Quality of life in myopia

A Review of Current Concepts of the Etiology and Treatment of Myopia

Myopia occurs in more than 50% of the population in many industrialized countries and is expected to increase; complications associated with axial elongation from myopia are the sixth leading cause of blindness. Thus, understanding its etiology, epidemiology, and the results of various treatment regiments may modify current care and result in a reduction in morbidity from progressive myopia. This rapid increase cannot be explained by genetics alone. Current animal and human research demonstrates that myopia development is a result of the interplay between genetic and the environmental factors. The prevalence of myopia is higher in individuals whose both parents are myopic, suggesting that genetic factors are clearly involved in myopia development. At the same time, population studies suggest that development of myopia is associated with education and the amount time spent doing near work; hence, activities increase the exposure to optical blur. Recently, there has been an increase in efforts to slow the progression of myopia because of its relationship to the development of serious pathological conditions such as macular degeneration, retinal detachments, glaucoma, and cataracts. We reviewed meta-analysis and other of current treatments that include: atropine, progressive addition spectacle lenses, orthokeratology, and multifocal contact lenses.

Effect of Orthokeratology on myopia progression: twelve-year results of a retrospective cohort study

BACKGROUND

Several studies reported the efficacy of orthokeratology for myopia control. Somehow, there is limited publication with follow-up longer than 3 years. This study aims to research whether overnight orthokeratology influences the progression rate of the manifest refractive error of myopic children in a longer follow-up period (up to 12 years). And if changes in progression rate are found, to investigate the relationship between refractive changes and different baseline factors, including refraction error, wearing age and lens replacement frequency. In addition, this study collects long-term safety profile of overnight orthokeratology.

METHODS

This is a retrospective study of sixty-six school-age children who received overnight orthokeratology correction between January 1998 and December 2013. Thirty-six subjects whose baseline age and refractive error matched with those in the orthokeratology group were selected to form control group. These subjects were followed up at least for 12 months. Manifest refractions, cycloplegic refractions, uncorrected and best-corrected visual acuities, power vector of astigmatism, corneal curvature, and lens replacement frequency were obtained for analysis.

RESULTS

Data of 203 eyes were derived from 66 orthokeratology subjects (31 males and 35 females) and 36 control subjects (22 males and 14 females) enrolled in this study. Their wearing ages ranged from 7 years to 16 years (mean ± SE, 11.72 ± 0.18 years). The follow-up time ranged from 1 year to 13 years (mean ± SE, 6.32 ± 0.15 years). At baseline, their myopia ranged from -0.5 D to -8.0 D (mean ± SE, -3.70 ± 0.12 D), and astigmatism ranged from 0 D to -3.0 D (mean ± SE, -0.55 ± 0.05 D). Comparing with control group, orthokeratology group had a significantly (p < 0.001) lower trend of refractive error change during the follow-up periods. According to the analysis results of GEE model, greater power of astigmatism was found to be associated with increased change of refractive error during follow-up years.

CONCLUSIONS

Overnight orthokeratology was effective in slowing myopia progression over a twelve-year follow-up period and demonstrated a clinically acceptable safety profile. Initial higher astigmatism power was found to be associated with increased change of refractive error during follow-up years.

Patient-reported Outcomes for Assessment of Quality of Life in Refractive Error: A Systematic Review

SIGNIFICANCE

This review has identified the best existing patient-reported outcome (PRO) instruments in refractive error. The article highlights the limitations of the existing instruments and discusses the way forward.

PURPOSE

A systematic review was conducted to identify the types of PROs used in refractive error, to determine the quality of the existing PRO instruments in terms of their psychometric properties, and to determine the limitations in the content of the existing PRO instruments.

METHODS

Articles describing a PRO instrument measuring 1 or more domains of quality of life in people with refractive error were identified by electronic searches on the MEDLINE, PubMed, Scopus, Web of Science, and Cochrane databases. The information on content development, psychometric properties, validity, reliability, and responsiveness of those PRO instruments was extracted from the selected articles. The analysis was done based on a comprehensive set of assessment criteria.

RESULTS

One hundred forty-eight articles describing 47 PRO instruments in refractive error were included in the review. Most of the articles (99 [66.9%]) used refractive error-specific PRO instruments. The PRO instruments comprised 19 refractive, 12 vision but nonrefractive, and 16 generic PRO instruments. Only 17 PRO instruments were validated in refractive error populations; six of them were developed using Rasch analysis. None of the PRO instruments has items across all domains of quality of life. The Quality of Life Impact of Refractive Correction, the Quality of Vision, and the Contact Lens Impact on Quality of Life have comparatively better quality with some limitations, compared with the other PRO instruments.

CONCLUSIONS

This review describes the PRO instruments and informs the choice of an appropriate measure in refractive error. We identified need of a comprehensive and scientifically robust refractive error-specific PRO instrument. Item banking and computer-adaptive testing system can be the way to provide such an instrument.

Topical Atropine in the Control of Myopia

Efforts to reduce myopia progression in childhood are driven by the increasing incidence of high myopia and its attendant health risks. Interventional approaches to reduce myopia progression in childhood have included the use of spectacles, contact lens, and pharmacological methods, of which the latter appear to be most promising. We review the use of topical atropine eye drops in the retardation of myopia progression in children and discuss the efficacy and safety profiles when used at different concentrations (1.0%, 0.5%, 0.1%, and 0.01%). Topical atropine reduces myopia progression and axial elongation in children in a dose-related manner, but a rebound phenomenon occurs with higher doses. Its use has been shown to be safe, but higher doses cause pupil dilation, loss of accommodation and near vision. Atropine 0.01% has the best therapeutic index, with clinically insignificant amounts of pupil dilation, near vision, and accommodation loss but remains as effective as higher doses.

Epidemiology of Pathologic Myopia in Asia and Worldwide

The myopia epidemic in Asia is evident because the prevalence of high myopia among young adults is higher among Asian (6.8%-21.6%) compared with non-Asian populations (2.0%-2.3%). High myopia is linked to pathologic myopia (PM), which may cause irreversible visual impairment (VI). This review will highlight updates on the prevalence of PM and the associated VI from PM. The prevalence of PM among the middle-aged and elderly (0.9%-3.1%) is higher than the prevalence among children and adolescents (<0.2%). The PM lesions detected among older adults include advanced lesions, such as posterior staphyloma, chorioretinal atrophy, lacquer cracks, and Fuchs spot (in descending frequency of occurrence). A relatively high prevalence of PM (8%) was recently reported among highly myopic young adults. As young individuals grow older, the early grades of PM lesions are likely to progress to advanced grades. Two longitudinal changes that occur frequently in PM include the enlargement of beta peripapillary atrophy and the development of chorioretinal atrophy. The lack of longitudinal changes in PM limits the causal inferences of PM. The prevalence of VI attributed to PM seems to be higher among Asian populations compared with Western and European populations. Pathologic myopia is ranked as a more important cause of blindness and low vision in Asian populations compared with Western and European populations. With the lack of effective treatment strategies and poor prognosis, PM threatens the vision health of populations in Asia and worldwide. To control this future epidemic, the prevention of myopia onset and progression is necessary.

The differences in level of trait anxiety among girls and boys aged 13-17 years with myopia and emmetropia

Background

A significant increase in myopia among children and teenagers can be observed all over the world. Yet at the same time, there is still an insignificant number of studies concerning this health problem.

The aim of this study was to assess the level of trait anxiety among myopic group of teenagers in comparison to teenagers with emmetropia, and to confirm whether the level of trait anxiety relates to age and gender.

Methods

Two hundred thirty-nine students aged 13–17 years were included in the study. The study group comprised 114 persons with myopia (81 girls and 33 boys), while the control group comprised 125 persons without refractive error (79 girls and 46 boys). Volunteers completed a set of questionnaires including: personal data, State-Trait Anxiety Inventory for Children (STAIC) (13–14 year-olds), or State-Trait Anxiety Inventory (STAI) (15–17 year-olds). The trait anxiety subscales were thus analyzed.

Results

Among younger adolescents (13–14 years of age) with myopia there was a significantly higher incidence of pathological intensification of anxiety as a constant trait. After taking into account the distribution of gender, there was a higher level of trait anxiety in the group of boys with myopia than in the control group aged 13–17 years and 13–14 years. There was also a higher level of trait anxiety detected in males than in females.

Conclusions

Myopia may affect the level of trait anxiety among 13–14-year-olds. In both age groups of girls, a higher percentage of patients with high level of anxiety was discovered (≥7 sten), as compared to their peers without vision defects. Our results can contribute to a more accurate analysis of young teenagers’ psychological problems, especially among boys diagnosed with myopia.

Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens

The purpose of this review is to summarize relevant data from publications appearing in the peer-reviewed scientific literature over the past decade since US Food and Drug Administration approval of the implantable collamer lens (ICL), and, in particular, to review studies relating to sizing methodology, safety, and effectiveness, as well as more recent studies reporting clinical outcomes of the V4c Visian ICL with KS Aquaport, VICMO. A literature search was conducted using two databases, PubMed.gov and Science.gov, to identify all articles published after 2005 related to the Visian ICL (STAAR Surgical, Inc.). Articles were examined for their relevance to sizing methodology, clinical safety, and effectiveness, and the references cited in each article were also searched for additional relevant publications. The literature review revealed that all currently reported methods of determining the best-fit size of the ICL achieve similarly satisfactory results in terms of vault, the safe distance between the crystalline lens and the ICL. Specifically, meta-analysis demonstrated that sulcus-to-sulcus and white-to-white measurement-based sizing methods do not result in clinically meaningful nor statistically significant differences in vault (two-sample two-sided t-test using pooled mean and standard deviations; t (2,594)=1.33; P=0.18). The reported rates of complications related to vault are very low, except in two case series where additional risk factors such as higher levels of myopia and older age impacted the incidence of cataract. On the basis of preclinical studies and initial clinical reports, with up to 5 years of follow-up, the new VICMO central port design holds promise for further reduction of complications. Given its safety record and the significant improvement in vision and quality of life that the ICL makes possible, the benefits of ICL implantation outweigh the risks.

Is myopia another clinical manifestation of insulin resistance?

Myopia is a multifactorial visual refraction disease, in which the light rays from distant objects are focused in front of retina, causing blurry vision. Myopic eyes are characterized by an increased corneal curvature and/or ocular axial length. The prevalence of myopia has increased in recent decades, a trend that cannot be attributed exclusively to genetic factors. Low and middle income countries have a higher burden of refractive error, which we propose could be a consequence of a shorter exposure time to a westernized lifestyle, a phenomenon that may also explain the rapid increase in cardiometabolic diseases, such as diabetes, among those populations. We suggest that interactions between genetic, epigenetic and a rapidly changing environment are also involved in myopia onset and progression. Furthermore, we discuss several possible mechanisms by which insulin resistance may promote abnormal ocular growth and myopia to support the hypothesis that insulin resistance and hyperinsulinemia are involved in its pathogenesis, providing a link between trends in myopia and those of cardiometabolic diseases. There is evidence that insulin have direct ocular growth promoting effects as well an indirect effect via the induction of insulin-like growth factors leading to decreases insulin-like growth factor-binding protein, also implicated in ocular growth.

Full-ring Intrastromal Corneal Implantation for Correcting High Myopia in Patients with Severe Keratoconus

The aim of this study was to evaluate the effect of the mechanical implantation of a MyoRing in patients with severe keratoconus and high myopia. The study involved 32 eyes of 32 patients (14 men and 18 women; mean age: 29.6 ± 6.7; age range: 20 - 44). The patients underwent MyoRing implantation with mechanical dissection using a Pocket Maker microkeratome, and outcomes were assessedat3 months after surgery. The main outcome measures were uncorrected and corrected distance visual acuity (UDVA and CDVA, both in Logarithm of the Minimum Angle of Resolution [logMAR] units), manifest refraction, and keratometry readings. There was a significant improvement in the UDVA, from 1.14 ± 0.32 to 0.35 ± 0.24 (P ˂ 0.001), and in the CDVA, from 0.47 ± 0.20 to 0.22 ± 0.15 (P ˂ 0.001). There was also a significant improvement in the spherical equivalent refractive error (-10.51 ± 2.81 D to -1.32 ± 2.29 D) (P ˂ 0.001). There was a significant decrease of manifest refraction in the mean sphere and cylinder of 7.70 and 2.6 D, respectively (P < 0.001). Furthermore, with regard to corneal topography, there was a significant reduction of 3.55 D (P ˂ 0.001) in the mean keratometry reading. The results show that the mechanical implantation of a MyoRing is effective for the correction of myopia in patients with keratoconus and high myopia.

APLP2 Regulates Refractive Error and Myopia Development in Mice and Humans

Myopia is the most common vision disorder and the leading cause of visual impairment worldwide. However, gene variants identified to date explain less than 10% of the variance in refractive error, leaving the majority of heritability unexplained (“missing heritability”). Previously, we reported that expression of APLP2 was strongly associated with myopia in a primate model. Here, we found that low-frequency variants near the 5’-end of APLP2 were associated with refractive error in a prospective UK birth cohort (n = 3,819 children; top SNP rs188663068, p = 5.0 × 10⁻⁴) and a CREAM consortium panel (n = 45,756 adults; top SNP rs7127037, p = 6.6 × 10⁻³). These variants showed evidence of differential effect on childhood longitudinal refractive error trajectories depending on time spent reading (gene x time spent reading x age interaction, p = 4.0 × 10⁻³). Furthermore, Aplp2 knockout mice developed high degrees of hyperopia (+11.5 ± 2.2 D, p < 1.0 × 10⁻⁴) compared to both heterozygous (-0.8 ± 2.0 D, p < 1.0 × 10⁻⁴) and wild-type (+0.3 ± 2.2 D, p < 1.0 × 10⁻⁴) littermates and exhibited a dose-dependent reduction in susceptibility to environmentally induced myopia (F(2, 33) = 191.0, p < 1.0 × 10⁻⁴). This phenotype was associated with reduced contrast sensitivity (F(12, 120) = 3.6, p = 1.5 × 10⁻⁴) and changes in the electrophysiological properties of retinal amacrine cells, which expressed Aplp2. This work identifies APLP2 as one of the “missing” myopia genes, demonstrating the importance of a low-frequency gene variant in the development of human myopia. It also demonstrates an important role for APLP2 in refractive development in mice and humans, suggesting a high level of evolutionary conservation of the signaling pathways underlying refractive eye development.

Gene variants identified by GWAS studies to date explain only a small fraction of myopia cases because myopia represents a complex disorder thought to be controlled by dozens or even hundreds of genes. The majority of genetic variants underlying myopia seems to be of small effect and/or low frequency, which makes them difficult to identify using classical genetic approaches, such as GWAS, alone. Here, we combined gene expression profiling in a monkey model of myopia, human GWAS, and a gene-targeted mouse model of myopia to identify one of the “missing” myopia genes, APLP2. We found that a low-frequency risk allele of APLP2 confers susceptibility to myopia only in children exposed to large amounts of daily reading, thus, providing an experimental example of the long-hypothesized gene-environment interaction between nearwork and genes underlying myopia. Functional analysis of APLP2 using an APLP2 knockout mouse model confirmed functional significance of APLP2 in refractive development and implicated a potential role of synaptic transmission at the level of glycinergic amacrine cells of the retina for the development of myopia. Furthermore, mouse studies revealed that lack of Aplp2 has a dose-dependent suppressive effect on susceptibility to form-deprivation myopia, providing a potential gene-specific target for therapeutic intervention to treat myopia.

Utility values among myopic patients in mainland China

PURPOSE

To elicit utility values of adult myopic patients in mainland China.

METHODS

A valid sample of 442 myopia patients (spherical equivalent at least -0.5 diopters) aged 17 to 44 years who were scheduled to undergo refractive surgery were recruited. Information on time trade-off ([TTO] years of life willing to sacrifice for treatment of myopia) and standard gamble (SG) for blindness (risk of blindness from therapy, willing to sacrifice for treatment of myopia) utility values and sociodemographic and clinical data were obtained.

RESULTS

The mean utility values based on TTO and SG were 0.96 ± 0.05 (95% confidence interval [CI], 0.95 to 0.96; median, 0.98) and 0.93 ± 0.09 (95% CI, 0.92 to 0.94; median, 0.97), respectively. Myopic patients using contact lens had significantly higher TTO utility values than those wearing glasses (p < 0.001). There was no significant difference in the TTO and SG utility values by age, sex, occupation, educational levels, residence, reasons for refractive surgery, and severity and duration of myopia (p > 0.05).

CONCLUSIONS

The TTO and SG produce similar mean utility values, but there is poor agreement between results for individuals from the two methods. Utility values associated with myopic patients obtained in this study or reported in the literature seem to be higher than those obtained for other ophthalmic conditions.

Epidemiology of myopia

Myopia is one of the most prevalent disorders of the eye. Higher myopia is associated with comorbidities that increase risks of severe and irreversible loss of vision, such as retinal detachment, subretinal neovascularization, dense cataract, and glaucoma. In recent years, reports from population-based prevalence studies carried out in various geographical areas now give a clear picture of the current distribution of refractive error. The scarcity of data from well-designed longitudinal cohort studies is still yet to be addressed. These studies have confirmed the previous data indicating that prevalence of refractive error varies according to ethnicity and geographic regions, and also point to an increase in myopia prevalence over the past half-century. The problem is particularly pronounced in affluent, industrialised areas of East Asia. Environmental risk factors for myopia related to socioeconomic status and lifestyle have been identified. The past decade has seen a greater understanding of the molecular biological mechanisms that determine refractive error, giving further support to the belief that myopia is the result of a complex interaction between genetic predisposition and environmental exposures. This review summarizes data on the prevalence, incidence, progression, associations, risk factors, and impact from recent epidemiological studies on myopia.

Effects of corneal cross-linking on contrast sensitivity, visual acuity, and corneal topography in patients with keratoconus

PURPOSE

To assess the effects of corneal collagen cross-linking (CXL) on contrast sensitivity (CS), visual acuity, and corneal topography investigating possible predictors of efficacy.

METHODS

Sixty-eight eyes of 34 patients with progressive keratoconus were enrolled in this prospective study. CXL was performed in one eye and the other eye was left untreated as a control. CS, best spectacle-corrected visual acuity (BSCVA), simulated keratometry in the steepest meridian (SimK-s), mean power in the central 3-mm zone (C-MP), mean power in the paracentral 3- to 5-mm zone (P-MP), maximum keratometric power in the central zone (C-Kmax), and maximum keratometric power in the paracentral zone (P-Kmax) were evaluated at baseline, 40 days, 3 months, 6 months, 1 year, and after 2 years of follow-up.

RESULTS

Treated eyes showed an improvement (P < 0.001) of +0.16 logCS and -0.16 logarithm of the minimum angle of resolution (logMAR) and a reduction in SimK-s of -0.61 diopter (D), C-Kmax -1.11 D, P-Kmax -0.99 D, C-MP -0.39 D, and P-MP -0.30 D. Of the treated eyes, 43.3% had a decrease in C-Kmax greater than 1 D, 50% by 0 to 0.99 D, and 6.7% had an increase of up to +0.89 D. Treated eyes with keratometric apex in the central 3-mm zone (CKA) improved BSCVA -0.19 logMAR and CS +0.19 logCS; whereas in treated eyes with paracentral keratometric apex (PKA), the improvement was -0.13 logMAR and +0.16 logCS.

CONCLUSIONS

CXL with riboflavin and UV-A improved CS and inhibited the progression of keratoconus. As a predictor of treatment efficacy, eyes with CKA showed greater improvement in BSCVA after CXL when compared with eyes with PKA.

Genetic contributions to myopic refractive error: Insights from human studies and supporting evidence from animal models

Genetic studies of both population-based and recruited affected patient cohorts have identified a number of genomic regions and candidate genes that may contribute to myopic development. Scientists have developed animal models of myopia, as collection of affected tissues from patents is impractical. Recent advances in whole exome sequencing technology show promise for further elucidation of disease causing variants as in the recent identification of rare variants within ZNF644 segregating with pathological myopia. We present a review of the current research trends and findings on genetic contributions to myopic refraction including candidate loci for myopic development and their genomic convergence with expression studies of animal models inducing myopic development.

The complex interactions of retinal, optical and environmental factors in myopia aetiology

Myopia is the commonest ocular abnormality but as a research topic remains at the margins of mainstream ophthalmology. The concept that most myopes fall into the category of 'physiological myopia' undoubtedly contributes to this position. Yet detailed analysis of epidemiological data linking myopia with a range of ocular pathologies from glaucoma to retinal detachment demonstrates statistically significant disease association in the 0 to -6 D range of 'physiological myopia'. The calculated risks from myopia are comparable to those between hypertension, smoking and cardiovascular disease. In the case of myopic maculopathy and retinal detachment the risks are an order of magnitude greater. This finding highlights the potential benefits of interventions that can limit or prevent myopia progression. Our understanding of the regulatory processes that guide an eye to emmetropia and, conversely how the failure of such mechanisms can lead to refractive errors, is certainly incomplete but has grown enormously in the last few decades. Animal studies, observational clinical studies and more recently randomized clinical trials have demonstrated that the retinal image can influence the eye's growth. To date human intervention trials in myopia progression using optical means have had limited success but have been designed on the basis of simple hypotheses regarding the amount of defocus at the fovea. Recent animal studies, backed by observational clinical studies, have revealed that the mechanisms of optically guided eye growth are influenced by the retinal image across a wide area of the retina and not solely the fovea. Such results necessitate a fundamental shift in how refractive errors are defined. In the context of understanding eye growth a single sphero-cylindrical definition of foveal refraction is insufficient. Instead refractive error must be considered across the curved surface of the retina. This carries the consequence that local retinal image defocus can only be determined once the 3D structure of the viewed scene, off axis performance of the eye and eye shape has been accurately defined. This, in turn, introduces an under-appreciated level of complexity and interaction between the environment, ocular optics and eye shape that needs to be considered when planning and interpreting the results of clinical trials on myopia prevention.

Is the pediatric quality of life inventory valid for use in preschool children with refractive errors?

PURPOSE

To determine the psychometric validity of the pediatric quality of life inventory (PedsQL 4.0) in assessing the impact of refractive errors on health-related quality of life (HRQoL) in preschool children in Singapore.

METHODS

Parents of toddlers (aged 25 to 48 months) and young children (49 to 72 months) completed the PedsQL 4.0, an HRQoL scale as part of population-based trial in Singapore. The outcome measures were the overall score, and the "physical"; "emotional"; "social"; and "school" functioning subscales. Rasch analysis was used to validate the PedsQL 4.0.

RESULTS

Parents of 939 (48.9%) toddlers and 982 (51.1%) young children completed the PedsQL 4.0 survey. The overall mean (±standard deviation) spherical equivalence for the right eye was 0.47 ± 1.13 diopter (D) for toddlers and 0.74 ± 1.22 D for young children. One hundred forty-nine (15.9%) toddlers and 90 (9.2%) young children were considered myopic (≥-0.50 D). Most participants (n = 1286, 89.6%) had presenting visual acuity 6/9 or better. Rasch analysis showed evidence of disordered category thresholds and poor person-item targeting for both groups. The separation reliability was 0.00 for toddlers and 0.03 for young children, indicating there was no variance in both samples. The PedsQL 4.0 overall and subscale scores displayed substantial multidimensionality as the variance values explained by the measures was <25% in both groups. A minimum value of 60% is usually considering acceptable.

CONCLUSIONS

The PedsQL 4.0 in its current state is not a valid psychometric scale to effectively evaluate the impact of refractive errors on HRQoL in preschool children in Singapore.

The Refractive Status and Vision Profile (RSVP): Translation Into Persian, Reliability and Validity

PURPOSE

To translate and test the reliability and validity of a Persian translation of the Refractive Status and Vision Profile (RSVP), a vision-related quality of life questionnaire, in Iran.

METHODS

Forward & backward translation, committee review and pilot testing were performed to develop a final Iranian version of the RSVP. Seventy-three consecutive patients with refractive error before or after refractive surgery at the LASIK ward of Farabi Eye Hospital completed the questionnaire. A convenience sample of 14 patients completed the questionnaire twice within one week. Reliability was measured by internal consistency (Cronbach's alpha) and the intraclass correlation coefficient for test-retest reliability. Validity was evaluated by correlation between the different RSVP subscales, known groups comparison analysis, and correlation between the subscales versus global items and traditional clinical measures.

RESULTS

Internal consistency was high (Cronbach's alpha : 0.71-0.92; except for the subscale expectations, alpha : 0.6). Test-retest reliability of subscales and the overall RSVP scale, as estimated by the intraclass correlation coefficient, was high except for optical problems and glare. Comparisons between pre- and post-operative groups of patients showed significantly higher (worse) scores for concern, physical/social functioning, and the overall score in the pre-operative group. Almost all subscales showed desirable inter-scale correlations.

CONCLUSION

The Iranian version of the RSVP is a reliable and valid measure of vision-related quality of life in patients with refractive error.

Pre-operative Quality of Life and psychological factors that influence patient decision making in LASIK

PURPOSE

To assess pre-operative visual function, psychological factors, personality traits and satisfaction in myopic patients seeking laser-assisted in situ keratomileusis (LASIK).

METHODS

Eligible patients seeking LASIK (n=183) and successful contact lens wearers (n=23) not interested in LASIK completed the Institute for Eye Research Quality of Life (QOL) Scale. Of the 183 patients seeking LASIK who completed the QOL instrument before LASIK, 30 declined the procedure and 153 underwent LASIK. One hundred and two patients who underwent LASIK attended their 3-month post-operative follow-up appointment and 51 patients failed to present for their post-operative follow-up appointment. Multiple comparisons (One-way Analysis of Variance (ANOVA)) were conducted to determine differences in visual function, psychological factors, personality traits and satisfaction between patient groups.

RESULTS

Successful soft contact lens (SCL) wearers reported better functional vision (P=0.001), felt more attractive (P=0.007), had a lower frequency of disturbing visual and ocular symptoms (P=0.027) and higher overall satisfaction with their current optical correction (P<0.001) than patients seeking LASIK. LASIK patients lost to follow-up showed higher self-efficacy, adaptability and well-being than the patients who completed their appointments and those who declined surgery (P<0.05).

CONCLUSIONS

Psychological characteristics, the perception of visual and ocular symptoms and satisfaction with the current method of optical correction play an important role in the decision to undergo LASIK. The IER QOL Scale is a valid and reliable instrument able to discriminate between different groups seeking choices for myopic correction. Psychological factors may influence the level of satisfaction with LASIK.

Visual impairment and its impact on health-related quality of life in adolescents

PURPOSE

To determine the impact of visual impairment on health-related quality of life (QoL) measures in adolescents.

DESIGN

School-based, cross-sectional study.

METHODS

Adolescents aged 11 to 18 years from the Singapore Cohort Study of the Risk Factors for Myopia were analyzed. QoL scores were determined using parallel child-self and parent proxy-report of PedsQL 4.0 Generic Core Scales. Refractive error was measured using the table-mounted autorefractor (model RK5 Canon Inc, Ltd, Tochigiken, Japan) and habitual distance logarithm of the minimal angle of resolution (logMAR) visual acuity charts were used.

RESULTS

Data on 1,249 adolescents and 948 parents were analyzed. The prevalence of better eye presenting visual impairment > 0.3 logMAR was 5.7%. The mean (standard deviation) total, physical, and psychosocial health scores of all adolescents were 83.6 (11.8), 89.9 (11.8), and 80.3 (13.7). Healthy adolescents with visual impairment reported statistically but not clinically lower total (-3.8; 95% confidence interval [CI], -7.1 to -0.5; P = .03), psychosocial (-4.2; 95% CI, -8.1 to -0.3; P = .03), and school functioning scores (-5.5, 95% CI, -10.2 to -0.9; P = .02) than those with normal vision. However, no significant difference was observed in the parent proxy-reported scores between the two groups. Differences in total scores between high (1.9; 95% CI, -0.6 to 4.4) and low-myopes (0.2; 95% CI, -1.3 to 1.6) compared with nonmyopes were not significant. Comparable scores were also reported by hyperopes, astigmatism, and their counterparts, as well as their parents. Concordance between child and parent proxy-report was < 0.07.

CONCLUSION

Healthy adolescents with visual impairment experienced statistically though not clinically impaired health related QoL, but refractive errors did not appear to have an impact on QoL.

Uncorrected wavefront error and visual performance during RGP wear in keratoconus

PURPOSE

To examine the relationship between uncorrected residual wavefront error and visual performance (VP) in rigid gas permeable (RGP) contact lens-wearing keratoconic eyes.

METHODS

Seven eyes from six subjects (six moderate, one severe) were studied (mean +/- SD age: 42.71 +/- 11.38 years). Significant corneal scarring was an exclusion criterion. Measurements were taken with RGP lenses in place. After pupil dilation, the VP measures of high contrast logMAR visual acuity (VA) and Pelli-Robson contrast sensitivity (PRCS) were measured through a 5-mm artificial pupil. Wavefront error was measured using a Shack-Hartmann wavefront sensor and calculated over 5 mm. For both VP and wavefront error, comparisons were made to previously collected normal values by calculating the interval encompassing 95% of normals, then reporting how many of the seven keratoconic eyes fell outside the normal interval. Additionally, second to sixth order aberrations were processed into four previously reported image quality metrics: root mean square of the wavefront (RMSw), root mean square of the slope (RMSs), average blur strength (Bave) and diameter containing 50% light energy (D50) and regressed against VP measures.

RESULTS

Five of seven keratoconic eyes fell outside the normal interval (-0.23 to 0.09) for VA and two of seven fell outside the normal interval (1.59 to 2.03) for PRCS. Five of seven keratoconic eyes fell outside the normal interval (0.07 to 0.35 microm) for total higher order RMS. Linear regressions demonstrated relationships between both VA and PRCS and the image quality metrics RMSw, D50, RMSs, and Bave with R values for VA = 0.30, 0.30, 0.47, 0.62, and PRCS = 0.21, 0.15, 0.45, 0.75 respectively.

CONCLUSIONS

VP in RGP-wearing keratoconic eyes is reduced and higher order wavefront aberrations are elevated compared to normals. Metrics of retinal image quality demonstrate a relationship between keratoconic VP and residual wavefront aberrations. This relationship suggests developing corrections that more completely correct aberrations may improve visual performance in keratoconus.

The Refractive Status and Vision Profile: Evaluation of psychometric properties and comparison of Rasch and summated Likert-scaling

The psychometric properties of the Refractive Status and Vision Profile (RSVP) questionnaire were evaluated using Rasch analysis. Ninety-one myopic patients from a refractive surgery clinic and general optometric practice completed the RSVP. Rasch analysis of the RSVP ordinal data was performed to examine for unidimensionality and item reduction. The traditional Likert-scoring system was compared with a Rasch-scored RSVP and a reduced item Rasch-scored RSVP. Rasch analysis of the original RSVP showed poor targeting of item difficulty to patient quality of life, items with a ceiling effect and underutilized response categories. Combining the underutilized response scales and removal of redundant and misfitting items improved the internal consistency and targeting of the RSVP, and the reduced 20-item Rasch scored RSVP showed greater relative precision over standard Likert scoring in discriminating between the two subject groups. A Rasch scaled quality of life questionnaire is recommended for use in refractive outcomes research.

A Quality of Life Comparison of People Wearing Spectacles or Contact Lenses or Having Undergone Refractive Surgery

PURPOSE

To demonstrate the use of the Quality of Life Impact of Refractive Correction (QIRC) questionnaire for comparing the quality of life of pre-presbyopic individuals with refractive correction by spectacles, contact lenses, or refractive surgery.

METHODS

The 20-item QIRC questionnaire was administered to 104 spectacle wearers, 104 contact lens wearers, and 104 individuals who had undergone refractive surgery (N = 312). These groups were similar for gender, ethnicity, socioeconomic status, and refractive error. The main outcome measure was QIRC overall score (scaled from 0 to 100), a measure of refractive correction related quality of life. Groups were compared for overall QIRC score and on each question by analysis of variance, adjusted for age, with post hoc significance testing (Sheffé).

RESULTS

On average, refractive surgery patients scored significantly better (mean QIRC score 50.2 +/- 6.3, F(2,309) = 15.18, P < .001) than contact lens wearers (46.7 +/- 5.5, post hoc P < .001) who were in turn significantly better than spectacle wearers (44.1 +/- 5.9, post hoc P < .01). Convenience questions chiefly drove the differences between groups, although functioning, symptoms, economic concerns, heath concerns, and well being were also important. Spectacle wearers with low strength prescriptions (46.18 +/- 5.05) scored significantly better than those with medium strength prescriptions (42.74 +/- 6.08, F(2,190) = 3.66, P < .05, post hoc P < .05). A small number (n = 7, 6.7%) of refractive surgery patients experienced postoperative complications, which impacted quality of life (37.86 +/- 2.13).

CONCLUSIONS

Quality of life was lowest in spectacle wearers, particularly those with higher corrections. Contact lens wearers had significantly better QIRC score than spectacle wearers. Refractive surgery patients scored significantly better than both. However, this was accompanied by a small risk of poor quality of life due to postoperative complications. The QIRC is an effective outcome measure for quality of life impact of refractive correction.

Utility values and myopia in medical students in Singapore

PURPOSE

Although technologies to correct myopia have progressed in recent years, it is not known how cost-effective such technologies are. In this paper, utility values of myopic medical students in Singapore were ascertained as a first step to deriving weights for quality adjustment in future cost-effectiveness studies of such technologies.

METHODS

Students (n = 120) aged 18-22 years with myopia (spherical equivalent at least -0.5 D) from Singapore's sole medical school were recruited. Information on lifetime intention to undergo refractive surgery, contact lens use, proportion of waking time spent wearing corrective devices, and utility values using the time trade-off and standard gamble for death methods, were obtained.

RESULTS

The mean utility values for time trade-off and standard gamble were 0.97 (95% confidence interval 0.96-0.98, median 1.00) and 0.99 (95% confidence interval 0.98-0.99, median 1.00), respectively. Utility values were significantly higher among those who reported a probability of less than 50% that they would undergo refractive surgery within their lifetime, compared with those who reported a probability of 50% or more (means 0.98 vs. 0.95, P < 0.001).

CONCLUSION

Utility values in myopic medical students obtained in this study appear to be relatively high, compared with those obtained for other ophthalmic conditions.

Social and visual function in nystagmus

AIM

To investigate the influence of nystagmus on visual and social function and determine if parents are able to assess visual and social function in children with nystagmus.

METHOD

A postal questionnaire comprising 14 questions related to visual function (VF-14) and questions pertaining to social function were sent to all 1013 members of the Nystagmus Network-a UK based organisation for nystagmus sufferers and their families. Visual and social function scores were compared by regression analysis.

RESULTS

180 adult, 233 parent, and 124 child questionnaires were returned. Idiopathic nystagmus was the most common cause. In adults the mean VF-14 score indicated very low visual function, in the same range as patients assessed in low vision services. Children's visual function scored better than adults, between scores of patients with age related macular disease and corneal grafts. There was a strong correlation between perceived visual and social function for adults (p<0.001) and parental assessment of their children (p<0.001), but not between child self assessment of visual and social function. There was strong correlation between parental and child assessment of visual and social function (p<0.001, p<0.001)

CONCLUSION

Questionnaires indicated that nystagmus is associated with very low visual function. There is a strong correlation between visual and social impairment. The authors have shown for the first time in an ophthalmic disease that parents are able to estimate the impact of nystagmus on their child both in terms of visual and social functioning, although they underestimate the impact of nystagmus on emotional aspects of wellbeing.

Impact of stereopsis on quality of life

PURPOSE

To investigate the impact of stereopsis on vision-related quality of life and general health status of the elderly.

METHODS

A quota of 200 subjects aged 65 years or older and had their households registered in Guando district was recruited for a general physical examination including ophthalmic evaluation. A structured questionnaire consisting of seven vision-specific items as well as 36-item short-form survey of the Medical Outcomes Study (SF-36) was administered. Stereoscopic level was divided into three groups: no stereopsis, gross stereopsis, and fine stereopsis. Fisher's exact test was used to detect any difference in subjective visual functioning and Mann-Whitney U test was used for analyses of SF-36 scores.

RESULTS

A total of 187 volunteers were recruited and 150 were analysed for stereoscopic levels. There was no significant difference in vision-specific difficulty among the three stereoscopic groups. For SF-36, having no stereopsis scored significantly less than having gross (P=0.005) and fine (P<0.0001) stereopsis in the vitality/energy dimension. General health perception dimension fared significantly lower in the group with no stereopsis compared to the fine stereoscopic group (P=0.01). In multivariate analysis, having fine stereopsis scored significantly higher in the energy/vitality dimension than having no stereopsis (P=0.02). On the other hand, visual impairment imposed significant adverse effect on five vision-specific items and had no significant relationship with the eight dimensions of SF-36.

CONCLUSIONS

Defective stereopsis in the elderly imposes no significant adverse effect on vision-related quality of life. However, subjects may feel more exhausted in accomplishing their usual tasks.

Assessment of visual function in chronic progressive external ophthalmoplegia

AIMS

To assess the visual function of patients with chronic progressive external ophthalmoplegia (CPEO) using the Visual Function Index (VF-14). To identify discriminatory questions that reflect visual disability in mitochondrial ocular myopathies. To investigate the relationship between visual impairment and the ocular parameters routinely measured in clinical practice.

METHODS

We studied 40 CPEO patients. Each patient underwent ophthalmological assessment, including best-corrected visual acuity, ptosis measures, and fundus examination for pigmentary retinopathy, and orthoptic assessment including cover test in the primary position, assessment of diplopia, and measurement of uniocular fields of fixation using the Goldmann perimeter. Patients were interviewed by telephone by an independent observer and their visual function was assessed using the VF-14.

RESULTS

A total of 38 patients (95%) were visually impaired. The mean VF-14 was 72 (95% CI 66-79). Patients reported having the most difficulty with reading small print and driving at night. No significant correlation was found between the VF-14 and ocular motility parameters, ptosis, or pigmentary retinopathy.

CONCLUSIONS

CPEO is associated with significant visual impairment. Measures of visual disability should be included in studies of natural history and treatment of mitochondrial ocular myopathies.

Assessing the Value of Laser in situ Keratomileusis by Patient-reported Outcomes Using Quality of Life Assessment

PURPOSE

To assess the value of laser in situ keratomileusis (LASIK) by patient-reported outcomes using quality of life assessment.

METHOD

This study included 288 consecutive patients treated by LASIK between July and December 2001 at two eye clinics. A Myopia-specific Quality of Life Questionnaire was developed in this study. The baseline quality of life corresponding to the situation where refractive error was corrected by glasses or contact lenses before LASIK treatment was evaluated by self-administered questionnaire. The evaluation was repeated at 4 days, and 1, 3, and 6 months after LASIK treatment. All question items were rated on a scale ranging from 1 (maximal dysfunction) to 5 (minimal dysfunction).

RESULTS

Factor analysis identified 34 questions in 4 subscales-visual function, visual symptoms, social role function, and psychological well-being. The Myopia-specific Quality of Life Questionnaire subscales proved to be internally consistent (Cronbach alpha = 0.70-0.95). Criterion validity was assessed by evaluating Spearman correlation between the overall or domain-specific quality of life and traditional measures of patient status. Overall Myopia-specific Quality of Life Questionnaire score changed from 3.21 preoperatively to 3.76, 4.00, 4.07, and 4.11 at 4 days, and 1, 3, and 6 months after surgery, respectively. Social role function showed the biggest improvement (score change: 1.51, P < .05), followed by psychological well-being (0.90, P < .05), visual function (0.72, P < .05), and visual symptoms (0.49, P < .05). Regression analysis results showed that the degree of uncorrected visual acuity, discomfort associated with myopia preoperatively, and location of eye center were significant factors affecting the magnitude of changes in quality of life after LASIK.

CONCLUSIONS

This study confirms that the value of LASIK went beyond the clinical achievement of refractive correction and extended to the improvement of quality of life.

The Quality of Life Impact of Refractive Correction (QIRC) Questionnaire: Development and Validation

BACKGROUND

The purpose of the study was to develop a questionnaire that could quantify the quality of life (QOL) of people with refractive correction by spectacles, contact lenses, and refractive surgery in the prepresbyopic age group.

METHODS

The questionnaire was developed and validated using traditional methods and Rasch analysis. A 90-item pilot questionnaire was developed through extensive literature search and use of professional and lay focus groups. Pilot study data were obtained from 306 subjects for item reduction to produce the 20-item Quality of Life Impact of Refractive Correction (QIRC) questionnaire. Validity and reliability studies (test-retest reliability with intraclass correlation coefficient and Bland-Altman limits of agreement, and internal consistency with Rasch fit statistics, factor analysis, and Cronbach's alpha) were performed from data of an additional 312 subjects.

RESULTS

Rasch analysis demonstrated QIRC has good precision, reliability, and internal consistency (person separation, 2.03; reliability, 0.80; root-mean-square measurement error, 3.25; mean square +/- SD infit, 0.99 +/- 0.38; outfit, 1.00 +/- 0.39; item infit range, 0.70 to 1.24; and item outfit range, 0.78 to 1.32). The items (mean score, 50.3 +/- 7.3) were well targeted to the subjects (mean score, 47.8 +/- 5.5) with a mean difference of 2.45 (scale range, 0 to 100) units. Test-retest reliability (intraclass correlation coefficient, 0.88; coefficient of repeatability, +/-6.85 units), factor loading range (0.40 to 0.76), and Cronbach's alpha (0.78) also indicated the reliability and validity of QIRC.

CONCLUSIONS

The 20-item QIRC questionnaire, which quantifies the QOL of people with refractive correction by spectacles, contact lenses, and refractive surgery in the prepresbyopic age group, was developed using Rasch analysis and shown to be valid and reliable. The use of Rasch scaling allows scores to be treated as a valid continuous variable. QIRC has broad applicability for cross-sectional and outcomes research.

Myopia: precedents for research in the twenty-first century

The myopic eye is generally considered to be a vulnerable eye and, at levels greater than 6 D, one that is especially susceptible to a range of ocular pathologies. There is concern therefore that the prevalence of myopia in young adolescent eyes has increased substantially over recent decades and is now approaching 10-25% and 60-80%, respectively, in industrialized societies of the West and East. Whereas it is clear that the major structural correlate of myopia is longitudinal elongation of the posterior vitreous chamber, other potential correlates include profiles of lenticular and corneal power, the relationship between longitudinal and transverse vitreous chamber dimensions and ocular volume. The most potent predictors for juvenile-onset myopia continue to be a refractive error </=+0.50 D at 5 years of age and family history. Significant and continuing progress is being made on the genetic characteristics of high myopia with at least four chromosomes currently identified. Twin studies and genetic modelling have computed a heritability index of at least 80% across the whole ametropic continuum. The high index does not, however, preclude an environmental precursor, sustained near work with high cognitive demand being the most likely. The significance of associations between accommodation, oculomotor dysfunction and human myopia is equivocal despite animal models that have demonstrated that sustained hyperopic defocus can induce vitreous chamber growth. Recent optical and pharmaceutical approaches to the reduction of myopia progression in children are likely precedents for future research, for example progressive addition spectacle lens trials and the use of the topical M1 muscarinic antagonist pirenzepine.

Contrast and glare testing in keratoconus and after penetrating keratoplasty

AIM

To compare the performance of keratoconus, penetrating keratoplasty (PK), and control subjects on clinical tests of contrast and glare vision, to determine whether differences in vision were independent of visual acuity (VA), and thereby establish which vision tests are the most useful for outcome studies of PK for keratoconus.

METHODS

All PK subjects had keratoconus before grafting and no subjects had any other eye disease. The keratoconus (n = 11, age 35.0 (SD 11.1) years), forme fruste keratoconus (n = 6, 33.0 (13.0)), PK (n = 21, 41.2 (7.9)), and control (n = 24, 33.7 (8.6)) groups were similar in age. Vision testing, conducted with optimal refractive correction in place, included low contrast visual acuity (LCVA) and Pelli-Robson contrast sensitivity (PRCS) both with and without glare, as well as VA.

RESULTS

Normal subjects saw better than PK subjects who in turn saw better than keratoconus subjects on all raw measures. However, when adjusted for VA, the normal group only saw significantly better than the keratoconus group on LCVA (low contrast loss 0.05 (0.04) v 0.15 (0.12), F(2,48) = 6.16; p<0.01, post hoc Sheffé p<0.05), and the decrements to glare were no worse than for normals. The forme fruste keratoconus group were indistinguishable from normals on all measures.

CONCLUSIONS

PK subjects have superior vision to keratoconus subjects, but not as good as normal subjects. Including mild keratoconus subjects within a keratoconus group could confound these differences in vision. While VA is an excellent test for comparing normal, keratoconus and PK groups, additional information can be provided by LCVA and PRCS, but not by glare testing. Outcomes research into keratoconus management should include a measure in the contrast domain.

Development and Validation of a Multidimensional Quality-of-Life Scale for Myopia

BACKGROUND

Five dimensions of health-related quality of life in myopia were hypothesized to affect satisfaction with visual correction modality. Items on these dimensions reflected the frequency of visual compromise and ocular symptoms; individual tolerance of these compromises and symptoms; cosmesis; psychological constructs (including situation-dependent characteristics such as adaptability, self-efficacy, and subjective well-being); and personality traits such as extraversion and introversion.

METHODS

Psychologically oriented items and visually oriented items were developed in two stages involving 1,647 participants. Item development was based on a comprehensive literature review, interviews with experts, myopic subjects, and graduate students, and written feedback. Items were selected through factor analysis and the examination of their ability to discriminate between treatment conditions (spectacle wear, daily use of contact lenses, continuous use of contact lenses, or laser-assisted in-situ keratomileusis for myopia). After development, selection, and validation of the psychological items and then the vision items, a final multidimensional scale combining both types of items was designed. The scale was administered to 124 subjects whose myopia was corrected by one of several treatment modalities to determine final construct validity.

RESULTS

Using principal axis factoring and oblimin with Kaiser normalization rotation methods, five factors with strong item loadings evolved as hypothesized. The final multidimensional scale consisted of 13 items related to specific aspects of frequency of visual compromise and ocular symptoms with 13 corresponding items for level of tolerance for these problems; three items related to cosmesis; 10 items related to psychological characteristics; and six items related to personality traits. Good internal consistency in each factor (Cronbach's alpha range, 0.76 to 0.92) for the scale was evident.

DISCUSSION

This report describes the development and validation of an easily administered, short, effective multidimensional health-related quality-of-life questionnaire for use in selecting and measuring success of methods for correcting myopia.

Visual functional outcomes of cataract surgery in the United States, Canada, Denmark, and Spain

PURPOSE

To compare functional outcomes after cataract surgery performed at 4 sites in 4 countries that have been described as having significant differences in the organization of care and patterns of clinical practice.

SETTING

Multicenter cohort study from the United States, Canada, Denmark, and Spain.

METHODS

Clinical data and patient interview data were collected preoperatively and 4 months postoperatively. Functional outcomes were assessed by the Visual Function Index (VF-14), a self-reported measure of visual function. Scores on the VF-14 range from 0 (maximum impairment) to 100 (no impairment).

RESULTS

Unilateral surgery was performed in 1073 patients. In this subgroup, the odds of achieving an optimal functional outcome (VF-14 score > or =95) were similar among sites after controlling for differences in case mix. Bilateral surgery was performed in 211 patients. A postoperative visual acuity of 0.50 or better in both eyes was reported in 155 patients. However, 37% of these patients reported visual function impairment (VF-14 score <95).

CONCLUSIONS

A previously identified variation in treatment modalities among the 4 sites did not have a significant effect on the odds of achieving an optimal functional outcome. In addition to visual acuity measurements, the VF-14 index provides information on functional outcomes that is useful, especially in studies assessing the benefits of cataract surgery in a public health care setting.

Health care economic analyses and value-based medicine

Health care economic analyses are becoming increasingly important in the evaluation of health care interventions, including many within ophthalmology. Encompassed with the realm of health care economic studies are cost-benefit analysis, cost-effectiveness analysis, cost-minimization analysis, and cost-utility analysis. Cost-utility analysis is the most sophisticated form of economic analysis and typically incorporates utility values. Utility values measure the preference for a health state and range from 0.0 (death) to 1.0 (perfect health). When the change in utility measures conferred by a health care intervention is multiplied by the duration of the benefit, the number of quality-adjusted life-years (QALYs) gained from the intervention is ascertained. This methodology incorporates both the improvement in quality of life and/or length of life, or the value, occurring as a result of the intervention. This improvement in value can then be amalgamated with discounted costs to yield expenditures per quality-adjusted life-year ($/QALY) gained. $/QALY gained is a measure that allows a comparison of the patient-perceived value of virtually all health care interventions for the dollars expended. A review of the literature on health care economic analyses, with particular emphasis on cost-utility analysis, is included in the present review. It is anticipated that cost-utility analysis will play a major role in health care within the coming decade.

Utility values and myopia in teenage school students

AIM

To ascertain the utility values of myopic teenage students in Singapore.

METHODS

Children (n=699) aged 15-18 years with myopia (spherical equivalent (SE) at least -0.5 dioptres (D)) in two high schools in Singapore were recruited. Information on time trade-off (years of life willing to sacrifice for treatment of myopia) and standard gamble for blindness (risk of blindness from therapy willing to sacrifice for treatment of myopia) utility values, demographic, and socioeconomic status data were obtained.

RESULTS

The time trade-off and standard gamble for blindness utility values were 0.93 (95% confidence interval (CI) 0.93 to 0.94) and 0.85 (95% CI 0.84 to 0.86), respectively. Children with presenting better eye logMAR visual acuity >0.3 had lower time trade-off utility values (mean 0.92 versus mean 0.94), after adjusting for race and sex. There were dose-response relations between standard gamble for blindness values and total family income, as well as both utility values and educational stream (all p values for trend <0.01), after controlling for the same factors.

CONCLUSION

The utility values in myopic students were higher for teenagers with better presenting visual acuity, children who wore spectacles or contact lenses, higher total family income, more "academic" schooling stream, and who were non-Muslims.

Visual function index (VF-14) in exudative age-related macular degeneration of long duration

PURPOSE

To evaluate the Visual Function Index (VF-14) questionnaire for its effectiveness in assessing visual function in patients with longstanding exudative age-related macular degeneration (AMD).

DESIGN

Observational case series.

METHODS

The records of 167 consecutive patients with recent neovascularization related to AMD between June 1990 and December 1994 at the Helsinki University Eye Clinic were analyzed in 1999. Of 121 patients still living, 74 (61%) attended the reexamination. After exclusions, data from 62 patients were analyzed. The VF-14 score, plus global assessment scores of satisfaction with vision and quality of vision, in which patients graded the subjective level of difficulty with their vision, best-corrected visual acuity (BCVA), contrast sensitivity, the area of the AMD lesion, and the shortest distance and direction from the center of the fovea to the edge of the subfoveal lesion, were analyzed.

RESULTS

The VF-14 score correlated significantly with BCVA (P <.01), contrast sensitivity (P <.01), and global assessment scores (P <.01), showing stronger correlations with global assessment scores than did BCVA. In multivariate regression analysis, the global assessment scale of overall quality of vision and BCVA in the better eye were significant predictors (P <.001) of the variability in the VF-14 score.

CONCLUSIONS

The VF-14 reflects visual function of patients with late AMD more effectively than BCVA measurement alone. The VF-14 can thus be used to compare the visual handicap of late AMD patients with that of patients with other eye diseases.