9.1.1 Observations and symptoms

9.1.2 General medical history and family history

The medical history in a patient with a red eye may be important in the differential diagnosis. For example, a history of a recent upper respiratory tract infection and contact with another person with a red eye could be suggestive of viral origin to the red eye, the history of a urogenital infection could be suggestive of Chlamydia, a history of cold sores is suggestive of herpes simplex virus conjunctivitis and a history of allergy with intensive itching is suggestive of allergic conjunctivitis.³

A history of hypertension, cardiovascular disease, cerebrovascular disease, obesity, physical inactivity, heavy alcohol intake, smoking, diabetes mellitus and hyperlipidaemia are important when considering if blood pressure measurement is indicated. When there is a positive family history the risk of developing hypertension is increased two to four times.⁴ The patient’s medical history should also include the current medical care for systemic conditions, frequency of monitoring for the conditions, previous and planned investigations for the conditions, medications prescribed and compliance with medication use. For example, if a patient has been diagnosed as hypertensive, is taking medication regularly and having their blood pressure regularly monitored, then there would be little need for optometric testing. If, however, the patient was previously diagnosed with hypertension, stopped taking their medication 6 months ago due to an adverse reaction and has not seen their physician to follow up, it would be prudent to take a blood pressure reading and advise the patient accordingly even in the absence of abnormalities on the ocular fundus examination.

When considering if carotid artery assessment is indicated, a history of hypertension, hyperlipidaemia, diabetes mellitus, coronary artery disease and smoking can be significant. If a patient has had one or more episodes of amaurosis fugax, it is important to determine if he has already sought medical care and if and what investigations have already been done or are being planned. It is not uncommon to determine that the patient has already seen his physician and that a carotid ultrasound or other investigations are being arranged. The patient is then presenting to determine if any additional information can be gained through a dilated fundus examination.

9.1.3 Slit-lamp biomicroscopy assessment

Various aspects of slit-lamp assessment can also help in differential diagnosis of a red eye, including the pattern of conjunctival injection (e.g., circumlimbal injection suggests anterior uveitis, segmental injection suggests episcleritis), flare and cells in the anterior chamber (present in anterior uveitis), the presence and quality of any discharge (e.g., watery suggests allergic conjunctivitis, mucopurulent suggests bacterial conjunctivitis). Other features to investigate are conjuctival chemosis (e.g., allergic conjunctivitis), palpebral conjunctival papillae or follicles (papillae suggest bacterial or allergic and follicles suggest viral conjunctivitis), lid swelling (e.g., allergic conjunctivitis and epidemic keratoconjunctivitis) and corneal abnormalities (e.g., corneal ulcers). The intraocular pressure is helpful in suspected cases of angle closure glaucoma and anterior uveitis when it would be elevated or decreased, respectively.

9.1.4 Fundus examination

Ocular fundus features suggesting hypertension and the possible need for sphygmomanometry are discussed in section 9.3 and Table 9.1. Ocular risk factors for significant carotid artery stenosis include emboli (Hollenhorst plaques), retinal vascular occlusions, peripheral retinal haemorrhages with dilated and tortuous veins (hypoperfusion retinopathy), microrubeosis iridis, ocular ischaemic syndrome, anterior ischaemic optic neuropathy, normal tension glaucoma and asymmetric diabetic retinopathy which is less advanced ipsilateral to the stenosis.^5,6

9.2.1 The lymph nodes in the head and neck

The lymph nodes are situated along the course of the lymphatic vessels. They are bean-shaped organs containing large numbers of leukocytes and phagocytes which filter out infectious and toxic material and destroy it. When infection occurs the nodes become enlarged and often painful and inflamed because of the production of anti-inflammatory lymphocytes and plasma cells.⁷

The lymphatic system of the head and neck is important in infections of the eye (Figure 9.1), particularly the preauricular lymph nodes which receive lymph from the upper eyelid, the outer half of the lower eyelid and the lateral canthus. They are located 1 cm anterior and slightly inferior to the tragus of the external ear at the temporomandibular joint. The submandibular lymph nodes lie in close proximity to the submandibular gland and drain lymph from the medial portion of the upper and lower eyelids, the medial canthus and the conjunctiva. They also drain lymph from the submental nodes that are located under the tip of the chin. The mental nodes also drain anterior aspects of teeth, tongue and lower lip so if an oral infection is present then they may be enlarged and this should not be mistaken for a sign of an ocular infection. The superior cervical nodes are located inferior to the ear and superficial to the sternocleidomastoid muscle. They receive lymph from the occipital nodes as well as the preauricular and post auricular nodes.⁷ The skin and orbicularis oculi muscles drain into the deep cervical nodes near the internal jugular vein (Figure 9.1).

9.2.2 Comparison of tests

Assessment of the lymphatic system by palpating the nodes is a quick and easy way of gaining information to aid in the differential diagnosis of a red eye. There are no alternative tests and there are no complications or contraindications to performing this technique other than being gentle with patients who have node tenderness.

9.2.3 Procedure for palpating the preauricular lymph nodes

See online video 9.1.

9.2.4 Procedure for palpating the cervical, submandibular and submental lymph nodes

See online video 9.2.

9.2.5 Recording

Record if the nodes are palpable (positive, +ve) or not (negative, –ve). The preauricular node is commonly abbreviated as PAN. If swollen nodes (lymphadenopathy) are found, describe their laterality (right, left or bilateral), size (big or small) and mobility (mobile or non-mobile) and indicate whether warmth and tenderness are present.

Examples:

9.2.6 Interpretation

In the absence of disease there should be no palpable lymph nodes. Palpable lymph nodes (lymphadenopathy) are seen in the following conditions:

The presence of preauricular lymphadenopathy will therefore help rule in one of the above conditions when it is present although if it is not present the condition cannot be reliably ruled out.⁸