Page 32 - VETcpd - Vol 6 - Issue 1

IntroductionA general physical examination must not be taken for granted. For every patient seen, ideally a thorough ‘nose to tail’ systematic physical examination should be carried out. It is often tempting, especially within the time constraints of a first opinion consultation, to focus your attention solely on the problem reported. However, by always performing a complete physical and ophthalmic examination using the same ordered steps, even under pressure, it is less likely that a clinical abnormality will be missed.

In human medicine, diagnostic errors are associated with a proportionally higher morbidity than other types of medical error (Brennan et al. 1991; Wilson et al. 1995; Thomas et al. 2000). It is known that standardisation of procedures reinforces pattern recognition and is one of the most effective ways to prevent errors (Leape 1997). This article aims to provide a systematic approach to the ocular examination. Repeated use of this examination structure will not only increase clinical recognition of normal versus abnormal ocular changes but also the clinician’s examination efficiency. The latter being of value in a time constrained consultation.

Author tip: For more challenging cases, it can be helpful to hospitalise a patient for a short time in order to perform a complete ophthalmic examination outside of the time constraints of the first opinion consultation.

What will you need?Although ophthalmologists have access to a wide array of specialist equipment, there is no doubt that a basic ocular

examination can be carried out with minimal equipment (Box 1; Figure 1).

The use of an ocular examination record form (Appendix 1) to accurately document your findings aids recall, helps order the ophthalmic examination, and allows historical comparison at future re-examinations.

Step 1: HistoryA thorough history should not only include questions about the primary ocular complaint but also the animal’s lifestyle and general physical health. As with the clinical examination, the author follows a standard ordered approach to history taking (Box 2). The author appreciates that in first opinion practice many of these questions do not need to be asked as the clinician will already be familiar with the patient and its medical history/lifestyle. The signalment of the patient (age, breed and sex) should also be noted as many ocular conditions are ‘breed related’ or inherited.

Step 2: Distant examinationIt is helpful to observe the patient as it walks into the room. While taking a history, if possible, allow patients to wander freely around the consultation room and watch their behaviour in an unfamiliar environment. Observe:• Patient demeanour• Patient movement • Ocular discomfort (Figure 2;

blepharospasm, increased blink frequency, epiphora)

• Ocular discharge• Vision

Peer Reviewed

Negar Hamzianpour BSc(Hons) BVSc PgCertSAOphthal MRCVSNegar graduated from the University of Liverpool in 2011. She developed an interest in veterinary ophthalmology during a small animal rotating internship at the Royal Veterinary College. Following this, whilst in general practice for several years she completed a certificate in veterinary ophthalmology and gained RCVS Advanced Practitioner status. Negar returned to referral work in 2017, completing an ophthalmology internship at Willows Veterinary Referrals and is currently undertaking an ECVO ophthalmology residency at the Eye Veterinary Clinic, Leominster.

Eye Veterinary Clinic, Leominster, Herefordshire HR6 0PHTel: 01568 616 616E-mail: info@eyevetclinic.co.ukwww.eyevetclinic.co.uk

SuBSCRiBE TO VETCPD JOuRNAl

Call us on 01225 445561 or visit www.vetcpd.co.uk

VETcpd - Ophthalmology

The Ophthalmic Examination in the Dog and CatAs veterinary surgeons our ability to diagnose and therefore treat diseases relies primarily on a structured and thorough physical examination. The beauty of the ocular examination is that the clinician can visualise the internal anatomy and pathology of the eye, something that is not possible for any other organ. By utilising the same systematic examination for every patient, as described in this article, the clinician can differentiate physiologically normal from pathologically abnormal clinical signs. This is the first and most important step in the pathway to making a diagnosis and is essential for effective treatment and monitoring.

Key words: Eye, examination, ophthalmic, diagnostics

Abbreviations: A – Afferent, E – Efferent, IOP – intraocular pressure, KCS – keratoconjunctivitis sicca, STT – Schirmer Tear Test

VETcpd - Vol 6 - Issue 1 - Page 33

Box 1: Basic equipment needed for an ocular examination (Figure 1)

• A room that can be darkened• Examination table

Author tip: It is useful, even for large dogs, to perform the ophthalmic examination at table height if possible.

• A bright focal light source e.g. Finoff transilluminator/otoscope light/torch of a smartphone

• Direct ophthalmoscope• Indirect funduscopic lens

Author tip: A 2.2 panoptic or 30 dioptre lens is a good starting lens for small animals

• Schirmer Tear Test (STT) strips• Fluorescein impregnated paper strips • Sterile cotton buds• Fine non-tooth forceps

e.g. Bennett cilia forceps• Lint free swabs• Saline or sterile eye wash• Proxymetacaine 0.5%• Tropicamide 1%• Tonometer

e.g. Tono-Pen, TonoVet, Schiotz tonometer• A camera or smartphone to take photos

Figure 1: The basic equipment needed for an ophthalmic examination in general practice

Figure 2: Ocular discomfort in the left eye of a cat as manifested by blepharospasm and epiphora. Signs of mild pain are best observed from a distance before manual handling as this may worsen any spastic component of painful conditions

Step 3: General physical examinationThe systemic health of the patient is important as some ocular signs can be a manifestation of systemic disease e.g. uveitis. It is also necessary for the appropriate and safe administration of medications.

Box 2: A standard approach to history taking

LiFestyLe and generaL inFormation• How long has the pet been in the

owner’s possession?• Where they got him/her from?

e.g. rescue, breeder, private seller.• Whether it is a pet or working dog?• Does the pet have any contact with

livestock/ where is it exercised routinely?• Are there any other pets at home?

If yes, are any related to the patient or also affected by the ocular disease?

• What diet is fed, including any dietary allergies?

• Any history of travel abroad?• Preventative health status

– vaccines, flea and worming?

generaL HeaLtH• Any previous surgeries?• Any other systemic problems

e.g. integument/ neurological?• Any vomiting, diarrhoea, coughing

or sneezing?• Normal appetite/drinking?• Normal behaviour and activity levels?

ocuLar HeaLtH• Any history of ocular problems?• What the current concern is?• When the problem started?• How the problem has progressed?• Has the eye appeared abnormal in any way? • Any blepharospasm noted or rubbing

of the eye/s?• Any discharge noted?

If so, what type (colour/consistency)?• Is the dog visual? If not:• Is he/she bumping into things?• Is there a difference with vision in light

and dark conditions?• How long has the visual deficit

been present?• Does he/she sleep with their eyes closed?

(particularly brachycephalic/neurological cases)

treatments• Any previous treatments used and whether

there was an improvement?• What current treatment is the dog receiving

(including supplements)?• Does the dog have any known medical

allergies or previous reactions?

Figure 4: A dog with microphthalmos (abnormally small eye) of the right eye. (Image courtesy of John Mould)

Step 4: Close ‘hands-off’ examination Ideally performed on an examination table. Observe:• Facial and orbital symmetry and/or

conformational changes (Figure 3)• Ocular discomfort (blepharospasm,

increased blink frequency, epiphora)

• Globe position within the orbit (Figure 3)• Third eyelid position and appearance

including colour • Globe size (Figure 4), colour,

specular light reflection (see cornea section below)

• Palpebral length (Figure 5) and position relative to the globe

Figure 3: (A) Exophthalmos and lateral strabismus of the left eye in a dog. Observing for a change in facial/orbital symmetry is best observed from a distance on the table. It is often helpful to compare the ocular position with the other eye. (B) Aerial view of exophthalmos in the same dog. It can be helpful to look over the top of the head to appreciate the forward (exophthalmos) or backward (enophthalmos) displacement of an eye. (Images courtesy of John Mould)

A

B

Figure 5: (A) A dog with a normal palpebral fissure (B) A dog with large palpebral fissures (macroblepharon).

A

B