50 Sudden acquired retinal degeneration INITIAL PRESENTATION Blind PRESENTING SIGNS Owners will present the patient because the animal has suddenly gone blind. This may have occurred literally overnight, or may have progressed over a few days. The patient is likely to be distressed and slightly disoriented, and might be depressed or clinically unwell – with the owners reporting increased appetite and thirst. However, the patient might be totally normal except that they are bumping into things. The owners might have also noticed a change in the appearance of the eyes – shiny, glassy or perhaps just looking different. Small breed, overweight female dogs are most frequently presented. The condition has not been described in cats. CASE HISTORY In most cases there is no previous history of ocular disease or relevant systemic disease. However, the patient might have recently gained weight and might show signs of polydipsia and polyuria. A few cases will have a history of low grade hyperadrenocorticism which is either not being treated or not controlled with treatment. CLINICAL EXAMINATION General clinical examination will reveal a lethargic, slightly overweight or even obese patient but no other specific abnormalities. The patient will be obviously totally blind – reluctant to walk, bumping into objects, head down smelling the floor and with a high stepping gait. There will be a ‘starey’ appearance to the eyes, due to the presence of dilated pupils. Menace responses will be absent. Pupils will be dilated in room light and in the dark, and will be symmetrically so. Pupillary light reflexes are usually totally absent, although slight pupil constriction might occur with a very bright light source. Dazzle reflexes will be absent. Intraocular examination will be normal – one would expect fundus abnormalities but this is not the case – the retina and optic nerve look normal initially. However, if the patient is not presented for several weeks the early signs of retinal degeneration, with tapetal hyper-reflectivity and blood vessel attenuation, might have developed. DIFFERENTIAL DIAGNOSES • Sudden acquired retinal degeneration (SARD) • Optic neuritis • Retinal detachment • Central blindness (for causes, see list below) • Hypertensive retinopathy • Toxic retinopathy • Other causes of acute blindness – glaucoma, uveitis Possible causes of central blindness include: • optic neuritis (retrobulbar) Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Medial canthal pocket syndrome Rabbit uveitis Leishmaniasis Limbal melanoma Stay updated, free articles. Join our Telegram channel Join Tags: Saunders Solutions in Veterinary Practice Small Animal Ophthalmo Sep 10, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Sudden acquired retinal degeneration Full access? Get Clinical Tree
50 Sudden acquired retinal degeneration INITIAL PRESENTATION Blind PRESENTING SIGNS Owners will present the patient because the animal has suddenly gone blind. This may have occurred literally overnight, or may have progressed over a few days. The patient is likely to be distressed and slightly disoriented, and might be depressed or clinically unwell – with the owners reporting increased appetite and thirst. However, the patient might be totally normal except that they are bumping into things. The owners might have also noticed a change in the appearance of the eyes – shiny, glassy or perhaps just looking different. Small breed, overweight female dogs are most frequently presented. The condition has not been described in cats. CASE HISTORY In most cases there is no previous history of ocular disease or relevant systemic disease. However, the patient might have recently gained weight and might show signs of polydipsia and polyuria. A few cases will have a history of low grade hyperadrenocorticism which is either not being treated or not controlled with treatment. CLINICAL EXAMINATION General clinical examination will reveal a lethargic, slightly overweight or even obese patient but no other specific abnormalities. The patient will be obviously totally blind – reluctant to walk, bumping into objects, head down smelling the floor and with a high stepping gait. There will be a ‘starey’ appearance to the eyes, due to the presence of dilated pupils. Menace responses will be absent. Pupils will be dilated in room light and in the dark, and will be symmetrically so. Pupillary light reflexes are usually totally absent, although slight pupil constriction might occur with a very bright light source. Dazzle reflexes will be absent. Intraocular examination will be normal – one would expect fundus abnormalities but this is not the case – the retina and optic nerve look normal initially. However, if the patient is not presented for several weeks the early signs of retinal degeneration, with tapetal hyper-reflectivity and blood vessel attenuation, might have developed. DIFFERENTIAL DIAGNOSES • Sudden acquired retinal degeneration (SARD) • Optic neuritis • Retinal detachment • Central blindness (for causes, see list below) • Hypertensive retinopathy • Toxic retinopathy • Other causes of acute blindness – glaucoma, uveitis Possible causes of central blindness include: • optic neuritis (retrobulbar) Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Medial canthal pocket syndrome Rabbit uveitis Leishmaniasis Limbal melanoma Stay updated, free articles. Join our Telegram channel Join Tags: Saunders Solutions in Veterinary Practice Small Animal Ophthalmo Sep 10, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Sudden acquired retinal degeneration Full access? Get Clinical Tree
