Ординатура / Офтальмология / Английские материалы / Pediatric Opthalmology_Mukherjee_2005

Adult inclusion body conjunctivitis is treated with 20% sulphacetamide drop three times a day along with oxytetracyclin eye ointment at bed time. Severe cases may require oral tetracycline 250 mg QID for three weeks or doxycyclin 100 mg once a day for same period.

Lymphogranuloma venerum

It is more of a sexually transmitted disease of genital tract and regional lymph nodes than ocular disease, however ocular manifestations are possible, which are generally missed due to lack of suspicion of the condition in children. The children are generally infected following child abuse and may pass among themselves especially in institutions like hostels or shelters for abandoned orphans.

The disease is caused by C. trachomatis serovars L1, L2 and L3. The incubation period varies between 3 days to three weeks.

The systemic involvement comprise of painless ulcer of genital followed by matted enlarged, inguinallymph nodes that may become tender that suppurate to form a sinus.

Ocular involvement consist of:

Granulomatous conjunctivitis with non suppurative preauricular lymph node, enlargement sub-mandibular. Sub clavian or neck lymph nodes may be enlarged.

The other mode of presentation is unilateral edema of lid, mucopurulent conjunctivitis, keratitis, interstitial keratitis, episcleritis, uveitis and retinal hemorrhages.

Diagnosis requires high index of suspicion that should be corroborated with genital lesion.

Other systemic viral disease with ocular manifestation

Almost, all systemic viral disease have ocular manifestations.

Adeno viruses

Adeno viruses are common cause of upper respiratory tract infection. They are DNA viruses. Man is the only known host. Incubation period is short i.e. two to ten days. The infection starts as pharyngitis with high fever and sub mandibular enlargement of lymph nodes. The disease is mostly self limiting. The infection commonly spreads from swimming pools.

Ocular involvement is mostly acute unilateral mucopurulent conjunctivitis. The other eye may get involved in three to four days. There may be superficial punctate keratitis.

No specific treatment is required. However cornea should be protected from secondary bacterial infections which may lead to frank corneal ulcer. The condition does not impart immunity.

Influenza

Influenza is caused by orthomyxo virus. There are mainly three types i.e. influenza A, B and C. The virus causes acute respiratory tract infection that starts in the upper part and spread to lower respiratory tract, with fever, pain all over the body and weakness. It is pandemic with episodes of out breaks mostly in winters. Though the condition is self limiting it can be fatal if it produces myocarditis, pericarditis or pneumonia. CNS involvement is rare.

Ocular involvement consists of congestion of the conjunctiva, conjunctivitis, retrobulbar pain, superficial punctate keratitis, dendritic ulcer, dacryoadenitis, anterior uveitis and optic neuritis. There may be difficulty in near work and diplopia when CNS is involved. There is no specific treatment.

Epstein-Barr virus25

This is a herpes virus that causes infectious mononucleosis. It has been blamed to be a causative factor in Burkitt’s lymphoma and nasopharyngeal carcinoma.26

Ocular involvement consists of conjunctivitis, membranous conjunctivitis, superficial punctate and dendritic ulcer, uveitis, chorioretinitis, optic neuritis, paralysis of internal as well as external ocular muscle, and dacryoadenitis.

MYCOTIC (FUNGUS) INFECTION

Fungi are micro organisms between bacteria and smallest plant. They belong to the phylum thallophyta29. The fungi are said to be plants without leaves, trunk or twigs. They do not contain chlorophyll and can not form carbohydrates. They have multiple ramified filaments called hyphae30,31. A network of hyphae is called mycelium. The fungi develop on living organism or on dead organic matter. They are either saprophytes or parasites. The saprophytic fungi can become pathogenic. Almost all fungi may become facultative pathogen if the environment is changed in their favour that can be brought about by change in the immunity of the host. An immune compromised body is more likely to develop fungal infection than an immuno competent. This has assumed an alarming situation due to rapid spread of AIDS. Prolonged use of antibiotics may eliminate the causative bacteria but encourages a relatively benign fungus to be invasive. This is worsened by use of steroid both local and systemic. General debility, diabetes, drug abuse, chemotherapy and radiation predispose mycoses.

The fungi can reproduce sexually or asexually. The spores are the reproductive bodies.

There are about 30-35 species of fungi that cause systemic mycoses in humans. All systemic mycoses have ocular involvement. Occasionally fungi may get access to the ocular structure following trauma that may be accidental or surgical. The pathogenic fungi have been put in two broad groups:

1.Schizomycetis—Nocardia and Actinomycosis (Actinomycosis is no more considered to be a fungus. It has been put between bacteria and higher moulds).

2.Fungi imperfecti (without spores)

Most of the fungi that have ocular manifestation belong to this group they cause:

1.Aspergillosis

2.Blastomycosis

3.Coccidioidomycosis

4.Candidiasis

5.Dermatophytosis

6.Histoplasmosis

7.Mucormycosis

8.Nocardiosis

9.Sporotrichosis

Fungal infection is suspected mostly clinically in predisposed patients.

The predisposing factors are—AIDS, prolonged use of antibiotics, steroids, immuno suppressive drugs, patient on radiation patients who had organ transplant, drug abusers, general debility, diabetics and trauma.

Fungus infections are always chronic in nature. They have long incubation period except candida. Most of the fungi grow slowly in culture media, can not be developed in laboratory animals.

They are identified:

1.Visually, by typical lesions on the skin, and mucous membrane.

2.Observing the characters of mycelium.

3.Microscopically by type of spores, hyphae, septae

4.Culture

5.Histologically. All fungal infection result in giant cell granuloma similar to typical tubercle.

The fungi can cause immediate hypersensitivity generally by non pathogenic fungus or delayed hypersensitivity by pathogenic fungi. Thus they can cause contact dermatitis, angioneurotic edema, reaction similar to serum sickness, sensitisation and agranulocytosis.

Aspergillosis

Aspergillosis is caused by a saprophyte fungus which is commonly found in soil, and decaying vegetable matters. It is found all over the world but it is more common in tropical and temperate countries.

The systemic manifestation starts with inhalation of spores leading to aspergillosis of respiratory tract and para nasal sinuses from where the disease is disseminated to distant organs like kidney, brain, skin and bones. Ear drum is rarely involved.

Ocular involvement. Common ocular involvement are orbital granuloma and corneal ulcer, followed by endophthalmitis that can either be exogenous following penetrating injury or surgery. Less common mode is metastatic endophthalmitis due to embolus of fungus from distant organ in an emaciated critically ill child.

Other parts of the eye involved can be chronic granulomatous ulcer in the lid and conjunctiva, canaliculitis and dacryocystitis. Orbital granuloma may spread to lacrimal gland. Intra ocular involvement are uveites, vitreous abscess, retinitis, retinal vasculitis. Intra ocular involvement is mostly endogenous.

Blastomycosis

Blastomycosis is caused by a dimorphic fungus balsomycisdermatidis, which is found in two phases—Mycelial phase at lower temperature and Yeast phases at body temperature.

Systemic involvement

The fungus is found mostly in the soil. The organism is generally inhaled leading to acute pulmonary infection that may be fatal or pass into chronic phase, which is difficult to eradicate. Skin is the next part to be involved. Other organs are bones, genitourinarytract and CNS. The common presentation is agranuloma.

Ocular manifestation32, 33

Granuloma of the skin of the lid is the commonest ocular involvement followed by orbital granuloma, granulomatousconjunctivitis, keratitis, rarely uveitis, endophthalmitis and panophthalmitis.

Coccidioidomycosis34

Coccidioidomycosis is caused by a saprophyte coccidioidesimmitis. It is a dimorphic fungus that changes with change in environment. In one form it grows as white fluffy mould on culture media. The second form is a spherule in the host. The organism multiplies in the host by small endospores in spherules. The mature spherules on maturity rupture releasing endospores that are transformed to spherules and the cycle is repeated. The infection occurs following inhalation of airborne spherules.

Systemic involvement is pulmonary infection. The disease may be asymptomatic and self limiting or may form a cavity in the lung. The fungus may spread to other organs by dissemination.

The patients with altered immunity are at a risk of relapse and pulmonary as well as extra pulmonary lesions. Person with AIDS are at greater risk than other immuno compromised. Other systemic lesions are arthritis, erythema multiforme and nodosum.

The ocular involvements are due to hematogenous spread from pulmonary lesion or due to hypersensitivity.

The ocular manifestation are35

The hematogenous lesions are—Progressive chronic pan uveitis, which is granulomatous in nature. The uveal lesions are independent of severity of pulmonary lesion. Other intra ocular lesions are—Chorioretinitis, vitritis, retinal exudates and haemorrhages.

The cornea may show keratitis. Granuloma of the lid, conjunctiva and lacrimal gland have been reported.

Candidiasis

Systemic and ocular infection by candida are very common world over. There are more than hundred species of candida, out of which candida albicans is the most common pathogen. The candida is a part of the normal flora of mucous membrane, skin, gastro intestinal tract, genito urinary tract and respiratory tract. It is found in conjunctiva and on lid margin. Candida grows profusely in keratitis sicca. It is also present in the soil, water and sometimes in food. It is also a dimorphic fungus that has two phases, the yeast and mycelia. The yeast form is more common.

Mode of infection is either due to local inoculation via abrasion or endogenous spread from primary systemic infection.

Systemic involvement is common in neonates, children and malnourished children. It may be seen as oral thrush of mucous membrane of neonates and infants. Less common is chronic mucocutaneous candidiasis, that may be associated with multiple endocrinal dysfunction that may result in diabetes, Addison’s disease, hypoparathyroidism, hypothyroidism. Ovarian dysfunction may be associated with pernicious or iron deficiency anaemia, hepatitis, cystitis, pyelitis, and vaginitis.

The ocular manifestations are:

Keratitis is commonest form of candidiasis that requires prompt treatment. It may produce pseudo-membranous-conjunctivitis, sometimes purulent conjunctivitis, conjunctival ulcer or phlycten. The lids may have blepharitis, granulomatous canaliculitis.

The intra ocular involvement may be in the form of frank endophthalmitis either endogenous or exogenous following penetrating injury, accidental or surgical. Other mode of intra ocular presentation is milder form of choroiditis, retinitis, chorioretinitis, papillitis, peri vasculitis, free floating snow balls in vitreous are almost diagnostic.

Dermatophytosis

It is a very common mycotic infection of skin commonly known as ringworm infection. It can involve nails. According to part of the skin involved it is called tinea capitis (scalp) T corporis (body), T pedis (athletes foot), T facici (face). No systemic involvement is known.

Ocular involvements. Mostly dermatitis of the lids, blepharitis, madarosis, chronic conjunctivitis.

Mucormycosis36, 37, 38

Mucormycosis is a serious infection that may be fatal. It is an opportunistic fungus belonging to species rhizopus, class phycomycetis and order mucorale. The organism is found all over the world in soil, water, manure, skin. It may contaminate the food with high sugar content. The non pathogenic strain changes to pathogenic strain in diabetic ketosis, AIDS, organ transplant, lymphomas and leukaemias.

The fungus is non-septate with branching hyphae that can be seen in culture and histology. The infection is acquired from the nature but not from person to person contact. Most probably the organism is inhaled or ingested.

The common systemic involvements are—para nasal sinuses, orbit, brain, respiratory system, gastro intestinal tract and skin.

The disease is considered to begin in the para nasal sinuses and from there it spread to adjacent structures like orbit and brain, trickle down the respiratory tract or GI tract. The main tissue to be involved is vascular, it produce invasive angiopathy that leads to ischemic or hemorrhagic necrosis.

Systemic involvement

The typical presentation is similar to bacterial sinusitis with fever, headache, running of nose, blood discharge from nose, facial pain, swelling of lids, and over the cheek. Common presentations are involvement of orbit and signs of CNS infection.

Ocular involvement

Commonest form is orbital involvement, most of the time due to extension from para nasal sinuses and less commonly due to injury to the skin of the lid or retained orbital foreign body.

The orbital involvement starts as unilateral apical pain, headache, diplopia, and diminished vision. The lids are edematous, the conjunctiva is chemosed. Proptosis is common that may lead to cavernous sinus thrombosis, superior orbital fissure syndrome and orbital apex syndrome.

Extension back into cranium leads to clouding of sensation, diminished mental faculty, cerebro vascular accident and multiple cranial nerve palsy.

The diagnosis is best confirmed by histopathology of tissue removed. The biopsy or excision is generally not associated with bleeding due to pre existing vasostasis. CT and MRI are two useful diagnostic methods to demonstrate involvement of sinus and intracranial tissue.

Nocardiosis

Nocardiosis is caused by an organism nocardia. The organism was previously thought to be fungus along with actinomyctes. Now both are classified as higher bacteria, which are found world over in the soil and decaying organic substance. It usually affects debilitated and immuno compromised persons. It is a gram positive, filamentous organism that stain with

Grocott-Gomori stain and periodic acid Schiff stain. It grows on most of the media but takes four to six weeks to grow. On agar plate the organism produces a star shaped colony which imparts the name nocardia asteroides to the fungus. They can survive inside the phagocytes.

The disease is more common in adults than in children. Males outnumber females in a ratio of 4:1. Systemic involvement is mostly pulmonary as pneumonia, which is sub acute with anorexia, fever, and loss of weight. There may be pleural pain and hemoptysis. The extra pulmonary lesions are due to hematogenous spread to many organ including skin. One of the possible modes of skin involvement is trans-cutaneous inoculation that may produce cellulitis, lympho cutaneous syndrome and mycetoma.

The ocular manifestations are keratoconjunctivitis, keratitis, anterior uveitis, chorioretinitis, endophthalmitis, orbital cellulitis and scleritis.

Histoplasmosis38

Histoplasmosis is a chronic disease caused by fungus histoplasma capsulatum. The organism is found world over in soil and dropings of bats and birds. However its manifestation in humans is not universal. It is mostly seen in white Americans. It has rarely been reported from Asia or Africa. Though it is a disease that is commonly seen in second to fifth decade, it can infect children as well.

The organism grows with ease on Sabouraud’s media at room temperature. The fungus is dimorphic, it shows both yeast as well as hyphae form. The yeast form is seen in various tissues causing granuloma. The hyphae develops spores at the ends. The disease is spread by liberated spores in the air.

Systemic involvement

The commonest mode of infection is by inhaling the small spores that on reaching lung develops budding forms. The multiplying organisms produce granuloma that caseates to necrose,

may get calcified. The lesions mimics tuberculosis in children. The lesions may heal without much treatment and get calcified at the hilum. In some cases the infection may continue to become fatal in children and immuno compromised. The organism can travel to liver and spleen.

Ocular manifestations

It is not clear if the ocular involvement is really caused by histoplasma at all. The ocular involvement is called presumed ocular histoplasmosis syndrome (POHS) that is confined to posterior segment. The anterior segment is unaffected. The ocular involvement is most probably hematogenous spread from the primary pulmonary focus in childhood which heals to leave multiple chorio retinal scars, which may be activated in adulthood.

The ocular syndrome consists of peri papillary chorio retinal scar, punched out inactive chorio retinal scar, hemorrhagic macular lesion. The left eye is involved more frequently39. In two third cases the condition is bilateral. Histoplasmosis is a major cause of choroidal neovascularisation. Rarely there may be a macular scar. The condition remains asymptomatic untill the macula is involved. Macular involvement is late but symptomatic. The common symptoms are metamorphopsia, diminished central vision, and central scotoma. The patient complains that his vision straight ahead is poor. The treatment of choice is laser photo coagulation of extra foveal and juxta foveal lesion following fluorescein angiography.

Sporotrichosis

It is a rare fungal disease. The fungus is found all over the world on plants and soil, hence it is but natural that those who work with soil and plants are most likely to get infected. It may manifest at any age. The fungus is found in yeast form and grows as budding yeast on media at 37ºC.

Systemic involvement

The commonest route of entry of the organism is via cutaneous wound. In a few days a sub cutaneous lesion develops which most of the time is a self healing lesion. It generally does not spread beyond the limb infected initially, though rarely hematogenous spread to lung and brain are known.

The commonest skin lesion is sub cutaneous painless diffuse nodule at the site of injury. Other form are lymphangitis, ulcer or nodule formation.

Ocular manifestations are rare but all parts of the eye have been reported to be involved from lid to the retina. Exogenous endophthalmitis occurs following penetrating injury.

Parasitic infection40, 41, 42

The systemic parasitic infection can either be due to protozoa or metazoa. The metazoa infection can be due to helminths that can either be cestodes or nematodes. Other organism that may infect eyes and its adnexa are arthropods or by insect larvae.

The commonest protozoa that involves the eye is toxopalsma. The other protozan infections are relatively uncommon and are caused by entamoebahistolytica, plasmodia, giardia, Leishmania, and trypanosoma.

The common helminths are—Taenia echinococcus, taenia solium, causing echinococcosis and cysticersosis respectively. The disease coenurosis is caused by taenia multiceps and taenia glomeratus. The helminth toxocara canis causes toxocariasis. The organism onchocerea volvulus causes river blindness. Thelaziasis is caused by the thelazia callipaeda, and thelazia californiensis. Loasis is caused by worm Loa loa also known as African eye worm. Trichinosis is caused by trichinellaspiralis. Less common ocular manifestations are Dracunculosis caused by dracanculus medinensis. Bilharziasis, sparganosis and ganthostomiasis are still less common in eyes.

Rarely the eyes are infested by acariasislumbricoidis and ankylostoma duodenale.

The arthropods found on ocular adnexa cause pediculosis, phthiriasis and demodicosis. Infections by insect larvae are called myiasis.

Toxoplasmosis42, 43, 44, 45, 46, 47

Toxoplasmosis is caused by protozoa toxoplasma gondii that is found universally. The prevalence of the disease may be as high as 50% in adults who are either asymptomatic or have some systematic or only ocular manifestation. The domestic cat is the definitive host. Other mammals are intermediate host that acquire the disease by eating contaminated food or water by faeces of the cats who excrete the parasite. The organism is obligatory intra cellular. The parasite has two phases:

1.Homologous host phase and

2.Heterologous host phase that is seen in humans.

Two forms are met with i.e. the pseudo cystic phase and cystic phase. The disease can either be congenital or acquired.

The congenital toxoplasmosis. The foetus is infected via transplacental route from already infected mother who is symptomsless but serologically positive. The mother may have acquired the disease during any phase of pregnancy or has been infected years ago; the disease has been dormant and has been activated during pregnancy.

The congenital toxoplasmosis43 is a common cause of abortions and still birth. The two organs commonly involved are the brain and the eyes that produce triad of three Cs i.e. convulsion, calcification (intra cranial) and chorioretinitis. Less frequent features are low birth weight, hepatospleenomegaly, purpuric spots, neonatal hypoxia, raised intra cranial pressure, and hydrocephalus.

The ocular lesion in congenital toxoplasmosis is generally bilateral central chorioretinitis that may be mistaken as coloboma of the macula.

There is a rough guideline regarding possibility of intra uterine infection i.e.

1.If the mother has been infected six months prior to the onset of pregnancy the chance of infection to the foetus is almost nil.

2.If the mother gets infected less than six months before the conception the foetus may be involved.

3.The chances of infection increases as the duration of infection and conception decreases.

4.If the mother is infected during first trimester the chances of transplacental spread is least but the disease in neonate is most severe.

5.In contrast to this if the mother is infected in last trimester the chances of foetal infection is most but features in new born are mildest.

Acquired toxoplasmosis44

Toxoplasmosis is acquired by ingestion of food or water contaminated by faeces of infected cats. The exact incubation period in not known. The common systemic involvements consist of skin, lymph glands, lungs, CNS, and heart.

The organism is known to become opportunistic and have a widespread involvement including eyes.

The ocular involvement consists of chorioretinitis that is located posteriorly as necrotising retinitis that has yellowish white cotton wool appearance with indistinct margins and the borders are hyperemic. The lesion may be unicentric or multi-centric and heal by scaring that has central white area with irregular pigmentation all round. Satellite lesion may develop little away from the active lesion during its active phase or after it has healed.

The acute stage of acquired toxoplasmosis does not produce any ocular changes. The changes are reactivation of either congenital lesion or a dormant acquired lesion. Anterior segment involvement is less common but is possible. Rarely the extra ocular muscles are involved. Involvement of optic nerve, cataract and glaucoma are common.

A child with a lesion in first three months has nystagmus, squint and very low vision. An asymptomatic child may have diminished vision and prone to develop reading difficulty.

Entamaeba histolytica

Infection by entamaeba histolytica is very common in tropics. It is estimated that one fifth of the population either suffers from this parasitosis or is carrier of the disease who are asymptomatic. Commonest systemic involvement is amaebic dysentery, this is followed by amaebic liver abscess and rarely cerebral abscess.

Ocular involvements are very few and rare. They do not have any distinguishing clinical features. There are no specific tests to establish the ocular diagnosis. The diagnosis is presumptive that is supported by improvement following systemic administration of anti amaebic chemotherapy.

The commonly reported ocular manifestations are40—Anterior and posterior uveitis, that may cause hypopyon, retinal periphlebitis and vitreous haemorrhage.41

Acanthameba is a free living amaeba found world over. It is mostly found in contaminated water. Contamination of water by acanthamoeba has become more frequent in last two decades. It causes granulomatous amaebic encephalitis. The organism reaches the brain via blood stream from sinuses, lungs or skin. Persons with AIDS are at higher risk.

Commonest ocular involvement is kerato acanthamoeba.

Malaria47, 48

It is an infection caused by protozoa plasmodium. There are four types of plasmodia that are responsible for malaria. They are—Plasmodium vivax, P ovale, P malariae and P falciparum. The last variety causes most serious form of malaria and can be fatal.

The disease is acquired and spread by bite of female anopheles mosquito.

Malaria is found in all parts of the world, but is more common in tropics and subtropical countries. The incubation period is different in different species of plasmodium.

The systemic features are fever, chill, body ache, abdominal discomfort, all of which can be mistaken as viral infection. Besides fever that may be periodic with definite cycle of fever alternating with afebrile period; there is enlargement of spleen, liver is less enlarged. There may be mild jaundice. There may be rashes all over the body with patechial haemorrhage on the skin and other mucous membrane including conjunctiva. Anaemia is very common.

It may cause dysentery like symptom. Cerebral malaria is caused by p falciparum. This is a life threatening condition.

Other manifestations are hypoglycemia, lactic acidosis, pulmonary edema and renal failure.

Ocular manifestations are rare. They can be divided into two groups:

1.Those caused by malaria.

2.Those caused due to toxicity of anti malarial drug.

The common ocular involvements are—Sub conjunctival patechial haemorrhage, superficial corneal ulcer, simulating dendritic ulcer. However patients with malaria are more prone to develop herpes simplex keratitis both superficial and deep. The deep keratitis is generally attributed to be interstitial keratitis due to malaria, which clears following systemic treatment with anti malarial drugs suggesting that plasmodium is capable of producing interstitial keratitis. Other ocular involvements are retinal haemorrhages and optic neuritis.

Commonest ocular feature of anti malarial treatment is quinine amblyopia.49 This is a dose related condition. The effect varies from patient to patient. It consists of sudden loss of bilateral central vision with central scotoma, due to optic neuritis that may end in optic atrophy. Other ocular features of quinine toxicity are retinal pigmentepitheliopathy, damage to bipolar and ganglion cells.

Giardiasis

Giaradiasis is world wide problem. It is caused by protozoa giardialamblia. It is found in small intestine of many mammals including humans. It causes endemic and sometime epidemic form of enterocollitis and diarrhoea. It is spread by drinking polluted water and ingesting contaminated food.

Ocular involvements are rare but can cause uveitis, keratitis, chorioretinitis and retinal haemorrhage all of which respond to anti giardial treatment.40

Leishmaniasis50

The disease is seen only in tropical countries. It is caused by a protozoa belonging to genus leishmania. It is a vector borne zoonosis. Humans are incidental host, small mammals are reservoirs. The disease is spread by bite of sand fly Phlebotomus.

There are three common types of leisheniasis in humans they are—Kala azar, cutaneous leishmaniasis and espundia (nasopharyngeal leishmaniasis).