The relationship between ocular and oral dryness in a cohort from the 65-year-old population in Norway

In the present study, the relationship between dry eyes and dry mouth was explored in 150 65-year-old subjects randomly selected from the general population in Oslo, Norway. The number of drugs, including xerogenic drugs, and current and previous systemic diseases were recorded. Ocular parameters recorded were the McMonnies Dry Eye Questionnaire, the Ocular Surface Disease Index, the Schirmer I Test, tear film break-up time and ocular surface staining. The oral parameters were xerostomia frequency, Summated Xerostomia Inventory, Clinical Oral Dryness Score, and unstimulated and stimulated whole saliva. The participants with current or previous systemic diseases had significantly more ocular and oral symptoms and significantly more oral clinical findings than the participants without a history of disease. Moreover, correlation and factor analyses demonstrated an association between subjective ocular and oral parameters. A significant correlation between the total number of drugs and the presence of ocular and oral symptoms was also noted. When the participants were categorized based on their ocular symptoms, poorer values were found for the oral parameters among the participants more troubled with dry eyes. The results in the present study call for increased awareness and an interdisciplinary approach in matters related to dry eyes and dry mouth.