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Editors Selection IGR 9-3
Screening and Prevention: Relatives of OAG patients in the USA
Comment by Fotis Topouzis on:
19568 Targeting relatives of patients with primary open angle glaucoma: The Help the Family Glaucoma Project, Okeke CN; Friedman DS; Jampel HD et al., Journal of Glaucoma, 2007; 16: 549-555
In a cross-sectional survey and prospective cohort study, Okeke et al. (832) assess the knowledge of patients with open-angle glaucoma (OAG) and their family members about OAG risk factors and evaluate the referral of family members for eye examination. High rates of undiagnosed glaucoma exceeding 50% are reported from various population studies in developed and developing countries, while current screening methods outside the clinical office have been proven to be non cost effective. Okeke et al. Targeted family members of OAG patients in order to evaluate the efficiency of family members screening approach to identify those at high-risk for OAG and improve glaucoma detection in the community. Authors identified 102 probands from the Faculty and Resident practices of the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD using specific criteria for glaucoma diagnosis. Probands completed a questionnaire about OAG risk factors and provided information on first-degree living relatives within the United States. Among 230 eligible family members 101 were interviewed. In both probands and family members there was high awareness that OAG is related to older age (85%). More probands than family members knew of the higher intraocular pressure being associated with OAG (95% vs 78%). In both groups 21% were not aware that OAG is hereditary but this is likely underestimate since initial mailing included information that OAG is hereditary. Only 53% of probands and 30% of family members knew that OAG is more common in certain ethnic groups. Among 101 family members only 21 qualified for referral for eye examination (11 were too young and 69 had an eye examination within the last 12 months). Only 7 among the 21 qualified had an eye examination and among those 2 were diagnosed as OAG suspects and 5 as normals. As expected, the authors found that family history of glaucoma was highly inaccurate.
A screening strategy to identify and to educate family members of existing OAG patients about their greater risk of disease is feasibleThere are some issues that deserve cautious interpretation when generalizing the data from this paper. First this is not a population-based study and therefore study participants are not representative of the general population which is a key issue when evaluating screening strategies. As the authors mentioned in the discussion the group studied was already successfully accessing the health care system and was highly educated and aware of glaucoma. This explains why in this study there were small numbers getting benefit from the screening strategy described. The majority of family members had an eye examination within the last 12 months and did not qualify for referral. However we don't know whether those family members with prior examination indeed had glaucoma remaining undiagnosed. It would be of interest to evaluate cost effectiveness of referral in this subgroup of patients. Visiting an eye doctor is an important factor in decreasing rates of undiagnosed glaucoma but beyond this there may be additional factors with regards to standardized examination protocol. Another issue with the study methods is that methods and criteria for glaucoma diagnosis were different between probands and family members. Glaucoma diagnosis was self-reported and unconfirmed in family members. In addition only 101 among 270 eligible family members participated. Based on the data provided it seems that the benefit from educating and referring family members may be low. However, because of the highly selected population studied the possible benefit is likely underestimated. The study demonstrated the feasibility of the screening strategy to identify and to educate family members of existing OAG patients about their greater risk of disease. However, this strategy needs to be evaluated for cost effectiveness in a more representative of the general population sample.