Congenital Color Blindness in Young Turkish Men

Dear Editor, Congenital color blindness is a matter of ophthalmic epidemiology, and we want to congratulate Citirik et al.¹ for investigating the prevalence of congenital red-green color blindness among young Turkish males. They reported that the subjects included in their study were randomly selected healthy recruits from different regions of Turkey.

Military service is an obligatory task in Turkey, and every young Turkish man who reaches 20 years old is called to primary health examination centers. Turkey is consisted of seven natural regions, 81 cities and, more than 800 districts. We, as military ophthalmologists guess that there must be more than 300 primary health examination centers in Turkey. If a military doctor suspects an illness or malingering in the primary regional health examination center, the man is referred to secondary regional health examination centers, the number of which are 43, and the third step includes only two hospitals: GATA Ankara (which is the authors' institution) and GATA Haydarpasa (which are referred from all regions in Turkey). So, an epidemiological study concerning all of the regions in Turkey has to be made in either several centers from the seven natural regions or in the tertiary referral centers. For this reason we want to learn more about the study design.

A second issue and the more problematic one is about malingering. The authors participated the examinations in the primary, secondary, and tertiary centers for years and are aware of the high incidence of the ocular malingering among this population. The GATA Ankara Hospital is the center that all diagnosed or suspected color blind soldiers have to be referred. Our retrospective review showed that 22 of 89 referred soldiers were malingering color blindness. Malingering color blindness, visual acuity decreases, or visual field losses are one of the most frequent problems that military ophthalmologists come face to face with. In GATA Ankara, we use Ishihara's test, Farnsworth-Munsell 100-Hue test, HRR plates, and a color-blind ophthalmologist (HIA). We want to ask to Citirik et al. whether they strictly diagnosed color blindness in each subject and whether they took the malingering into consideration in this potentially malingering population.