At the completion of this CPD activity, optometrists will have developed their knowledge of glaucoma management. Including:
- Understand the value of well-structured, mutually-agreed individualised collaborative frameworks for shared-care
- Clinically identify which cases of glaucoma could be co-managed between optometry and ophthalmology
- Establish a co-management frameworks focused on individual patient care
- Identify barriers to glaucoma co-management
NOTE: Optomery Australia members can enter their details at the bottom of this article to have it automatically added to their Learning Plan.
As the diagnostic armamentarium evolves, eyecare professionals are re-writing their traditional roles in glaucoma management. Using ‘co-managed case reports’, the authors trace two patients’ divergent journeys from initial optometric consultation to ophthalmology referral in Tasmania.
Damon Hannay
BOptom
Optometry Director, Specsavers Launceston, Tasmania
Dr Dean Cugley
MB BS (Tas) FRANZCO
Ophthalmologist, Launceston Eye Institute, Tasmania
The cascading effects of glaucoma impacts individuals, families, communities and a broad range of healthcare professionals. As the demographics of Australia change and the population of the country shifts, there is a growing need to develop new methods of collaborative care and provide timely and effective screening and treatment.
Because of the progressive nature of the disease, it’s critical to ensure everyone over 40 years old receives routine eye exams. Making a real difference means addressing key issues: cost, delayed diagnosis and loss to follow up.
Burden on ophthalmology
Glaucoma affects roughly 200 000 Australians,1,2 a further 200,000 have strong suspicion and a further 380,000 may be classed ‘ocular hypertension’. This represents around 4% of the general population and, if seen twice yearly, equates to 1.5 million glaucoma exams annually.3,4
This burden may be heightened in regional areas. For instance, in parts of northern Tasmania, there is just one ophthalmologist for every 45,000 people. This equates to 3,600 glaucoma assessments a year for each ophthalmologist in Northern Tasmania. This, of course, leaves little room for other conditions to be managed.
Over-referral
It’s vital that patients with isolated findings such as elevated intraocular press (IOP) or large optic nerve cupping are evaluated by their optometrists – but not automatically referred unless a comprehensive clinical picture is found.
Ultimately, optometrists who have command of relevant clinical equipment are more likely to provide long-term care for the patients who don’t require referral, which will eliminate unnecessary costs and wasted time and lighten the load on ophthalmology.
Synergy of equipment and ethos
Our Specsavers practice in Launceston is a large, seven-room clinic with access to a Topcon Maestro and a ZEISS CIRRUS OCT. As per our protocol, every patient is screened first with the Maestro; those with suspicious results then go on to have CIRRUS scans. Our practice has the Humphrey Field Analyzer 3 (HFA3); a Pachmate pachymeter; a CLARUS ultra-widefield camera; a 4-mirror gonio lens; a Perkins, iCare and standard non-contact tonometers; and we run ZEISS FORUM Glaucoma Workplace software.
Locally, there are two ophthalmology practices that also use a CIRRUS OCT, HFA and ZEISS FORUM Glaucoma Workplace software. We have found that collaborating with these practices allows for more definitive ‘like-for-like’ analysis, regardless of the location of scans. We are also able to send raw DICOM files of HFA and OCT data to be downloaded into FORUM software at each practice.
This synergy of equipment and ethos has meant we have been able to develop a co-management protocol that lightens the burden of glaucoma care for the ophthalmologist, ensures prompt follow up and encourages informed referral and optimum treatment.
CASE 1 – NORMAL TENSION GLAUCOMA
Patient presents at optometrist
A 62-year-old female presented for a routine eye examination in September. She was on no medications, had no family history of glaucoma and denied any relevant ocular history.
IOP with iCare tonometer was 9 mmHg in each eye. Screening OCT with Topcon Maestro (Figure 1A and Figure 1B) showed retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) maps within normal limits for both eyes. Pachymetry was thin at 480 microns.
Figures 1A and 1B – clearer images.
Ophthalmoscopy revealed a deep inferior notch at the right disc and more careful examination with the Maestro OCT showed obvious relative inferior thinning of the RNFL compared to the fellow eye.
We went on to perform 24-2C visual field testing and CIRRUS OCT which, given its retinal tracking function, allows for more consistent readings when looking at progression over time. It also allows for data importation into the ZEISS FORUM Glaucoma Workplace platform.
Glaucoma Workplace collates data from the HFA3, CIRRUS OCT and CLARUS ultra widefield camera to provide two valuable functions:
- Structure Function Single Visit Reporting – allowing for simultaneous and overlapping analysis of visual field plots comparing to associated structural damage.
- Structure-Function Guided Progression Analysis (SF-GPA) software allowing for a multi-modal comparison of OCT, HVF and true-colour fundus images over the full time series in a user-friendly, single screen interface.
Figure 2 – clearer image.
The patient was diagnosed with normal tension glaucoma and started on Xalatan. Her response was checked in a month and was found to be 6 mmhg. The patient was then referred to a local glaucoma specialist as per clinical guidelines for confirmation of treatment plan and co-management.
Patient is referred to ophthalmologist
In November, the referred patient presented at the Launceston Eye Institute (LEI) with high suspicion of normal tension glaucoma. History revealed no ocular trauma, medications associated with optic neuropathy, or medical comorbidity such as migraines or Raynaud’s phenomena. There was no known family history of glaucoma.
The ocular examination revealed normal colour vision bilaterally and visual acuity of an unremarkable anterior segment with no signs of pseudoexfoliation (PXF) or pigment dispersion syndrome with open angles on gonioscopy and no significant crystalline lens opacity. IOP was 7 mmHg bilaterally on Goldmann applanation tonometry at 10:25am. Pachymetry revealed central corneal thickness (CCT) of 482 microns right and 478 microns left. Fundoscopy revealed optic discs of normal vertical height (1.7 mm) size with cup-to-disc ratio (CDR) 0.65 right with inferior notch and 0.55 left with borderline inferior thinning with no disc haemorrhage or nerve fibre layer defect.
There was no evidence of cystoid macular oedema. There was corresponding right disc and field abnormalities consistent with early right glaucoma. See the combined assessment in Figure 3.
Figure 3 – clearer image.
Compared with the optometric assessment, the visual field was less marked and the RNFL more marked, again on CIRRUS OCT. (The former may be due to some degree of patient familiarisation effect with the visual field test, and the latter due to assessment through an undilated pupil).
Diagnosis
A diagnosis of normal tension glaucoma with adequate intraocular pressure (IOP) response and tolerance to first line prostaglandin. Target IOP was set at 7 mmHg (20% reduction in IOP). First choice agent of prostaglandin analogue was appropriate and tolerated well since commencement.
This case was classified as ‘early glaucoma’ (< 6dB HVF loss and no loss within central 10 degrees).
Discussion
This is an ideal case for optometry-led glaucoma management due to the adequate initial response to first-line therapy. The patient was seen again approximately six months after the initial consultation, and the patient in fact questioned the need for ongoing reviews with an ophthalmologist. Instead, she preferred optometry reviews. She was duly discharged back to optometric led care.
Guidelines for referral back to ophthalmology review were communicated, and would represent unstable disease which may include:
- Unknown disease velocity (first presentation, lost to follow up etc.)
- IOP fluctuations of 3 mmHg or more above target IOP (determined during initial baseline medical assessment)
- Structural changes in the previous three-year period (clinically or on OCT of RNFL / GCL)
- Concern of anterior segment angle compromise, typically in phakic patients
- Medication issues, such as suspected side effects, intolerance or compliance issues – for example cystoid macular oedema, prostaglandin associated orbitopathy etc.
Patient returns to the care of the optometrist
After two years of stability (see right eye Guided Progression Analysis summary Figure 4), the patient was discharged back to optometrist for ongoing six-monthly monitoring. The shared use of progression software and the initial strong communication between optometry and ophthalmology allowed for an excellent patient outcome with reduced cost and stress on a regional ophthalmology clinic.
Figure 4 – clearer image
This patient can be safely followed in a primary care setting with the knowledge that any future progression or issues can be shared with the collaborating ophthalmologist.
Case 2
Patient presents at the optometrist
A 70-year-old female presented for her first eye examination at our optometry practice complaining of gradual reduced vision in both eyes. She reported a history of being diagnosed with glaucoma around five years prior but had not been seen in the last four years and had stopped treatment around the same time.
Gaining an insight into a patient’s individual barriers to care is the first important step in trying to steer her journey in a new direction. Discussing the factors leading to this decision revealed three common challenges in glaucoma care:
- Significant ocular irritation with latanoprost, with rapid symptomatic improvement on cessation
- Out-of-pocket costs were financially limiting, and she felt therefore unable to return to her ophthalmologist to discuss alternate treatment strategies. (Unfortunately, these concerns were not communicated to the treating ophthalmologist at that time to discuss alternatives).
- A lack of understanding of the disease and relative early asymptomatic nature, meant because she felt her vision was ‘fine’ and that she would return only if she became symptomatic, which would likely represent advanced disease or other ocular comorbidity.
Breaking down barriers
We were able to look at the Structure-Function report (Figure 5) together showing the significant GCL and RNFL defects more evident in the right eye associated with the dense superior field loss. It was not hard to understand the consequence the untreated glaucoma had had on her vision. Deferring treatment at this point could be devastating.
We had a discussion about the different modalities of glaucoma therapy and the ability to tailor the management plan as needed. We discussed the frequent ocular surface irritation experienced with medical therapy in glaucoma and the ways in which this may be overcome.
Figure 5 – clearer image.
Avenues available to minimise out-of-pocket costs through the use of the public system and our optometry practice (where appropriate) were discussed. However, in this circumstance – given the advanced nature of her right eye disease – we recommended that an ophthalmologist should be taking the lead decisions.
The patient was started on Lumigan PF to determine what affect benzalkonium chloride (BAK preservative) may have been having on her initial experience. She was asked to touch base with us by phone a week later to ensure she wasn’t experiencing any side effects.
I also organised for her to see a local glaucoma specialist the following month for confirmation of treatment plan and to identify if and when surgical intervention might be warranted in light of relatively advanced disease.
Patient is referred to ophthalmologist
At the LEI, we were referred a 70-year-old Caucasian female with established right-greater-than-left visual field loss consistent with advanced glaucomatous optic neuropathy and symptomatic cataracts. She was tolerating preservative free-bimatoprost better than previously trialled latanoprost, suggesting a degree of BAK intolerance.
The patient was seen promptly in light of the review in August. Clinical examination revealed significant cataracts, moderate angle shallowing with low risk of occlusion and no evidence of secondary causes. The intraocular pressure was 23 mmHg (OD) and 20 mmHG (OS) after only two weeks of topical bimatoprost. There was established disc cupping bilaterally with no disc haemorrhage.
The combined assessment, shown below, corresponds with the optometrist referral assessment. It indicates advanced disease in the right eye (> 12dB loss and within central 10 degrees) with dense superior field loss and moderate in the left (6-12dB loss without loss in the central 10 degrees) with inferior arcuate scotoma. Again, there was disc field concordance but discrepancy between total and pattern deviation suggesting a degree of media opacity (that is: cataract).
The ophthalmology management plan included:
- Discussions about the diagnosis of glaucoma, irreversible nature of established disease, extent of disease in her eyes, the plethora of treatment options and the importance of adequate treatment, follow up and compliance with both
- Binocular estermann suprathreshold visual field examination to ensure visual field at current driving standard for private vehicle given extensive right superior field loss
- Preparation for cataract surgery
- Comprehensive and regular communication with the referring optometrist with updates and plan for post-operative spectacle update and thereby opportunistic IOP checks at these visits and enquiry regarding compliance
- Continuation of bimatoprost and review in two months
An IOP check two months later revealed IOP of 15 mmHg right and 13 mmHg left indicating a good response to monotherapy.
Standard phacoemulsification cataract surgery was performed with significant improvement in visual acuity and IOP stability throughout.
At most recent review, the patient was referred back to the optometrist for a refraction update, which would present the opportunity for incidental IOP check.
This case was recommended to be ophthalmologist-led due to the established visual field loss and will be monitored closely for signs of progressive optic neuropathy and uptitration of therapy, if indicated.
Conclusion
A well-structured, mutually-agreed individualised collaborative framework for shared-care has the potential to reduce cost, increase convenience and shorten wait times with no sacrifice to patient care.
Communication, trust and investment in such a team-based model between patient, optometrist and ophthalmologist is vital for success.
Transferable software platforms significantly improve ease of continuity-of-care between shared providers and potentially allows for earlier detection of progression and altered management plans.
The vast majority of optometrists have the training and resources available to support and implement collaborative glaucoma care. While a broad national framework like the RANZCO and Optometry Board Australia guidelines are helpful, a local individualised discussion at a community level between optometry and ophthalmology clinics can allow for a more tailored and likely better collaborative approach.
Meetings between individual optometry and ophthalmology practices to discuss all these factors allows mutually motivated professionals to discuss the best approach for their community in regard to glaucoma care.
References
1. Keel S, Xie J, Foreman J, et al. Prevalence of glaucoma in the Australian National Eye Health Survey. Br J Ophthalmol. 2019; 103 (2): 191-195. doi:10.1136/bjophthalmol-2017-311786
2. Mitchell P, Smith W, Attebo K, et al. Prevalence of open-angle glaucoma in Australia. The Blue Mountains Eye Study. Ophthalmology. 1996; 103 (10): 1661-1669.
3. Rochtchina E, Mitchell P. Projected number of Australians with glaucoma in 2000 and 2030. Clin Exp Ophthalmol. 2000;28(3):146-148.
4. Chauhan BC, Garway-Heath DF, Goñi FJ, et al. Practical recommendations for measuring rates of visual field change in glaucoma. Br J Ophthalmol. 2008; 92 (4): 569-573.
5. The Royal Australian and New Zealand College of Ophthalmologists. Clinical Practice Guidelines for the collaborative care of glaucoma patients and suspects by ophthalmologists and optometrists in Australia [Internet]. Sydney: RANZCO; 2019 [cited 2022 Feb 15] Available from: https://ranzco.edu/wp-content/uploads/2018/11/Guidelines-for-the-Collaborative-Care-of-Glaucoma-Patients.pdf
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