damage, increased intraocular pressure, or complete vision loss. They were also less likely to report that someone close to them experienced vision loss because of eye disease. Especially important to our focus here, the group of unconcerned patients was more likely to report that their doctor did not tell them what to expect from the future regarding their glaucoma. The authors report that this latter characteristic was shared with doctor-dependent learners. Those unconcerned about potential vision loss also "reported receiving less information and fewer answers to questions from their physicians and were less likely to report receiving a demonstration on using drops or being told by their physician about stinging and burning as a possible side effect. Finally, the unconcerned were more than twice as likely to have a charted notation of a missed appointment."

Some of the other variables less directly related to doctor-patient communication still warrant our consideration under the same light. Patients having difficulty paying for medications and/or taking medications while travelling or away from home may still benefit from enhanced doctor-patient communication in that these barriers still need to be detected and identified, and may be overcome by "physician-initiated problem solving". Those patients who did not acknowledge stinging and burning had lower adherence than those who did acknowledge these adverse effects of their medication. It is possible that a patient who does not acknowledge any adverse effects might not be taking their medication correctly. This is another reason to be routinely asking patients about potential adverse effects and to take the opportunity to properly demonstrate eye drop instillation.

The authors report that their multivariate model based on these eight variables explained 21% of the variance in the outcome measure of adherence. Thus, there are still other variables that impact patient adherence and other ways to measure adherence that are likely to help identify the most important barriers. Nonetheless, the important results of this study led the authors to reiterate that: "physicians should ensure that all patients have an understanding of their disease that supports appropriate concern about future consequences." The authors stress that this is particularly important for patients who exhibit the more passive characteristics of doctor-dependent learners, for example, those patients who "give the appearance of taking in the given information because they do not ask clarifying questions and do not reveal confusion or lack of confidence in their knowledge." Indeed, the authors state that, "Although doctor-dependent learners may be in the greatest need of being encouraged to ask questions and to be asked directly if they understand, our analysis shows that they are the least likely to report receiving these interventions." For these and perhaps all patients, the authors recommend that, "Physicians can assess patients' understanding and concern about the consequences of glaucoma and simultaneously can detect and activate passive doctor-dependent learners by applying an ask-tell-ask communication strategy." For details of the ask-tell-ask strategy, as well as for the methods, results, limitations and caveats of this study, readers of the of the OGS E-Journal are encouraged to seek out this and other papers on GAPS.

Brad Fortune OD, PhD

1. Friedman DS, Hahn SR, Gelb L, Tan J, Shah SN, Kim EE, Zimmerman TJ, Quigley HA. Doctor-Patient Communication, Health-Related Beliefs, and Adherence in Glaucoma Results from the Glaucoma Adherence and Persistency Study. Ophthalmology. 2008 Mar 3. [Epub ahead of print]

A major concern of glaucoma patients — their fitness to drive.
The study of Bhargava et al (1) provides information about concerns that glaucoma patients have regarding their visual status and their treatment. This is an interview-based study of 82 patients attending two glaucoma clinics. The authors developed a statistic of importance based on the patients’ responses (score awarded to a factor divided by the sum for all factors). As there were 10 factors in the questionnaire (8 real and 2 dummies), importance should be 10% (1/10) in the absence of any association. This group found that the greatest concern among patients was the risk of moderate visual impairment (38%) and blindness (27%) with an average 33% importance for vision loss. In contrast the use of topical medications and surgery returned an importance of 13%, on average. Within this context of patient concern, it is worth noting that Owen et al. (2) report that older adults in the UK view the surrender of a driving license as a significant life event, resulting in the loss of self-esteem as well as mobility and social independence. Not surprisingly they note that those who have stopped driving are at greater risk of worsening depression, which not only impacts on their own lives but that of their caregivers, family and friends (2).

In this context Owen et al argue that an appropriate position for glaucoma intervention is to prevent or delay the onset of the loss of one’s driving license.

Fitness to drive in the UK not only requires a minimum subtense of peripheral visual field (120° width) but also the absence of scotomata in the binocular central field. Here, Owen et al. suggest that clinicians should consider visual capacity in terms of the binocular integrated visual field (IVF). These authors prefer the IVF representation (3) to the Esterman binocular test because the former is a threshold outcome whereas the latter is based on suprathreshold measures having limited central representation. The IVF is established on a point-wise basis by using the highest sensitivity at a given location derived from both monocular fields. The authors propose that any point in the IVF having a sensitivity <10dB should correspond with an Esterman outcome. However, they also note that the IVF has a greater number of test points and propose the criterion for failing a driving fitness assessment should be a cluster of at least 4 contiguous abnormal points (<10 dB) within the central 20° with a further non-contiguous point within this region or two elsewhere.

Using the IVF analysis and the fail criterion given above, the authors reviewed the visual fields of 199 glaucoma patients who had been followed in the glaucoma clinic of Moorfields Eye Hospital over a 17 year period (1986 to 2003). They found that some 30% of glaucoma patients failed to meet this criterion after a 14 year follow up, making it likely that these individuals would have been required to surrender their driving licenses. What is interesting in this data is that the IVF is a good predictor for future loss of vision and that 1/3 of patients or, 10% of the total glaucoma group, showed rapid deterioration over the first 2 years of follow-up. It needs to be mentioned that the authors did not establish whether driving licenses were actually surrendered, only that they would have developed a vision loss consistent with this potential, nor do they report on what the variability was in applying this diagnostic approach.

The take home message of this work is that many patients most fear a loss of vision to the point where they will have to surrender their driving license, and that clinicians can use an IVF approach to monitor the prospect of this and treat aggressively to prevent its occurence. An ancillary finding is that the first two years after diagnosis are important in establishing future prospects of vision loss and the capacity to retain a driving license.

Algis Vingrys BScOptom, PhD

References
1. Bhargava JS, et al. Views of glaucoma patients on aspects of their treatment. Invest Ophthalmol Vis Sci, 2006: 47: 2885-88.
2. Owens VMF, et al. Glaucoma and fitness to Drive. Invest Ophthalmol Vis Sci, 2008: 49: 2449-55.
3. Crabb DP, et al. Simulating binocular visual field status in glaucoma. Br J Ophthalmol 1998; 82: 1236-41.

VISUAL FIELD REVIEW

How many tests are needed to detect significant glaucomatous visual field change?
If you manage patients with glaucoma, possibly the most important tool you can get your hands on this year comes in the form of a paper by Chauhan et al. (1) A free, full-text copy is available through the BMJ journals scheme and I highly recommend downloading one for yourself. An impressive group of thought leaders jointly authored this paper, shining a light on that often-uttered question: How many visual field tests will I need before I can tell if my patient’s glaucoma is progressing?

The paper commences with a compelling argument for the regular measurement of visual fields in general and the use of standard automated perimetry (SAP) in particular. Generally, visual field damage is perhaps the best functional predictor we have of a patient’s quality of life. In particular, SAP is the test that was used as the primary functional endpoint in almost all of the large-scale randomized clinical trials and has the largest amount and longest duration of clinical information available.

The main thrust of this paper is that you must "measure the rate of visual field progression." Although it is acknowledged that there are several ways to do this, there is no doubt that estimating the rate of change dictates that a threshold test should be employed. The authors also suggest that examining mean deviation or mean defect (MD) over time is probably the best compromise between sensitivity to change and specificity in the face of variable results. Furthermore, you should not chop and change. It is best to stick with the same thresholding algorithm and visual field pattern if possible and changes should be made only when compelling reasons exist. If resources are tight, no other functional (SWAP, FDT) or structural (CSLT, OCT, SLP) test should be used in place of SAP. In other words, if you can only do one test (other than IOP) then make it SAP.

Perhaps the most striking recommendation is that six visual field exams should be performed in the first two years of management. The logic behind this suggestion is two-fold. First, it will afford the clinician a decent chance of detecting those eyes bound for a very rapid rate of decline and second, it will establish a very good baseline and thus enable some determination of the rate of change in those eyes that are going to have a more moderate or slower course to be detected. However, six tests in two years represents a minimum. If your patient has major risk factors for progression and visual impairment (i.e. suspicion of ONH change within the interval, poor IOP control, morbidity in the fellow eye) or is slightly more variable than average, then it might be prudent to perform even more than six tests.

If you are thinking that six tests in two years sounds like too many then take a look at what rate of change you can reliably detect using such a schedule (their Tables 1 & 2). Given the expected test–retest variability for MD, a -2dB change should just be statistically detectable with five or six tests in two years. This represents a -1dB per year rate of decline. If we bear in mind the patient’s age, their life expectancy and that significant increases in rates of driving accidents and falls occur even when relatively early visual field damage exists, it is easy to see the increased risk this kind of patient is exposed to if we do not detect such a visual field trajectory quickly.

Even though Chauhan et al recommend using a trend based analysis, in this case the linear regression of MD over time, event based analyses have been used in several of the large scale glaucoma clinical trials (OHTS, EMGT) and there may be situations where event based analyses are preferable. Ease of implementation and clinicians’ comfort and understanding of different analysis techniques may be part of the glaucoma progression equation that was not explored in this important paper. However, a similar number (or density) of visual field exams would likely be required to reliably detect change even when using event based analyses, nonetheless consistent with one of the essential recommendations of this stimulating paper.

Shaban Demirel BScOptom, PhD.

1. Chauhan BC, Garway-Heath DF, Goñi FJ, Rossetti L, Bengtsson B, Viswanathan AC, Heijl A. Practical recommendations for measuring Rates of visual field change in glaucoma. British Journal of Ophthalmology, 2008;92:569-573.

Figure 1 and 2 show retinal photographs of the right eye. The image on the left ( Figure 1A, 1B) shows the 2003 appearance while the image on the right (Figure 2A, 2B) shows the development of a retinal nerve fiber layer (RNFL) defect at the 7 o’clock position that was visible in 2007. Figure 1B and 2B are magnified views of Figure 1A and 2A. The rim tissue looks thinner both superiorly and inferiorly in 2007.

Figure 1a.

Figure 2a.

Figure 1b.

Figure 2b.

Figure 1A shows retinal photographs of the right eye. The image on the left shows the 2003 appearance while the image on the right shows the development of a retinal nerve fiber layer (RNFL) defect at the 7 o’clock position that was visible in 2007. Figure 2B shows a magnified view of Figure 2A. The rim tissue looks thinner both superiorly and inferiorly in 2007.

Figure 3a.

The HRT OU report (Figure 3A- September 12, 2007) shows change in OD as seen by the red-colored pixels at the inferior rim tissue. Asymmetry is noted as the right optic disc is shown to have a larger cup, thinner rim tissue, and a greater number of sectors flagged on the Moorfields Analysis. Figure 3B shows the topographic change report with change first seen in 2005, and confirmed over the next two visits. The red area on the reflectance images at 7 o’clock confirms that this area has become thinner statistically when compared to the baseline examinations. Figure 4 shows the OCT image, which confirms that the RNFL is thinner inferiorly OD when compared to the patient’s OS and the instrument’s internal normative ranges. Although the OCT scans are in agreement with the other imaging modalities, it should be noted that the scan location relative to the optic disc cannot be confirmed in the right eye because of artifact over the fundus image, and it is decentered inferiorly in the left eye, which would cause the RNFL to appear thinner inferiorly and thicker superiorly. The TSNIT curve shows loss inferiorly for the right eye, which is also seen in the sector and quadrant graphs. The OS appears to be within normal limits. Figure 5A shows the GDx symmetry analysis performed on an image taken in September 2007. The OD has an NFI of 38 along with a dark region showing loss on the Right RNFL map and pixels flagged in the OD superiorly and inferiorly. The dark spot on the OS image inferonasally is due to a vitreous floater obscuring the view of the retina. Other than this artifact, the OS appears to be healthy. The printout found in the middle of the page shows that the OD RNFL is reduced when compared to OS. Figure 5B shows the GPA for the GDx, a recently released software tool. Likely progression is noted in the image progression map, TSNIT progression graph, and summary parameters. The image progression map shows change in both the superior and inferior RNFL (red colors). The TSNIT progression graph also shows change inferiorly and superiorly. The inferior average summary parameter graph shows the steepest slope, with significant change noted. The bottom of the printout summarizes the changes found, with loss greatest inferiorly.

Figure 3b.

Figure 4.

Figure 5a.

Figure 5b.

When progression is noted, reevaluation of the therapeutic regimen needs to occur. Often further IOP reduction is indicated, either by the addition of medication if possible or the use of laser trabeculoplasty or filtration surgery. In this case, dorzolamide (Trusopt) was added and the IOP was reduced by a further 2 mm Hg. Imaging in this case was done yearly but an option could be to image more frequently often immediately after the diagnosis is made because at least five images are needed for the software progression tools to work efficiently.

Murray Fingeret, OD

QUARTERLY CASE

Figure 1.

Figure 2.

Figure 3a.

Figure 3b.

Figure 4.

Figure 5.

Figure 6a.

Figure 6b.

Switch or add in glaucoma therapy?
Medical therapy for the glaucomas is thoroughly heterogeneous. As most therapies in all fields of medicine, the "art/science" continuum varies widely. We long for the day when "science" is 90%, and "art" is only 10% of the equation in our patient care decision making, but for now, "art" is the predominant factor in glaucoma care. For all the wonderful studies published over the past decade, the care of individual patients remains largely a physician’s decision.

"Adding" medical therapy is clearly the observable modus operandi of glaucoma care. Face it, adding is just plain easy; just keep stacking on the medicines until the target IOP is reached. Combination medicines further fuel this "throw the sink at it" mentality.

"Switching" requires relatively laborious effort, a little extra cerebral energy, and probably more office visits; however, patients merit the very best of our clinical efforts.

Scenario A could be: initial therapy with a once-a-day medicine such as a prostaglandin analog (PGA) or a non-selective beta-blocker (with a sufficiently long half-life such as timolol of levobunolol). If at least a 20% reduction in IOP is achieved, this medicine can be considered "effective." If, however, the initial drug does not achieve target IOP, then we recommend setting the initial drug aside (at least temporarily), and trying the other "once-daily" medicine alone to see if it can achieve target IOP. If both medications achieve at least 20% IOP reduction, then try using the beta-blocker in the mornings and the PGA in the evenings — thus yielding twice daily therapy.

Scenario B could be: the beta-blocker did not achieve more than a 10% effect (or, for whatever reason, it could not be used). The PGA performed as expected, but failed to achieve target IOP. Now the question is whether to choose a topical carbonic anhydrase inhibitor (CAI) or an alpha-adrenergic agonist. Either way, the patient will now be instilling three drops per day. In our experience, our success rate is roughly equal between these two drug classes. We typically start with a topical CAI, and default to an alpha-agonist if the CAI does not achieve target IOP.

Scenario C could be: the PGA did not provide more than a 10% reduction in IOP, and therefore would be considered a PGA failure. We do not switch intraclass. The beta-blocker came close, but failed to achieve target. Now — and only now — would it be prudent to try adding either Cosopt or Combigan to the PGA, since we have already established the efficacy of the beta-blocker component. We would never add any combination drug to a PGA, unless we had established lack of target IOP achievement with at least one component of the combination drug.

As can readily be seen, intelligence and thoughtful switching is superior to adding in most cases. At a time when "polypharmacy" is observably epidemic, we encourage all glaucoma clinicians to strive for a minimally invasive, maximally simple therapy. There are many such "switching" (and "adding") possibilities. We hope this brief overview will stimulate our colleagues to strive for utopic therapeutic intervention.

Randall K. Thomas, OD Ron Melton, OD

ARVO 2008 Round-Up. How glaucoma affects functions required for daily life.

This year's annual meeting of the Association of Research in Vision and Ophthalmology (ARVO) was again held in Fort Lauderdale, Florida, from April 27th to May 1st. Over 4500 abstracts were registered for presentation and you can search these online at ARVO's website. Although information on glaucomatous loss of visual function, such as central visual field testing, is an essential tool for each patient's clinical management, the poor and variable relationship between visual field test outcome with conventional quality of life measures strongly suggest that neither are useful at informing us about how glaucoma affects functions required for daily life. A number of presentations at this year's ARVO explored this theme, investigating the degree to which glaucoma impacts on life, both in terms of aspects of vision not commonly measured in clinical situations, and also more generally. An investigation of the impact of glaucoma on reading was reported by Ramulu et al. of the Wilmer Eye Institute (program no 5447). This study was part of a population-based, cross-sectional evaluation of visual function and disability in the elderly. Both reading impairment (defined as reading <=90 words/minute) and reading speed were evaluated at four different text sizes. Univariate analysis revealed a significantly (p=0.006) greater proportion of reading impairment in individuals with bilateral glaucoma (28.4%) than individuals without glaucoma (16%). For all text sizes, average reading speed was slowest amongst study participants with bilateral glaucoma, and fastest for individuals without glaucoma. Although the differences were not statistically significant when all degrees of glaucoma were grouped together, they became highly significant (p=0.005) when those with worst field loss only ('bilateral glaucoma, highest quartile visual field damage') were compared with controls, with such individuals reading on average 37 words less per minute than those without glaucoma, representing a reduction in reading speed of approximately 25%. These data appear powerful due to the cross-sectional 'population study' design, although the completeness of the sample was not reported, and as such some selection bias may be present.

Another study by Smith et al of City University, London (program number 1110) considered a different type of visual outcome, that being an exploration of eye movements in glaucomatous patients when viewing photographs. Their study used a case-control design with controls being age-matched to the glaucoma patient group, who were recruited such that binocular field loss was present, with at least two depressed Humphrey Field Analyzer test locations on binocular fields (integrated threshold sensitivity levels of <20dB). Eye movements were measured using a head-mounted gaze-tracking device. Two specific experiments were performed. Firstly, subjects were asked to look passively at a series of photographs as they would when viewing a slideshow. Under these circumstances, subjects with glaucoma had a decreased number of saccades, viewing area and increase in fixation duration compared to controls. The second experiment comprised a search task and subjects were asked to locate a specific item or location in an image in each of a series of photos. In this viewing scenario, glaucoma patients made, on average, significantly fewer saccades had greater saccade amplitude and fixation duration than controls and took longer to find the search item. The investigators concluded that patients with glaucoma exhibited altered eye movements and search patterns compared with controls. Discussion with the author at the poster provided some insight into the research group’s ongoing and future work which includes investigation of the relationship between the point of regard and spatial location of binocular field defects.

Black et al. from Queensland University, Brisbane, Australia investigated the relationship between visual field loss and falls amongst older patients with glaucoma (program number 5458). Amongst a sample of 74 glaucoma patients aged over 65 years, they found that 35% of participants had fallen on at least one occasion in the previous twelve months, although no control data was available for comparison. Postural instability was measured on even and uneven surfaces using a Swaymeter and was found to be significantly associated with binocular field loss, with the rate of falls doubling for every 9dB reduction in Mean Deviation of a subject's 24-2 Sita-Standard HFA result in their better-eye. Potential confounders, such as general health or systemic medication were not controlled by the observational study design.

An exploratory study of eye-hand coordination deficits in glaucoma was presented by Kotecha et al (program number 1158), also from City University. This case-control study investigated the reaching and grasping behaviour amongst a group of glaucoma patients with early to moderate visual field loss in their better eye (MD range =-3.5 to -10.2dB). Hand movement kinematics were initially captured on digital video and converted into digital 3D plots from which spatial behaviour (such as position and velocity) of predefined points on each patients hand could be quantified when the subject was asked to move their hand to grasp a given object in a set location.

A digitised 3D plot from Kotecha et al. The large green object is a cylinder which subjects were asked to grasp. Movements of fixed locations on each subjects hand (shown as red, blue and black circles) were used to quantify hand movements.

Patients with glaucoma were found to have significantly slower hand movement initiation and poorer reaching dynamics, such as the time to reach peak hand velocity and a prolonged duration of the deceleration phase of movement occurring when a hand homes-in on an object ('low velocity profile'). The authors concluded that patients with asymmetric visuals field loss and relatively minor binocular field defects show deficits in prehension compared to controls with normal visual fields.

These studies show that we are only beginning to figure out how daily tasks are affected by glaucoma and that other outcomes, in addition to visual fields help to provide more detailed information on this subject.

Paul GD Spry PhD BSc MCOptom DipGlauc

International Perimetric Society — focussing beyond the visual field

The International Perimetric Society (IPS) biannual meeting was held at Nara, Japan on May 21-24, 2008. In general, the meeting and the accompanying social program were exceptionally good. Nara is the historical and spiritual center of Japan, and the Convention Center is located in the center of Nara Park. Attendees and accompanying persons were treated to an opening banquet that included entertainment from a drum and percussion group, a Japanese dinner with musical entertainment, a feeding of the deer, a Noh dramatic performance, a walking tour of the grounds in Nara park, and a magnificent closing banquet complete with its tradition of singing in national groups.

In my opinion, the quality and content of the presentations at this IPS meeting were the best of any IPS meeting. Sessions incorporating papers and posters related to structure/function relationships, optic nerve head and nerve fiber imaging, brain changes in monkey models of glaucoma, new perimetric techniques, comparison of tests, visual field analysis procedures, and glaucomatous progression were presented. In many instances, the papers included empirical results, statistical analysis, mathematical modeling and well-constructed experimental designs. It was clear that all presenters had conducted a creative and thorough evaluation of their research topic. Although the presentations were of high relevance and quality, none stood out from all the others, which is an indication of the high caliber of this meeting. In particular, several keynote presentations were given by Drs. Michael Patella, Anders Heijl, Yijun Huang, Fritz Dannheim, Masaaki Sasaoka, Ron Harwerth, Ulrich Schiefer and Yoshi Kitazawa. Dr. Dannheim was the IPS lecturer and spoke about the history of optic disc evaluation in glaucoma, and Dr. Heijl was the Aulhorn lecturer and spoke about the rate of visual field progression in glaucoma. In an attempt to encourage attendance by other investigators with related interests, the name of the group was changed to the Imaging and Perimetric Society, embracing the new focus while keeping the several decades old acronym (IPS).

In all, the 2008 IPS meeting was a most worthwhile intellectual encounter blended with generous amounts of entertainment, social interaction and collegiality among its members and guests. It is my sincere hope that this excellence will continue to grow for succeeding IPS meetings.

Chris A. Johnson PhD

CLINICAL QUESTIONS AND ANSWERS

If you would like us to answer a clinical question, please send it to paul.spry@uhbristol.nhs.uk with "OGS question" as the subject. The questions can concern anything related to glaucoma, for example, analysis of an optic nerve image, optic disc, a challenging case or side effect of a medication. We welcome your questions and we will try to address as many as possible in each issue.

All Eyes on Glaucoma Website
A new online resource to help clinicians was recently launched. The Optic Nerve Resource Center, www.alleyesonglaucoma.com, is a tool that will be useful to optometrists to learn about the latest technologies available to examine the optic nerve to detect anatomic damage, potentially before functional vision loss. The goals of the site are to provide online educational resource for eye health professionals to review optic imaging technologies, highlight the role of optic nerve imaging techniques in detecting ongoing structural changes in glaucoma and reinforce the importance of ongoing optic nerve assessment in management of glaucoma. The site will be updated as new technologies become available.

Joint Meeting of the Optometric Glaucoma Society and the American Academy of Optometry
On Wednesday morning, October 22, 2008, the Optometric Glaucoma Society (OGS) will hold its first joint meeting with the American Academy of Optometry (AAO). All attendees of both the OGS and AAO meetings are invited to attend, with the symposium occurring as part of the AAO annual meeting. Brad Fortune, the program chair, has put together a stellar program with the 8-10am session titled Pathogenic Mechanisms of Glaucoma. The different mechanisms for why glaucoma may develop will be presented by Douglas Anderson, Claude Burgoyne, John Morrison and Jack Cioffi. The second session (10am-12pm) is titled Clinical Implications: Pathogenic Mechanisms of Glaucoma with the same speakers explaining why understanding the different pathogenic mechanisms is important for the clinician. The program will take place at the Anaheim Convention Center in room 207 A/B.

World Glaucoma Congress 2009
The Optometric Glaucoma Society and the World Glaucoma Association would like to invite optometrists to attend the 2009 World Glaucoma Congress (WGC), to be held in Boston, MA from July 8-11th. Clinicians and scientists from around the world will come together to discuss and learn about glaucoma. The world’s experts will be present in a forum only seen every other year. This is the first time the WGC is being held in North America, and should provide a great learning environment for all ODs.

i2i: Conversations to Enhancing Adherence
A program titled i2i:Conversations to Enhance Adherence will take place during the upcoming American Academy of Optometry annual meeting. The program will take place on Wednesday evening, October 22, 2008 at the Sheraton Park Hotel in Anaheim, CA. Steven R. Hahn, MD and David S. Friedman, MD will be the presenters with Murray Fingeret, OD the moderator. This program is similar to one presented at the AAO in Denver that was very well received.

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Editor in Chief Paul Spry PhD MCOptom Associate Editors Brad Fortune, OD, PhD Shaban Demirel, BScOptom, PhD Algis Vingrys BScOptom, PhD

Editorial Board Douglas Anderson MD Paul Artes PhD MCOptom Dick Bennett OD Murray Fingeret, OD Ron Harwerth, PhD Chris Johnson, PhD Tony Litwak, OD John McSoley, OD Ron Melton, OD Bruce Onofrey, OD, RPh Leo Semes, OD Randall Thomas, OD Thom Zimmerman, MD, PhD   Art/Production Director Joe Morris

 

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