A Case of Uveal Colobomas Showing Marked Left-Right Difference in Diabetic Retinopathy.
OBJECTIVE
Congenital uveal colobomas, including inferior iris and choroidal colobomas, are associated with microcornea and microphthalmia and often show left-right differences (laterality). The purpose of this study was to report a case of choroidal coloboma associated with left-right differences in diabetic retinopathy (DR).


METHODS
This study reports a 59-year-old male with bilateral iris and choroidal colobomas. The colobomatous area in the patient's right eye extended to the macula, and his right eye had been amblyopic since birth. The colobomatous area in his left eye was less extensive and did not involve the macula. Examination of the patient's left eye revealed multiple hemorrhages and hard exudates in the macula due to DR, but examination of his right eye showed almost no changes in DR, thus revealing a marked left-right difference. Optical coherence tomography showed more extensive retinal thinning in the patient's right eye than in his left eye. Fluorescein fundus angiography revealed a retinal nonperfusion area only in the left eye, and panretinal photocoagulation was subsequently performed.


CONCLUSIONS
Our findings show that the reason for the left-right difference in DR was attributed to the more severe choroidal coloboma and retinal thinning in the patient's right eye compared to his left eye, thus reducing oxygen demand, as is also seen in eyes with severe myopia.
Department of Ophthalmology, Osaka Kaisei Hospital, Osaka, Japan.
Takeshi
T
Moriya
Department of Ophthalmology, Osaka Kaisei Hospital, Osaka, Japan.
Ryosuke
R
Ochi
Department of Ophthalmology, Osaka Kaisei Hospital, Osaka, Japan.
Yukihiro
Y
Imagawa
Department of Ophthalmology, Osaka Kaisei Hospital, Osaka, Japan.
Bumpei
B
Sato
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Seita
S
Morishita
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Masahiro
M
Tonari
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Masanori
M
Fukumoto
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Hiroyuki
H
Suzuki
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Takatoshi
T
Kobayashi
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Teruyo
T
Kida
Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan.
Tsunehiko
T
Ikeda
Choroidal coloboma; Diabetic retinopathy; Fluorescein fundus angiography; Left-right difference; Optical coherence tomography