by Charles Bankhead, Senior Editor, MedPage Today October 6, 2022

CHICAGO -- Patients with normotensive glaucoma had a significantly increased risk of Alzheimer's disease that was not modified by use of glaucoma medications, a large retrospective review from Taiwan showed.

After adjustment for multiple comorbidities, normotensive glaucoma was associated with 52% greater relative risk of Alzheimer's as compared with age- and sex-matched patients without normotensive glaucoma during a 13-year median follow-up period (6.7% vs 4.2% incidence, P<0.0001), reported Yu-Yen Chen, MD, PhD, of Taichung Veterans General Hospital in Taiwan, at the American Academy of Ophthalmology (AAO) meeting.

The study added to existing evidence of an association between glaucoma overall and Alzheimer's disease. Two previous studies from Germany and Japan showed a glaucoma prevalence of 25.9% and 23.9% in patients with Alzheimer's disease versus 6.5% and 9.0% in control groups without Alzheimer's diagnoses. The results were also consistent with a recent study showing a significant association between cataract surgery and dementia.

The study included 15,317 patients with normotensive glaucoma diagnoses from January 2001 through December 2013, identified through a Taiwanese national health insurance database. The control group comprised 61,268 patients identified from the same database.

The increased incidence of Alzheimer's disease persisted after controlling for diabetes, hypertension, hyperlipidemia, coronary artery disease, and stroke -- all of which had significant associations with the neurologic condition.

Analysis of multiple types of glaucoma medication showed no significant adverse or beneficial association with Alzheimer's disease.

Fewer Reoperations With Combined Eye Surgery

Concurrent glaucoma and cataract surgeries were associated with a lower reoperation rate as compared with standalone glaucoma procedures, according to data from the AAO's Intelligent Research in Sight (IRIS) Registry.

The 3-year reoperation rate was 11.5% for trabeculectomy alone versus 7.3% when combined with phacoemulsification. The rates were 7.8% versus 5.4%, respectively, for standalone glaucoma drainage device (GDD) placement and concurrent phacoemulsification. Both differences achieved statistical significance (P<0.001) in favor of concurrent procedures, reported Elizabeth Ciociola, BA, of the University of North Carolina School of Medicine in Chapel Hill.

Patients who had standalone procedures had higher baseline intraocular pressure (IOP) and greater IOP reduction with standalone glaucoma surgery. However, IOP reduction was similar at 1 year for standalone and combined procedures. Combined surgery led to better visual acuity, whereas visual acuity declined after standalone procedures.

The study included 286,096 patients who underwent trabeculectomy or GDD during 2013-2019. Data analysis included 66,939 patients who had standalone trabeculectomy, 28,985 who had trabeculectomy with phacoemulsification, 50,758 with GDD only, and 6,672 who had GDD plus cataract procedures.

Younger age, female sex, normotensive glaucoma diagnosis, and milder preoperative glaucoma were associated with better surgical outcomes.

Herpes Zoster and Impaired Vision

Herpes zoster ophthalmicus (HZO) was associated with significantly increased risk of visual impairment and blindness, as well as statistically, but not clinically, worse outcomes after cataract surgery, data from the IRIS Registry showed.

Patients with a history of HZO had a 21.8% prevalence of moderate visual impairment as compared with 14.2% among patients with no HZO. Rates of blindness were 11.8% with HZO and 7.3% without. Both differences achieved statistical significance (P<0001), reported Nakul Shekhawat, MD, of Johns Hopkins Medicine and the Wilmer Eye Institute in Baltimore.

The analysis comprised 54,583 eyes of patients with HZO and 50,214 without. The primary outcomes were change in the logarithm of minimum angle of resolution (logMAR) of visual acuity over time with linear mixed effects modeling of trends in logMAR visual acuity change. Moderate visual impairment was defined as logMAR 0.544-1.0 and blindness as logMAR >1.0 for HZO versus non-HZO eyes.

Patients with HZO had worse visual acuity at diagnosis (0.044 logMAR difference) and a 60% greater likelihood of developing moderate visual impairment over time. The risk of blindness was 66% greater in patients with HZO. Among patients who developed blindness, the time to blindness was accelerated in patients with HZO. All these differences were significant at P<0.0001.

In a separate analysis, Shekhawat and colleagues analyzed the impact of HZO on outcomes of cataract surgery. The analysis included 18,557 eyes of 16,359 patients who underwent cataract surgery, including 9,351 eyes with HZO. The primary outcome was change in mean logMAR of visual acuity before versus after cataract surgery.

HZO eyes again had worse baseline visual acuity (P<0.0001) and more rapid worsening of visual acuity prior to surgery (P<0.0001). Shekhawat reported that 63% of HZO and non-HZO eyes met the visual acuity threshold of Snellen ≥20/40 at 30 days and 74-75% at 90 days. Additionally, 67% of eyes in both groups met the 30-day threshold of ≥20/60 and 77-78% in each group by 90 days.

HZO eyes exhibited greater deterioration of visual acuity over time after surgery (logMAR 0.008875 vs logMAR 0.001946, P<0.0001). Though statistically significant, the small difference was not clinically significant, said Shekhawat.

Charles Bankhead is senior editor for oncology and also covers urology, dermatology, and ophthalmology. He joined MedPage Today in 2007. Follow

Chen reported having no relevant relationships with industry.

The study of standalone versus combined surgery was supported by UNC Chapel Hill, Research to Prevent Blindness, and the Massachusetts Eye and Ear Infirmary.

Ciociola and coinvestigators reported having no relevant relationships with industry.

The herpes zoster ophthalmicus study was supported by Research to Prevent Blindness and the American Academy of Ophthalmology.

Shekhawat reported having no relevant relationships with industry.

Source Reference: Chen YY, et al "Association between NTG and the risk of Alzheimer disease" AAO 2022; Abstract PO133.

Source Reference: Ciociola E, et al "Effectiveness of trabeculectomy and tube shunt surgery with versus without concurrent phacoemulsification in the United States: IRIS Registry longitudinal analysis 2013-2019" AAO 2022; Abstract PO124.

Source Reference: Shekhawat N, et al "Visual outcomes of cataract surgery in eyes with versus without herpes zoster ophthalmicus: Analysis of the IRIS Registry" AAO 2022; Symposium 47.

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