Usefulness of handheld electroretinogram system for diagnosing blue-cone monochromatism in children

• Published in: Japanese journal of ophthalmology 2021-01, Vol.65 (1), p.23-29
• Main Authors: Haseoka, Takashi, Inagaki, Risako, Kurata, Kentaro, Arai, Shinji, Takagi, Yuri, Suzuki, Hiroko, Hikoya, Akiko, Nishimura, Kasumi, Hotta, Yoshihiro, Sato, Miho
• Format: Article
• Language: English
• Subjects: Abnormalities; Acuity; Children; Clinical Investigation; Diagnosis; Electroretinograms; Eye diseases; Luminous intensity; Medical diagnosis; Medicine; Medicine & Public Health; Nystagmus; Ophthalmology; Retina; Visual acuity
• ISSN: 0021-5155; 1613-2246
• DOI: 10.1007/s10384-020-00782-9

Purpose To report the diagnosis of three childhood patients with blue-cone monochromatism (BCM) using S-cone electroretinograms (ERG) recorded with RETeval ® Complete. Study design Prospective clinical study. Methods We examined three boys initially suspected of having rod monochromatism. S-cone ERG was performed with red background and blue flashed light stimulation using two different intensities: 0.25 cd × s/m 2 and 1 cd × s/m 2 . Results Case 1 was a 12-year-old boy with a visual acuity of 0.1 OU. Case 2 was an 8-year-old boy with a visual acuity of 0.3 OD and 0.2 OS. Both cases showed a myopic fundus and nystagmus without any other ocular abnormalities. Case 3 was a 6-year-old boy with a visual acuity of 0.3 OD and 0.4 OS. He also showed myopic fundus changes, but nystagmus was not observed. Rod and maximal responses recorded with RETeval ® were likely to be within normal range; however, cone responses were absent in all cases. S-cone ERGs showed positive responses at 40 ms with 0.25 cd × s/m 2 intensity in Case 2, and at approximately 30–40 ms with 1.0 cd × s/m 2 intensity in all three cases. These ERG findings led to a diagnosis of BCM. Conclusions S-cone ERG of RETeval ® was helpful in diagnosing with minimal invasion BCM in childhood patients.