Marginal keratitis and Salzmann's corneal degeneration

CASE 1 - ROSACEA
A white, female patient, aged 42, rang on a Monday morning to say she had had a sleepless night experiencing a profusely watery, red and photophobic eye and a foreign-body sensation in the left eye.
The patient is normally a daily disposable contact lens wearer, but she had not worn her lenses for three days so the irritation was apparently unrelated to contact lens wear.

Signs
VA was 6/6 each eye
Right cornea, conjunctiva and eyelids appeared normal
Left cornea had a 2mm sub-epithelial corneal lesion in the periphery at six o'clock (Figure 1)
Surrounding the ulcer there were few infiltrates
Inferior conjunctiva was hyperaemic
There was a fair amount of tearing.

Diagnosis
The pain was mild, consequently Acanthamoeba keratitis was ruled out. The surrounding infiltrates could have been due to viral infection. Asking the patient further regarding skin-flushing, she revealed she had been experiencing spots on the skin recently.
From this, we suspected that she had marginal keratitis following rosacea. The patient was referred to an eye specialist who confirmed sterile keratitis due to acne rosacea and he immediately started her on prednisolone 0.5 per cent qds eyedrops.
The patient reported a marked improvement in her redness and discomfort of the eyes within five days. Eventually, she was discharged with a proviso that, should the eyes flare up again she should consult the specialist immediately and at that stage she would also consult a dermatologist.

CASE 2 - BLEPHARITIS
A male patient, aged 50 and not a contact lens wearer, came in for a routine eye examination having experienced a red, watery and sticky eye for the past week. His general health was fine and there was no previous history of an eye infection.

Signs
Multiple grey, white corneal lesions approximately 1mm in diameter (Figure 2)
Lesions were located in the subepithelial to superior stromal region
Lesions were arranged in a crescent around the limbal margins
The conjunctiva was grade 2-3 hyperaemic and the papillary conjunctiva was inflamed
The eyelashes were matted and there were signs of eyelash loss (Figure 3).

Diagnosis
The lesions showed very similar appearance to adult inclusion conjunctivitis, but this was thought unlikely on the basis of age.
A diagnosis of acute blepharitic bacterial conjunctivitis together with marginal keratitis was made and the patient was referred to an eye specialist. The eye specialist confirmed the findings and started him on chloramphenicol eyedrops as well as prednisolone 0.5 per cent eyedrops. This was continued for three weeks, with the prednisolone slowly being tapered from four times a day down to three times, twice and finally once a day.

Discussion
Marginal keratitis is commonly associated with staphylococcal blepharitis and facial rosacea. Middle-aged people are more commonly affected compared to children. The self-limiting lesion is non-infectious and it is thought to be due to hypersensitivity reaction to staphylococcal exotoxins.
Our male patient experienced a severe episode of blepharitis, together with an inflammatory reaction to the staphylococcal antigen. The 10 o'clock and two o'clock positions were probably affected by the subepithelial infiltrates and this then spread in a crescent form to involve the temporal cornea.
Our female patient showed a typical inferior paralimbal, superficial stromal corneal lesion with 1-2mm of clear area of uninvolved cornea between the lesion and the limbus (called the interval of Vogt). The inferior conjunctiva was injected and inflamed, as is usually the case. Both patients experienced discomfort rather than pain and both eyes had an intact epithelium.
The peripheral location of the lesion in both of these patients points to inflammatory reaction to gram-positive or gram-negative bacteria, rather than an infection which would be more centrally located (Figure 4) and more painful. A simple way to remember the signs and symptoms of an infection is by 'PEDAL' mnemonic:

Pain
Epithelial defect
Discharge
Anterior chamber reaction - cells or flare
Location - central/paracentral position.

FACIAL ROSACEA
Rosacea is a common dermatological condition that affects the mid-facial regions (cheeks, chin, nose and central forehead). The onset typically begins after the age of 30 and it affects mainly fair-skinned people of Celtic or Scandinavian origin. In addition, it affects both men and women equally and its UK prevalence ranges from 5 per cent to 10 per cent. Trigger factors for rosacea include hot environments, spicy food, alcohol, stress/anxiety, chemical irritants (perfumes or shampoo) and vasoactive medications. The primary features are patients complaining of blushing cheeks and the appearance of dome-shaped red papules concentrated on the nose, cheeks and forehead. One of the secondary signs is the typical rhinophyma (wrongly associated with alcoholism).

OCULAR ROSACEA
Sixty per cent of patients with rosacea develop secondary problems confined to the ocular surface and eyelids. In 20 per cent of cases, the initial assault targets the skin around the eyes, leading to red, itching or burning eyelids. The ocular manifestations of rosacea can be summarised as follows:

Eyelid inflammation
Burning or itching
Gland obstruction leading to styes or chalazia
Watery eyes
Photophobia
Conjunctival hyperaemia
Foreign-body sensation
Marginal keratitis
Neovascularisation.

Treatment
Advise patients to avoid alcohol, hot spicy food, hot tea or coffee, jacuzzis and saunas. Short, tepid baths should be preferable to prolonged hot showers. Zinc oxide face coating or face masks would help those working in cold storage facilities. Advice on sun protection may help some patients.
Ocular symptoms can be managed by an ophthalmologist using topical steroids for acute flare-ups and symptomatic relief or, alternatively, lid hygiene could be recommended. Artificial tears may also help in relieving the foreign-body sensation.
Systemic drug therapy is especially effective. Oral tetracylines provide relief for moderate to severe disease. Doxycycline 100 to 200mg initially, then tapering over one to two months before discontinuing helps recovery. Alternatively, tetracyclines 250mg, metronidazole 1,000mg and minocycline (Minocin) 50-250mg can be used.
Topical therapy may commence simultaneously with oral therapy. Metronidazole is the most popular topical agent used and is available in 1 per cent cream (Noritate) or 0.75 per cent Metrocrem, Metrogel or Metrolotion. Patients should apply the preparation five minutes after gently cleansing the skin.

CASE 3 - SALZMANN'S
Degeneration
A white female (a soft, two-weekly contact lens wearer) presented with blurred vision in the right eye and a history of recurrent infection. She was seen by an eye clinic three weeks previously for conjunctivitis and prescribed chloramphenicol and a week later given the go-ahead for contact lens wear. Previous history involved the patient being seen by an eye specialist for corneal infection but she was not stopped from wearing contact lenses. The spectacle prescription was: R -7.00DS VA 6/12 and N8; L -7.50DS VA 6/6 and N5.

Signs
Corneal nodules about 1mm from the limbus in both eyes (Figure 5. Light coloured eyes make it very difficult to photograph the raised nodules)
In the right eye, central corneal oedema 
Right eye circumferential corneal pannus and vascularisation 
Left cornea had top and bottom corneal pannus with white, raised corneal nodules
Conjunctival hyperaemia
Conjunctival papillary changes under eyelids.

Diagnosis
The patient was referred to an eye specialist for a possible chlamydial conjunctivitis or Salzmann's corneal degeneration. Contact lens wear was immediately ceased.

Treatment
The specialist diagnosed Salzmann's corneal degeneration and immediately started the patient on Maxidex eyedrops due to the central corneal involvement in the right eye. Within a month the conjunctival hyperaemia had disappeared, the central cornea was clear and the visual acuity was back to 6/6 in the right eye. The corneal scarring still remained and the patient was told not to wear any contact lenses (not even gas permeables).

NODULAR DEGENERATION
Salzmann's nodular degeneration usually follows a previous episode of ocular inflammation, often in childhood. It is associated with previous history of contact lens wear, corneal epithelial dystrophy or corneal surgery. It is also associated with disorders such as interstitial keratitis, vernal keratoconjunctivitis and trachoma.
Patients are usually asymptomatic except when there is a decrease in visual acuity or photophobia and watering of the eyes following recurrent corneal erosion. In our patient's case, she had an episode of recurrent corneal erosion which led to the oedema encroaching on to her visual axis.
Clinically, Salzmann's degeneration appear as an accumulation of elevated, multiple, bluish-white superficial nodules in the corneal mid-periphery. The eye is generally not inflamed except when there is corneal erosion. Some reports claim this condition is seen more frequently in females than in males, and is often bilateral.

Treatment
Observe
Discontinue contact lens wear
Topical lubricants for gritty sensation, especially in the early stages between bouts of recurrent corneal erosions. The lubricants will also provide a smooth corneal surface, allowing for even tear distribution and preventing exposure. It is thought that exposure leads to hyalisation (the same process responsible for conjunctival pingueculae development)
In severe cases, superficial keratectomy to remove nodules from the superficial cornea
Excimer phototherapeutic keratectomy can be successful
Topical steroids should be avoided apart from in cases where the central vision is affected. The use of steroids introduces an unnecessary risk in an already compromised epithelium.

Kirit Patel is an optometrist practising in Radlett, Hertfordshire