Oral Bisphosphonates and Risk of Wet Age-Related Macular Degeneration

Risk of developing age-related macular degeneration in patients with osteoporosis: a population-based, longitudinal follow-up study

Osteoporosis was suggested to be associated with higher odds of age-related macular degeneration. However, the temporal relationship between osteoporosis and age-related macular degeneration has not been explored. This population-based longitudinal follow-up study showed an increased risk of age-related macular degeneration in both men and women with osteoporosis.

PURPOSE

To investigate the long-term risk of age-related macular degeneration (AMD) in patients with osteoporosis.

METHODS

This is a retrospective cohort study using the Longitudinal Health Insurance Database 2005, a subset of Taiwan's National Health Insurance research database. A total of 23,611 individuals aged 50 to 79 who were diagnosed with osteoporosis between January 1, 2002 and December 31, 2006, were enrolled in the osteoporosis group. An exactly equal number of propensity score-matched individuals without osteoporosis comprised the comparison group. The variables used in propensity score matching included age, sex, comorbidities, and socioeconomic status. Cox proportional hazard regression analysis was used to evaluate the association between osteoporosis and AMD. The main outcome measure is the occurrence of newly diagnosed AMD.

RESULTS

The hazard ratio (HR) of AMD in the osteoporosis group was 1.34 times higher than in the comparison group (95% confidence interval [CI] 1.22-1.47, p < 0.05). The AMD-free survival rate of the osteoporosis group was significantly lower than that of the comparison group (p < 0.0001). Sex-stratified analysis revealed a significantly increased risk of AMD in both osteoporotic men (HR 1.45; 95% CI 1.20-1.76, p = 0.0002) and women (HR 1.31; 95% CI 1.17-1.46, p < 0.0001) compared with their non-osteoporotic counterparts.

CONCLUSION

This longitudinal follow-up study revealed an increased risk of developing AMD in both men and women with osteoporosis.

Ocular Side Effects of Bisphosphonates: A Review of Literature

In rare cases, bisphosphonates are well established to cause ocular inflammation, presenting as uveitis, episcleritis, scleritis, orbital inflammation, and/or conjunctivitis. Some reports of bisphosphonate-associated neuro-ophthalmic complications also exist. We identified 101 reports in the literature relating to bisphosphonate-associated ocular complications. In a great majority of cases, symptoms resolve after discontinuation of the drug and anti-inflammatory treatment. Many cases recur if rechallenged with the same bisphosphonate. First-generation nonamino bisphosphonates, including clodronate and etidronate, are not associated with ocular inflammation. Only 2nd- and 3rd-generation amino bisphosphonates, including pamidronate, alendronate, risedronate, ibandronate, and zoledronate are associated with these complications. The mechanism of bisphosphonate-induced ocular inflammation may be related to activation of γ/δ T cells or M1 macrophages. Intravenous forms, such as pamidronate and zoledronate, tend to have higher rates and faster onset of ocular inflammation, generally presenting within days of infusion. In oral bisphosphonates, such as alendronate and risedronate, these complications present with more sporadic timing. Rates of complications are also higher when bisphosphonates are used for malignancy, as doses tend to be higher compared with doses for osteoporosis.

Osteoporosis, bisphosphonates, and ocular inflammation

BACKGROUND

Osteoporosis, as a musculoskeletal disease, is very common, especially in the era of aging society. It is described by a reduction in bone strength and increased risk of fractures, which are linked to considerable morbidity, mortality, and high healthcare burdens. Bisphosphonates are the most commonly used drugs to manage osteoporosis and they consequently reduce fracture risk. However, one of the clinical challenges is fear of side effects in patients who are using bisphosphonates as the administration of these drugs is lengthy. Ocular inflammation has been reporting as one of the potential vision-threatening side effects of bisphosphonates.

PURPOSE

To review previously reported ocular inflammation in patients taking bisphosphonates.

METHOD

A literature survey was conducted using databases in order to collect data for a narrative review of published reports regarding ocular side effects of bisphosphonates.

RESULTS

People taking bisphosphonates were at a relatively low risk of ocular inflammation, with the onset from a few hours after exposure up to more than 3 years. The release of inflammatory mediators mainly by activated gamma delta T cells in response to bisphosphonates was the main cause of ocular inflammation.

CONCLUSION

Strategies for treating patients with osteoporosis should consider the potential ocular side effects of bisphosphonates. Ocular inflammation, as one of the side effects of bisphosphonates, is a serious sight-threatening sign and should be taken seriously. Greater awareness of the association between bisphosphonate use and ocular inflammation may allow for earlier identification and timely treatment of future cases.

The effect of etidronate on choroidal neovascular activity in patients with pseudoxanthoma elasticum

Aim

To assess the effect of the bisphosphonate etidronate on choroidal neovascular (CNV) activity in patients with pseudoxanthoma elasticum (PXE).

Methods

This is an ancillary study in a single center, randomized, double-blind placebo-controlled trial (RCT) in which 74 patients with PXE were assigned to either one-year etidronate or placebo treatment. Spectral domain optical coherence tomography (SD-OCT) imaging and color fundus photography were performed every three months for one year and were systematically assessed on signs of CNV activity.

Results

In the etidronate group, 11 (30%) of the patients had CNV activity at baseline, compared to 25 (67%) of the patients in the placebo group (P = 0.005). The proportion of eyes with CNV activity during the study ranged from 18–33% in the etidronate group and 42–56% in the placebo group and no significant difference in improvement or worsening of CNV activity was found (P = 0.168). Using a generalized mixed model for repeated measures, there was a protective effect of etidronate in crude analysis (RR 0.86, 95% CI 0.75–0.98) that disappeared when adjusting for baseline CNV activity (RR 0.97, 95% CI 0.84–1.13).

Conclusion

In this post-hoc RCT analysis we did not observe a protecting or deteriorating effect of etidronate on CNV activity in patients with PXE after adjustment for baseline CNV.

Extra-skeletal effects of bisphosphonates

Bisphosphonates (BPs) are pyrophosphate analogues widely used in diseases related to bone loss and increased bone turnover. Their high affinity for bone hydroxyapatite makes them ideal agents for bone diseases, while preventing them from reaching other cells and tissues. Data of the last decade, however, have demonstrated extra-skeletal tissue deposition and a variety of non-skeletal effects have been recently recognized. As such, BPs have been shown to exert anti-tumor, immunomodulatory, anti-inflammatory and anti-diabetic effects. In addition, new delivery systems (liposomes, nanoparticles, hydrogels) are being developed in an effort to expand BPs clinical application to extra-skeletal tissues and enhance their overall therapeutic spectrum and effectiveness. In the present review, we outline current data on extra-skeletal actions of bisphosphonates and attempt to unravel the underlying pathophysiological mechanisms.

Risk of Cataract Surgery and Age-Related Macular Degeneration After Initiation of Denosumab vs Zoledronic Acid for Osteoporosis: A Multi-Database Cohort Study

BACKGROUND AND OBJECTIVE

There is a relative lack of head-to-head comparisons of denosumab against other osteoporosis drugs on safety. We aimed to explore ocular outcomes in patients with osteoporosis initiating denosumab vs zoledronic acid.

METHODS

We conducted a cohort study using claims data (2010-15) from two large US commercial insurance databases including patients with osteoporosis who were aged 50 years or older and initiators of denosumab or zoledronic acid. The primary outcomes were (1) receipt of cataract surgery and development of (2) wet age-related macular degeneration and (3) dry age-related macular degeneration within 365 days after initiation of denosumab vs zoledronic acid. Propensity score fine stratification and weighting were used to control for potential confounding, and we calculated the incidence rate and hazard ratio for each outcome in the cohorts. The estimates from the two databases were combined with a fixed-effects model meta-analysis.

RESULTS

The study cohort included 50,821 denosumab and 67,471 zoledronic acid initiators. In the propensity score-weighted analysis, compared to zoledronic acid use, denosumab was associated with a modestly decreased risk of undergoing cataract surgery (hazard ratio 0.91; 95% confidence interval 0.85-0.98) but not with the risk of wet age-related macular degeneration (hazard ratio 1.29; 95% confidence interval 0.99-1.70) or dry age-related macular degeneration (hazard ratio 1.03; 95% confidence interval 0.98-1.09).

CONCLUSIONS

In this large population-based cohort study of 118,292 patients with osteoporosis, initiation of denosumab was associated with a modestly decreased risk of cataract surgery vs zoledronic acid. The risk of age-related macular degeneration was similar between the two drugs.

Alendronate induced chorioretinitis: The importance of meticulous assessments

Purpose

To report a case of presumed bilateral chorioretinitis secondary to alendronate therapy.

Observations

A 71-year-old female presented to the clinic in July 2017 with six months history of difficulty in reading along with floaters in both eyes which were more severe in the right eye. Past medical and surgical history revealed a history of hypertension, gout, hyperthyroidism, osteoporosis, and humerus fracture. She was started on alendronate three months before developing ocular symptoms. On ocular examination, best corrected visual acuity was 20/30 in the right and 20/25 in the left eye. Slit-lamp examination demonstrated normal anterior chamber examination in both eyes. Dilated fundus examination revealed geographic chorioretinal lesions around the optic nerve head in both eyes, more extensively in the right eye; and superior and temporal to the macula in the right eye. Past ocular records in February 2015 did not reveal any such findings. Fundus autofluorescence demonstrated hyper-autofluorescence in the peripapillary lesions in both eyes. The lesion adjacent to the macula in right eye displayed mixed hyper and hypo-autofluorescence. Fluorescein angiography showed combined hyper- and hypo-fluorescence compatible with window defect, staining and blockage. However, no leakage was appreciated in the macula, peripapillary, and peripheral lesions in both eyes. Optical coherence tomography scan showed septate hyporeflective intraretinal spaces in the right eye.

Conclusion and importance

The index report underscore the importance of considering alendronate as an etiologic cause of chorioretinitis, especially in subjects with atypical lesions developing after alendronate therapy. We, therefore, recommend discontinuation of this medication in subjects who develop chorioretinitis after employing this medication.

Oral bisphosphonate use and age-related macular degeneration: retrospective cohort and nested case-control study

Our objective here was to determine whether oral bisphosphonate (BP) use is associated with the incidence of age-related macular degeneration (AMD). We performed a population-based study using electronic health records from UK primary care (Clinical Practice Research Datalink). A cohort of 13,974 hip fracture patients (1999-2013) was used to conduct (1) a propensity score-matched cohort analysis and (2) a nested case-control analysis. Hip fracture patients were aged ≥50 years without AMD diagnosis before hip fracture date or in the first year of follow-up. Among 6208 matched patients and during 22,142 person-years of follow-up, 57 (1.8%) and 42 (1.4%) AMD cases occurred in BP users and non-BP users, respectively. The survival analysis model did not provide significant evidence of a higher risk of AMD in BP users (subhazard ratio: 1.60; 95% confidence interval (CI): 0.95-2.72; P = 0.08), although there was a significant increased risk among BP users with high medication possession ratio (MPR) (top quartile) relative to non-BP users (odds ratio: 5.08, 95% CI: 3.11-8.30; P < 0.001, respectively). Overall, oral BP use was not associated with an increased risk of AMD in this cohort of hip fracture patients, although the risk increased significantly with higher MPR. More data are needed to confirm these findings.

Assessing the feasibility of the Effectiveness of Discontinuing Bisphosphonates trial: a pilot study

The Effectiveness of Discontinuing Bisphosphonates (EDGE) study is a planned pragmatic clinical trial to guide "drug holiday" clinical decision making. This pilot study assessed work flow and feasibility of such a study. While participant recruitment and treatment adherence were suboptimal, administrative procedures were generally feasible and minimally disrupted clinic flow.

INTRODUCTION

The comparative effectiveness of continuing or discontinuing long-term alendronate (ALN) on fractures is unknown. A large pragmatic ALN discontinuation study has potential to answer this question.

METHODS

We conducted a 6-month pilot study of the planned the EDGE study among current long-term ALN users (women aged ≥65 with ≥3 years of ALN use) to determine study work flow and feasibility including evaluating the administrative aspects of trial conduct (e.g., time to contract, institutional review board (IRB) approval), assessing rates of site and participant recruitment, and evaluating post-randomization outcomes, including adherence, bisphosphonate-associated adverse events, and participant and site satisfaction. We assessed outcomes 1 and 6 months after randomization.

RESULTS

Nine sites participated, including seven community-based medical practices and two academic medical centers. On average (SD), contract execution took 3.4 (2.3) months and IRB approval took 13.9 (4.1) days. Sites recruited 27 participants (13 to continue ALN and 14 to discontinue ALN). Over follow-up, 22% of participants did not adhere to their randomization assignment: 30.8% in the continuation arm and 14.3% in the discontinuation arm. No fractures or adverse events were reported. Sites reported no issues regarding work flow, and participants were highly satisfied with the study.

CONCLUSIONS

Administrative procedures of the EDGE study were generally feasible, with minimal disruption to clinic flow. In this convenience sample, participant recruitment was suboptimal across most practice sites. Accounting for low treatment arm adherence, a comprehensive recruitment approach will be needed to effectively achieve the scientific goals of the EDGE study.