J Korean Ophthalmol Soc.
1968 Jun;9(2):1-5.
Electroretinographic Changes Experimentally Induced by the Intraocular Copper
- Affiliations
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- 1Department of Ophthalmology, College of Medicine, Seoul National University, Seoul, Korea.
Abstract
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Copper fragment was introduced into the vitreous body of fourteen albino rabbits through the scleral incision at equatorial region. Both photopic and scotopic ERGs were recorded for 30 days thereafter stimulated by the electronic photoflash of 2 msec duration.The changes in scotopic b-potential were roughly classified into 3 types. The first type (5 eyes) showed acute, severe reduction, extinguishing from 6 to 24 days. The second type (3 eyes) was characterized by the absence of any remarakble changes during the whole observation period, the final b'potential being 82,4% of the original value. In the third type (6 eyes), the b-potential decreased gradually and 24.3% of the pre' operative value was attained after 30 days. The latent time and the implicit time of the b-potential increased proportionally to the reduction of the b-wave. The scotopic a-wave behaved parallel to the b-wave, and in later stage, negative (-) type of ERGs were frequently encountered. The photopic a- and b-waves changed in the similar way as the scotopic a- and b-waves, respectively. The slitlamp biomicroscopy and ophthalmoscopy revealed the fibrous tissue proliferation around the copper fragment in relatively early stage. When the proliferation progressed and extended into the vitreous body, ERG showed reduction in b-potential, and sometimes increase in b-potential was noted In cases in which connective tissue encapsulated the copper and did not extend into the vitreous body, ERG changes were much milder and slower. In histological sesctions performed 2 weeks and 3 weeks after the insertion of copper fragment, the degeneration of the retina began both in the visual cell layer and ganglion cell layer almost simultaneously. When the ERG was extinguished, the retinal tissue showed complete destruction.