Individualised treatment

Early diagnosis and effective, individualised treatment can enable patients with glaucoma to retain their vision and enjoy a good quality of life – for life.

Glaucoma treatment must therefore be tailored to each patient, at various stages of the disease, and the personal target pressure adapted to the patient’s life expectancy. Adherence, lifestyle and side effects, if any, also play a role in choice of treatment.¹

AbbVie Eyecare collaborates with professionals to facilitate treatment and enable healtcare professionals to individualise this treatment. SSY Engine is a practical tool that helps the treating physician to assess and determine patient-specific target pressure based on rate of progression and life expectancy.²

The burden of adhering to glaucoma treatment

* Group-based trajectory modelling results from a retrospective longitudinal cohort analysis, where beneficiaries ≥40 years old enrolled in a U.S. managed care plan for ≥7 years between 2001–2012 and were newly diagnosed and treated for open-angle glaucoma (N=1,234).⁶

In an exploratory study including those with OAG, suspect glaucoma, and OHT, reasons for non-adherence included:^**,7

• difficulty with proper administration of eye drops
• remembering to take medication
• physisians not spending enough time sharing information about their eye condition

** Results of in-depth interviews conducted with 80 individuals diagnosed with open-angle glaucoma, glaucoma suspect, or OHT. Interviews took place between April–December 2007 and included individuals from two eye clinics based within 2 hospitals in Southeast US.⁷

Improving patient adherence may result in slower deterioration in VF function over time^†,8,9

† The longitudinal relationship between medication adherence and visual field progression was evaluated among patients enrolled in the medication arm (n=306 with adherence data) of the CIGTS, a randomized, multicenter clinical trial comparing initial treatment with trabeculectomy in patients with newly diagnosed glaucoma.⁶

Predicted average VF loss in MD for different levels of adherence using a linear mixed regression model ⁶

Adapted from Newman-Casey PA et al. 2019.⁸
* The longitudal relationship between adherence and visual field progression was evaluated among patients enrolled in the medication arm (n=305 with adherence data) of the CIGTS, a randomnized, multicenter clinical trial comparing initial treatment with trabeculectcomy in patients with nnewly diagnosed glaucoma.⁸
** p=0.007.⁸
† p<0.0001. Error bars show 95% confidence interval.⁸
CIGTS, The Collaborative Initial Glaucoma Treatment Study; MD, mean deviation; VF, visual field.

Primary open-angle glaucoma

Although not yet fully understood, the level of IOP in POAG is thought to be related to retinal ganglion cell death. High IOP may be caused by increased resistance to aqueous outflow via the trabecular meshwork.⁹

Pathogenesis of POAG:⁹
1. An increased IOP can cause mechanical stress and strain on posterior structures of the eye, particularly the lamina cribrosa and adjacent tissues. Here, the optic nerve fibers (retinal ganglion cell axons) exit the eye
2. Stress and strain may result in compression, deformation, and remodelling of the lamina cribrosa, causing mechanical axonal damage
3. Possible disruption of axonal transport (seen to occur early in the pathogenesis of glaucoma in experimental systems)

Schematic illustration of normal anatomy and neurodegenerative changes associated with glaucomatous
optic neuropathy⁹

Adapted from Weinreb R et al. 2014.⁹
LGN, lateral geniculate nucleus; RG, retinal ganglion.

Retinal ganglion cell loss causes progressive deterioration of visual fields, which usually begins in the midperiphery and may progress centripetally until either a central or peripheral island of vision remains.⁹

Normal and glaucomatous optic nerve heads and visual field test results⁹

Adapted from Weinreb R et al. 2014.⁹

Primary angle-closure glaucoma

The main feature distinguishing PACG from POAG is that the angle (the site of aqueous outflow in the eye) is obstructed by apposition of the iris, resulting in an anatomically closed angle (defined if at least 270° of the angle is occluded).⁹

Pupillary block is the most common mechanism of angle closure and is caused by resistance to aqueous humor flow from the posterior to anterior chambers at the pupil. Aqueous humor accumulates behind the iris, increasing its convexity and subsequently causing
angle closure.⁹

Glaucoma staging and diagnosis

Glaucoma staging is based on the severity of VF damage. Several staging systems have been developed.¹⁰
A simple system based on MD alone is acceptable (see below, simplified from Hodapp-Parrish-Anderson classification):¹⁰

• Early glaucomatous loss: MD ≤ 6 dB

• Moderate glaucomatous loss: 6 > MD ≤ 12 dB

• Advanced glaucomatous loss:  MD > 12 dB

Worse MD values are associated with higher risk of blindness.¹⁰

Early glaucoma

In the early stages, glaucoma does not usually cause any symptoms, and many cases are only diagnosed at routine visits to
eye care professionals.¹¹

Many people may have lost some vision by the time they are diagnosed.¹³

Moderate glaucoma

Glaucoma can present with a diverse range of visual symptoms.¹³

Most common visual symptoms reported by all patients*^,13

Adapted from Hu C et al. 2014.¹³
* Results of a prospective study that administered a questionnaire to US patients (from July 2011–December 2011) clinically diagnosed with various forms and stages of glaucoma with questions about their most common visual symptoms (N=99).¹³

Advanced glaucoma

As vision loss progresses in the later stages of glaucoma, in addition to symptoms already listed in mild/moderate glaucoma, patients may experience tunnel vision due to total loss of peripheral vision.^9,14  This can still occur independent of whether patients are having treatment.¹⁵

of OAG patients went on to go blind in one eye over 15 years of follow-up even with treatment, due to poor IOP control.¹⁶

Among the 1 billion people worldwide who have a near or distance vision impairment that could have been prevented or has yet to be addressed,

are estimated to have this vision impairment due to glaucoma.¹⁷

References and abbreviations

1. European Glaucoma Society (EGS). Terminology and Guidelines for Glaucoma. Fourth edition. EGS. 2014.

2. Heijl A, Brandel M. If we don't change direction soon, we'll end up where we're going: a description of the SSY Engine. Acta Ophthalmol. 2020;doi:10.1111/aos.14612.

3. Leske C, Heijl A, Hyman L, et al. Predictors of long-term progression in the early manifest glaucoma trial. Ophthalmology 2007;114(11):1965-1972.

4. Heijl A, Buchholz P, Norrgren G, et al. Rates of visual field progression in clinical glaucoma care. Acta Ophthalmol 2013;91(5): 406-412.

5. Chauhan C, Mikelberg F, Balaszi G, et al. Canadian Glaucoma Study: 2. risk factors for the progression of open-angle glaucoma. Arch Ophthalmol 2008;126(8):1030-1036.

6. Newman-Casey PA. Blachley T, Lee P P et al. Patterns of Glaucoma Medication Adherence over Four Years of Follow-Up. Ophthalmology 2015; 122(10): 2010–2021.

7. Stryker JE, Beck A D, Primo S A et al. An exploratory study of factors influencing glaucoma treatment adherence. J Glaucoma 2010; 19(1): 66–72.

8. Newman-Casey PA, Niziol, Gillespie et al. The Association between Medication Adherence and Visual Field Progression in the Collaborative Initial Glaucoma Treatment Study (CIGTS). Ophthalmology 2020; 127(4): 477–483.

9. Weinreb R, Aung, Medeiros. The pathophysiology and treatment of glaucoma: a review. JAMA 2014; 311(18): 1901–1911.

10. European Glaucoma Society. Terminology and Guidelines for Glaucoma. 5th edition. 2020.

11. Quigley HA and Jampel HD. How Are Glaucoma Patients Identified? J Glaucoma 2003; 12(6): 451–455.

12. Musch DC, Gillespie, Richter et al. Visual Field Progression in the Collaborative Initial Glaucoma Treatment Study: The Impact of Treatment and other Baseline Factors. Ophthalmol 2009; 116(2): 200–207.

13. Hu C, Zangalli, Hsieh et al. What do patients with glaucoma see? Visual symptoms reported by patients with glaucoma. Am J Med Sci 2014; 348(5): 403–409.

14. Crabb DP, Smith, Glan et al. How does glaucoma look?: patient perception of visual field loss. Ophthalmology 2013; 120(6): 1120–1126.

15. Chen P. Blindness in patients with treated open-angle glaucoma. Ophthalmology 2003; 110: 726–733.

16. World Health Organization. World Report on Vision. WHO 2019. Available at: https://www.who.int/publications/i/item/world-report-on-vision.  Accessed: July 2024. 

17. World Health Organisation. Blindness and Impairment. 2023. Available at https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment. Accessed July 2024

IOP, intraocular pressure; OAG, open-angle glaucoma. IOP, intraocular pressure; PACG, primary angle-closure glaucoma; POAG, primary open-angle glaucoma. MD, mean deviation; VF, visual field. CIGTS, Collaborative Initial Glaucoma Treatment Study; MD, mean deviation; OAG, open-angle glaucoma; VF, visual field. CIGTS, The Collaborative Initial Glaucoma Treatment Study; OAG, open-angle glaucoma; OHT, ocular hypertension; POAG, primary-open angle glaucoma; VF, visual field.

SE-OPHTHG-240004 v1.0 July 2024