Ординатура / Офтальмология / Английские материалы / Ophthalmic Drugs Diagnostic and Therapeutic Uses 5th edition_Hopkins, Pearson_2007

Figure 16.9 Contact-lens- induced giant papillary conjunctivitis (reproduced from Kanski 2003, with permission).

Treatment

Contact lens wear might need to be discontinued for up to 2 months in severe cases until the inflammatory tarsal conjunctival changes have resolved. The main plank of the treatment is the removal of the cause and the advent of monthly and daily disposable hydrogel lenses, which accumulate less surface deposits, has significantly reduced the prevalence of this problem. In some cases, it may be necessary to change the lens material, change the lens care system, or to institute more rigorous cleaning of non-disposable lenses.

Relief of symptoms can be obtained by the use of a mast cell stabilizer, such as lodoxamide, initially for four times a day then slowly tapered to less frequent administration. Alternatively, combined antihistamine/mast cell stabilizers such as ketotifen and olopatadine can be prescribed.

In severe cases, short-term use of a topical corticosteroid (four times daily for 2 weeks) might be necessary.

Figure 16.10 Bacterial keratitis (reproduced from Kanski 2003, with permission).

Treatment

Immediate treatment is necessary because this is a sight-threatening condition. Most of the common, commercially available antibiotic drops do not have a sufficiently broad antibiotic spectrum to cope with the organisms normally present. It is possible that more than one organism is present, each with differing susceptibilities. Custom-made mixtures are usually employed along with systemic antibiotics. The fluoroquinolones, ciprofloxacin and ofloxacin can be used as monotherapy. However, whichever drop is used, frequent (i.e. hourly during the waking hours) dosing will be required to maintain sufficiently high levels of agent. A cycloplegic can be used to reduce pain and to prevent the development of posterior synechiae.

Topical steroid therapy is a contentious issue but can be used following at least 1 week’s treatment with antibiotics by which time cultures should be sterile.

In the case of contact lens wearers, no further use can be allowed of the current lenses, the storage case and all opened solutions.

Herpes simplex keratitis

Treatment

Figure 16.11 Large dendritic ulcer stained with fluorescein (reproduced from Kanski 2003, with permission).

chloramphenicol or ciprofloxacin. More severe cases will require a topical steroid such as prednisolone sodium phosphate four times daily for a week then slowly tapered as the condition resolves.

VIRAL KERATITIS

Key features

The eye, like the skin, can be affected by herpes viruses, usually herpes simplex and herpes zoster. Herpes simplex exists in two types: herpes simplex I and herpes simplex II. Type I affects structures above the waist and can produce viral keratitis and cold sores whereas type II is associated with sexually transmitted infections.

Initial infection occurs during childhood, often without producing symptoms. After initial infection, the virus travels along the axon of a sensory nerve to the trigeminal ganglion, where it resides in a dormant state until activated by a trigger such as trauma. In the re-activated state, the virus travels back down the axon to infect the surface structure, leading to keratitis.

The initial superficial punctate or stellate keratitis can be followed, with further loss of surface epithelium due to viral replication, by a branching dendritic ulcer and an amoeboid or geographic ulcer (Fig. 16.11). Symptoms include lacrimation, ocular discomfort and photophobia.

Many different compounds have been used in the past for treatment of dendritic ulcers, but those used principally are topical aciclovir (ointment) and ganciclovir (eye gel). Either one should be applied five times a day for at least a week.

If topical steroids are used to suppress the inflammation, they must be tapered over a period of months to avoid a rebound response.

Herpes zoster ophthalmicus

Figure 16.12 Eyelid involvement in herpes zoster ophthalmicus (reproduced from Kanski 2003, with permission).

Key features

Although the herpes zoster virus is very similar to herpes simplex, the clinical effects are very different. The initial infection normally produces the well-defined condition of chickenpox. When the virus is re-activated, it affects the region supplied by the nerve in whose ganglion, the virus remained dormant. The eruptions, known as shingles, are thus constrained to a discrete region. If the virus has been resident in the trigeminal ganglion and travels down the ophthalmic division, the resulting condition is referred to as herpes zoster ophthalmicus. It does not always follow that there will be ocular involvement. Unlike herpes simplex infection, there is a general feeling of lassitude and the patient complains of being ‘off-colour’. This is followed by neuralgia in the region served by the sensory nerve. The cutaneous eruptions then follow the classic picture of macules followed by pustules, which then crust over. If lesions are seen at the tip of the nose then ocular involvement usually follows. During the vescicular stage, the condition is contagious and patients should particularly avoid contact with pregnant women. Shingles varies a great deal in severity and this is true for the eye. There can be an acute epithelial keratitis which clears up spontaneously in a few days or a more persistent inflammation involving the stroma and other ocular structures such as the cornea, sclera and anterior uvea.

Depending on the degree of ocular involvement, there may be symptoms of lacrimation, blurring of vision and photophobia (Fig. 16.12).

Figure 16.13 Epithelial changes and pseudodendrite in acanthamoeba keratitis (reproduced from Kanski 2003, with permission).

Clinical note

In the case of contact lens wearers, no further use can be allowed of the current lenses, the storage case and all opened solutions. The patient’s

compliance with the recommended routine for lens care should be reviewed, together with the antimicrobial efficacy of the products being used.

Figure 16.15 Limbal phlycten (reproduced from Kanski 2003, with permission).

Treatment

Episcleritis

Figure 16.16 Simple diffuse episcleritis (reproduced from Kanski 2003, with permission).

The condition normally responds to a topical course of steroids such as fluoromethalone, although any associated bacterial infection should be treated.

SCLERA

Key features

Episcleritis is a common, localized inflammation of the episclera, which can be sectorial or diffuse and often resolves spontaneously, especially when there are no nodules. Nodular episcleritis as its name suggests is associated with the development of small raised nodules. The condition is frequently unilateral and the patient, typically a young adult, complains discomfort, tearing and redness (Fig. 16.16).

Scleritis

Treatment

Uveitis

Figure 16.17 Diffuse nonnecrotizing anterior scleritis (reproduced from Kanski 2003, with permission).

Key features

Scleritis is less common and more serious than episcleritis. It can range from minor self-resolving events to extreme sight-threatening attacks. Scleritis normally affects the anterior sclera in diffuse, nodular and necrotizing forms and can result from a variety of causes, such as trauma from surgery or infection. It is particularly associated with rheumatoid arthritis and other systemic diseases, including Wegener’s granulomatosis, polyarteritis nodosa and systemic lupus erythematosus. In the less frequent posterior scleritis, the inflammation is mostly posterior to the equator. The patient experiences more discomfort than in episcleritis, the eye appears inflamed and the severity of the symptoms reflects the degree of inflammation (Fig. 16.17).

Topical treatments are ineffective and oral non-steroidal antiinflammatory agents or steroids are required.

UVEA

Key features

The term ‘uveitis’ spans a range of conditions, covering some or all parts of the uvea. Anterior uveitis can involve the iris (iritis) or the iris and ciliary body (irido-cyclitis). Acute attacks are associated with ocular pain, redness, photophobia and slightly decreased vision. Aqueous cells

Figure 16.18 Ciliary injection in acute anterior uveitis (reproduced from Kanski 2003, with permission).

Treatment

and flare are present in the anterior chamber and keratitic precipitates might be seen on the endothelium of the cornea.

There is a circumcorneal hyperaemia of the perilimbal blood vessels which is termed ciliary injection or flush. Posterior synechiae can occur as complications (Fig. 16.18).

Treatment must be initiated promptly and is aimed at relieving symptoms, and preventing or breaking down if they are formed, of posterior synechiae. Cycloplegics are used to relax the iris sphincter muscle and prevent constriction of the pupil in the inflamed iris. In the past atropine drops were used, but normally, cyclopentolate produces sufficiently a mydriasis, of sufficiently long duration. Short courses of steroids (e.g. prednisolone) are used, with frequent instillation at the outset, which is tailed off gradually over several weeks.