Compliance is an important yet often overlooked consideration when managing patients with glaucoma. This article presents a case study on the consequence of potentially avoidable glaucomatous progression that can occur in the face of poor patient compliance.
As Janelle Tong writes, patientcentred care is key to limiting non-compliance. Simple steps that address potential barriers associated with adherence to recommended review periods and treatment regimens can help minimise the long-term impacts of glaucoma on patients’ quality of life.
CASE STUDY
A 57-year-old male patient was seen at the Centre for Eye Health in 2020 for his second appointment for ongoing monitoring as a glaucoma suspect. He was last seen in 2017 where a six-month review was originally recommended. Despite numerous phone and email reminders around the time, he was overdue for this second appointment; forgetfulness was cited as the reason for the delay in returning for follow-up.
He denied experiencing any changes to his vision over this period of time. His medical history was unremarkable, and he has a positive family ocular history for glaucoma in his father and older brother, who were both diagnosed in their 40s.
Visual acuities were 6/6 in both eyes with multifocal spectacle correction. Slit-lamp and gonioscopic examination revealed open angles with no evidence of secondary glaucomas, and applanation intraocular pressures (IOPs) were measured as 21 mmHg in the right eye and 20 mmHg in the left eye. While these measurements were on the upper end of the normative range at face value, they became more concerning in the context of previous measurements of 12 mmHg in both eyes and central corneal thickness measurements of 510 µm in both eyes.
Funduscopic examination revealed the development of an inferior notch in the neuroretinal rim and a contiguous retinal nerve fibre layer (RNFL) wedge defect in the right eye from the baseline visit. Thinning of the inferotemporal RNFL and macular ganglion cell-inner plexiform layer (GCIPL) was confirmed using optical coherence tomography (OCT). No structural changes were noted in the left eye, and 24-2 visual fields remained clear in both eyes.
Due to these findings, the patient’s diagnosis was updated to pre-perimetric open-angle glaucoma in the right eye. After discussion of treatment options in collaboration with an ophthalmologist from the local public hospital clinic, the patient chose to undergo selective laser trabeculoplasty (SLT) in the right eye under the public hospital system, and was recommended to use Xalatan in the right eye only while awaiting treatment.
Unfortunately, despite numerous phone call and email reminders, once again the patient was lost to follow-up over another three-year period, likely in part due to the COVID-19 pandemic. When he returned for his third appointment in early 2023, he revealed that he did not attend the SLT appointment and had not commenced Xalatan.
While visual acuities remained 6/6 in both eyes, applanation IOPs were measured as 25 mmHg in the right eye and 24 mmHg in the left eye. Over this time, significant progression in both structural and visual field results were observed. Funduscopic examination revealed almost complete loss of the inferior neuroretinal rim and diffuse loss of the inferior RNFL, in addition to a new superior notch in the neuroretinal rim, in the right eye. An inferior notch in the neuroretinal rim and a contiguous RNFL wedge defect had also developed in the left eye. OCT findings were consistent with the funduscopic examination, including further reduction in inferotemporal RNFL and GCIPL thickness in both eyes, with additional superior GCIPL loss and a possible new supertemporal RNFL defect in the right eye.
24-2 visual field results had drastically worsened by this appointment, with deep superior arcuate defects worse in the right eye than the left. The mean deviation changed by approximately -10.00 dB in the right eye and -4.00 dB in the left eye over three years, or an annual rate of -3.33 dB/year in the right eye and -1.33 dB/year in the left. Using evidencebased definitions of visual field progression in glaucoma, these are equivalent to catastrophic progression in the right eye (at least -2.00 dB/ year) and fast progression in the left (at least -1.00 dB/year).1,2 Additional 10-2 assessment revealed that these visual field defects encroached on central vision, although were shallower in the left eye relative to the right. Hence, over this three-year period, this patient had developed convincing advanced openangle glaucoma in the right eye, and at least early open-angle glaucoma in the left eye.
MAPPING INDIVIDUAL DISEASE TRAJECTORY
While open-angle glaucoma is generally perceived as a slowly progressive disease, 4.3 to 12.5% of glaucoma eyes demonstrate fast progression and 1.5% demonstrate catastrophic progression.1,2 Risk factors for rapid progression include worse baseline mean deviation, previous glaucoma surgery, lower baseline IOPs, and presence of cardiovascular disease.3 However, in line with the vast heterogeneity in glaucoma, risk factors alone cannot fully predict an individual’s likelihood of progression, with some patients, such as our patient in this case study, exhibiting catastrophic progression in the absence of any of these risk factors.
This possibility emphasises the importance of tailoring review periods to an individual’s clinical findings and risk factors, as how quickly an individual progresses can only be confirmed by analysing data collected over several visits of monitoring. Depending on whether stability or suspected but unconfirmed progression are observed, durations between follow-up visits can then be extended or shortened accordingly.
PATIENT COMPLIANCE TO REVIEW
Naturally, this approach of ongoing monitoring is contingent on patient cooperation with attending follow-up review appointments as recommended. Our case study is an example of the consequences of non-compliance to recommended follow-up and treatment, combined with a rapid to catastrophic disease trajectory.
Common reasons why patients with glaucoma do not attend appointments as scheduled are inadequate understanding of the importance of ongoing monitoring and poor satisfaction with how their glaucoma was explained to them.4,5 This is perhaps unsurprising: given that glaucoma is typically asymptomatic, and in light of time commitments to attend appointments, the battery of sometimes uncomfortable tests involved, and associated costs, patients may feel that there is no perceivable benefit to attending ongoing follow-up examinations.
Other factors that have been attributed to loss to follow-up include errors in administrative processes, patient forgetfulness, and comorbid conditions affecting ability to attend appointments.4-6 Alarmingly, patients that are lost to follow-up tend to have more severe glaucoma at baseline and have a high risk of progression upon resumption of care, with one study finding deterioration of visual acuity with a greater proportion of delayed visits.6,7
This highlights that patient education on the importance of ongoing monitoring and potential risks of non-compliance are imperative, and resources such as those available on the Glaucoma Australia website (glaucoma.org.au/i-treat-glaucoma/ resources) can provide patients with further information to supplement the advice provided during their consultation.
Additionally, given the potential ramifications of non-compliance to recommended review periods on vision, it is important to protect yourself from a medicolegal perspective. Steps to take include implementation of adequate processes within your practice to follow-up on patients that miss appointments, and documentation of these steps should there be the possibility of non-compliance despite these efforts, such as in our case example.
PATIENT COMPLIANCE TO TREATMENT REGIMENS
Compliance with topical ocular hypotensive medications is another well-known issue in glaucoma management. Across studies, noncompliance rates to prescribed medication schedules of at least 25% have been reported, and adherence to therapy decreases with longer durations of treatment, with poor persistency with treatment being reported in over 75% of glaucoma patients.8,9 Given the lifelong nature of glaucoma and that the benefits of treatment only occur with regular and consistent use, non-compliance can contribute to poorer treatment outcomes, even in the face of good compliance with review schedules.
Patients with a poor understanding of their glaucoma and the need for ongoing medication usage are more likely to be non-compliant with their prescribed treatment regimen, once again highlighting the importance of patient education in adherence to therapy.
Additional barriers affecting compliance with medications include difficulties with remembering medication schedules, side effects of medications, difficulties with administration, and associated costs.8-10 As the effects of these barriers can compound with increased dosage requirements, an obvious step is to simplify the medication schedule by using single or fixed combination medications requiring once daily dosages where possible.
Studies have also reported that automated reminders can improve adherence to glaucoma medications, although long-term effects have not been reported to date.9 In terms of medication side effects, choosing preservative-free options where possible, and appropriate management of comorbid ocular surface disease, can help improve compliance with glaucoma medications. Inoffice guidance regarding drop instillation can ensure patients are correctly administering their medications. There are numerous devices available facilitating drop instillation that could be recommended for patients with persistent difficulties due to dexterity-related issues. Finally, for suitable patients, SLT could be recommended to replace medical therapy or in addition to existing medical therapy.
Janelle Tong BOptom (Hons) BSc is a Staff Optometrist with the Centre for Eye Health (CFEH), where she is also undertaking her PhD studies with a PhD titled ‘Application of novel techniques enabling detection of early function deficits with ocular pathologies’. This research will continue the work she began as a research optometrist at CFEH to develop new methods that enable the early, accurate detection of eye diseases such as glaucoma.
References
- Jackson, A.B., Martin, K.R., Coote, M.A., et al. Fast progressors in glaucoma: Prevalence based on global and central visual field loss. Ophthalmology 2023;130(5):462–8.
- Chauhan, B.C., Malik, R., Shuba, L.M., et al., Rates of glaucomatous visual field change in a large clinical population. Invest Ophthalmol Vis Sci 2014;55(7):4135–43.
- Chan, T.C.W., Bala, C., Siu, A., et al.,. Risk factors for rapid glaucoma disease progression. Am J Ophthalmol 2017;180:151–7.
- Haines, C., Hart, K., Phu, J., et al., Clinical practice guide for the diagnosis and management of open angle glaucoma. South Melbourne, Australia: Optometry Australia; 2020.
- Kim, Y.K., Jeoung, J.W., Park, K.H., Understanding the reasons for loss to follow-up in patients with glaucoma at a tertiary referral teaching hospital in Korea. Br J Ophthalmol 2017;101(8):1059–65.
- Davis, A., Baldwin, A., Hingorani, M., et al., A review of 145,234 ophthalmic patient episodes lost to follow-up. Eye (Lond) 2017;31(3):422–9.
- Singh, A., Udayakumar, B., Duraisamy Ravilla, T., et al., Factors affecting follow-up adherence of glaucoma patients. Ophthalmic Epidemiol 2023:1–9.
- Schwarz, G.F., Compliance and persistency in glaucoma follow-up treatment. Curr Opin Ophthalmol 2005;16:114–21.
- Robin, A.L., Muir, K.W., Medication adherence in patients with ocular hypertension or glaucoma. Expert Review of Ophthalmology 2019;14(4-5):199–210.
- Zaharia, A.C., Dumitrescu, O.M., Radu, M., Rogoz, R.E., Adherence to therapy in glaucoma treatment: A review. J Pers Med 2022;12(4).
