Ординатура / Офтальмология / Английские материалы / Pediatric Opthalmology_Mukherjee_2005

Ocular involvement includes sever uveitis with coffee coloured hypopyon, endophthalmitis, panophthalmitis, orbital cellulitis. Edema of the lids, chemosis of conjunctiva, sever ocular pain, fever, loss of vision, acute rise of intra ocular pressure are the hallmarks of the disease.

Management

In all cases of gas gangrene, initial treatment should be directed towards systemic manifestation of shock, haemolytic anaemia, fever by IV injection of gas gangrene antitoxin 50,000 units every six hourly for first two days. Hyperbaric oxygen when available may be useful. Antibiotics to which the organism is sensitive are—Penicillin G. sodium, cefazoline, chloramphenical, amoxicillin, cefotoxamime.

Management of ocular involvement is more difficult. Hyperbaric oxygen therapy seems to have some beneficial effect. Local antibiotic drops do not have any therapeutic effect. Sub conjunctival injection is better alternative. Intra vitreous route is the best mode of administration of antibiotic. Early vitrectomy removes highly toxic necrotic material, improving visual prognosis.

Clostridium tetani

Tetanus is a severe neuromuscular disease, it is one of the top ten causes of death in children in under developed countries where there is lack of universal immunisation. It can infect a person at any age. Clostridium tetani is found as spores in soil, dust, animal and human faeces.

Symptomless humans can carry tetanus spores in gastro intestinal tract in about ten percent of population in non-immunised community.

The organism is gram positive, anaerobic, motile spore wearing organism. The spore is terminal and colourless. The organism produces a neurotoxin called tetanospasmin, which causes muscle spasm.

The disease is caused following injury on any part of the body with introduction of organism. The incubation period varies between two hours to several months. Short incubation period is associated with more severe infection. Distance of the injury from the central nervous system is important, nearer the wound to CNS more serious is the condition.

Clinically there are four forms of tetanus—Neonatal, cephalic, generalised and localised.

Systemic involvement is wide spread neuromuscular involvement.

Typical findings are—Lock jaw (trismus), risus-sardonicus, restlessness, irritability, stiffness, cramps, dysphagia and arched back.

Ocular involvement—Ocular involvements are due to neuromuscular involvements and their sequel. They are—Bilateral blepharo spasm, paralysis of all the cranial nerves from third to twelfth resulting into ptosis, external ophthalmoplegia, internal ophthalmoplegia, total ophthalmoplegia, facial palsy, supra nuclear palsy, corneal exposure, conjunctival congestion, corneal ulcer, conjunctivitis.

Management5

Tetanus is one of the most fatal diseases, which is fully preventable following proper immunisation.

All expectant mothers should get two shots of tetanus toxoid irrespective of immunisation status. All children should get usual DPT as per national programme of universal immunisation. The child must get a booster dose by seventh year and repeated every ten years or following tetanus prone injuries that could be systemic or ocular. The systemic tetanus prone injuries are unattended wound of more than six hours, with depth more than 1 cm, all road traffic accidents, sports injuries, burns where the wound is contaminated by dirt.

Tetanus prone ocular injuries are - Corneal and scleral perforation, lacerated wounds of lids, peri orbital structures.

Non immunised children with tetanus prone injury should get injection of human tetanus immunoglobulin.

Treatment of actual disease is mostly symptomatic and supportive:

1.The child should be admitted in specialised wards the child is put on life supportive measure with sedation under supervision of expert trained person dealing with such emergencies.

2.Antibiotics are given to prevent secondary infection. Common antibiotic’s are— Penicillin G, tetracycline, erythromycin, metronidazole. The child should get an extra dose of tetanus toxoid and human tetanus immunoglobulin.

Clostridium botulinum

Botulism is a paralytic disorder that begins with cranial nerves and spreads downwards, is a fatal disease. Main types of botulism are - Infantile botulism, wound related botulism and food related botulism.

C. Botulinum is gram positive that forms sub terminal spore, anaerobic in nature, found in soil and seawater. It produces most potent bacterial toxin. Incubation period is short i.e. 18 to 36 hrs in food related botulism and may be as long as 10 days in wound related botulism.

Clinical picture in both is almost same. The systemic involvement includes descending paralysis beginning with ptosis, going through diplopia, dysphagia, dysarthria, may involve neck and thorax. Other symptoms are that of food poisoning i.e. nausea, vomiting, abdominal pain, paralytic ileus, urinary retention.

Ocular involvement consists of bilateral ptosis, diplopia, fixed dilated pupil, and cycloplegia.

Management

The child should be hospitalised in food related botulism. Trivalent antitoxin is administered, intestinal antibiotics are given to reduce the organism present in the gut.

Corynebacterium diphtheriae

This is an acute, life threatening disease with extensive ocular involvement. Healthy asymptomatic carriers may be responsible for spread of infection in non-immunised community. The

disease is fully preventable except in a few individuals who may be infected by the disease in spite of proper immunisation. The effect of disease in such cases in mild and nonfatal.

The organism is a surface saprophyte affecting naso pharyngeal area. It is gram positive, club shaped, non motile, pleomorphic organism. It produces a strong toxin that affects heart, central nervous system, cranial nerves, and eyes. Respiratory obstruction is caused due to accumulation of necrotic exudate consisting of leucocytes, RBC and respiratory exudates.

Systemic involvement comprises of fever, chills, cutaneous diptheria, myocarditis, and polyneuritis. Respiratory tract involvement includes sore throat, rhinorrhea, hoarseness, dysphagia, cough, and pneumonia.

Ocular involvement’s are mostly extra ocular. The commonest involvement is conjunctival that start as congestion proceeding to—catarrhal conjunctivitis, purulent conjunctivitis, membranous and pseudo membranous conjunctivitis. There may be small sub conjunctival haemorrhage, as the condition proceeds towards membrane formation the lids become swollen and hard due to development of tarsitis and meibomianitis.

Corneal involvement—Superficial keratitis, frank corneal ulcer, sloughing corneal ulcer and perforation.

Cranial nerve involvement includes—Ptosis, paralysis of extra ocular muscles, paralysis of accommodation without mydriasis, internal ophthalmoplegia, convergence and divergence paralysis. Optic neuritis is rare. Late complications of conjunctival and corneal involvement lead to trichiasis, entropion, symblepharon, and xerophthalmia.

Management

The most effective management begins with immunisation of all children against diphtheria along with tetanus and whooping cough. The immunisation needs to be repeated after 3 to 5 years.

Once the disease has been diagnosed, the management consists of neutralising the circulating toxin and reducing the bulk of bacteria by antibiotic, along with life supportive measures.

Ocular involvement is treated by instillation of anti toxin, local instillation of penicillin G., erythromycin, mydriatic and cycloplegic.

Escherichia Coli

This is a commensal found in the gastro intestinal tract. Other common portal of entry is urinary tract. The organism is gram negative rod.

Systemic involvement cause diarrhoea, dysentery, haemorrhagic colitis, urinary tract infection. It can cause fatal haemolyticuremic syndrome in children.

Ocular involvement’s are relatively less frequent. It may be as mild as mucopurulent conjunctivitis to as serious as metastatic endophthalmitis. It can also cause pseudo membranous conjunctivitis, keratitis, corneal ulcer, uveitis, gas in AC, hyphema, hypopyon, and endophthalmitis.

Management consists of systemic antibiotic. Common antibiotics used are—Ampicillin, cephalosporin, nitrofurantoin, trimethoprinsulfamethoxazole, gentamicin, kanamycin, amikacin.

Ocular management is management of conjunctivitis, corneal ulcer, uveitis and endophthalmitis by standard methods along with management of systemic condition.

Hemophilus influenza and Koch-Weeks bacillus

Both the organisms belong to the group of hemophilus, have identical staining pattern, clinical presentation and are sensitive to same type of antibiotics. The Koch-Weeks bacillus is also known as H. aegyptius. There are many more strains of hemophilus. Both are pleomorphic, gram-negative cocco-bacilli.

Hemophilus is a common bacterial infections in children that cause upper respiratory tract infection, have seasonal variations, seen in small epidemics, may present as pink eyes followed by respiratory infection or vice versa.

Systemic involvement consist of—Fever, malaise, upper respiratory tract infection, sinusitis, bronchitis. In sever form it causes pneumonia, Otitis media is less common. Severe infection may cause meningitis and bacteremia, septic arthritis.

Ocular involvement’s are common. They are - Rapidly developing mucopurulent conjunctivitis, pseudo membrane formation, edema of the lids with violet colour, keratitis, central ulcer is rare. Conjunctivitis resolves in eight to ten days that may leave conjunctival scar in the tarsal conjunctiva. Phlycten are common after clearing of acute conjunctivitis.

Ocular management is instillation of broad spectrum antibiotics like ciprofloxacilin drops frequently with same ointment at bed time along with management of corneal ulcer when present.

Mycobacterium tuberculosis

Infection by this bacillus is one of the oldest known chronic disease world-wide. It still is a major cause of death in developing countries. It can infect any organ in the body in all ages in both sexes. It is not a hereditary disease but it is common to see more than one person infected by tuberculosis in the same family. Broadly it is divided in to two groups i.e. pulmonary tuberculosis and extra pulmonary tuberculosis.

Mycobacterium tuberculosis is a rod shaped, non spore forming, slender, aerobic bacterium. It does not stain with gram stain. It is an acid-fast organism.

It spreads by droplet from the infected person who is positive for tuberculosis organism.

Systemic involvement - Commonest organs to be infected are the respiratory organs. Common infections are seen in lungs and pleura. It can infect the small intestine, urinary tract, meninges. It can form intra cranial tuberculoma. Bones and joints are also involved.

The disease is characterised by tissue destruction and replacement by granulomatous tissue forming typical tubercles, which has central caseation. The severity of the lesion depends on many factors i.e. organ involved, tissue hypersensitivity, immunity and overall resistance power of the individual. Inflammatory process and tissue destruction is mostly due to tissue hypersensitivity while healing is immunity dependent.

Ocular involvement

Primary ocular involvement is rare and mostly seen in the lids as cutaneous tuberculosis or tubercular conjunctivitis, which may produce a cock’s comb like growth in the conjunctiva. Incidence of tuberculoma of the conjunctiva has become very rare.

It is rare for a case of frank pulmonary tuberculosis to develop tuberculosis of the eye. The common conjunctival lesion is phlyctenular conjunctivitis. Conjunctival ulceration is seen with cutaneous tuberculosis involving the lid margin.

Cornea

Commonest involvement is phlyctenular kerato conjunctivitis, followed by fascicular ulcer of the cornea. Frank keratitis by tubercular bacilli is very rare; more common is interstitial keratitis. Superficial keratitis is more common in cases of non tubercular myco-bacterial infection.

In sclera two common involvements are episcleritis and scleritis. A scleritis nodule near the limbus may cause sclerosing keratitis.

Involvement of orbit is rare but may cause mild proptosis. A tubercular sinus may develop on the skin or conjunctival fornix.

The conjunctival, corneal and scleral involvement’s are immunity mediated but orbital involvement is either due to extension from infected sinuses or via blood.

Intraocular involvement

All vascular intra ocular structures may be involved either as hematogenous spread which is rarer than more common hypersensitivity to the tubercular protein.

It can be present as acute mild iritis to severe posterior uveitis. The uveitis is granulomatous in nature with vitritis. Tubercular endophthalmitis has not been reported. The iris may have multiple tubercular nodules in chronic stage. Ciliary body may be involved as part of iridocyclitis or may have large nodule that may be large enough to cause angle closure glaucoma and confused as a neoplasm which can be differentiated only on B scan ultrasonography.

Choroidal involvement may be in the form of solitary patch of choroiditis or there may be multiple patches of choroiditis. The choroid may be involved in miliary tuberculosis.

Retinal involvement is rare. It is involved as patch of chorioretinitis, periphlebitis is more common than retinitis.

Extra ocular muscle palsies are seen in cases of tubercular meningitis and intracranial tuberculoma. Sub tentorial tuberculoma are common in children that my lead to papilledema and post papilledematous optic atrophy. Optic neuritis is less common, however, anti tubercular drug induced optic neuritis is common which is dose related and resolves following reduction in dose of the drug.

Management

Prophylaxis—BCG injection soon after birth saves the child from serious forms of tubercular infection like miliary tuberculosis and meningitis.

The best prophylaxis is early detection and complete eradication of infection in the individual.7

Preventive chemotherapy is popular in developed countries. Its place in under developed countries has not been fully evaluated.

chorioretinitis. This type of infection is not preventable by caesarean section. The second is more common and called as gonococcal ophthalmia neonatorum.

Pediatric and adolescent gonococcal ophthalmia is clinically similar to adult gonococcal ophthalmia. It is generally associated with child abuse or assault. However with development of early sexual activity and precociousness, incidence of adolescent ophthalmia is on the rise.

Other ocular involvement’s are:

Bilateral central corneal ulcer, gonococcus is one of the few organisms that can pass the intact corneal epithelium causing not only corneal ulcer but also anterior uveitis. Hence all cases of ophthalmia neonatorum should be treated as gonococcal unless proved otherwise. All cases of gonococcal conjunctivitis should also get local atropine in appropriate dose.

Perforation of central corneal ulcer may lead to acute endophthalmitis, panophthalmitis and loss of eye. Smaller perforation generally lead to collapse of AC, bringing the lens in contact with the cornea resulting in formation of anterior polar cataract. The perforation generally heals and a central leucoma results. This leads to a triad of central corneal opacity, anterior polar cataract and nystagmus.

Gonococcal infection may lead to mild iritis to sever plastic uveitis.

Management

Management of gonococcal infection in new-born child begins with ante natal examination of mother and if found to be suffering from genital gonococcal infection, she should be treated adequately. Caesarean section may save the child from neonatal infection. All children born of infected mother should also get adequate systemic antibiotic.

All neonates irrespective of their infective status should get prophylaxis for ophthalmia neonatorum either as single drop of 2% silver nitrate solution in each eye or 2.5% single drop of povidone iodine in each eye. In absence of above two, any broad spectrum antibiotic may be used as local drop.

Neisseriae meningitidis

Neisseria meningitidis or meningiococcus is a gram negative diplococcus that perish on exposure to drying and chilling. It is found only in human beings. The natural habitat of the organism is the nasopharynx. Meningococcal infection is mostly seen in children world wide. The infection may be sporadic or there may be localised outbreak, epidemics are no more seen.

It spreads either by inhalation of infected droplets or direct oral contact of infected person.

Systemic involvement is more common and serious than ocular involvement. The organism has a short incubation period. The clinical manifestations vary from transient bacteremia with good health to irreversible shock, hemorrhagic shock and death.

The systemic involvement follows a set pattern of clinical manifestation that begins as upper respiratory infection followed by bacteremia and meningitis. To begin with there is soar throat, rhinorrhea, cough, headache, redness of the eye, with fever, meningeal irritation.

Less frequent manifestation are arthritis, pneumonia, sinusitis, otitis media, endocarditis, pericarditis.

Neurological complications are common they include encephalitis, brain abscess, extra ocular muscle palsy.

Ocular involvement

Ocular involvement’s are less frequent and may be overlooked due to more severe systemic manifestation. Ocular involvement is mostly metastatic, however acute conjunctivitis may be due to direct droplet infection or spread from nasopharynx. Meningococcus like gonococcus can pass intact corneal epithelium. Fortunately corneal involvement is rare, there may be pseudo membrane formation over the conjunctiva.

Other ocular features are—Pupillary changes due to involvement of third nerve in basal meningitis. Mydriasis is more common than miosis. Transient extra ocular muscle palsy is common. So is optic neuritis ; there may be papilledema due to raised intra cranial pressure.

There may be metastatic uveitis that may be mild or as severe as endophthalmitis.

Management is mostly medical by systemic antibiotic for meningitis, pneumonia and endocarditis.

Local treatment consists of atropine ointment once a day and broad spectrum antibiotic drops given frequently.

Moraxella

This group of mild to moderate infectiveness consists of many strains. The same organism is known by more than one name. Previously due to its similarity in morphology and staining characteristic to gonococcus, it was thought to belong to neisseriae. With more study of DNA, it has been put in genus branhamella. It was formerly known as diplococcus of MoraxAxenfeld, Moraxella lacunata, Moraxella catarrhalis or even Neisseria catarrhalis.

The organism is a gram negative paired organism that resembles gonococcus due to its bean shaped appearance. It is found in the upper respiratory tract of almost fifty percent asymptomatic children.

Systemic involvement includes—Otitis media, sinusitis and pneumonia. Ocular manifestations are seen in malnourished, chronically ill children. It causes blepharitis, dermatitis of the outer canthus, chronic angular conjunctivitis, corneal ulcer that may terminate in hypopyon corneal ulcer.

The organism is sensitive to fluoroquinolones, erythromycin, and many other antibiotics. The organism produces an enzyme protease that is specifically counteracted by zink sulphate as 0.25 % to 0.5% drops.

Pneumococcal infection

The organism is better called streptococcus peumoniae due to its tendency to form chains and predilection for respiratory tract. It is one of the major causes of pneumonia in all ages. Children under two years are more prone to get the infection than older children.

The natural habitat of the organism is human nasopharynx. It has been isolated from nasopharynx of 5% to 10% of healthy adults and 20% of healthy children. It is also found as commensal of many healthy persons. The organism is a gram positive, capsulated

diplococcus with short incubation period. Mode of spread is through droplet from infected person. Once the organism gets into the nasopharynx it spreads quickly. The common modes of spread are - Direct spread over the respiratory epithelium mostly in the respiratory tract, middle ear, lacrimal sae and conjunctiva.

Conjunctiva gets infected by:

1.Change of organism from commensal to pathogenic state.

2.Spread via lacrimal passage

3.Hematogenous spread

4.Direct infection by droplet.

Systemic involvement consists of—Bilateral pneumonia, consolidation of lung, otitis media, sinusitis, meningitis, peritonitis, salpingitis, osteomyelitis and pericarditis. Pneumonia and consolidation may lead to empyema. Pneumococcus is known as true ocular pathogen.

Ocular involvement’s are mostly conjunctival. There may be acute, bilateral mucopurulent conjunctivitis with or without petechial haemorrhages. Pseudo membrane formation is common. Conjunctivitis may be associated with superficial keratitis, corneal ulcer, which is generally fast spreading serpiginous ulcer with large hypopyon.

There are three ways by which the uvea may get involved: 1 By way of pneumococcal ulcer

2.Spread of toxin from lacrimal sac

3.Metastatic spread from other organs.

Uveal involvement may present as endophthalmitis. Chronic dacryocystitis is very common. The lacrimal sac may harbour pneumococci without symptom, may have chronic dacryocystitis. Occasionally there may be acute orbital cellulitis.

Management

Pediatrician should manage the systemic conditions by antibiotics. Common anti microbials used are—B. lactame antibiotics; once penicillin was the first drug choice, now more and more organisms have become resistant to it. Other commonly used drugs are—Trimethoprime, cephalosporins, erythromycin, clindamycin, chloramphenicol. The organism is less susceptible to the qunolones.

Ocular management

Conjunctivitis responds well with local erythromycin ointment, bacitracin drops. Even fresh solution of penicillin, but poorly by qunolones. In all cases of suspected pneumococcal conjunctivitis, cornea should be carefully watched for any evidence of its involvement. The anterior chamber should be examined for AC reaction, cells, flare or even hypopyon. Hypopyon is so common with pneumococcal dacryocystitis that in all cases of hypopyon with or without ulcer the sac should be examined for stagnation or frank infection.

Acute dacryocystitis, orbital cellulitis, endophthalmitis require systemic anti pneumococcal antibiotic in appropriate dose for sufficient time.

Corneal ulcer is treated as ophthalmic emergency.

Pseudomonas areuginosa

The organism is one of the commonest sources of hospital infection and infects accidental as well surgical wounds frequently. It is ubiquitous, free living, opportunistic, gram negative, small, straight or slightly curved motile organism. It produces a blue green pigment called pyocyanin that colours the pus and exudate making its diagnosis easy.

It produces large quantity of proteases that rapidly cause stromal necrosis. It is found in 50% of water, plants, animals and humans. About 5% of symptomless persons have stool infected by the organism. The organism does not produce clinical symptoms in healthy adults. It mostly invades the tissue following trauma accidental or surgical or following invasive procedures. It may involve the skin or mucous membrane primarily, from where it may spread by continuity or metastasis. Out of all infections, ocular infections are most devastating.

The systemic involvement consists of:

Respiratory infection that may be mild or life threatening, associated with cough, fever, chills, dyspnea, cyanosis. Ear infection is common. Generalised bacterimia, endocarditis, CNS involvement, Bones and joint involvement may be traumatic or non traumatic.

Ocular involvement by pseudomonas is a serious problem. It should be treated as ocular emergency. Predisposing factors are—Contact lenses, soft extended wear contact lens are more likely to be contaminated by pseudomonas; hard contact lenses are no exception. The organism may be adherent to the contact lens. Other source of contact lens contamination is contact lens solutions.

Fluorescein drops are notoriously contaminated by pseudomonas. Hence it is better to use sterilised fluorescein strip rather than hospital prepared drops. If use of drops is inevitable, it should be autoclaved frequently and kept away from any possible source of contamination. The organism may be passed from one patient to other via tonometer, gonioscope etc.

Clinical presentation of pseudomonas infection consist of redness, pain, discharge, mucopurulent conjunctivitis, foreign body sensation, excess of watering, increased pain herald onset of corneal ulcer. The ulcer is generally central with massive bluish green hypopyon. Peripheral ulcer may be associated with scleritis. The ulcer if not treated progresses fast and leads to perforation that may end up in endophthalmitis and panophthalmitis.

Management

Pseudomonas is sensitive to many broad spectrum antibiotics. Some of them are—Tobramycin, ciprofloxacilin, ofloxacilin.

Staphylococcus

This is one of the most common infection world over. The organism is ubiquitous that commonly develops colonies on the skin and mucous membrane without much symptom or may remain asymptomatic, 15 to 50% of population being the reservoir. They are a public health hazard. They are the commonest organism to cause nosocomial infection. Beside skin and mucous membrane, they are found in water, dust and soil, inanimate objects of the hospital. Many of the persons working in the hospital are carriers of the organism. Contamination of bioprosthesis including IOL, contact lenses, irrigating tubes, irrigating solutions are common by staphylococci. The stain S. aureus is most important human pathogen.