Prevalence of Convergence Insufficiency-Type Symptomatology in Parkinson's Disease.

BACKGROUND: Individuals with Parkinson's disease (PD) often present with visual symptoms (e.g., difficulty in reading, double vision) that can also be found in convergence insufficiency (CI). Our objective was to estimate the prevalence of CI-type visual symptomatology in individuals with PD, in comparison with controls. METHODS: Participants ≥50 years with (n=300) and without (n=300) PD were recruited. They were administered the Convergence Insufficiency Symptom Survey (CISS-15) over the phone. A score of ≥21 on the CISS-15, considered positive for CI-type symptomatology, served as the cutoff. Data from individuals (n=87 with, n=94 without PD) who were approached but who reported having a known oculovisual condition were analysed separately. Student's t test and chi-square at the 0.05 level were employed for statistical significance. RESULTS: A total of 29.3% of participants with versus 7.3% without PD presented with a score of ≥21 on the CISS-15 (p=0.001). Of the participants having a known oculovisual condition, 39.1% with versus 19.1% without PD presented with a score of ≥21 on the CISS-15 (p=0.01). CONCLUSIONS: The prevalence of CI-type visual symptoms is higher in individuals with versus without PD whether or not they have a coexisting oculovisual condition. These results suggest that PD per se places individuals with the disease at greater risk of visual symptomatology. These results further underline the importance of providing regular eye exams for individuals with PD.

Visual impairment in older institutionalised Canadian seniors with dementia.

PURPOSE: To estimate the prevalence of visual impairment (VI) in a sub-population of Canadian long-term care facilities, i.e. residents affected by dementia. METHODS: This study was conducted in the long-term care facility units at the Institut universitaire de gériatrie de Montréal. All residents ≥65 years old (y.o.), having a clinical diagnosis of dementia, and able to understand French or English, were eligible for participation in the study. All residents participating in the study received a complete eye exam by an experienced optometrist. For the purpose of the study, VI was defined as a distance visual acuity (VA) <6/12 (0.30 logMAR, 20/40) in the better seeing eye. RESULTS: One hundred and fifty residents, 68-102 y.o. took part into the study. All participants had a diagnosis of dementia recorded in their clinical chart. VI was present in 37.3% (95% CI: 29.1-46.1%) (n = 50) of residents in whom monocular VA could be measured. Ocular refraction for their better seeing eye improved the VA to ≥6/12 (0.30 logMAR, 20/40) in 40% (n = 20) of those 50 residents. When VI remained after refraction, it was due in order of frequency to cataract, age-related macular degeneration, and primary open angle glaucoma. CONCLUSIONS: Our data showed that an appreciable proportion (37.3%) of older residents with dementia also have VI, and that VI can be corrected in many by updating their refraction. Others could potentially be helped through cataract surgery. It is therefore important to offer regular eye care services to those residents, knowing that many are not able to express their visual needs.

Changing vergence function in persons with Parkinson's disease and convergence insufficiency.

Individuals with Parkinson's disease and convergence insufficiency were assigned vergence training. After two months, average positive fusional vergence increased and average near point of convergence decreased. Vergence can be improved with training in persons with Parkinson's disease who also have convergence insufficiency.

Tool for Screening Visual Acuity in Older Individuals With Dementia.

Rationale/Objective: To develop a screening and referral algorithm tool to help identify which older institutionalized individuals with dementia need an eye examination. METHODS: The visual acuity (VA) screening test was developed on an iPad retina display. Three optotypes were used (letters, numbers, and tumbling E's) to determine whether one works best with dementia. The screening VA results and algorithm decision were validated against those obtained by an optometrist performing a complete eye examination. RESULTS: Of the 150 participants, 14.7% did not respond to any optotype, while 85.3% responded to letters, 84.0% to numbers, and 66.0% to tumbling E's. The VA achieved was superior for letters. The concordance for the screening versus eye examination was >80% for VA and 90% for the algorithm. CONCLUSION: The results indicate that the tool was successful at identifying older individuals with dementia needing an eye examination.

Orthoptic Treatment of Convergence Insufficiency in Parkinson's Disease: A Case Series.

Introduction: This study reports a case series of orthoptic treatment (OT) for convergence insufficiency (CI) in individuals with Parkinson's disease (PD). Method: We are reporting two cases of individuals with PD who completed OT for CI. Both had a confirmed diagnosis of CI, accompanied by CI-type symptomatology. They each underwent an OT program consisting of three office-based visits and 8 weeks of home-based exercises. Treatment outcome was based on the changes measured pre- versus post-OT on the near point of convergence, positive fusional vergences, and symptomatology score. Results: The two participants successfully completed therapy, gained ability to converge, had fewer symptoms, and were satisfied with the OT-induced changes they felt in their day-to-day lives. Conclusion: This case series show that OT for CI in PD is possible. Further research is required as these results demonstrate that OT has the potential to improve symptomatic CI in these patients. In the meantime, the positive results obtained in these two cases should encourage clinicians to consider OT (a therapy with no/minimal risk) for CI in patients with PD whose quality of life is affected by this binocular dysfunction.

Prevalence of Convergence Insufficiency in Parkinson's Disease.

BACKGROUND: We recently reported that convergence insufficiency (CI)-type visual symptomatology was more prevalent in participants with Parkinson's disease (PD), compared to controls. The objective of this work was to determine the prevalence of a confirmed clinical diagnosis of CI in PD, compared to controls. METHODS: Participants with (n = 80) and without (n = 80) PD were recruited and received an eye exam. Published criteria were used to arrive at a clinical diagnosis of CI. The Convergence Insufficiency Symptom Survey (CISS-15) questionnaire was administered to each participant, with a score of ≥21 being considered positive for CI symptomatology. Student t test, chi-square, or nonparametric tests at the 0.05 level were used for statistical significance. RESULTS: A total of 43.8% of participants with versus 16.3% without PD had a clinical diagnosis of CI (P ≤ 0.001). A total of 53.8% of participants with versus 18.8% without PD had scores on the CISS-15 of ≥21 (P ≤ 0.001). CONCLUSIONS: These results indicate that individuals with PD have a higher prevalence of CI and CI symptomatology than controls. These data provide evidence supporting the notion that treatment for symptomatic CI should be investigated in individuals with PD.

Visual acuity in institutionalized seniors with moderate to severe dementia.

OBJECTIVE: The evaluation of visual acuity (VA) in cognitively impaired older individuals may be limited by a reduced ability to cooperate or communicate. The objective of this research was to assess VA in older institutionalized individuals with cognitive impairment, including severe dementia, using various acuity charts. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Three groups of 30 participants each were recruited: (1) young participants; (2) older participants with no history of cognitive or communication disorders; and (3) older participants with cognitive impairment, including severe dementia, residing in long term care facilities. The Mini-Mental State Examination was performed for each institutionalized subject. VA was measured using 6 validated charts [Snellen, Teller cards, Early Treatment Diabetic Retinopathy Study (ETDRS)-letters, -numbers, -Patty Pics, -Tumbling Es] presented in random order. Nonparametric tests were used to compare VA scores between charts, after Bonferroni-Holm corrections for multiple comparisons. RESULTS: Participants in groups 1 and 2 responded to all charts. A large proportion of participants with dementia responded to all charts (n = 19), whereas only one did not respond to any chart. In group 3, VA charts with the lowest scores were the Teller cards (20/65) and Patty Pics (20/62), regardless of the level of dementia, whereas the highest VA scores were obtained with the Snellen (20/35) and ETDRS-letter (20/36) charts. Across all groups, the ETDRS-letter chart was the only one whose scores did not differ from those obtained with the standard Snellen chart. CONCLUSIONS: Visual acuity can be measured, and should at least be attempted, in older cognitively impaired individuals having a reduced ability to communicate.