Diseases of conjunctiva

Ophthalmology

1. Ophthalmology By Dr. Laraib Jameel Rph Follow me on slideshare.net https://www.slideshare.net/

2. Conjunctiva Definition: The conjunctiva is the clear, thin membrane that covers part of the front surface of the eye and the inner surface of the eyelids. The  conjunctiva is a  mucous membrane, similar to mucous membranes elsewhere in the body . Anatomically It has two segments: Bulbar conjunctiva.  This portion of the conjunctiva covers the outer surface of the eye or  sclera (the "white" of the eye). The bulbar conjunctiva stops at the junction between the sclera and cornea; it does not cover the cornea. Palpebral conjunctiva.  This portion covers the inner surface of both the upper and lower eyelid s. (Another term for the palpebral conjunctiva is tarsal conjunctiva .) The bulbar and palpebral conjunctiva are continuous. This feature makes it impossible for a contact lens (or anything else) to get  lost

3. Anatomy & physiology Besides palpebral & bulbar conjunctiva, the Third part of conjunctiva is Fornix conjunctiva . I t Forms the junction between the bulbar and palpebral conjunctivas : Function: It is loose and flexible, allowing the free movement of the lids and eyeball . It is composed of unkeratinized ,  stratified squamous epithelium  with  goblet cells , and  stratified columnar epithelium. The conjunctiva is highly vascularised , with many  microvessels .

4. Blood Supply: the circulations of the bulbar conjunctiva and palpebral conjunctiva are linked, so both bulbar conjunctival and palpebral conjunctival vessels are supplied by both the ophthalmic artery and the external carotid artery, to varying extents. Microanatomy : The epithelial layer contains blood vessels, fibrous tissue, and lymphatic channels . Accessory lacrimal glands in the conjunctiva constantly produce the aqueous portion of tears . Additional cells present in the conjunctival epithelium include melanocytes, T and B cell lymphocytes

5. Conjunctiva Function The primary functions of the conjunctiva are: Keep the front surface of the eye moist and lubricated . Keep the i nner surface of the eyelids moist and lubricated so they open and close easily without friction or causing eye irritation. Protect the eye from dust , debris and infection-causing microorganisms. The conjunctiva has many small blood vessels that provide nutrients to the eye and lids. It also contains special cells that secrete a component of the tear film to help prevent dry eye syndrome .

6. Conjunctivitis Definition: is inflammation of the thin, clear covering of the white of the eye and the inside of the eyelids (conjunctiva ). Synonym: Pink eye Conjunctivitis can have several causes, but many eye doctors use the term "pink eye" to refer only to viral conjunctivitis. When small blood vessels in the conjunctiva become inflamed, they're more visible. This is what causes the whites of your eyes to appear reddish or pink.

7. Types of conjunctivitis Types: Allergic conjunctivitis Allergic conjunctivitis affects both eyes and is a response to an allergy-causing substance such as pollen. Mechanism: In response to allergens, your body produces an antibody called immunoglobulin E ( IgE ). This antibody triggers special cells called mast cells in the mucous lining of your eyes and airways to release inflammatory substances, including histamines. Your body's release of histamine can produce a number of allergy signs and symptoms, including red or pink eyes . IgE – Mast cell production--- in mucus lining of eye--- inflammatory substance (histamine)---- allergic signs Symptoms: If you have allergic conjunctivitis, you may experience intense itching, tearing and inflammation of the eyes as well as sneezing and watery nasal discharge . Treatment: Most allergic conjunctivitis can be controlled with allergy eyedrops .

8. Infectious Conjunctivitis 1- Bacterial conjunctivitis  is an infection most often caused by staphylococcal or streptococcal bacteria from your own skin or respiratory system . Respiratory bacteria: Bacterial causes include  Staphylococcus aureus , Streptococcus pneumoniae , Haemophilus species , and, less commonly ,   Chlamydia trachomatis . Bacterial conjunctivitis is sometimes caused by a sexually transmitted infection (STI), such as  Chlamydia . I f symptoms do not disappear after a month, this may indicate an STI . Most other types of bacterial conjunctivitis will resolve more quickly with treatment. Infective conjunctivitis is extremely contagious and can easily be passed on to another person . Ophthalmia neonatorum  is a severe form of bacterial conjunctivitis that occurs in newborn babies. This is a serious condition that could lead to permanent eye damage if it is not treated immediately. Ophthalmia neonatorum occurs when an infant is exposed to chlamydia or gonorrhea while passing through the birth canal. 

9. 2- Viral conjunctivitis  is most commonly caused by contagious, viruses associated with the common cold . It can develop through exposure to the coughing or sneezing of someone with an upper respiratory tract infection . Viral conjunctivitis can also occur as the virus spreads along the body's own mucous membranes , which connect the lungs , throat , nose , tear ducts and conjunctiva. Since the tears drain into the nasal passageway, forceful nose blowing can cause a virus to move from your respiratory system to your eyes . Viruses that cause conjunctivitis include adenoviruses and some types of herpes virus.

10. The other type of conjunctivitis is chemical or irritant conjunctivitis: the eye coming into contact with things that can irritate the conjunctiva , such as shampoo or chlorinated water, or a loose eyelash rubbing against the eye this is known as irritant conjunctivitis.

11. Difference between different strains which cause pink eye Viral strains  are the most common -- and may be the most contagious -- forms. They tend to start in one eye, where they cause lots of tears and a watery discharge . Within a few days , the other eye gets involved . Symptoms: You might feel a swollen lymph node in front of your ear or under your jawbone. Bacterial strains   usually infect one eye but can show up in both. Your eye will put out a lot of pus and mucus. Allergic types  produce tearing, itching, and redness in both eyes. You might also have an itchy, runny nose.

12. Symptoms: They depend on the cause of the  inflammation , but may include: Redness in the white of the eye or inner eyelid Swollen conjunctiva More tears than usual Thick yellow discharge that crusts over the  eyelashes , especially after  sleep . It can make your eyelids stick shut when you wake up. Green or white discharge from the eye Itchy eyes Burning  eyes Blurred vision More sensitive to light Swollen lymph nodes (often from a  viral infection )

13. Diagnosis: Don’t assume that all red, irritated, or swollen eyes are pinkeye (viral conjunctivitis). Your symptoms could also be caused by seasonal allergies, a sty,  iritis ,  chalazion   or  blepharitis   . These conditions aren’t contagious . Your eye doctor will ask you about your symptoms , give you an eye exam, and may use a cotton swab to take some fluid from your eyelid to test in a lab. That will help find bacteria or viruses that may have caused conjunctivitis, including those that can cause a sexually transmitted disease, or  STD. Testing , with special emphasis on the conjunctiva and surrounding tissues, may include : Visual sharpnes measurements  to determine whether vision has been affected . Evaluation of the conjunctiva and external eye tissue   using bright light and magnification. Evaluation of the inner structures of the eye  to ensure that no other tissues are affected by the condition .

14. Treatment: Allergic conjunctivitis can usually be treated with anti-allergy medications such as antihistamines . If possible, you should avoid the substance that triggered the allergy . The first step is to remove or avoid the irritant, if possible. Cool compresses and artificial tears sometimes relieve discomfort in mild cases. In more severe cases , nonsteroidal anti-inflammatory medications and antihistamines may be prescribed . Antihistamines (either oral or drops) can give relief in the meantime. ( But remember that if you have dry eyes, taking antihistamines by  mouth can make your eyes even drier.)

15. Treatment for Bacteria .  If bacteria, including those related to STDs , caused your pinkeye, you’ll take antibiotics in the form of eyedrops , ointments, or pills . You may need to apply eyedrops or ointments to the inside of your eyelid 3 to 4 times a day for 5 to 7 days. You would take pills for several days. The infection should improve within a week . The most commonly prescribed antibiotics for infective conjunctivitis are: fluoroquinolones tetracyclines sulfonamides chloramphenicol These are eye drops or ointment, administered straight onto the eye. Dosage depends on the type

16. Viral conjunctivitis.   No drops or ointments can treat viral conjunctivitis. Antibiotics will not cure a viral infection . Like a common cold, the virus has to run its course, which may take up to two or three weeks . Symptoms can often be relieved with cool compresses and artificial tear solutions . For the worst cases, topical steroid drops may be prescribed to reduce the discomfort from inflammation. However , these drops will not shorten the infection .

17. Preventions: T he most effective prevention is good hygiene , especially avoiding rubbing the eyes with infected hands . Vaccination against adenovirus,  Haemophilus influenzae , pneumococcus, and  Neisseria meningitidis  is also effective. N ever share personal items  such as washcloths, hand towels or tissues. Cover your nose and mouth  when coughing or sneezing . When swimming , wear swim goggles to protect yourself from bacteria and other microorganisms in the water that can cause conjunctivitis . If you wear contact lenses , follow your eye doctor's instructions for lens care and replacement, and use contact lens solutions properly or consider switching to daily disposable contact lenses . If you know you suffer from seasonal allergies , ask your doctor what can be done to minimize your symptoms before they begin.

18. Trachoma Definition: Trachoma ( truh -KOH- muh ) is a bacterial infection that affects your eyes. It's caused by the bacterium Chlamydia trachomatis.  Trachoma is contagious , spreading through contact with the eyes, eyelids, and nose or throat secretions of infected people. It can also be passed on by handling infected items . Trachoma is the leading preventable cause of blindness worldwide . The World Health Organization (WHO) estimates that nearly 2 million people have been blinded by trachoma.

19. Trachoma

20. Causes Trachoma is caused by certain subtypes of Chlamydia trachomatis, a bacterium that can also cause the sexually transmitted infection chlamydia . There are different types of  Chlamydia trachomatis . Types A, B, Ba, and C cause blinding trachoma. Other types (D to K) are associated with sexually transmitted chlamydia infection. Epidemiology: In areas where trachoma is endemic , active (inflammatory) trachoma is common among preschool-aged children , with prevalence rates which can be as high as 60–90%. Infection becomes less frequent and shorter in duration with increasing age

21. Clinical manifestation: In its early stages, trachoma causes conjunctivitis ( pink eye). Early symptoms begin to appear within five to 12 days of exposure to the bacterium. These symptoms can include: mild itching and irritation of the eyes and eyelids, and a discharge from the eyes As the infection progresses , it causes eye pain and blurred vision . If the infection is untreated , scarring occurs inside the eyelid . This leads to the  eyelashes turning inward toward the eye . This condition is called  trichiasis . The eyelashes brush and scratch against the cornea , the clear, dome-shaped window at the front of the eye. This continual irritation turns the cornea cloudy . It can lead to the development of  corneal ulcers and vision loss.

22. Symptoms: Signs and symptoms of trachoma usually affect both eyes and may include: Mild itching and irritation of the eyes and eyelids Discharge from the eyes containing mucus or pus Eyelid swelling Light sensitivity (photophobia) Eye pain

23. The WHO grading system for trachoma classifies the disease in 5 grades : Trachomatous inflammation -- follicular (TF) : The first sign is the presence of follicles, which are small bumps  formed by swollen lymph tissue on the back of the upper eyelid and sometimes extending to the top part of the eye . The presence of five or more follicles greater than 0.5 mm in size on the  conjunctiva lining the back of the upper eyelid is considered grade TF. Trachomatous inflammation -- intense (TI) : The next phase is swelling (inflammation) of the conjunctiva that view the normal deeper blood vessels of the conjunctiva. Trachomatous scarring (TS) : Bands of scar tissue form within the conjunctiva lining the inside of the upper eyelid. Trachomatous trichiasis (TT): The bands of scar tissue tighten, causing the lid margins to turn inward ( entropion ) and the eyelashes to rub against the eye ( trichiasis ). Over time, this rubbing results in abrasions of the cornea, the clear central covering of the front of the eye. Corneal opacity: Corneal abrasions can lead to infectious ulcers and ultimately opaque scarring that blocks light from entering the eye, leading to blindness.

24. Risk factors Factors that increase your risk of contracting trachoma include: Poverty.  Trachoma is primarily a disease of extremely poor populations in developing countries. Crowded living conditions.  People living in close contact are at greater risk of spreading infection. Poor sanitation.  Poor sanitary conditions and lack of hygiene, such as unclean faces or hands, help spread the disease. Age.  In areas where the disease is active , it's most common in children ages 4 to 6. Sex.   In some areas, women's rate of contracting the disease is two to six times higher than that of men. Flies.  People living in areas with problems controlling the fly population may be more susceptible to infection. Lack of latrines.  Populations without access to working latrines — a type of communal toilet — have a higher incidence of the disease

25. Diagnosis: Your ophthalmologist can diagnose most cases of  conjunctivitis  through an eye exam . He or she may take a sample (culture) if you visited a country where trachoma is common. To do this, he or she will numb your eye and swab the surface. The laboratory test will show if trachoma is the source of the eye infection. In more severe cases of trachoma, an eye exam will reveal: scarring on the inside of the upper eyelid new blood vessel growth in the  cornea , and eyelashes turned inward

26. Treatment: Medication: In the early stages of trachoma , treatment with antibiotics alone may be enough to eliminate the infection . Your doctor may prescribe tetracycline eye ointment or oral azithromycin (Zithromax). Azithromycin appears to be more effective than tetracycline, but it's more expensive. The World Health Organization (WHO) recommends giving antibiotics to an entire community when more than 10 percent of children have been affected by trachoma. The goal of this guideline is to treat anyone who has been exposed to trachoma and reduce the spread of trachoma.

27. Surgery Treatment of later stages of trachoma — including painful eyelid deformities — may require surgery. WHO guidelines recommend surgery for people with the advanced stage of trachoma. In eyelid rotation surgery ( bilamellar tarsal rotation), your doctor makes an incision in your scarred lid and rotates your eyelashes away from your cornea . The procedure limits the progression of corneal scarring and may help prevent further loss of vision. If your cornea has become clouded enough to seriously impair your vision, corneal transplantation may be an option that may improve vision. Frequently, however, with trachoma, this procedure doesn't have good results. You may have a procedure to remove eyelashes (epilation) in some cases. This procedure may need to be done repeatedly. Another temporary option, if surgery isn't an available option , is to place an adhesive bandage over your eyelashes to keep them from touching your eye

28. Prevention and control Elimination programmes in endemic countries are being implemented using the WHO-recommended SAFE strategy. This consists of: S urgery to treat the blinding stage ( trachomatous trichiasis ); A ntibiotics to clear infection, particularly mass drug administration of the antibiotic azithromycin, which is donated by the manufacturer to elimination programmes , through the International Trachoma Initiative; F acial cleanliness; and E nvironmental improvement, particularly improving access to water and sanitation.

29. P inguecula Definition: The term “ pinguecula ” refers to a pyramid-like growth that appears as a yellow discoloration on the conjunctiva  A pinguecula (pin-GWEK- yoo - lah ) is a yellowish, slightly raised thickening of the conjunctiva on the white part of the eye (sclera), close to the edge of the cornea . Pingueculae are non-cancerous bumps on the eyeball and typically occur on top of the middle part of the sclera, the part that's between your eyelids and therefore is exposed to the sun. Usually pingueculae affect the surface of the sclera that's closer to the nose, but they can occur on the outer sclera (closer to the ear) as well.

30. Pinguecula

31. Causes: In fact, the word “ pinguecula ” comes from a Latin word that originally means “fatty .” A pinguecula forms when the tissue in your conjunctiva changes and creates a small bump. Some of these bumps contain fat, calcium, or both . Risk factors: Ultraviolet radiation  from the sun is the primary cause of the development of pingueculae , frequent exposure to dust and wind also appear to be be risk factors.  For this reason, pinguecula is sometimes known as “surfer’s eye,” Dry eye disease  also may be a contributing factor and can promote the growth of pingueculae

32. Mechanism: Histologically, there is degeneration of the collagen fibers of the conjunctival   stroma (beneath the epithelium, covers the tarsus)  with thinning of the overlying epithelium  and occasionally calcification. (globular protein) actinic exposure of the thin conjunctival tissue is thought to cause fibroblasts to produce more elastin fibers, which are more twisted than normal elastin fibers and may lead to the degradation of the collagen fibers . Actin exposure of thin conjunctival tissue--- forms fibroblast----- produces more elastin fibers (yellow color)---- causes degradation of collagen fibers   It is thought that the high reflectivity of the solid white scleral tissue underlying the conjunctival tissue may result in additional UV exposure to the back side of the tissue .  The side of the nose also reflects sunlight on to the conjunctiva. As a result, pingueculae tend to occur more often on the nasal side of the eye.  Calcification: hardening of tissue by the deposition of calcium compounds .

33. Sign & Symptoms: It is seen as a yellow-white deposit on the conjunctiva adjacent to the  limbus   (the junction between the cornea and sclera ). In most people, pingueculae don't cause many symptoms. But when they do, those symptoms usually stem from a disruption of the tear film. Because a pinguecula is a raised bump on the eyeball, the natural tear film may not spread evenly across the surface of the eye around it, causing dryness . This can cause dry eye symptoms, such as a burning sensation, stinging, itching, blurred vision and foreign body sensation. Another symptom of pingueculae is the appearance of extra blood vessels in the conjunctiva that covers the sclera, causing red eyes. In some cases , pingueculae can become swollen and inflamed. This is called pingueculitis .

34. Diagnosis: A pingueculum is typically diagnosed by a careful clinical examination.

35. Treatment: It usually don’t need any type of treatment for a pinguecula unless it causes discomfort because A pingueculum does not grow on the cornea or threaten sight.  If eye does hurt, your doctor can give you eye ointment or eye drops to relieve redness and irritation . Pingueculae also can lead to localized inflammation and swelling that is sometimes treated with steroid eye drops or non-steroidal anti-inflammatory drugs (NSAIDs). You can talk to your doctor about having the pinguecula surgically removed if its appearance bothers you. In some cases, the growth might need to be removed. Surgery is considered when a pinguecula : grows over your cornea , as this can affect your vision causes extreme discomfort when you try to wear contact lenses is constantly and severely inflamed, even after you apply eye drops or ointments

36. wear photochromic lenses , which block out 100 percent of ultraviolet radiation. They are designed to protect the eyes from the harmful high-energy blue light by automatically darkening when coming into contact with that level of sunlight.

37. Scleral contact lenses sometimes are prescribed to cover the growth, protecting it from some of the effects of dryness or potentially from further UV exposure.

38. Complications: The surface of the conjunctival tissue overlying a pinguecula interferes with the normal spreading of the tear film. Preventions: If you spend a lot of time outdoors due to work or hobbies, you’re more likely to develop pingueculae . However, you can help prevent these growths by wearing sunglasses when you’re outside. You should wear sunglasses that have a coating that blocks the sun’s ultraviolet A (UVA) and ultraviolet B (UVB) rays . Sunglasses also help protect your eyes from wind and other outdoor elements, such as sand. Keeping your eyes moisturized with artificial tears might also help prevent pingueculae . You should also wear protective eyewear when working in a dry and dusty environment.

39. Pterygium Definition: A pterygium ( tuh -RIJ- ee - uhm ) is a growth of the conjunctiva or mucous membrane that covers the white part of your eye over the cornea. The cornea is the clear front transparent covering of the eye. This benign or noncancerous growth is often shaped like a wedge. A  pterygium  is a pinkish , triangular tissue growth on the cornea of the  eye. It typically starts on the cornea near the nose .   It may slowly grow but rarely grows so large that the pupil is covered. Often both eyes are involved.

40. Pterygium

41. Cause: The exact cause is unknown , but it is associated with excessive exposure to wind, sunlight, or sand . Therefore, it is more likely to occur in populations that inhabit the areas near the  equator (tropical regions), as well as windy locations . In addition, pterygia are twice as likely to occur in men than women . Some research also suggests a genetic predisposition due to an expression of  vimentin , which indicates cellular migration by the keratoblasts embryological development , which are the cells that give rise to the layers of the cornea. Supporting this fact is the congenital pterygium , in which pterygium is seen in infants .   These cells also exhibit an increased P53 (tumor protein) expression likely due to a deficit in the tumor suppressor gene . These indications give the impression of a migrating  limbus  because the cellular origin of the pterygium is actually initiated by the limbal epithelium

42. Pathophysiology The large number of theories that exist to explain the pathogenesis of pterygium growth underscores the uncertainty of the etiology. The increased prevalence in hot dry climates and regions nearer to the equator suggest a role of environmental factors such as UV radiation and dryness. Actinic changes seen on histopathology similar to actinic keratoses on the skin also supports the role of UV radiation. It has been suggested that radiation activated fibroblasts may result in excessive production of material resulting in pterygia . Other proposed theories include choline deficiency , (supports the development of the retina of the eye and impacts vision throughout life) an inflammatory disorder , disregulation of angiogenesis , immune system abnormalities , tear film abnormalities , as well as the possible role of a viral stimulus . Angiogenesis  is the formation of new blood vessels. This process involves the migration, growth, and differentiation of endothelial cells, which line the inside wall of blood vessels. The process of  angiogenesis  is controlled by chemical signals in the body.

43. Symptoms: Pterygia usually occur on the side of the eye closer to the nose , but they can also develop on the side closer to the ear as well and can affect one eye or both eyes. Many people with mild surfer's eye may not experience symptoms or require treatment. But large or growing pterygia often cause a gritty, itchy or burning sensation or the feeling something is "in" the eye (called a foreign body sensation). Also , these pterygia often become inflamed, causing unattractive  red eyes. If a pterygium significantly invades the cornea, it can distort the shape of the front surface of the eye , causing  blurred vision and   higher-order deviations  that affect vision.

44. Diagnosis: Pterygium (conjunctiva) can be diagnosed without need for a specific exam, however  corneal topography is a practical test (technique) as the condition worsens The diagnosis is made by slit-lamp examination of the typical limbal growth at the characteristic location within the palpebral fissure. The diagnosis is most often clear clinically, but histopathologic confirmation is performed routinely . Physical examination External examination (lids, lashes , lacrimal apparatus) Examination of bulbar and palpebral conjunctiva as well as fornices Topography : the distribution of parts or features on the surface of or within an organ or organism.

45. Treatment: Treatment of surfer's eye depends on the size of the pterygium , whether it is growing and the symptoms it causes. Regardless of severity, pterygia should be monitored to prevent scarring that could lead to vision loss. If a pterygium is small, your eye doctor  may prescribe lubricants or a mild steroid eye drop to temporarily reduce swelling and redness . Contact lenses are sometimes used to cover the growth, protecting it from some of the effects of dryness or potentially from further UV exposure. Topical cyclosporine also may be prescribed for dry eye . If pterygium surgery is required, several surgical techniques are available . Pterygium excision may be performed either in a room at the doctor's office or in an operating room. It's important to note that pterygium removal can induce astigmatism, especially in people who already have astigmatism. Surgery for pterygium removal usually lasts no longer than 30 minutes, after which you likely will need to wear an eye patch for protection for a day or two. You should be able to return to work or normal activities the next day.

46. Surgery Conjunctival Flap/Graft : this is considered the Gold Standard of care and carries an approximate rate of recurrence of 5-10% with minimal complications . However, it is a lengthier procedure and technically slightly more complicated

47. Complication: Recurrence Unfortunately, pterygia often return after surgical removal , possibly due to oxidative stress and/or continued UV exposure. To prevent regrowth after a pterygium is surgically removed, your eye surgeon may suture or glue a piece of surface eye tissue onto the affected area. This method, called autologous conjunctival autografting , has been shown to safely and effectively reduce the risk of pterygium recurrence . A drug that can help limit abnormal tissue growth and scarring during wound healing , such as mitomycin C, (chemotherapeutic activity) also may be applied topically at the time of surgery and/or afterward to reduce the risk of pterygium recurrence. After removal of the pterygium , the doctor will likely prescribe steroid eye drops for several weeks to decrease swelling and prevent regrowth. In addition to using your drops, it's very important to protect your eyes from the sun with UV-blocking sunglasses or photochromic lenses after surgery, since exposure to ultraviolet radiation may be a key factor in pterygium recurrence .

48. Difference between Pterygium & pinguecula Pterygium Pterygia have a flesh-colored (pink) appearance and are round, oval, or elongated. Pterygia are more likely to grow over the cornea, Pterygia  is the growth of fleshy tissue that can start as a pinguecula , but it grows large enough to cover the cornea and affect vision P inguecula A pinguecula is yellowish in color and typically has a triangular shape. Less likely to grow on cornea & when pinguecula that grows onto the cornea is known as a pterygium . Pinguecula do not grow, do not cover the cornea, and do not affect vision .

49. Similarities between Pterygium & P inguecula Both pterygium and a pinguecula are abnormal growths that form on the surface of the eye. Pingueculae and pterygia are both benign and grow near the cornea. They’re both linked to exposure to the sun, wind, and other harsh elements . Redness, irritation, grittiness Abnormal growth Benign tumor Cause Symptoms

50. Opthalmia neonatorum Definition: is defined as conjunctival inflammation occurring within the first 30 days of life. Synonym : Neonatal conjunctivitis  a type of neonatal infection   contracted by newborns during  delivery.

51. Opthalmia neonatorum

52. Cause with respect to classification It may be aseptic or septic . Aseptic= free of disease causing microbe Septic= disease causing microbes. 1- Aseptic neonatal  conjunctivitis: Aseptic neonatal conjunctivitis most often is a chemical conjunctivitis that is induced by silver nitrate solution, which is used at birth as prophylaxis of infectious conjunctivitis . Chemical conjunctivitis is becoming less common owing to the use of erythromycin ointment or povidone iodide in place of silver nitrate solution for the prophylaxis of infectious conjunctivitis . Silver nitrate is a surface-active chemical that facilitates agglutination and inactivation of gonococci . Ironically, silver nitrate was later found to be toxic to the conjunctiva, particularly in higher concentrations, potentially causing a sterile neonatal conjunctivitis.

53. 2- S eptic neonatal  conjunctivitis: Bacterial  and viral infections are major causes of septic neonatal conjunctivitis, with  Chlamydia  being the most common infectious agent. Infants may acquire these infective agents as they pass through the birth canal during the birth process . Many different bacteria and viruses can cause conjunctivitis in the neonate. The two most common bacterial causes are 1- Chlamydia trachomatis  is an obligate intracellular parasite and has been identified as the most common infectious cause of neonatal conjunctivitis.   The reservoir of the organism is the maternal cervix or urethra . Infants who are born to infected mothers are at high risk (approximately 25%-50%) of developing an infection. 2- Neisseria gonorrhoeae  is a gram-negative diplococcus and is potentially the most dangerous and virulent infectious cause of neonatal conjunctivitis. As with chlamydia, maternal cervical and urethral mucosa provide a reservoir for  N gonorrhoeae ,  which is acquired during birth . Gonococci can penetrate intact epithelial cells and divide rapidly inside them.

54. Other bacteria The most commonly identified gram-positive organisms include  Staphylococcus aureus,Streptococcus pneumoniae,Streptococcus viridans ,  and  Staphylococcus epidermidis .  These bacteria make up 30-50% of all cases of infectious neonatal conjunctivitis.   Gram-negative organisms , such as  Escherichia coli, Klebsiella pneumoniae , Serratia marcescens ,  and  Proteus, Enterobacter ,  and  Pseudomonas  species, also have been implicated. There has been one reported case of  Eikenella corrodens  neonatal conjunctivitis.   Infants of low birth weight and low gestational age with clinical signs of conjunctivitis in the neonatal intensive care unit (NICU) should be evaluated and treated for a gram-negative etiology. Herpes simplex virus Herpes simplex virus (HSV) is a rare cause of neonatal  keratoconjunctivitis , found in less than 1% of cases,   and can be associated with a generalized herpes simplex infection. Most infants with such an infection acquire the disease during the birth process. Caesarean delivery is strongly considered when active maternal genital disease is recognized at term since the risk of transmitting HSV to the neonate during vaginal delivery is 25-60%.

55. Sign & Symptoms: Chemical conjunctivitis  secondary to topical prophylaxis usually appears within 6 to 8 h after instillation and disappears spontaneously within 48 to 96 h . (2-3 days) Chlamydial ophthalmia  usually occurs 5 to 14 days after birth . It may range from mild conjunctivitis with minimal mucopurulent discharge to severe eyelid edema with copious drainage and pseudomembrane formation. Follicles are not present in the conjunctiva, as they are in older children and adults. Gonococcal ophthalmia  causes an acute purulent conjunctivitis that appears 2 to 5 days after birth or earlier with premature rupture of membranes. The neonate has severe eyelid edema followed by chemosis and a profuse purulent exudate that may be under pressure. If untreated, corneal ulcerations and blindness may occur.

56. Conjunctivitis caused by other bacteria  has a variable onset, ranging from 4 days to several weeks after birth. Herpetic keratoconjunctivitis  can occur as an isolated infection or with disseminated or CNS infection . It can be mistaken for bacterial or chemical conjunctivitis, but the presence of dendritic keratitis is pathognomonic.

57. Diagnosis: Diagnostic Gram stain or Giemsa stain smears obtained from genitourinary or ocular mucosal scrapings reveal characteristic gram-negative intracellular diplococci . Conjunctival material is Gram stained, cultured for gonorrhea ( eg , on modified Thayer-Martin medium) and other bacteria, and tested for chlamydia ( eg , by culture, direct immunofluorescence, or enzyme-linked immunosorbent assay [samples must contain cells ]). Conjunctival scrapings can also be examined with Giemsa stain; if blue intracytoplasmic inclusions are identified, chlamydial ophthalmia is confirmed. Viral culture is done only if viral infection is suspected because of skin lesions or maternal infection.

58. Treatment: Systemic , topical, or combined antimicrobial therapy Neonates with conjunctivitis and known maternal gonococcal infection or with gram-negative intracellular diplococci identified in conjunctival exudates should be treated with ceftriaxone or  cefotaxime . In chlamydial ophthalmia ,  systemic therapy is the treatment of choice, because at least half of affected neonates also have nasopharyngeal infection and some develop chlamydial pneumonia.  Erythromycin  ethylsuccinate 12.5 mg/kg po q 6 h for 2 wk or azithromycin 20 mg/kg po once/day for 3 days is recommended . A neonate with  gonococcal ophthalmia   is hospitalized for evaluation of possible systemic gonococcal infection and given a single dose of ceftriaxone 25 to 50 mg/kg IM or IV to a maximum dose of 125 mg. Infants with hyperbilirubinemia or those receiving calcium-containing fluids should not receive ceftriaxone and may be given a single dose of  cefotaxime  100 mg/kg IV or IM. Frequent saline irrigation of the eye prevents secretions from adhering.

59. Conjunctivitis due to other bacteria usually responds to topical ointments containing polymyxin plus bacitracin, erythromycin, or tetracycline. Herpetic keratoconjunctivitis should be treated (with an ophthalmologist’s consultation) with systemic acyclovir 20 mg/kg q 8 h for 14 to 21 days and topical 1%  trifluridine  ophthalmic drops or ointment

60. Complications: If untreated, peripheral corneal ulceration may occur in  N gonorrhoeae  infection and rapidly progress to corneal perforation. When unrecognized and not immediately treated,  Pseudomonas  infection may lead to endophthalmitis and subsequent death . Pneumonia has been reported in 10-20% of infants with chlamydial conjunctivitis.   HSV keratoconjunctivitis can cause corneal scarring and ulceration . Additionally , disseminated HSV infection often includes central nervous system involvement .