“Is it just about genes?’
There is often despair in this query from epidemiologists interested in Ophthalmology, who view what appears to be an increasingly narrow pathway for involvement in a traditionally wide-open field. There is no doubt of the contributions that can and will be made in the present environment to knowledge of the pathophysiology of blinding diseases through the investigation of genetic and gene-environment interactions. Yet, as this issue of Ophthalmic Epidemiology illustrates, good epidemiological studies can advance knowledge on a variety of important fronts. And in this issue in particular, one can view the panoply of approaches that are being used to address questions that affect the global eye care community.
With health care reform a hot topic (at least while this editorial was being written), more data on the cost effectiveness of alternative programs and practice patterns will continue to be needed as part of the evidence base for support. Frick et al. have used this methodology in the evaluation of the cost- effectiveness of school based versus primary eye care-based screening for refractive error and fitting spectacles in IndiaCitation1. This is not a theoretical exercise. India, with its estimated 1.17 billion population and China, with its 1.34 billion population, face an enormous problem of refractive error and its consequences, and need information on alternative approaches. Simple data on outcomes of interventions, like cataract surgery services, provide critical feed back on the success achieved for the investment made. As Murthy et al. report for Gujarat, India, outcomes that are less than satisfactory should be further investigatedCitation2. In this case, post operative uncorrected refractive error and posterior capsular opacification explained most of the visual impairment following surgery. pointing out the need for sustained provision of access to eye care services post-surgery.
Health disparities, especially in access to health care, is one of the drivers for a reevaluation of the health care system in the United States. Of special concern is the lack of sufficient numbers of primary care physicians. In the eye-care field, avoiding blindness form cataract requires sufficient numbers of cataract surgeons with equitable geographic distribution. One way to start to assess this issue is using methods as shown by Ono et al. for LaosCitation3. Using a statistical method that measures inequality, Gini co-efficient, they showed that over time, the cataract surgery rate and distribution of eye care professionals improved. Even the opportunity to assess basic potential differences in eye diseases by ethnicity may reveal disparities, as the multi-ethnic study being launched in Singapore is poised to doCitation4. While genetic and environmental risk factors are clearly the primary motivation for this important study, the opportunity to identify community and societal factors as influencing the course of the eye diseases should not be missed.
Research into the impact of visual loss is being pulled into the broader arena of aging research, with its multi-dimensional framework. Loss of vision does not happen among our elders typically as an isolated event, and may be the proverbial “straw that broke the camel’s back,” tipping a person just coping with other deficits into disability and dependency. Yet most of our quality of life studies seem to ignore this fundamental tenet. Isolating the visual component may be less important than deepening our understanding of how vision interacts with other impairments to produce functional loss. As Fischer et al. in this issue illustrate, multiple sensory impairment affects domains that are part of quality of life, and notably, vision loss is a critical and sometimes overriding componentCitation5, particularly for physical and elnotional health.
Internationally, classic ophthalmic epidemiology is alive. This is well evidenced by the studies regarding the general magnitude of the problemCitation6–8, some addressing risk factors that help elucidate pathophysiological mechanisms of eye diseaseCitation9,10, and others evaluations of interventionsCitation1,2. The breadth and wealth of information that epidemiology and public health in general can bring to bear in research towards blindness prevention does not appear to be limited at all, if this issue be any guide.
Sheila K. West
Editor-in-Chief
Opthalmic Epidemology
REFERENCES
- Frick KD, Riva-Clement L, Shankar MB. Screening for refractive error and fitting with spectacles in rural and urban India: Cost-effectiveness. Ophthalmic Epidemiol. 2009;V.16:378–387.
- Murthy GVS, Vashist P, John N, Pokharel G, Ellwein LB, SEWA-Rural Cataract Study Group. Prevalnce and vision-related outcomes of cataract surgery in Gujarat, India. Ophthalmic Epidemiol 2009;V.16:400–409.
- Ono K, Visonnavong V, Konyama K, Hiratsuka Y, Murakami A. Geographical distribution of eye health professionals and cataract surgery in Loa People’s Democratic Republic. Ophthalmic Epidemiol 2009;V.16:354–361.
- Lavanya R, Jeganathan VSE, Zheng Y, Raju P, Cheung N, Tai ES, Wang JJ, Lamoureux E, Mitchell P, Young TL, Cajucom-Uy H, Foster PJ, Aung T, Saw SM, Wong TY. Methodology of the Singapore Indian Chinese Cohort (SICC) Eye Study: Quantifying ethnic variations in the epidemiology of eye diseases in Asians. Ophthalmic Epidemiol 2009;V.16:325–326.
- Fischer ME, Cruickshanlts KJ, Klein BEK, Klein R, Schubert CR, Wiley TL. Multiple sensory impairment and quality of life. Ophthalmic Epidemiol 2009;V.16:346–353.
- Li Z, Sun D, Cuj H, Zhang L, Lju P, Yang H, Baj J. Refractive error among the elderly in rural Southern Harbin, China. Ophthalinic Epidemiol 2009;V.16:388–394.
- Limburg H, Keunen JEE. Blindness and low vision in The Netherlands from 2000 to 2020-modleing as a tool for focused intervention. Ophthalmic Epidemiol 2009;V.16:362–369.
- Muecke J, Hammerton M, Aung YY, Warrier S, Kong A, Morse A, Holmes M, Yapp M, Hamilton C, Selva D. A survey of visual impairment and blindness in children attending sever schools for the blind in Myanmar. Ophthalmic Epidemiol 2009;V.16:370–377.
- Gichuhi S, Bosire R, Mbori-Ngacha D, Gichuhi C, Wamalwa D, Maleche-Obimbo E, Farquhar C, Wariua G, Olieno P, John-Stewart GC. Risk factors for neonatal conjunctivitis in babies of HIV-1 infected mothers. Ophthalmic Epidemiol 2009;V.16:337–345.
- Pinna A, Pes A, Zinellu A, Carta A, Solinas G. Glucosa-6-phosphate dehydrogenase (G6PD) deficiency and senile cataract in a Sardinian male population, Italy. Ophthalmic Epidemiol 2009;V.16:395–399.