advertisement
Stoutenbeek et al. performed an interesting study on the additional benefit of a periodic screening program for open-angle glaucoma (OAG) using data previously collected by the Rotterdam Study. This population-based cohort study enrolled 6773 participants who had two ophthalmic visits separated by 6.5 years. The authors compared the number of cases of incident OAG that were detected on the follow-up visit to the cases detected by regular ophthalmic care. They found that 23 of 78 (29%) cases of incident OAG had already been detected during regular care, whereas 51 (71%) had remained undetected. Cases that remained undetected more often had glaucomatous optic neuropathy without visual field loss. Only a small proportion of undetected cases had significant visual field damage. The authors suggest that the additional yield of period screening would be less than expected as many cases had already been detected by regular ophthalmic care, and only a minority of undetected cases had severe enough disease at risk of blindness during lifetime. It is important to note, however, that this study was conducted in a developed country where the population most likely has high standards of health care. That could explain the relatively high number of OAG cases detected by regular ophthalmic care. This situation might not be realistic in underdeveloped or developing countries or even in other developed regions where the population access to standard ophthalmic care is not as easy as in Rotterdam. It is also possible that, by having participated in a large study, the cohort of the Rotterdam study became more aware of the benefits of regular ophthalmic care which could have resulted in more subjects undergoing periodic ophthalmic examinations. Although most of the undetected cases had small amounts of visual field damage, the assessment was performed using a supra-threshold screening test which may not be particularly reliable for staging the severity of visual field loss. In conclusion, the study by Stoutenbeek et al. helps to shed light in the controversial topic of screening for OAG. However, additional studies evaluating different populations will be necessary to assess the feasibility and benefit of regular screening programs.