The International Society for Clinical Electrophysiology of Vision (ISCEV) published the first standardized basic protocol in 1989 so that comparable electroretinograms (ERGs) could be recorded throughout the world. The latest version of the ISCEV ERG protocol was approved at the annual ISCEV meeting in 2008 and documented in 2009. While this protocol describes a procedure for human ERGs, it is often applied to animal ERGs. In order to help researchers and technicians easily understand this latest protocol, the present article reviews a summary of ISCEV ERG protocol, and different points between 2004's version and the latest one. Additionally, consideration when the protocol is applied to animal ERGs is described here.

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Recently, Melan-100 has been marketed as a simple inspection apparatus for the diagnosis of sudden acquired retinal degeneration in dogs. Although vision disturbance is observed in retinal diseases such as sudden acquired retinal degeneration and inherited retinal degeneration, pupil light reflex is usually unaffected. In this study, Melan-100 was clinically assessed using 54 eyes that were suspected of or had vision impairment in 27 dogs showing pupil light reflex.
The eyes were examined by menace test/dazzle test, and according to the results, the dogs were divided into 4 groups as follows: Group 1, +/+; Group 2, -/+; Group 3, -/- Group 4, +/-. The eyes examined with Melan-100 were evaluated and classified into 3 categories depending on their response: “Normal,” “Abnormal,” and “No response.” “Normal” was defined as complete pupil constriction wherein the observed pupil diameter was less than 4 mm in response to red and blue light; “Abnormal” was defined as incomplete pupil constriction wherein the pupil diameter was less than 4 mm in response to blue light alone; “No response” was defined as absent or decreased pupil constriction wherein the observed pupil diameter was above 4 mm in response to red and blue lights.
Of the 27 dogs, 25 were of any of 12 breeds and 2 were mixed breeds. “Abnormal” and “No response” eyes were present in all the groups. Fourteen eyes (14 of 23, 60.9%) in Group 1, 6 eyes (6 of 17, 35.3%) in Group 2, 8 eyes (8 of 12, 66.7%) in Group 3, and 1 eye (1 of 2, 50.0%) in Group 4 were classified as “Abnormal.” Three eyes (3 of 23 13.0%) in Group 1, 10 eyes (10 of 17, 58.8%) in Group 2, 4 eyes (4 of 12, 33.3%) in Group 3, and 1 eye (1 of 2, 50.0%) in Group 4 were classified as “No response.” Although the dazzle reflex was observed in Groups 1and 2, the number of eyes that were classified as “Abnormal” in Group 1 and the number of eyes that were classified as “No response” in group 2 were high. None of the eyes in Groups 3 and 4 were classified as “Normal.” Most of the examined eyes had suffered from cataract and retinal diseases. Thirteen of twenty-five cataractous eyes (52%) were classified as “Abnormal”; this number was very similar to that for eyes with retinal diseases (14 of 25 eyes, 56%). None of the eyes with retinal diseases were classified as “Normal,” but some of the cataractous eyes were.
Therefore, our results showed that Melan-100 may be useful for the evaluation of retinal photoreceptor function in dogs with cataract as well as retinal diseases, provided they showed pupil light reflex.

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A 9-year 9-month-old male beagle dog was suspected to have optical deficits. The dog therefore underwent ophthalmologic examinations. During follow-up, at 10 years and 4 months of age, paralysis of the extremities developed. The prognosis was hence considered to be poor. The dog was examined pathologically after euthanasia.
The ophthalmologic examination revealed binocular mydriasis and the disappearance of ophthalmologic reflex reactions, indicating vision loss. Fundus examinations showed yellow coloration around the optic disk. On pathological examination, cupping of the optic disc and peripapillary atrophy were observed. In addition, the bilateral optic nerves exhibited infiltration of inflammatory cells (lymphocytes, plasma cells and macrophages), and atrophic degeneration of fibers. In the brain and the spinal cord as well, infiltrations of inflammatory cells the same as those observed on the optic nerves were extensive and perivascular. In particular, Th5 of the thoracic cord showed remarkable granulomatous inflammation.
These results suggested that this dog had first developed the “ocular type” of granulomatous meningoencephalomyelitis (GME), resulting in vision loss. Subsequently, the inflammation had apparently progressed to the “disseminated type” of GME, resulting in paralysis of the extremities.

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