In this chapter we briefly describe the problems of acute diseases and injuries of the eyes at sea. We do not go into details of anatomy or general clinical problems of the eyes, but offer simple methods for diagnosis and acute assistance.
Because treatment of eye conditions is difficult for the non-ophthalmologist, there is a fine line between local assistance and urgent transfer to specialized centres. Approximately 10 per cent of all eye injuries happen during work. Most of them can be prevented by appropriate measures, protection glasses, etc.
Distance from care can cause special problems in the maritime industry as many serious eye injuries and acute diseases require urgent specialist appraisal and treatment. This means that the prevention of eye injury is a high priority at sea and that radiomedical advice should be obtained urgently for both injuries and rapidly developing symptoms such as eye pain or loss of vision.
Injuries of the Outer Eye, the Deeper Eye and the Orbita
In general, the eye is well protected by its position deep in a bony cavity, as well as by the eye lids. A blunt trauma, which might frequently happen on board, may lead to haematoma of the eye lids which is easily visible. Only in severe cases a compression bandage for 1 – 2 days is indicated. Broken bones in the vicinity of the eye require medical assistance as soon as possible!
Injuries to the eyes may cause blood to appear in the anterior chamber of the eye (hyphaema), visible as a red segment below the pupil. This condition requires the attention of an ophthalmologist. This also is true for damage to the iris or lens without perforating injury because shockwaves might damage the retina in the posterior part of the eye.
Defects in the cornea
A direct trauma to the eye may lead to superficial defects of the corneal epithelium (the most external layer of corneal cells). This condition should be treated with a light compression bandage for at least 24 hours. If pain continues, ointment or drops contained in the medical chest should be applied.
Penetrating injury to the cornea
A penetration of the cornea can be diagnosed by means of a good pocket lamp by looking for irregularity of the pupil (not perfectly round) or dislocation of the iris (prolapse) as shown in Fig. 1. If the injury has caused damage to the lens, the lens will quite rapidly turn opaque (grey, non transparent). This can be observed by looking directly into the eye. Fig. 2.
All penetrating injuries require the attention of an ophthalmologist
Fig. 24.1 Prolapse of the iris
Fig. 24.2 Cataract
Sometime, e.g. working with a drill, foreign bodies might enter underneath the lids, or onto the cornea, sometimes causing pain. The foreign body can be located by turning the lids. This is done by pulling them off the eye at the eye lashes. Once located, the foreign body can be removed by the use of e.g. a cotton swab (Q-tip). If the foreign body is located on the conjunctiva (outside the cornea), ointment or drops and a compression bandage for 24 hours are helpful. In the rare cases where foreign bodies are stuck within the cornea anaesthesizing drops are helpful, even a cornea scraper. Superficial corneal defects – or defects after removal of foreign bodies – can be localized by use of fluorescine drops, resulting in green colour of the corneal defect.
Sometimes without an external injury eyes may get “red”, which means an abnormal filling of the superficial conjunctival or deeper scleral vessels. This may be caused by an internal inflammation due to germs or viruses from inflight to general circulation. The local type of such an inflammation is called “iridocyclitis” with in the beginning can be treated by drops, containing antibiotics as well as corticosteroids. Only if this condition improves after 1 or 2 days without remaining pains or visual problems, rapid referral to an ophthalmologist is not too urgent. On the other hand corticosteroids may cause superficial corneal defects (fluorescein-test!) or even rise of intraocular pressure which could lead to glaucoma.
Manifestations of Eye Diseases
Glaucomas are caused by an increase in the intraocular pressure.
The most common form is the chronic glaucoma which occurs even in younger people. The condition is often not recognised by the patient himself before damage to the nerve tissue, or visual defects have already occurred. The increased intraocular pressure cannot be measured on board. In severe cases the eye feels harder than a normal eye when pressure is applied to the eye with a finger tip. The condition is initially treated with special eye drops, but may later require surgery.
The acute glaucoma develops very rapidly and may within a few hours lead to serious pain and deterioration of the vision. In these cases the eye feels hard like a stone. The cause is generally a too short eye, a so called “hyperopia”. This may lead to a sudden closure of the chamber angle, caused by dilatation of the pupil, e.g. in darkness with consequent rapid increase in the intraocular pressure. Because this condition may lead to blindness within 1-2 days, a rapid transfer to specialist attention is mandatory . Meanwhile, the patient may need strong painkillers (morhpin). If available, he should also receive pilocarpine eyedrops to reduce the intraoccular pressure. The eye should not be covered.
Cataract, a cloudy lens, is generally a disease of old age and very rarely occurs quickly.
Diseases of the Retina and adjacent Tissues
Diseases of the retina and the adjacent tissues occur mostly at high age. In some cases a circulation failure may cause bleedings that disturb the vision. These conditions require quick medical assistance.
In people with normal, healthy eyes, retinal detachment causing defects in the field of vision rarely happens. However, when they occur, rapid medevac to specialist attention is required .
In most cases eye problems can be diagnosed on board. Superficial injuries and mild diseases may be treated on board, whereas deep injuries and serious diseases need immediate medical assistance.