ABSTRACT
The corneal endothelium is vital for transparency and proper hydration of the cornea. Here, we conduct a genome-wide association study of corneal endothelial cell density (cells/mm2), coefficient of cell size variation (CV), percentage of hexagonal cells (HEX) and central corneal thickness (CCT) in 6,125 Icelanders and find associations at 10 loci, including 7 novel. We assess the effects of these variants on various ocular biomechanics such as corneal hysteresis (CH), as well as eye diseases such as glaucoma and corneal dystrophies. Most notably, an intergenic variant close to ANAPC1 (rs78658973[A], frequency = 28.3%) strongly associates with decreased cell density and accounts for 24% of the population variance in cell density (ß = -0.77 SD, P = 1.8 × 10-314) and associates with increased CH (ß = 0.19 SD, P = 2.6 × 10-19) without affecting risk of corneal diseases and glaucoma. Our findings indicate that despite correlations between cell density and eye diseases, low cell density does not increase the risk of disease.
Subject(s)
Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/genetics , Corneal Dystrophies, Hereditary/genetics , Endothelium, Corneal/metabolism , Glaucoma/genetics , Polymorphism, Genetic , Adult , Aged , Aged, 80 and over , Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism , Case-Control Studies , Cell Count , Cell Size , Corneal Dystrophies, Hereditary/diagnosis , Corneal Dystrophies, Hereditary/pathology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Endothelium, Corneal/pathology , Female , Gene Expression , Gene Expression Profiling , Genetic Loci , Genome-Wide Association Study , Glaucoma/diagnosis , Glaucoma/pathology , Humans , Intraocular Pressure , Male , Middle Aged , Whole Genome SequencingABSTRACT
PURPOSE: To examine the corneal endothelium and establish the 7-year cumulative incidence of cornea guttata (CG). METHODS: Population-based prospective cohort study with 573 participants (third wave of the Reykjavik Eye Study (RES) in 2008). Four hundred and thirty-seven subjects had either right or left eyes available for analysis after excluding confounding eye conditions. The baseline for eyes at risk for developing CG is the second wave of the RES in 2001. Participants underwent specular microscopy and a standardized eye examination. RESULTS: The cumulative 7-year incidence of CG in either eye was estimated as a 95% confidence interval for the expected value for both genders combined (15-23%), for males (8-18%) and for females (19-29%). In right eye only, the 7-year cumulative incidence for both genders combined was estimated to be 6-11%. For genders combined and for males only, the data indicated no correlation between 7-year cumulated incidence and age at baseline. In women, however, the change of 7-year incidence for CG in at least one eye appeared to be correlated to age at baseline. Reduction of endothelial cell density for corneas with CG at baseline was found [CI (0.95)-132 ± 94]. CONCLUSION: The cumulative 7-year incidence of primary central CG for a middle-aged and older Caucasian population without history of potentially confounding eye disease has been established. Women tend to have higher incidence if onset occurs at middle age. If CG is present, the cell density and the cell size variation decrease within a 7-year period.
Subject(s)
Corneal Diseases/epidemiology , Descemet Membrane/pathology , Endothelium, Corneal/pathology , Age Distribution , Aged , Aged, 80 and over , Cell Count , Corneal Diseases/classification , Corneal Diseases/diagnosis , Corneal Pachymetry , Female , Finland/epidemiology , Follow-Up Studies , Humans , Incidence , Male , Microscopy , Middle Aged , Prospective Studies , Sex Distribution , Time Factors , White PeopleABSTRACT
PURPOSE: To establish the age- and gender-specific prevalence of cornea guttata (CG) in citizens of Reykjavik, Iceland, 55 years and older. DESIGN: Cross-sectional, random, population-based study. PARTICIPANTS: The 774 participants were those participating in the second examination of the Reykjavik Eye Study. At baseline, we had a response rate of 75.8%, and at the 5-year follow-up, 88% of the survivors participated. METHODS: We used slit-lamp and non-contact specular microscopy and endothelial specular photography as well as computer-assisted morphometry. We used a standardized grading system for CG. MAIN OUTCOME MEASURES: Diagnosis of primary central CG. RESULTS: The prevalence of CG is 11% for females and 7% for males both for right eyes and left eyes. Higher weight and higher body mass index are found to be associated with decreased risk of CG. Having smoked more than 20 pack-years increased the risk of CG more than 2-fold (P<0.02). CONCLUSIONS: Cornea guttata seem to be found more commonly in women than in men. Smoking for more than 20 pack-years increases the risk of developing CG more than 2-fold.