TRACHOMA

April 8, 2023 Dr Sanjay Shrivastava 1

TRACHOMA

• At one time known as Egyptian Ophthalmia, endemic in middle east during prehistoric period, spread far and wide in Europe by French army during Napoleonic wars. Trachoma is still a leading cause of preventable blindness world wide, third after cataract and glaucoma.


Epidemiology

• Approximately 1/5th population of world is affected by Trachoma, amounting to 150 million people across the 48 countries . It is estimated that 6 million people are blind in both eyes. It still remains a significant problem in areas of Africa, South East Asia, the Middle East and Australia.


Etiology

• Trachoma is caused by Chlamydia Trachomatis immunotypes / serotypes A,B and C. Chlamydia organisms shares properties of both, bacteria and virus. It is an obligatory intracellular bacteria.


Predisposing Factors

• Unhygienic and crowded surroundings

• Low socio-economic status

• Lack of water

• No race is exempted


Transmission

• Direct transmission from eye to eye through discharge

• Through fomites, flies and eye cosmetics

• Disease is contagious in acute phase

• Incubation period is 5 -12 days


Clinical Features


Symptoms

• Pure Trachoma is usually asymptomatic condition or there may be minimum symptoms

• There may be redness, irritation, discharge, foreign body sensation, watering and photophobia

• Systemic symptoms like rhinitis, pre auricular lymphadenopathy and upper respiratory tract infection may be present


Symptoms … Contd

• Onset is usually sub-acute, but may occur as acute when infection is massive as occurs in experimental or accidental or clinical infection


Signs

• Primary infection is epithelial, involving conjunctiva and cornea characterized by:conjunctival congestion, upper tarsal conjunctiva appears red and velvety, later may become uniformly thick like jelly. Follicles are found in lower fornix, upper fornix, upper margin of tarsus, caruncle, plica, palpabral conjunctiva, bulbar conjunctiva near limbus


Signs … contd.

• Follicles are small (0.5 mm in diameter) but may measure up to 5 mm in diameter.

• Papillary enlargement.


Corneal Signs

• Superficial Keratitis in upper part• Epithelial erosion, extending deep into

stroma• Pannus is lymphoid infiltration with

vascularization seen in upper half, tending to spread towards the centre . Whole cornea may be covered with pannus . Vessels are superficial between epithelium and Bowman’s membrane.


Corneal Signs.. Contd

• Stages of Pannus:Progressive (infiltration is beyond vascularization)Regressive (infiltration has receded and vessels are ahead of infiltration)

• Corneal ulcer , chronic, occurs anywhere but commonest at the advancing edge of pannus, are shallow ulcer with little infiltration.


Pathology

• Chlamydia Trachomatis is seen in conjunctival scarping in the form of colonies in the epithelial cells as Halberstaedter Prowazek inclusion bodies

• Inclusion bodies are composed of innumerable elementary bodies embedded in carbohydrate matrix


Pathology … Contd

Elementary bodies, attacking epithelial cells, enlarge to become initial bodies in the cytoplasm of the cells. Numerous initial bodies, in cells divide to form innumerable elementary bodies embedded in carbohydrate matrix. The nucleus of cell is displaced , degenerates and cell burst to release elementary bodies, to attack new cells.


Pathology … contd.

• In acute inflammatory stage , polymorphonuclear cell infiltration is noticed and later on lymphocytes are dominant

• Lymphocytic infiltration in Adenoid layer• Aggregation of lymphocyte without capsule

forms follicles• Follicles shows necrosis and contains large

multinucleated Laber cells• An attack confers little immunity


Pathology …. Contd.

• Trachomatous infiltration may spread deep into subepithelial tissues of the palpabral conjunctiva and even invade the tarsal plate

• Invasion of lacrimal passages may also be there.

• Fibrosis around follicles giving rise to cicatricial bands (Arlt line in superior tarsus)


Diagnosis

• Culture of Chlamydia Trachomatis in irradiated McCoy cells

• Micro-Immunofluorescence (Micro-IF) test

• Monoclonal Direct Antibody test

• Demonstration of inclusion bodies in conjunctival epithelial scrapping


Clinical Diagnosis

• Is based on identification of at least two of the following signs:1. Follicles2. Epithelial Keratitis3. Pannus4. Limbal Follicles/ Herbert Pits5. Typical Trachomatous Scarring (Stellate or Linear Scarring of upper tarsus)

• Diagnosis is confirmed by demonstration of inclusion bodies


Trachoma Classification

I. MacCallan’s Classification

Stage I : Immature follicles on tarsus , SPK and Pannus

Stage II : Florid superior tarsal follicular reaction with mature follicles or marked papillary hyperplasia , pannus, limbal follicles, superior corneal epithelial infiltrates


MacCallan Classification

Stage –III : Signs of stage II with cicatrization

Stage – IV : Cicatrization and its sequelae


II. WHO Classification (FISTO)

Stage – I Trachomatous Infiltration – Follicular (TF): 5 or more follicles of at least 0.5 mm in diameter. If treated properly, patient recovers with no or minimal scarring

Stage -II Trachomatous Infiltration – Intense (TI): Follicles, papillae, thickening of conjunctiva obscuring >50% conjunctival blood vessels. Severe infection with high risk of complication.


WHO Classification… Contd

Stage – III : Trachomatous scarring (TS)

Stage – IV : Trachomatous Trichiasis (TT)

Stage - V : Corneal Opacity (CO) corneal opacity occupying pupillary area


Sequelae of Trachoma

• Distortion of lids

• Trachomatous Ptosis

• Entropion

• Trichiasis

• Tylosis


Late Complications

• Sever dry eye

• Keratitis

• Corneal scarring

• Fibrovascular pannus

• Corneal Bacterial Superinfection


Treatment

• Tetracycline, Erythromycin, Rifampicin and Sulphonamides are effective orally

• Topical Erythromycin and Tetracycline ointment


Treatment … contd

Treatment of TF Stage – Topical Erythromycin eye ointment twice a day for 6 weeks

Oral Azithromycin 1 Gm single dose

Tetracycline 250 mgm qid for 2 weeks

Doxycycline 100 mgm twice for 2 weeks


Treatment … Contd

Treatment of TI Stage : same as TF stage

Treatment of TS stage : Ocular lubricants

Treatment of TT Stage : Epilation , tarsal rotation , radiofrequency/ diathermy or electrolysis epilation or cryotherapy


Treatment … Contd

• Treatment of CO Stage : After treatment of lid deformities LKP or PKP, depending on depth of corneal opacity


WHO’s GET 2020

• WHO in 1997 started Global Elimination of Trachoma by 2020 programme called WHO GET 2020 programme, under which ‘SAFE’ strategy has been adopted.

• S : Surgery for entropion/ trichiasis • A : Antibiotics for infectious trachoma• F : Facial cleanliness to reduce

transmission• E : Environmental improvement


Trachoma Control Programme

• Tetracycline eye ointment 1% twice daily on 5 consecutive days every month for 12 months

• Mass treatment should be annual in endemic zones ( <35% children are affected) and biannually in hyperendemic zones (>50% children are affected)


Ophthalmia Nodosa

Nodular conjunctivitis, resembling tuberculosis, due to irritation caused by caterpillar hairs.

Small semi-translucent pinkish, reddish or pale gray nodules formed in bulbar, palpabral conjunctiva, cornea and rarely in iris tissue.


Ophthalmia Nodosa .. Contd

Hairs are surrounded by giant cells and lymphocytes.

Treatment: Symptomatic, local steroids in selected cases, under supervision and excision of conjunctival nodules.


Chronic Non-specific Conjunctivitis

Is a clinical condition resulting from continuation of acute conjunctivitis or due to variety of etiological factors, characterized by chronic redness in one or both eyes with persistence of annoying symptoms.


Etiology

1. Exposure to Chronic irritants like, smoke, dust, heat, poor quality air, late hours, alcohol abuse.2. Hypersensitivity to allergen.3. Concretions, misdirected eyelash(es), dacryocystitis , chronic rhinitis, sinusitis, blepharitis, seborrhoea , dandruff etc4. Unilateral Conjunctivitis foreign body retained in conjunctiva or dacryocystitis


Symptoms

* Discomfort, burning, grittyness, especially in the evening when eyes becomes red and eyelid margins feel hot and dry.* Difficulty in keeping eyes open.* Increased secretions, mucoid or mucopurulent discharge, lids may stick together in the morning on waking up. together


Signs

• Hyperaemic lid margins

• Conjunctival congestion particularly in lower fornix

• Papillary hyperplasia


Treatment

• Elimination of cause

• Treatment of infection foci in nose and upper respiratory passage

• Treatment of conjunctival infection with appropriate antibiotic

• Treatment of meibomian gland abnormality by mechanical expression and warm compression.


Allergic Conjunctivitis

• Allergy or Hypersensitivity: is a state which is commonly regarded as an unfortunate by-product of the process of immunity whereby the tissues react by an abnormal and injurious response to foreign substances (allergens)


Allergy

• Two types of reactions:

a. Immediate and

b. Delayed Hypersensitivity


Immediate Hypersensitivity

• Ten days after initial exposure to foreign protein, anaphylactic reaction follows after second exposure to same protein. Characterized by circulating antibodies.


Delayed Hypersensitivity

• There are no circulating humoral antibodies of any kind. The sensitization is the property of the cells themselves. The hypersensitivity is caused by prior contact of the tissue with a protein and seems to be due to the development of sessile antibodies on or within the cells so that when they are re-exposed to the same antigen a reaction causing cellular damage develops which may even involve necrosis.


Delayed Hypersensitivity

• This reaction does not occur immediately and reach its maximum only after 24 to 72 hours.

• Typical example is tuberculin reaction.


Autosensitization

• In this case individual’s own tissue protein are altered and thus rendered “foreign” by a pathogenic agent, either bacterial or a chemical acting as a haptene, repeated contacts may result in hypersensitivity reaction eg Sulphonamide allergy and autosensitization induced by the haemolytic Streptococcus.


Physical Allergy

• Certain individuals react to physical agents such as heat, cold, light or mechanical irritation by a typical hypersensitive response often of urticarial type. Some individuals are hypersensitive to light of a certain wave-band.


Physical Allergy

• The reaction is due to auto-antigen liberated in the tissues either due to alteration of their specificity or due to their capability of reacting with antibody only under the physical condition created by the stimulus.


Types of Allergic Conjunctivitis

1. Simple Allergic Conjunctivitis

A. Immediate Anaphylactic (Hay fever) type mediated by circulating antibody

B. Delayed Type

(i) Contact Dermatoconjunctivitis due to local chemicals

(ii) Microbial Allergic Conjunctivitis

(iii) Keratoconjunctivitis Medicamentosa due to ingestion of drugs like arsenic and gold.


Types of Allergic Conjunctivitis

2. Interstitial Allergic Conjunctivitis

A. Phlyctenular Keratoconjunctivitis – Delayed reaction- Endogenous microbial allergy.

B. Vernal Catarrh – Allergic disease of immediate type – an exogenous allergy.


Acute or Sub-acute Allergic Catarrhal Conjunctivitis

• Is an allergic condition characterized by hyperaemia which is not as intense as found in bacterial conjunctivitis, accompanied by watery secretion containing eosinophils. Itching is a prominent symptom.

• Etiology: Exogenous allergen, contact with animals, pollens, flowers, chemicals, cosmetics, dye, medications etc. and sometimes bacterial protein of endogenous nature, the most common being staphylococcal infection.


Clinical Picture

• Symptoms: Itching, watering, redness, swelling of lids and there may symptoms of hay fever

• Signs: Conjunctival congestion, edema of lids may be there, watery discharge, presence of eosinophils and elevated IgE level


Treatment

1. Removal of allergen from environment

2. Astringent lotion, adrenalin 1:10000, antihistaminic drops (chlorpheniramine), mast cell stabilizers (sodium cromoglycate, olopatadine, ketotifen etc)

3. Short course corticosteroid drops

4. Topical 2% sodium cromoglycate drops.

TRACHOMA

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