Troels Vinding

Prevalence and causes of visual impairment according to World Health Organization and United States criteria in an aged, urban Scandinavian population: The Copenhagen City Eye Study

PURPOSE To evaluate the prevalence and causes of visual impairment in an epidemiologic study of aged, urban individuals in Denmark. DESIGN Cross-sectional study. PARTICIPANTS The study population consisted of 1000 randomly selected residents aged 60 to 80 years in Copenhagen, Denmark. Of 976 eligible persons, 946 (96.9%) could be examined. Information about best-corrected visual acuity (VA) was obtained from 944 cooperative persons (96.7%). METHODS Data from the Copenhagen City Eye Study were used to assess the cause-specific prevalence of visual impairment as defined by the World Health Organization (WHO) (VA worse than 20/60-20/400 in the better eye) and the criteria used most commonly in the United States (VA worse than 20/40 but better than 20/200 in the better eye). Eligible subjects underwent an extensive ophthalmologic examination at The National University Hospital of Denmark. MAIN OUTCOME MEASURES Best-corrected VA and primary causes of visual impairment. RESULTS The prevalence of low vision according to the WHO definition ranged from 2.6% in subjects aged 70 to 74 years to 4.8% in subjects 75 to 80 years of age, with an age-adjusted relative prevalence of 1.58%. Using the U.S. definition, the overall age-adjusted prevalence of visual impairment was 2.9%. The causes of visual impairment according to the WHO criteria were age-related macular degeneration (AMD) (44.4%), cataract (33.3%), glaucoma in combination with cataract (11.1%), myopic macular degeneration (5.6%), and diabetic retinopathy (5.6%). However, according to the U.S. criteria, cataract was the most frequent primary cause (50.0%) and AMD was the second most frequent primary cause (34.4%) of visual impairment. Furthermore, using the U.S. criteria diabetic retinopathy was revealed as equally important as AMD and cataract as a cause of visual impairment among persons aged 65 to 69 years (33.3%). CONCLUSIONS Increasing age was an independent predictor of visual impairment. Cataract and AMD were the leading causes. Adequate implementation of surgery to treat cataract could reduce visual impairment by 33.3% according to the WHO criteria and by 50% according to the U.S. criteria.

Human papillomavirus in normal conjunctival tissue and in conjunctival papilloma. Types and frequencies in a large series.

Aim: To examine conjunctival papilloma and normal conjunctival tissue for the presence of human papillomavirus (HPV). Methods: Archival paraffin wax-embedded tissue from 165 conjunctival papillomas and from 20 histological normal conjunctival biopsy specimens was analysed for the presence of HPV by PCR. Specimens considered HPV positive using consensus primers, but with a negative or uncertain PCR result using type-specific HPV probes, were analysed with DNA sequencing. Results: HPV was present in 86 of 106 (81%) β-globin-positive papillomas. HPV type 6 was positive in 80 cases, HPV type 11 was identified in 5 cases and HPV type 45 was present in a single papilloma. All the 20 normal conjunctival biopsy specimens were β-globin positive and HPV negative. Conclusion: There is a strong association between HPV and conjunctival papilloma. The study presents the largest material of conjunctival papilloma investigated for HPV and the first investigation of HPV in normal conjunctival tissue. HPV types 6 and 11 are the most common HPV types in conjunctival papilloma. This also is the first report of HPV type 45 in conjunctival papilloma.

Human papillomavirus and pterygium. Is the virus a risk factor

Background: Pterygium is a disease of unknown origin and pathogenesis that might be vision threatening. It is characterised by a wing-like conjunctival overgrowth of the cornea. Several studies have investigated human papillomavirus (HPV) as a risk factor for the development of pterygia, but the results are inconclusive. Aim: To investigate a large sample of pterygia for the presence of HPV in order to clarify the putative association between pterygia and HPV. Methods: 100 specimens of pterygium from Danish patients and 20 normal conjunctival biopsy specimens were investigated for the presence of HPV with PCR technique using β-globin primers to access the quality of the extracted DNA and the HPV primers MY09/11 and GP5+/6+. HPV-positive specimens underwent subsequent HPV typing with type-specific HPV primers and further investigation with DNA in situ hybridisation (ISH). Results: 90 of 100 investigated pterygia proved suitable for HPV analysis by PCR. As β-globin could not be amplified, 10 specimens were excluded from the study. 4 of 90 pterygia harboured HPV. HPV type 6 was identified in all four HPV-positive pterygia. The 20 normal conjunctival biopsy specimens were β-globin positive and HPV negative. All four pterygia that were HPV type 6 positive were DNA ISH negative. Conclusions: The low presence of HPV DNA in pterygia does not support the hypothesis that HPV is involved in the development of pterygia in Denmark.