Quality of life in medically & surgically treated patients with glaucoma

Materials & Methods

This prospective study was conducted at the department of Ophthalmology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India, a tertiary care academic institution following the Declaration of Helsinki, after obtaining clearance from its Institutional Ethics Committee. All participants received a patient information sheet and a consent was obtained from them in their local language.

Study population

A total of 321 individuals with glaucoma were seen in the glaucoma clinic during the study period (October 2022 to December 2023). Participants flow is shown in figure. Participants were selected based on clinical indications for trabeculectomy, including failure to achieve target intra ocular pressure (IOP) on maximum tolerable medical therapy or progression of glaucoma. The same cohort was considered for calculating the GQL-15 score after surgical therapy. Normative values of the GQL-15 scores were obtained from a control group comprising 30 eyes of 15 age and sex-matched healthy individuals (non-glaucoma).

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Figure.

Flowchart depicting the distribution of screened glaucoma individuals into various categories such as paediatric and adult glaucoma, further categorizing adult glaucoma as open angle glaucoma or angle closure glaucoma, showing allocation into medical management and surgical management groups (surgically treated group being enrolled in the study).

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All 46 participants (54 eyes) were on medical management before enrolment, consisting of topical and/or systemic anti-glaucoma medications. Inclusion criteria included individuals on medical management planned for trabeculectomy. Most eyes (n=34, 63%) were receiving at least three (5.5%) antiglaucoma drugs; two and four drugs were being used in three and 17 (31.5%) eyes, respectively. Medications used included prostaglandin analogues (n=45), beta-blockers (n=44), alpha agonists (n=42), carbonic anhydrase inhibitor (n=41) and miotics (n=12). Figures in parentheses indicates the number of eyes in which the medications were being administered, singly or in combination. Exclusion criteria included unwillingness to participate or other ocular conditions affecting visual fields or QoL. The sample size was based on convenient sampling with a six-month follow up post-trabeculectomy.

Results

Of 54 eyes evaluated in our study, 6 (11.1%) had mild glaucoma, 18 (33.3%) had moderate glaucoma, and 30 (55.6%) had Severe glaucoma. All 46 participants were on medical management at enrolment, with a mean of 2.57±0.728 topical anti-glaucoma medications and 17 participants on systemic medications. Duration of glaucoma was also noted for all participants and grouped as <1 yr, 1-5 yr, and >5 yr with 5, 24 and 17 participants, respectively. Males predominated (74%), with a mean age of 55.2±14.9 yr. Sixteen participants suffered from hypertension, nine from diabetes mellitus, and five had a history of smoking.

There was no statistically significant difference between the best corrected visual acuity in medically managed group as compared to surgically managed group (0.37±0.39 logMAR vs. 0.34±0.39 logMAR, P= 0.8). IOP showed a significant decline from the preoperative value (18.90+6.67 mm Hg) to the postoperative values at one month (10.90+3.06 mm Hg, P< 0.001), three months (12.20+2.56 mm Hg, P<0.001), and six months (12.25+2.65 mm Hg, P<0.001). Our study showed a significant decrease in the number of topical anti-glaucoma medications at six months follow up (2.57±0.728 to 0.35+0.594; P=0.00). 17 out of 46 patients were on systemic anti-glaucoma medications while on medical management. However, no participants needed systemic anti-glaucoma medications at six months follow up.

GQL scores comparing control, medically managed patients, and surgically managed population are shown in table I. GQL-15 scores showed significant correlations with duration of glaucoma (r=0.844, P=0.00) and number of anti-glaucoma medications (surgical therapy: r= -0.282, P=0.045). The population was not evenly distributed among OAG and ACG groups, so no correlation could be calculated with type of glaucoma. Macular RNFL, GCL+, and GCL++ showed significant negative correlation with QoL both pre- and post-operatively. GQL-15 did not demonstrate any significant correlation with total or quadrant wise superior/temporal or nasal peripapillary RNFL; or optic nerve head (ONH) rim area/volume/cup area. GQL-15 scores varied by severity, with severe glaucoma showing the highest scores (poorest QoL) (Table II).

A statistically significant reduction in scores was observed between scores for participants on medical management and surgical management for all four parameters, conveying better quality of life of patients after trabeculectomy pertaining to all four domains of the questionnaire (Supplementary Table).

Discussion

The study found a significant increase in GQL scores in glaucoma patients, suggesting poorer quality of life than healthy individuals. These scores decreased after trabeculectomy, suggesting that trabeculectomy may improve QoL in moderate to severe glaucoma patients compared to medical therapy, likely due to reduced medication burden and ocular side effects.

Quality of life is a subjective perception of an individual. For years, diseases and their management have impacted it in numerous ways¹¹. Therefore, assessment of the QoL in patients becomes a crucial measure of the functional outcomes of the concerned treatment. The ocular discomfort observed in glaucoma patients is attributed to the preservatives in anti-glaucoma medications. Therefore, a reduction in quality of life is inevitable when a patient suffers from resultant dry eye disease. It tends to interfere with daily functioning, thereby adding to the pre-existing load of the disease^12-16. Our study echoed the same by showing a significant correlation of GQL Scores with both duration of glaucoma and the number of anti-glaucoma medications (P<0.05).

There was a significant reduction in the number of topical anti-glaucoma medications at six months follow up with no patients on systemic medications. The significant reduction in medication burden post-trabeculectomy likely contributed to improved QoL, as ocular surface disorders from anti-glaucoma medications negatively impact QoL. Binibrahim et al⁴ found a decrease in a number of drops and oral anti-glaucoma medication post-operatively, illustrating that the patient’s quality of life has also improved.

Studies have shown that reduced peripheral contrast sensitivity resonates well with glaucoma progression as measured on OCT RNFL measurements. This decrease in contrast sensitivity hinders in daily activities of the patient¹⁷. Our study showed a significant correlation of QoL with macular RNFL, GCL+, and GCL++. This study reinforced that structural changes predict changes in various visual functions, causing a reduction in quality of life.

A statistically significant decrease in GQL-15 scores after trabeculectomy compared to medical management in our study suggests a better quality of life in patients after trabeculectomy. Moreover, a significant difference was observed in scores for all subgroups and individual questions of the GQL-15 questionnaire.

A similar study from South India and the meta-analysis done by Wang et al¹⁸ found a significantly worse quality of life in glaucoma patients compared to the control group using the GQL-15 questionnaire. Significant differences existed between the scores of the mild, moderate, and severe glaucoma patients, suggesting poorer quality of life with increased glaucoma severity^8,18. We also found significant differences among glaucoma patients and controls. The QoL decreased steadily with increasing severity of glaucoma. Our study mostly had moderate to severe cases where trabeculectomy proved to be an efficacious and justifiable procedure in improving the QoL.

Zhang et al¹⁹ explored the implications of illness perceptions on vision-related quality of life (VRQoL) in Chinese glaucoma patients using a brief illness perception questionnaire (BIPQ), GQL-15 questionnaire, and a questionnaire regarding sociodemographic and clinical information. The BIPQ total score was positively correlated with the total GQL-15 and its four dimensions, indicating that a more negative perception of illness was associated with worse VRQoL.

Bektaş et al²⁰ examined the association of structural and functional tests of visual function and the 25-item NEI-VFQ-25 and the 36-item short form health survey (SF-36) in patients with different stages of glaucoma. Contrast sensitivity was the sole parameter that showed a significant correlation with glaucoma suspects, whereas in the early stages, visual acuity was the most strongly associated parameter with the total NEI-VFQ-25 score. Our study used a specific GQL-15 questionnaire to assess the quality of life in glaucoma patients. We also found macular RNFL, GCL+ and GCL++ to be significantly correlated with GQL scores. This is a novel finding as to how these structural changes can predict changes in QoL and need further research to validate such correlations.

Muralidharan et al² evaluated quality of life in glaucoma patients undergoing medical therapy, trabeculectomy, and glaucoma drainage device (GDD) surgery using both vision-specific (NEIVFQ25) and glaucoma-specific GQL15 instruments along with a surgery specific questionnaire (SSQ). The mean GQL-15 scores in the medical, trabeculectomy, and GDD groups were 20.63, 26.23, and 28.43, respectively. QoL assessed by NEIVFQ25 was better in surgically managed patients, while GQL-15 was better in medically managed patients. The rise in scores in the surgical groups may be due to an increase in the severity of glaucoma and associated visual impairment in these patients as compared to those on medical therapy. Our study tried to eliminate this selection bias to some extent by considering the same cohort for medical and surgical therapy, though maximum patients enrolled in our study also had severe glaucoma.

Glaucoma is a global burden. This study emphasizes the decreased quality of life in glaucoma patients and portrays the importance of trabeculectomy in a low-resource country. It shows trabeculectomy as one of the means of ameliorating the quality of life in moderate to severe glaucoma patients. Where previous studies have shown variable effects of medical or surgical therapy on quality of life which could be well attributed to varying severity of glaucoma, our study improvised by choosing the same cohort for both the therapies. The six-month follow up period allowed us to capture early improvements in QoL post-trabeculectomy, but long-term studies are essential to confirm the persistence of these benefits, as surgical outcomes may evolve over time.

However, the study had some limitations. This study was conducted at a single tertiary care centre with a modest sample size (54 eyes from 46 participants), limiting generalizability and external validation. The selection of patients planned for trabeculectomy introduces potential selection bias, as these participants had more severe or uncontrolled glaucoma. The six-month follow up period is relatively short, limiting assessment of long-term QoL outcomes. The GQL-15 questionnaire, while user-friendly, does not capture broader psychological or social factors, and the use of Snellen charts may introduce variability. The study did not adjust for potential confounders in a multivariable analysis due to sample size constraints. Larger, multicentre studies with longer follow up and comprehensive QoL tools are required to validate the results.

To conclude, selecting surgical intervention such as trabeculectomy can significantly enhance a patient’s quality of life by reducing medication burden and associated ocular surface issues, especially for patients with moderate to severe glaucoma, in low resource settings like India. This study underscores the importance of incorporating QoL assessments into treatment decisions, emphasizing that surgical management may offer not only better intraocular pressure control but also meaningful improvements in daily functioning and overall well-being.