Ординатура / Офтальмология / Английские материалы / Pediatric Opthalmology_Mukherjee_2005

46.Glasser J.S. ; Neurophthalmology. p-258, Harper and Row, London, 1982.

47.Butten C.L., Young B.R. : Chronic orbital myositis. Arch. Oph. 100 : 1749-1751, 1982.

48.Ratnakar K.S. ; Pathology of orbital space occupying lesion in Pathology of the eye and orbit. First edition, p-204–205, Jay Pee Brothers, New Delhi, 1997.

49.Scheie, H.G. and Albert D.M. : Ophthalmic radiology in Text Book of Ophthalmology. p- 252–253, 9th edition, W.B. Saunders Company, philadelphia, 1977.

50.Scheie H.G. and Albert D.M. : Medical ophthalmology in Text book of ophthalmology. p- 454–455, 9th edition, WB Saunders Company, Philadelphia, 1977.

51.Carol L. Shields and Sheilds J.A. ; Orbital rhabdomyosarcoma in Current ocular therapy. Edition fifth, p-256–258, Edited by Fraunfelder F.T. and Roy F.H. WB Saunders Company, philadelphia, 2000.

52.Levin R.A. ; Orbital tumors in Principle and practice of ophthalmology. Vol. III, p-2161–2165, First Indian edition, edited by Peyman G.A., Sander D.R. and Goldberg MF. Jay Pee Brothers, New Delhi, 1987.

53.Kanski J.J. ; The orbit in Clinical ophthalmology. Second edition, p-41, Butterworth, London, 1989.

54.Levin R.A. ; Orbital tumors in Principle and practice of ophthalmology. Vol. III, p-2156–57, First Indian edition, edited by Pyeman G.A., Sander D.R. and Goldberg M.F. Jay Pee Brothers, New Delhi, 1987.

55.Fraunfelder F.T. ; Ewing’s sarcoma in Current ocular therapy. Edition fifth, Edited by Fraunfelder F.T. and Roy F.H. p-235–236, WB Saunders Company, Philadelphia, 2000.

56.Jakobicc F.A. Root man J., Jones I.S. ; Secondary and metastatic tumors of orbit in Clinical opthalmology. Vol. II, Edited by Duane T.D., p-1–67, Harper and Row, 1982.

57.Khurana A.K., Ahluwalia B.K. and Gupta S. ; Bilateral proptosis due to metastatic Ewing’s sarcoma. Ind.Jr.Oph. 40 : 15-17, 1992.

58.Karp, L.A., Zimmerman L.E., Payne T. ; Intra ocular involvement in Burkitts lymphoma. Arch. Oph. 85 : 295, 1971.

59.Feman S.S., Niwayama G., Hapler R.S., Foos R.Y. ; Burkitt’s tumor with intra ocular involvement. Surv. Oph. 14 : 106, 1969.

60.Vyas P. and Chandrashekhar G. ; Orbital lymphoma and allied conditions in Modern ophthalmology. Edited by Dutta L.C. First edition, p-124, Jay Pee Brothers, New Delhi, 1994.

61.Natrajan M. ; Tumors of optic nerve in Neurophthalmology. First edition, p-14.1–14.14, Arvind eye hospital, maduri.

62.Glaser J.S. : Neurophthalmology. p-116–117, Harper and Row, 1982.

63.Boger, P.W., Peterson R.A. ; Paediatric ophthalmology in Manual of ocular diagnosis and therapy. Edited by Deborah Pavan Langston, p-283–284, Little Brown.

64.Melen O. ; Ophthalmic manifestation of brain tumors in Principle and practice of ophthalmology. Edited by Peyman G.A., Sander D.R., Goldberg M.F. Ist Indian edition, p- 2012–2015, Jay Pee Brothers, New Delhi, 1987.

65.Scheie H.G. and Albert D.M. ; Ophthalmic radiology in Text book of ophthalmology. 9th edition, p-147–148, WB Saunders Company, Philadelphia, 2000.

66.Apple D.J., Pandey S.R., Gomez M.E. ; Langerhans cell histocytosis in Current ocular therapy. 5th edition, p-289–290. Edited by Fraunfelder F.T. and Roy F.H. WB Saunders Company, Philadelphia, 2000.

67.Rubin P.A.D. ; Orbital disorders in Manual of ocular diagnosis and therapy. 5th edition, p-56–66, Edited by Deborah Pavan Langston, Lippincot Williams and Wilkins, philadelphia, 2002.

is a potential space without much clinical importance except that antibiotics and steroids can be injected in this space for better penetration. The Tenon’s capsule acts as synovial-mem- brane for the sclera.

The visible part of the sclera is covered by bulbar conjunctiva, which can also be lifted off the sclera by fluid injected in the sub conjunctival space.

In normal eyes the vessels seen over the sclera are conjunctival in nature and can be moved with conjunctiva. There are only a few visible episcleral vessels in normal eye, in chronically inflamed eyes and absolute glaucoma, prominent episcleral vessels can be visible.

Attachment of the extra ocular muscles

All extra ocular muscles are inserted in the sclera. The four recti are attached in front of the equator and the two obliques behind the equator. The distance of attachment of the recti are not equal from the limbus. The medial rectus is attached 5.5 mm away from the limbus. The inferior rectus is attached 6.5 mm away from limbus and the lateral and superior rectus 7.00 mm and 8.1 mm respectively. The tendons of the extra ocular muscle get mingled with the sclera very intimately. The inferior oblique has the shortest tendon i.e. 1 mm. Attachments of recti are on the thinnest part of the sclera. Care should be taken not to nick the sclera during detaching these muscles or passing sutures during strabismus surgery.

Weak spots in the sclera

The sclera is not of uniform thickness, it is precariously thin at the equator. The sclera has multiple apertures through which vessels and nerves pass. These are also potentially weak spots. Besides these anatomical weak spots the sclera may be thinned at other place following injury and inflammation.

Thus the weak spots on the sclera are - Corneo scleral junction, equator, over the ciliary body and posterior pole.

Colour of the sclera

The colour of the adult sclera is white. At birth it has a bluish tinge due to choroid shinning under thin sclera. The sclera is thin in childhood, by five to seven years it becomes as white and as thick as adult sclera.

Histologically sclera is divided into:1

1.Episclera

2.Scleraproper

3.Lamina fusca.

The episclera is an ill defined layer of connective tissue that lies between the Tenon’s capsule and the sclera. It is loosely attached to both. It is thin at the equator and under the bulbar conjunction and thick round the optic nerve. It is less vascular than conjunctiva but more vascular than sclera proper, is more likely to be inflamed than sclera.

The sclera proper consist of large bundles of collagen, packed densely. The superficial fibers are larger than the deeper. The space in between the fibers is filled by mucopolysaccharides. The fibers round the limbus and optic nerve are concentric with these structures, the fibers in between are arranged irregularly.

Lamina Fusca—It is a thin ill defined layer that contains melanocyte on the inner side of the sclera.

Functions of the sclera

The main function of the sclera is to protect intra ocular structures, to maintain the shape of the globe and to keep the retina in optically correct position. For sharp focus it is essential that the interior of the eye remains in darkness, which is brought about by small mobile pupil, pigment in uvea and opaque sclera.

The opacity of the sclera is due to irregular arrangement of its large fibres and low water content.

Development of sclera2

Developmentally sclera is mesodermal. It develops from condensation of mesodermal tissue round the optic cup. The anterior part develops early, to which the developing recti are attached. The limbus is placed well behind its normal position initially, the limbus gradually moves anteriorly. By 12 weeks the posterior sclera develops round the optic nerve and a well formed posterior pole becomes obvious. The lamina also develops at this time. The scleral spur develops by 12th week. The Tenon’s capsule develops along with the eyeball. Surprisingly the shape and configuration of the eyeball are least influenced by sclera. These are regulated by developing retina3. (See page 3)

Congenital anomalies of the sclera (See page 8-9)

The congenital anomalies of the sclera are few and are mostly due to defect in:

1.Development of optic cup and its further progress

2.Failure of development of mesodermal tissue round the optic vesicle resulting into malformation of globe with—

(a) Intact sclera—Microphthalmos

(b) With scleral defect i.e. microphthalmos with cyst and cystic eyeball.

The other congenital anomalies of sclera are:

1.Blue sclera

2.Inter scleral nerve loop

3.Nanophthalmos

4.Sclerocornea

5.Congenital staphyloma

Blue sclera

Sclera of the new borne is more translucent than adult. The sclera of a new borne is thinner than adult sclera and number of scleral fibres are also less. With age both increases and the sclera becomes white. The colour of a blue sclera is in fact a blue tinge due to the uvea shining through. In some cases, the sclera fails to attain normal white colour and remains blue, without any other ocular anomaly and does not predispose any disease.

Sometimes blue sclera is associated with systemic anomalies. Commonest combination is blue sclera with brittle bone in osteogenesis imperfecta with deafness.

The other condition associated with blue sclera is Ehlers-Danlos syndrome. This is generally an autosomal dominant disorder; occasionally it can be autosomal recessive as well. Most striking feature of the condition is hyper elasticity of the skin due to loss of collagen tissue in the dermis. The skin of the upper lid can be pulled as far as the check. The ligaments of the joints are also lax leading to hyper extensibility of joints with frequent subluxation of joints. The other possible ocular components are blue sclera, keratoconus, micro cornea, subluxation of lens, angioid streak, may have choroidal haemorrhage.

Inter scleral nerve loop3

In this case, a branch of long ciliary nerve changes its course to enter the substance of the sclera and emerges on the scleral surface under the conjunctiva as a tender nodule. It is generally appears on the nasal side, but has been reported from other sites also. It is generally a grey nodule but sometimes, it is surrounded by choroidal pigments. The cause of the anomaly is not known. It does not require any treatment.

Nanophthalmos

This is generally sporadic in nature, does not follow any fixed hereditary pattern. It can be unilateral or bilateral. The development of the globe is arrested in all dimension after the foetal fissure has fused leading to a small globe even smaller than a globe of a new born and remain small throughout the life. There are no other anomalies in the globe. The lens continues to grow as in other eyes. The result of small globe manifests as narrow inter palpebral aperture and deep set eyes. The distant vision is poor, occasionally with poor near vision in childhood, brought about by axial hypermetropia. The hypermetropia is always more than + 10 D. The child may have nystagmus; squint is common. Other cause of diminished vision is hypoplasia of macula. The eyes have tendency to develop simple glaucoma. Commonest complication of the condition is uveal effusion syndrome6 following penetrating injury accidental or surgical.

Sclerocornea

This is a combined anomaly of cornea and sclera, generally discussed under congenital anomaly of cornea along with corneaplana. The cornea and sclera blend into each other without trace of limbus. The condition may be localised on the peripheral cornea or may extend well into the centre of cornea.

Congenital staphyloma

Congenital staphyloma is congenital dehiscenes of sclera with bulging of the scleral coat that is lined either by ciliary body or choroid. The congenital scleral staphyloma’s are equatorial and posterior. Ciliary staphylomas are rarely congenital.

About 6% to 14% of eyes have staphylomas5 without symptoms and are discovered during strabismus or retinal surgery.

Posterior staphylomas develop in eyes with myopia more than – 8 D. All high myopic eyes do not develop posterior staphyloma. Posterior staphylomas develop in the posterior pole. It may involve the optic nerve head also. These eyes are generally large eyes with pseudo proptosis. The distant vision is poor and not corrected fully by glasses. On retinoscopy the staphyloma shows more myopia than rest of the globe. Direct ophthalmoscope requires more

minus lenses to focus the bottom of the staphyloma. The retinal vessels seem to disappear in the wall of the excavated staphyloma.

A posterior staphyloma is best visualised with indirect ophthalmoscope.

In presence of hazy media, presence of posterior staphyloma is confirmed by B scan ultrasonography. It is also well delineated by C.T. scan.

Other cause of scleral staphyloma in children is buphthalmos7, which produces ciliary as well as equatorial staphylomas. Ciliary staphylomas are more common. Raised intra ocular tension does not produce posterior staphyloma.

Intercalary staphylomas are least common in children. They are seen following badly repaired wounds, accidental or surgical at the limbus where the root of the iris in incarcerated in the dehiscenced wound.

Scleral staphyloma are occasionally seen in older children in cases of oculo sporidiosis in endemic areas8.

Infection and inflamation of the sclera do not develop in children. However inflamation of episclera i.e. episcleritis may occur in older children suffering from collagen disease. It is generally confused with phlycten of the conjunctiva, which is very common in children.

REFERENCES

1.Nema H.V., Singh V.P. and Nema N. ; The sclera in Anatomy of the eye and its adnexa. Second edition, p-10–12, Jay Pee Brothers, New Delhi 1991.

2.Nema H.V., Singh V.P. and Nema N. ; Development of the eye and its adnexa in Anatomy of the eye and its adnexa. Second edition, p-129, Jay Pee brothers, New Delhi 1991.

3.Duke Elder S., Cook C. ; System of ophthalmology. Vol. III, Part II, p-162–167, Henry Kimpton, London 1963.

4.Duke Elder S. Wybar K.C. ; The nerves of the eye in system of ophthalmology. Vol I, p-385, Henry Kimpton, London 1961.

5.Faris. B.M. and Freeman H.M. ; Scleral staphytoma and dehiscences in Current ocular therapy. Fifth edition, p-336–337, Edited by Fraunfelder F.T. and Roy. F.H., W.B. Saunders Company, Philadelphia 2000.

6.Dutta L.C. ; Uveal effusion syndrome in Ophthalmology Principle and practice. First edition, p-122–123, Current book international, Calcutta, 1995.

7.Duke Elders S. Leigh A.G. ; Disease of the sclera in system of ophthalmology. Vol. VIII, Part 2, p-998–1003, Henry Kimpton, London 1965.

8.Mukherjee P.K. ; Rhino spordiosis in Current ocular therapy. Fifth edition, p-66–67, Edited by Fraunfelder F.T. and Roy F.H., W.B. Saunders Company, Philadelphia 2000.

Chronic bacterial diseases are generally associated with granulomatous ocular disease or can cause allergic reaction to bacterial protein.

Various systemic bacterial diseases that have ocular involvement are arranged in alphabetical order. All of which are not equally common. Some may have minimal ocular ocular morbidity. Others may have widespread ocular involvement. Most of them respond to specific antibiotics.

Acinetobacter (Herellea Vaginicola)

This is an opportunistic organism, present widely in water and soil. The organism belongs to family Neisseriaceae. It is an aerobic, gram-negative cocobacilli, infects children with compromised immunity.

Systemic involvement

Multi systemic infection—Pneumonia, meningitis, urinary tract infection, and septicemia.

Ocular involvement is less common—They include: Blepharitis, purulent conjunctivitis, superficial punctate keratitis, sloughing corneal ulcer, and endophthalmitis, mostly following trauma—accidental or surgical.

Management consists of correct diagnosis by culture. It is sensitive to many antibiotics, both local as well as systemic, common antibiotics used are—Trimethoprimesulpha methoxazole, aminoglycocides, fluroquinolones.

Actino mycosis

This was previously thought to be a fungus infection, now it is classified as mycobacterium. This is an anaerobic organism. The organism is of low virulence with chronic course, does not cause impairment of vision.

Systemic involvement—Cutaneous especially skin of face and neck, teeth and gums.

Ocular involvement is generally unilateral, canaliculitis of lower lid leading to epiphora, swelling over the canaliculi. On pressing the inflamed canaliculus, there is regurgitation of yellow creamy material, which on microscopy contains concretion, like sulphur granules. Rarely there may be chronic dacryoadenitis.

Management consists of systemic tetracycline, cephalosporin or penicillin. Local antibiotics are tetracycline ointment, or aminoglycocide drops frequently.

Bacillus cereus

The organism B. cereus belongs to genus bacillus that also contains bacillus anthracis or anthrax bacillus, which has acquired notoriety as a tool of biological warfare with lethal effect. Bacillus cereus is commonly found in water, soil, air and dust. It is highly virulent, generally resistant to penicillin and cephalosporins. It is aerobic, gram-positive, spore forming.

Systemic involvement is relatively rare, seen in drug addicts who use infected needles. It reaches the eye as hematogenous spread due to contaminated intravenous injection or more commonly due to penetrating injury, mostly accidental rarely surgical.

Ocular involvement is fast developing endophthalmitis often leading to panophthalmitis and loss of the eye.

Commonest cause of post operative endophthalmitis is due to failure to destroy B Cereus by usual autoclaving because of its spore bearing character.

The endophthalmitis develops within twenty-four hours, may have fever and raised WBC Count. The severity is directly proportionate to the capacity of the organism to produce exotoxin.

The outcome of the condition is devastating visual loss.

Management is an ocular emergency, fast developing endophthalmitis with rapid fall of vision, fever, leucocytosis points toward possibility of B Cereus infection that is conformed by AC or vitreous tap, and positive culture of organism.

IV ciprofloxacilin 400 mg BD has been reported to give good result.

Intra vitreous injection of vancomycin, gentamycin and clindamycin give better result than intra venous antibiotics. Early vitrectomy may salvage some vision.

Brucellosis

Brucellosis is mostly a zoonosis i.e. a disease that spreads from animal to man. The disease spreads following consumption of unpasteurised milk and milk products or direct contact with infected animals.

The organism is a gram negative, intra cellular, non-motile, aerobic organism. There are four types of organisms that may infect man. The animals transmitting the disease may be any of the following: dogs, cattle, horses, sheep, goats and pigs.

Systemic involvement

Intermittent fever, headache, chills, joint pain, weight loss, speenogegaly and generalised lymphadenopathy. Other organs can also be involved.

Ocular involvement

In milder form it can cause swelling of lid, conjunctivitis, nummular keratitis. In sever form it causes sever anterior uveites, retinal haemorrhage, retinal edema, endophthalmitis, optic neuritis, extra ocular muscle palsy.

Management

The organism is sensitive to many antibiotics i.e. tetracycline, doxycycline, trimethoprinsulphamethoxazole, streptomycin and rifampin. It requires four to eight weeks continuous medication to eradicate the organism.

Clostridium perfringes

This is commonly known as gas gangrene organism that has dangerous systemic involvement, mostly involving large muscles.

The organism is opportunistic, gram positive bacillus. It is an anaerobic gas forming organism.

The systemic and ocular diseases are of acute onset, starting within twenty four hours of onset of infection. It can produce—Intestinal disorder, suppurative deep tissue infection, skin and soft tissue infection.