The Woes of Bug-eyed Bubsy

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Dr Katrin Voelter, our visiting specialist ophthalmologist, works on a patient presenting with a common eye issue that most owners, and even some vets, will miss! Join us in uncovering the issues behind Bubsy's eyes together - we hope we can help everyone recognise the early signs of the disease and understand it better.

PRESENTATION

Bubsy is a 8 year old male neutered Pug that presented to our emergency department for neurological symptoms. On physical examination, our emergency veterinarians noted changes in both eyes, unrelated to the neurological symptoms. Our visiting ophthalmologist, Dr Katrin Voelter, was asked to assess and assist in the case.

Have a look at Bubsy’s eyes below – can you describe the changes you see in his eyes? Think about your assessment of his eyes and see if your diagnosis matches with Dr Katrin’s!

ASSESSMENT AND OTHER EXAMPLES

Click on the spoiler tab below to show Dr Katrin’s assessment:

Click here to see Dr Katrin’s assessment and diagnosis!

Left eye:

  • Mildly hyperemic conjunctiva
  • Moderate to severe generalised corneal oedema
  • Moderate nasal subepithelial neovascularisation
  • Severe nasal 1/3 corneal epithelial pigmentation

Right eye

  • Mildly hyperemic conjunctiva
  • Cornea with central mucous plaque – rough, dry, uneven surface (with severe fluorescein stippling on test)
  • Diffuse oedema and neovascularisation
  • Diffuse severe pigmentation

Diagnosis

  • Left eye: Moderate pigmentary keratitis
  • Right eye: Severe end-stage pigmentary keratitis.

In this case, Bubsy has pigmentary keratitis in both eyes, which can have devastating effects such as permanent blindness if it is not picked up early enough.

Let’s look at a few other examples, not too dissimilar to what Bubsy has.

Example 1

This is a patient with mild pigmentary keratitis – note the amount of corneal oedema around the area of pigmentation.

Example 2

This patient has moderate pigmentary keratitis – as treatment has already commenced for this patient, we can see that this eye has no neovascularisation and little corneal oedema.

Example 3

This patient has severe pigmentary keratitis and generalised corneal oedema.

A PUGGY PROBLEM

We commonly find corneal pigmentation with associated inflammation of the nasal cornea and conjunctiva in pugs and brachycephalic dogs. Next to possible heritable factors, pigmentary keratitis is associated with:

  • A large palpebral fissure (wide eyelids) which often lead to tear film instability
  • The presence of inwardly folded lid margins (entropion) that leads to corneal irritation by rubbing hair
  • Nasal fold hair can additionally increase irritation
  • A decreased corneal sensitivity in brachycephalic dogs

PROGRESSION AND TREATMENT

Unfortunately, mild symptoms are often not noticed at early stages. If left untreated, animals can become blind over time as the pigmentation will often progress.

LEARNING POINT

Once the cornea is completely pigmented, it is irreversible and cannot be surgically removed – the patient is permanently blind.

To limit the progression of pigmentation and inflammation, anti-inflammatory drugs and tear substitutes are employed as long-term treatment. Life-long treatment is generally indicated.

In severe or rapidly progressive cases, on top of topical drug application, a surgical correction is recommended to reduce the lid length and correct entropion at the same time. This often leads to better protection of the cornea and helps reduce the progression of pigmentation.

As the disease is multifactorial and often progressive, it is recommended for the patient’s eyes to be examined thoroughly by an ophthalmologist to discuss tailored treatment options for the individual patient. Regular rechecks and monitoring by general practitioners or specialists are needed in most cases.

Surgical removal of the corneal pigmentation through freezing of the corneal surface has been attempted, but an increase in corneal scarring and recurrence of pigmentation unfortunately limit the success of surgery. This makes early recognition and adequate treatment protocols all the more important, as the disease process cannot be reversed by surgery.

OUTCOME FOR BUBSY

Unfortunately for Bubsy, his right cornea has been completely pigmented and he is thus irreversibly blind in that eye. However, that does not mean treatment stops for him. Bubsy will continue to be treated life-long in both eyes with topical immunosuppressive eye drops, which increase tear production, tear quality, and decrease inflammation. He will also need artificial tears to make life more comfortable.

We hope this Case Chronicle was able to show you how we can identify corneal pigmentation and early signs of pigmentary keratitis, and the importance of early recognition and tailored treatment processes.

If you have any questions or an ophthalmology case where you need some referral advice, the VES ophthalmology team is always ready to help – please contact VES Hospital and we will be more than happy to help out!

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