Eye conditions part 2
By Dr Nigel Stollery
By Dr Nigel Stollery
Corneal ulcers are usually unilateral and, depending on their location, may affect visual acuity. Ulcers can be caused by a number of different conditions, including herpes simplex, herpes zoster, marginal keratitis and bacterial infection. Those caused by keratitis or bacterial infection may be painful.
Diagnosis can be confirmed by instilling fluorescein drops, which collect in the ulcer and reveal its shape and position.
Treatment depends on the cause, but should not be delayed as corneal scarring may occur, with a resultant decrease in visual acuity that may require corneal grafting.
In most cases, a haematoma around the eye is a bruise of the bony orbital rim caused by blunt trauma. The laxity of the tissue surrounding the orbit means that sometimes these bruises can be quite dramatic, although damage to the eye is uncommon.
Rarely, blunt trauma can lead to bleeding behind the eye itself and the formation of an orbital haematoma.
As the haematoma increases in size the eye can be pushed forward, leading to visual disturbance and damage to the optic nerve.
Subconjunctival haemorrhages are common and usually caused by the rupture of a conjunctival blood vessel secondary to straining or coughing.
In the majority of cases the haemorrhage will resolve over a couple of weeks and no treatment is necessary.
However, there are two red flags that may indicate a more serious condition:
• If the haemorrhage is associated with a conjunctival defect, which can be detected by fluorescein staining, a penetration injury may be indicated. Penetration injuries should be considered in children who have been using pencils or adults who have been using grinding or cutting tools without wearing protective goggles.
• If the back border of the haemorrhage cannot be seen, the bleeding may be coming from the orbit or an orbital fracture and the optic nerve may be at risk.
Small polyps can arise from the conjunctival surface of the eye. These do not tend to cause any problems and treatment is not usually required.
However, occasionally the polyp will enlarge significantly and prolapse over the tarsal plate. When this occurs, the polyp may interfere with the function of the lower eyelid and become sore and infected.
Polyps can be removed easily under local anaesthesia by snipping or curetting the base. Suturing is not required, although prophylactic topical antibiotic eyedrops should be considered.
In cases of ectropion the lower eyelid droops away from the conjunctival surface. It is most common in old age, when the skin becomes lax, although it may also occur after the paralysis of facial muscles in conditions such as Bell's palsy or leprosy.
The lower eyelid normally acts as a ‘windscreen wiper' against the eyeball, sweeping the tears towards the tear duct. However, in ectropion this function is impaired and patients complain of tears continually running down their cheeks. The exposed conjunctiva may also become inflamed and dry.
In many cases no treatment is necessary. However, if treatment is required surgical wedge excision with removal of the redundant skin is the therapy of choice.
Naevus of Ota
A naevus of Ota is an area of bluish hyperpigmentation on one side of the face affecting the region supplied by the ophthalmic and maxillary divisions of the trigeminal nerve. The sclera is often affected, as in the case shown in the picture. No treatment is required.
Naevus of Ito is a similar condition, which affects the areas supplied by the posterior supraclavicular and lateral brachial cutaneous nerves.Corneal ulcer Haematoma Subconjunctival haemorrhage Conjunctival polyp Ectropion Naevus of Ota Author
Dr Nigel Stollery
MB BS DPD
GP, Kibworth, Leicestershire and clinical assistant in dermatology, Leicester Royal Infirmary