Congress on Demand 2021: Ophthalmology

Any opacity of the lens or its capsule is known as a cataract, and they have many different causes. Cataracts are much more common in dogs than cats, it is important to recognise them In oredrand understand what to do next. A good ophthalmic examination will help you differentiate cataracts from nuclear sclerosis. It will also allow you to assess for any other pathology in the eye and decide if it is related to the cataract. Cataracts can be removed surgically, by phacoemulsification, but not all cataracts or indeed eyes are suitable for this to be performed. Many cases will require medical treatment to control the uveitis associated with cataract development, but it is important to note that there is no medical treatment that removes the cataracts themselves. Careful and thorough patient assessment is required, with tonometry, gonioscopy, ultrasound and electroretinography all essential in the work-up prior to considering surgery. Many cataracts are small and non-progressive, never requiring medical or surgical intervention. Others may progress and lead to vision loss, with some maturing very quickly, resulting in uveitis (Phacolytic) or even lens rupture due to intumescence (Phacoclastic). Knowing how to distinguish between these types of opacities is key to being able to give a prognosis for the affected eyes and patients.

What the heck am I dealing with? Part 1: Emergencies can be pretty daunting! Most patients with an ocular emergency present with an uncomfortable (closed) eye, often red and cloudy, and the first challenge is working out what you’re dealing with. This short presentation considers some common ocular emergencies, including deep stromal ulcers, lens luxation and proptosis.

What the heck am I dealing with? Part 2: More common ocular emergencies, including glaucoma, corneal foreign bodies and sudden blindness. A recording of a live discussion follows.

SCCEDs, endothelial degeneration: Superficial corneal ulcers that fail to heal in the expected time are a common problem. Identifying the cause, however, can be a challenge. This presentation looks at examples of two conditions: spontaneous chronic corneal epithelial defects (SCCEDs) and corneal endothelial failure.

Feline indolent ulcers: Superficial non-healing ulcers are not as common a problem in the cat as they are in the dog. However, when they do occur, they can be a real challenge to treat. Getting these ulcers to heal is difficult and the key is to understand the cause and treat that too. Interventions such as keratotomies (grid, punctate, diamond burr and phenol) cannot be used in the cat, as they predispose to the development of corneal sequestra. Brachycephalic cats are at particular risk due to corneal exposure; this, combined with poor corneal sensitivity and evaporative tear film loss, is the perfect recipe for poor healing. The other main consideration is the role of Feline Herpes Virus (FHV) in these cases. Once the diagnosis of ‘indolent ulcer’ is established then debridement of the loose epithelial edges is recommended, this can be combined with the use of a contact lens. Topical prophylactic antibiotics and tear replacement should be given and in cases where FHV is involved, topical or systemic antivirals should also be used. The debridement can be repeated several times but if the ulcer sill fails to heal then a superficial keratectomy is recommended. These cases are at risk of developing a corneal sequestrum in the ulcer bed, and if this does occur will definitely need a keratectomy to bring about healing.