A Clinical Case from the Archives : 30/01/2006

Posted on January 30, 2006 by davidwilliams

[tab name=”The Case”]So why is its eye enlarged? The intraocular pressure is 29mmHg just in case that helps you (or on the other hand it might just confuse you!)[/tab][tab name=”David’s view”]The most likely explanation is that inflammatory debris has clogged up the iridocorneal drainage angle with a mild but long-term rise in intraocular pressure. The other possibility is that the enlarged lymphoid follicles in the peripheral iris have resulted in an angle-closure glaucoma. We won’t know till the eye comes out but for the moment the cat is comfortable and the pressure lowish (presumably because of the interaction between the glaucoma raising it and the inflammation lowering it) so we’ll leave surgery for the time being![/tab][end_tabset] 

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A Clinical Case from the Archives : 30/01/2006

Posted on January 30, 2006 by davidwilliams

[tab name=”The Case”]This six year old Jack Russell terrier is presented you because he seemed to have an uncomfortable eye over the weekend but appears to have recovered now. What can you see and what might his problem be? What might you see in his other eye?[/tab][tab name=”David’s view”]There is a central area of corneal oedema in that image and, given his breed, the likelyhood is that he had an anterior lens luxation which caused endothelial cell dysfunction with subsequent corneal oedema, before the lens fell back through the pupil. There was indeed a ‘wobbling’ appearance to the pupil which we term iridodonesis (because ‘a wobbling appearance’ deosn’t sound very scientific does it?!) and this is caused because the iris isn’t supported by the posteriorly luxated lens any more. Here is the other eye – a tricky sign to spot here but can you see a whisp of vitreous poking through the pupil on the right hand side? This lens is subluxated as well and both really need to be removed.[/tab][end_tabset] 

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A Clinical Case from the Archives : 17/01/2006

Posted on January 17, 2006 by davidwilliams

[tab name=”The Case”]Thsi ten year old labrador has gone gradually blind and shows no ocular signs apart from possible changes in the optic nerve as here. She is polydipsic and polyphagic and has abnormally high cortisol levels after an ACTH stimulation test but a normal reduction after a low dose dexamthasone test. What might the cause of the blindness be and is it reflected in the appearance of the optic nerve?[/tab][tab name=”David’s view”]Here is an MRI picture with gadolinium enchancement showing a pituitary chromophobe macroadenoma with surrounding oedema (the big white circle in the centre of the image for those of you as clueless about radiology as I am!) which is causing pituitary-dependent hyperadrenocorticism and pushing down on the optic chiasm too resulting in the blindness. Radiotherapy gave back some vision for 6 months but eventually blindness returned. The big question is whether the optic nerve is showing any swelling – papilloedema. You could convince yourself that it is, knowing the results of the MRI but I’m not so sure – what do you think?[/tab][end_tabset] 

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A Clinical Case from the Archives : 17/01/2006

Posted on January 17, 2006 by davidwilliams

[tab name=”The Case”]What is happening in this twelve year old Boxer dog? What should be done to correct the problem?[/tab][tab name=”David’s view”]There is a chronic non-healing vascularising corneal ulcer caused by a small lid mass abrading the cornea – here’s another case where a paracentral ulcer is associated with a small benign lid tumour, probably an adenoma. Removal of the mass with a wedge resection together with debridement of the ulcer edge and protection of the corneal surface with a contact lens or third eyelid flap should solve the problem.[/tab][end_tabset] 

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A Clinical Case from the Archives : 14/01/2006

Posted on January 14, 2006 by davidwilliams

[tab name=”The Case”]What is happening in this chinchilla eye? What might be the consequences?[/tab][tab name=”David’s view”]This is a lens luxation, although you might well mistake it for an Encephalitozoan cuniculi uveitis as seen in this rabbit. I don’t think chnichillas get E cuniculi though if I’m wrong please let me know! A lens luxation could result in glaucoma but this one has fallen posteriorly and needs no treatment other than phototherapy, the results of which are presented as the first image here![/tab][end_tabset] 

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A Clinical Case from the Archives : 14/01/2006

Posted on January 14, 2006 by davidwilliams

[tab name=”The Case”]This twelve year old Cocker spaniel is presented to you with an eye that is irritating her. What sign in this image confirms this and what might be the cause?[/tab][tab name=”David’s view”]The protrusion of the third eyelid suggests that there is some globe retraction asociated with the discomfort. The eyelid tumour – an adenoma – doesn’t seen to be causing any irritation until you evert the lid as here, and see that it does have a much larger mass rubbing on the cornea than might be evidence initially. The moral of the story is that such masses should be removed when small, not causing any problems and are easily removed with a simple wedge resection.[/tab][end_tabset] 

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A Clinical Case from the Archives : 16/12/2005

Posted on December 16, 2005 by davidwilliams

[tab name=”The Case”]This cat is a fascinating (to me at least!) telediagnosis from Lucy Wheeler – thanks to her for a great image! This is a four year old cat with sudden blindness, dilated pupils and this orange mass in the anterior chamber of each eye. What is going on and what work-up would you do?[/tab][tab name=”David’s view”]Well we haven’t exhausted our work-up yet, but the cat is somewhat pyrexic and definitely hypertensive (200 mmHg). My feeling is that the cat has a hypertensive retinopathy that is making it blind, although we can’t see the retina through that brownish deposit in the anterior chamber. I guess this is a fibrinoid deposit arising from plasma protein exuded through iris vessels because of the hypertension. If it were associated with uveitis there would be a miosis not mydriasis wouldn’t there? I’ve suggested treatmemnt with oral amlodipine to resolve the hypertension, but maybe we should use intracameral tissue plasminogen activator to get rid of this fibrinoid mass.[/tab][end_tabset] 

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A Clinical Case from the Archives : 13/12/2005

Posted on December 13, 2005 by davidwilliams

[tab name=”The Case”]Juliet Bazior-langhan has asked for a quick telediagnosis on this duck, presenting with a purulent conjunctivitis. What differenbtials might you suggest?[/tab][tab name=”David’s view”]The lesion is unilateral and there are no concurrent respiratory signs so I’m not worried about avian flu. But should I be? I’ve suggested taking a bacteriology sample and cytology swab for fungal hyphae and cryptosporidium too. Abrahams and colleagues have written a useful guide to the numerous differentials in Conjunctivitis in birds.
Vet Clin North Am Exot Anim Pract 2002 5:287-309. I’ll let you know what happens with the duck![/tab][end_tabset] 

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A Clinical Case from the Archives : 04/12/2005

Posted on December 4, 2005 by davidwilliams

[tab name=”The Case”]This puppy was given milk replacer for three weeks in the first two months of its life because of illness in the dam. Does that explain this ocular pathology?[/tab][tab name=”David’s view”]The simple answer is ‘yes’! There is a ring of opacified lens which has been laid down while the animal was fed its milk replacer. Its not quite clear what the pathogenesis of the cataract is, but it is likely to be an osmotic effect on developing lens fibres. Nutritional cataacts in timber wolves were attributed to an arginine deficincy and recently Ranz and colleagues reported two litters of puppies with just these ‘ring-like’ opacities (J Nutr 132:1688S-1689S)although they too attributed changes to deficiencies in specific amino acids in the milk. Previous studies have included that of Glaze and Blanchard reporting cataracts in a Samoyed litter (JAAHA 19:951-954) while Martin and Chambreau showed the changes in experimentally orphamed puppies (JAAHA 18:115-119).
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A Clinical Case from the Archives : 27/11/2005

Posted on November 27, 2005 by davidwilliams

[tab name=”The Case”]Here is a good example of a delightful young lady (well some are young, others may be verging on the senile!)we see from time to time in ophthalmology. She has a twin sister who we see more regularly – but she’s not an identical twin. Who are these two females?![/tab][tab name=”David’s view”]Well pardon the rather lame joke, but that was Polly Coria (i.e. many pupils as there is iris atrophy giving holes which appear as additional pupils – note there is also cataract here). Here sister is of course Ann Iso Coria (i.e. differently sized pupils), pictured here in a cat with Horner’s syndrome giving a constricted pupil, enophthalmos with third eyelid protrusion and upper eyelid ptosis as well.[/tab][end_tabset] 

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