Reduced visual function and its association with physical functioning in the Finnish adult population : Prevalence, causes, and need for eye care services

The purpose of this study was to estimate the prevalence and distribution of reduced visual acuity, major chronic eye diseases, and subsequent need for eye care services in the Finnish adult population comprising persons aged 30 years and older. In addition, we analyzed the effect of decreased vision on functioning and need for assistance using the World Health Organization’s (WHO) International Classification of Functioning, Disability, and Health (ICF) as a framework. The study was based on the Health 2000 health examination survey, a nationally representative population-based comprehensive survey of health and functional capacity carried out in 2000 to 2001 in Finland. The study sample representing the Finnish population aged 30 years and older was drawn by a two-stage stratified cluster sampling. The Health 2000 survey included a home interview and a comprehensive health examination conducted at a nearby screening center. If the invited participants did not attend, an abridged examination was conducted at home or in an institution. Based on our finding in participants, the great majority (96%) of Finnish adults had at least moderate visual acuity (VA ≥ 0.5) with current refraction correction, if any. However, in the age group 75–84 years the prevalence decreased to 81%, and after 85 years to 46%. In the population aged 30 years and older, the prevalence of habitual visual impairment (VA ≤ 0.25) was 1.6%, and 0.5% were blind (VA < 0.1). The prevalence of visual impairment increased significantly with age (p < 0.001), and after the age of 65 years the increase was sharp. Visual impairment was equally common for both sexes (OR 1.20, 95% CI 0.82 – 1.74). Based on self-reported and/or register-based data, the estimated total prevalences of cataract, glaucoma, age-related maculopathy (ARM), and diabetic retinopathy (DR) in the study population were 10%, 5%, 4%, and 1%, respectively. The prevalence of all of these chronic eye diseases increased with age (p < 0.001). Cataract and glaucoma were more common in women than in men (OR 1.55, 95% CI 1.26 – 1.91 and OR 1.57, 95% CI 1.24 – 1.98, respectively). The most prevalent eye diseases in people with visual impairment (VA ≤ 0.25) were ARM (37%), unoperated cataract (27%), glaucoma (22%), and DR (7%). One-half (58%) of visually impaired people had had a vision examination during the past five years, and 79% had received some vision rehabilitation services, mainly in the form of spectacles (70%). Only one-third (31%) had received formal low vision rehabilitation (i.e., fitting of low vision aids, receiving patient education, training for orientation and mobility, training for activities of daily living (ADL), or consultation with a social worker). People with low vision (VA 0.1 – 0.25) were less likely to have received formal low vision rehabilitation, magnifying glasses, or other low vision aids than blind people (VA < 0.1). Furthermore, low cognitive capacity and living in an institution were associated with limited use of vision rehabilitation services. Of the visually impaired living in the community, 71% reported a need for assistance and 24% had an unmet need for assistance in everyday activities. Prevalence of ADL, instrumental activities of daily living (IADL), and mobility increased with decreasing VA (p < 0.001). Visually impaired persons (VA ≤ 0.25) were four times more likely to have ADL disabilities than those with good VA (VA ≥ 0.8) after adjustment for sociodemographic and behavioral factors and chronic conditions (OR 4.36, 95% CI 2.44 – 7.78). Limitations in IADL and measured mobility were five times as likely (OR 4.82, 95% CI 2.38 – 9.76 and OR 5.37, 95% CI 2.44 – 7.78, respectively) and self-reported mobility limitations were three times as likely (OR 3.07, 95% CI 1.67 – 9.63) as in persons with good VA. The high prevalence of age-related eye diseases and subsequent visual impairment in the fastest growing segment of the population will result in a substantial increase in the demand for eye care services in the future. Many of the visually impaired, especially older persons with decreased cognitive capacity or living in an institution, have not had a recent vision examination and lack adequate low vision rehabilitation. This highlights the need for regular evaluation of visual function in the elderly and an active dissemination of information about rehabilitation services. Decreased VA is strongly associated with functional limitations, and even a slight decrease in VA was found to be associated with limited functioning. Thus, continuous efforts are needed to identify and treat eye diseases to maintain patients’ quality of life and to alleviate the social and economic burden of serious eye diseases.

Cardiac function before and after treatment for various types of loading conditions and in myocardial restriction : A prospective study on pediatric patients with two- and three-dimensional echocardiography and measurement of serum natriuretic peptides

Background: The incidence of all forms of congenital heart defects is 0.75%. For patients with congenital heart defects, life-expectancy has improved with new treatment modalities. Structural heart defects may require surgical or catheter treatment which may be corrective or palliative. Even those with corrective therapy need regular follow-up due to residual lesions, late sequelae, and possible complications after interventions. Aims: The aim of this thesis was to evaluate cardiac function before and after treatment for volume overload of the right ventricle (RV) caused by atrial septal defect (ASD), volume overload of the left ventricle (LV) caused by patent ductus arteriosus (PDA), and pressure overload of the LV caused by coarctation of the aorta (CoA), and to evaluate cardiac function in patients with Mulibrey nanism. Methods: In Study I, of the 24 children with ASD, 7 underwent surgical correction and 17 percutaneous occlusion of ASD. Study II had 33 patients with PDA undergoing percutaneous occlusion. In Study III, 28 patients with CoA underwent either surgical correction or percutaneous balloon dilatation of CoA. Study IV comprised 26 children with Mulibrey nanism. A total of 76 healthy voluntary children were examined as a control group. In each study, controls were matched to patients. All patients and controls underwent clinical cardiovascular examinations, two-dimensional (2D) and three-dimensional (3D) echocardiographic examinations, and blood sampling for measurement of natriuretic peptides prior to the intervention and twice or three times thereafter. Control children were examined once by 2D and 3D echocardiography. M-mode echocardiography was performed from the parasternal long axis view directed by 2D echocardiography. The left atrium-to-aorta (LA/Ao) ratio was calculated as an index of LA size. The end-diastolic and end-systolic dimensions of LV as well as the end-diastolic thicknesses of the interventricular septum and LV posterior wall were measured. LV volumes, and the fractional shortening (FS) and ejection fraction (EF) as indices of contractility were then calculated, and the z scores of LV dimensions determined. Diastolic function of LV was estimated from the mitral inflow signal obtained by Doppler echocardiography. In three-dimensional echocardiography, time-volume curves were used to determine end-diastolic and end-systolic volumes, stroke volume, and EF. Diastolic and systolic function of LV was estimated from the calculated first derivatives of these curves. Results: (I): In all children with ASD, during the one-year follow-up, the z score of the RV end-diastolic diameter decreased and that of LV increased. However, dilatation of RV did not resolve entirely during the follow-up in either treatment group. In addition, the size of LV increased more slowly in the surgical subgroup but reached control levels in both groups. Concentrations of natriuretic peptides in patients treated percutaneously increased during the first month after ASD closure and normalized thereafter, but in patients treated surgically, they remained higher than in controls. (II): In the PDA group, at baseline, the end-diastolic diameter of LV measured over 2SD in 5 of 33 patients. The median N-terminal pro-brain natriuretic peptide (proBNP) concentration before closure measured 72 ng/l in the control group and 141 ng/l in the PDA group (P = 0.001) and 6 months after closure measured 78.5 ng/l (P = NS). Patients differed from control subjects in indices of LV diastolic and systolic function at baseline, but by the end of follow-up, all these differences had disappeared. Even in the subgroup of patients with normal-sized LV at baseline, the LV end-diastolic volume decreased significantly during follow-up. (III): Before repair, the size and wall thickness of LV were higher in patients with CoA than in controls. Systolic blood pressure measured a median 123 mm Hg in patients before repair (P < 0.001) and 103 mm Hg one year thereafter, and 101 mm Hg in controls. The diameter of the coarctation segment measured a median 3.0 mm at baseline, and 7.9 at the 12-month (P = 0.006) follow-up. Thicknesses of the interventricular septum and posterior wall of the LV decreased after repair but increased to the initial level one year thereafter. The velocity time integrals of mitral inflow increased, but no changes were evident in LV dimensions or contractility. During follow-up, serum levels of natriuretic peptides decreased correlating with diastolic and systolic indices of LV function in 2D and 3D echocardiography. (IV): In 2D echocardiography, the interventricular septum and LV posterior wall were thicker, and velocity time integrals of mitral inflow shorter in patients with Mulibrey nanism than in controls. In 3D echocardiography, LV end-diastolic volume measured a median 51.9 (range 33.3 to 73.4) ml/m² in patients and 59.7 (range 37.6 to 87.6) ml/m² in controls (P = 0.040), and serum levels of ANPN and proBNP a median 0.54 (range 0.04 to 4.7) nmol/l and 289 (range 18 to 9170) ng/l, in patients and 0.28 (range 0.09 to 0.72) nmol/l (P < 0.001) and 54 (range 26 to 139) ng/l (P < 0.001) in controls. They correlated with several indices of diastolic LV function. Conclusions (I): During the one-year follow-up after the ASD closure, RV size decreased but did not normalize in all patients. The size of the LV normalized after ASD closure but the increase in LV size was slower in patients treated surgically than in those treated with the percutaneous technique. Serum levels of ANPN and proBNP were elevated prior to ASD closure but decreased thereafter to control levels in patients treated with the percutaneous technique but not in those treated surgically. (II): Changes in LV volume and function caused by PDA disappeared by 6 months after percutaneous closure. Even the children with normal-sized LV benefited from the procedure. (III): After repair of CoA, the RV size and the velocity time integrals of mitral inflow increased, and serum levels of natriuretic peptides decreased. Patients need close follow-up, despite cessation of LV pressure overload, since LV hypertrophy persisted even in normotensive patients with normal growth of the coarctation segment. (IV): In children with Mulibrey nanism, the LV wall was hypertrophied, with myocardial restriction and impairment of LV function. Significant correlations appeared between indices of LV function, size of the left atrium, and levels of natriuretic peptides, indicating that measurement of serum levels of natriuretic peptides can be used in the clinical follow-up of this patient group despite its dependence on loading conditions.

Evaluation of Vestibular Function with Visual Feedback Posturography and Motorized Head Impulse Test.

Objectives: To evaluate the applicability of visual feedback posturography (VFP) for quantification of postural control, and to characterize the horizontal angular vestibulo-ocular reflex (AVOR) by use of a novel motorized head impulse test (MHIT). Methods: In VFP, subjects standing on a platform were instructed to move their center of gravity to symmetrically placed peripheral targets as fast and accurately as possible. The active postural control movements were measured in healthy subjects (n = 23), and in patients with vestibular schwannoma (VS) before surgery (n = 49), one month (n = 17), and three months (n = 36) after surgery. In MHIT we recorded head and eye position during motorized head impulses (mean velocity of 170º/s and acceleration of 1 550º/s²) in healthy subjects (n = 22), in patients with VS before surgery (n = 38) and about four months afterwards (n = 27). The gain, asymmetry and latency in MHIT were calculated. Results: The intraclass correlation coefficient for VFP parameters during repeated tests was significant (r = 0.78-0.96; p < 0.01), although two of four VFP parameters improved slightly during five test sessions in controls. At least one VFP parameter was abnormal pre- and postoperatively in almost half the patients, and these abnormal preoperative VFP results correlated significantly with abnormal postoperative results. The mean accuracy in postural control in patients was reduced pre- and postoperatively. A significant side difference with VFP was evident in 10% of patients. In the MHIT, the normal gain was close to unity, the asymmetry in gain was within 10%, and the latency was a mean ± standard deviation 3.4 ± 6.3 milliseconds. Ipsilateral gain or asymmetry in gain was preoperatively abnormal in 71% of patients, whereas it was abnormal in every patient after surgery. Preoperative gain (mean ± 95% confidence interval) was significantly lowered to 0.83 ± 0.08 on the ipsilateral side compared to 0.98 ± 0.06 on the contralateral side. The ipsilateral postoperative mean gain of 0.53 ± 0.05 was significantly different from preoperative gain. Conclusion: The VFP is a repeatable, quantitative method to assess active postural control within individual subjects. The mean postural control in patients with VS was disturbed before and after surgery, although not severely. Side difference in postural control in the VFP was rare. The horizontal AVOR results in healthy subjects and in patients with VS, measured with MHIT, were in agreement with published data achieved using other techniques with head impulse stimuli. The MHIT is a non-invasive method which allows reliable clinical assessment of the horizontal AVOR.