CHAPTER I

INTRODUCTION

A pterygium is an elevated, superficial, external ocular mass that usually

forms over the perilimbal conjunctiva and extends onto the corneal surface.

Pterygia can vary from small, atrophic quiescent lesions to large, aggressive,

rapidly growing fibrovascular lesions that can distort the corneal topography, and,

in advanced cases, they can obscure the optical center of the cornea.

A pterygium commonly grows from the nasal side of the sclera. It is

usually present in the palpebral fissure. It is associated with, and thought to be

caused by ultraviolet-light exposure (e.g., sunlight), low humidity, and dust.

1

CHAPTER II

LITERATURE REVIEW

2.1. Conjunctiva

The conjunctiva is the mucous membrane lining the eyelids and

reflecting onto the sclera of the anterior surface of the eye.1

A transparent mucous membrane, known as the conjunctiva, lines

the inner surface of the eyelids (palpebral conjunctiva) and covers the

sclera of the anterior portion of the eye (bulbar conjunctiva). The

conjunctiva is composed of a stratified columnar epithelium that contains

goblet cells overlying a basal lamina and a lamina propria composed of

loose connective tissue. Secretions of the goblet cells become a part of the

tear film, which aids in lubricating and protecting the epithelium of the

anterior aspect of the eye. At the corneoscleral junction, where the cornea

begins, the conjunctiva continues as the stratified squamous corneal

epithelium and is devoid of goblet cells. 1

Figure 1 Conjunctiva

2.2. Cornea

The cornea is the transparent, avascular, and highly innervated

anterior portion of the fibrous tunic that bulges out anteriorly from the

orb. It is slightly thicker than the sclera and is composed of five

histologically distinct layers1:

2

Corneal epithelium

Bowman's membrane

Stroma

Descemet's membrane

Corneal endothelium

The corneal epithelium, the continuation of the conjunctiva (a

mucous membrane covering the anterior sclera and lining the internal

surface of the eyelids), is a stratified, squamous, nonkeratinized

epithelium, composed of five to seven layers of cells, that covers the

anterior surface of the cornea. The larger superficial cells have microvilli

and exhibit zonulae occludentes. The remaining cells constituting the

corneal epithelium interdigitate with and form desmosomal contacts with

one another. Their cytoplasm contains the usual array of organelles along

with intermediate filaments. The corneal epithelium is highly innervated

by numerous free nerve endings. Mitotic figures are observed mostly near

the periphery of the cornea, with a turnover rate of approximately 7 days.

Damage to the cornea is repaired rapidly as cells migrate to the defect to

cover the injured region. Subsequently, mitotic activity replaces the cells

that migrated to the wound. The corneal epithelium also functions in

transferring water and ions from the stroma into the conjunctival sac.1

Bowman's membrane lies immediately deep to the corneal

epithelium. Electron micrographs reveal it to be a fibrillar lamina, 6 to 30

μm thick, composed of type I collagen fibers arranged in an apparently

random fashion. It is believed that Bowman's membrane is synthesized by

both the corneal epithelium and cells of the underlying stroma. Sensory

nerve fibers pass through this structure to enter and terminate in the

epithelium.1

The transparent stroma is the thickest layer of the cornea,

constituting about 90% of its thickness. It is composed of collagenous

connective tissue, consisting mostly of type I collagen fibers that are

arranged in 200 to 250 lamellae, each about 2 μm in thickness. The

3

collagen fibers within each lamella are arranged parallel to one another,

but fiber orientation shifts in adjacent lamellae. The collagen fibers are

interspersed with thin elastic fibers, embedded in ground substance

containing mostly chondroitin sulfate and keratan sulfate. Long, slender

fibroblasts are also present among the collagen fiber bundles. During

inflammation, lymphocytes and neutrophils are also present in the stroma.

At the limbus (sclerocorneal junction) is a scleral sulcus whose inner

aspect at the stroma is depressed and houses endothelium-lined spaces,

known as the trabecular meshwork, that lead to the canal of Schlemm.

The canal of Schlemm is the site of outflow of the aqueous humor from

the anterior chamber of the eye into the venous system.1

Descemet's membrane is a thick basement membrane interposed

between the stroma and the underlying endothelium. Although this

membrane is thin (5 μm at birth) and homogeneous in younger persons,

electron microscopy has demonstrated that it becomes thicker (17 μm)

and has cross-striations and hexagonal fiber patterns in older adults.1

The corneal endothelium, which lines the internal (posterior)

surface of the cornea, is a simple squamous epithelium. It is responsible

for synthesis of proteins that are necessary for secreting and maintaining

Descemet's membrane. These cells exhibit numerous pinocytotic vesicles,

and their membranes have sodium pumps that transport sodium ions

(Na+) into the anterior chamber; these ions are passively followed by

chloride ions (Cl-) and water. Thus, excess fluid within the stroma is

resorbed by the endothelium, keeping the stroma relatively dehydrated, a

factor that contributes to maintaining the refractive quality of the cornea.1

4

Figure 2 Cornea

2.3. Pterygium

2.3.1. Definition

Pterygium is a fibrovaskuler growth of conjunctiva which is

degenerative and invasive.2

2.3.2. Epidemiology

The prevalence rates of pterygium obtained for a number of

populations vary widely, from 1.2% in urban, temperate white

people3 to 23.4% in the black population of tropical Barbados.4

These study populations differ in race, latitude, and sun exposure,

but generally prevalence rates in the tropics are higher than at

temperate latitudes. Research in Indonesia in Riau showed 17.0%

prevalence of pterygium.5

5

2.3.3. Risk Factors

Risk factors that influence the occurrence of pterygium is:

1. Age

It is uncommon for patients to present with pterygium prior

to age 20 years. Patients older than 40 years have the highest

prevalence of pterygia.6

2. Ultraviolet light exposure

There is close relationship between pterygium and

ultraviolet rays in ophthalmology. The incidence of pterygium

is much higher in outdoor workers who are working for long

hours in the sun-belt area. Ultraviolet light which plays a role

in pterygium is ultraviolet B. UV-B rays can cause chronic

inflammatory reactions that formed fibrovaskular tissue.7

3. Geographic

Several surveys have shown that the countries nearer the

equator have higher rate of pterygium than the other regions,

the possible reason is due to stronger exposure to ultraviolet

rays.6

4. Gender

Pterygium are reported to occur in males twice as

frequently as in females.6

5. Hereditary

In black african, there was a positive family history of

pterygium in 36% of cases. In Australia 38% of patients

admitted for pterygium surgery compared with 8 - 12% of

controls admitted for other conditions had a family history of

the growth. In South Africa 30 - 35% of urban predominantly

white individuals who had attended an ophthalmic practice

because of pterygium had a positive family history.8

6. Microtrauma

6

Mikrotrauma because of certain particles such as cigarette

smoke, dust and sand is one of the risk factors for pterygium.

Mikrotrauma a trigger of chronic inflammation that causes the

occurrence of pterygium.6

2.3.4. Pathogenesis and Pathophysiology

A central process in pterygium pathogenesis is thought to

be matrix metalloproteinase (MMP) activation by ultraviolet light

(UV) and subsequent MMP activity against interstitial tissue. A

number of MMP’s are involved but MMP–1 is abundantly

expressed in pterygium.9

The pathophysiology of pterygia is characterized by

elastotic degeneration of collagen and fibrovascular proliferation,

with an overlying covering of epithelium. Histopathology of the

abnormal collagen in the area of elastotic degeneration shows

basophilia with hematoxylin and eosin stain. This tissue also stains

with elastic tissue stains, but it is not true elastic tissue, in that it is

not digested by elastase.6

2.3.5. Staging

Based on the degree of growth, the pterygium can be classified

into 4 stage10:

1. Stage 1

Fibrovaskular tissue growth confined to the limbus.

Figure 3 Stage 1 Pterygium

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2. Stage 2

Fibrovaskular tissue growth has been through limbus but not

greater than 2 mm across the cornea.

Figure 4 Stage 2 Pterygium

3. Stage 3

Fibrovaskular tissue growth beyond 2 mm of the cornea, but

does not exceed the edge of the pupil of the eye.

Figure 5 Stage 3 Pterygium

4. Stage 4

Fibrovaskular tissue growth has been over the edge pupils.

Figure 6 Stage 4 Pterygium

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Based on its location, pterygium generally classified into

unilateral and bilateral pterygium. Unilateral pterygium

pterygium is that only occurs in one eye, whereas bilateral

pterygium was found in both eyes. In addition, pterygium

pterygium also can be classified into the nasal, temporal, or nasal

and temporal part in one eye is commonly called kissing

pterygium.

Almost 97% pterygium in nasal. Only about 3% which is in

the temporal. In some cases, can be found kissing pterygium.The

predominance of pterygia on the nasal side is possibly a result of

the sun's rays passing laterally through the cornea, where it

undergoes refraction and becomes focused on the limbic area.

Sunlight passes unobstructed from the lateral side of the eye,

focusing on the medial limbus after passing through the cornea.

On the contralateral (medial) side, however, the shadow of the

nose medially reduces the intensity of sunlight focused on the

lateral/temporal limbus.9

2.3.6. Diagnosis

Patients with pterygia present with a variety of complaints,

ranging from no symptoms to significant redness, swelling, itching,

irritation, and blurring of vision associated with elevated lesions of

the conjunctiva and contiguous cornea in one or both eyes.11

The clinical presentation can be divided into 2 general

categories, as follows6:

One group of patients with pterygium can present with

minimal proliferation and a relatively atrophic appearance.

The pterygia in this group tend to be flatter and slow

growing and have a relatively lower incidence of recurrence

following excision.

9

The second group presents with a history of rapid growth

and a significant elevated fibrovascular component. The

pterygia in this group have a more aggressive clinical

course and a higher rate of recurrence following excision.

2.3.7. Complication

Complications of pterygium include visual impairment,

impaired eye movement, and dry eye. Visual impairment occurred

primarily in pterygium stage 3 and 4. Visual impairment in

pterygium mainly caused by the pull of the cornea, causing

astigmatism. Pterygium block the entry of light into the retina,

especially in pterygium who had passed the edge of the pupil of the

eye.6

Eyeball movement disorders can occur due to pterygium

causing adhesions and restrictions on movement of the eyeball.

Pterygium will cause the conjunctiva and sclera that loosely binds

become sticky so that movement of the eye becoming more

difficult. In addition, the existence of pterygium growth will cause

the area to the movement of the eyeball becomes smaller.6

Dry eye often occur in pterygium. This is caused by defects

of the tear film. Conjunctiva is one of the forming of the tear film.

Goblet cells in the conjunctiva will not produce a layer of tears if

the surface is covered by the pterygium. This is what causes dry

eye in the pterygium.6

2.3.8. Treatment

Patients with pterygia can be observed unless the lesions

exhibit growth toward the center of the cornea or the patient

exhibits symptoms of significant redness, discomfort, or alterations

in visual function. Pterygia can be removed for cosmetic reasons,

as well as for functional abnormalities of vision or discomfort.12

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1. Medical Care

Medical therapy of pterygia consists of artificial tears/topical

lubricating drops as well as occasional short-term use of

topical corticosteroid anti-inflammatory drops when

symptoms are more intense.

Artificial tears provide topical ocular surface lubrication and

fill defects in the tear film, in patients with irregular corneal

surfaces and irregular tear films. These conditions are very

common in the setting of pterygium.

Topical corticosteroid is used to reduce inflammation on the

ocular surface and other ocular tissues. Corticosteroids can be

helpful in the management of inflamed pterygia by reducing

the swelling of the inflamed tissues of the ocular surface

adjacent to the lesions. 12

2. Surgical Care

Surgical care is indicated for stage 3 and stage 4 pterygium.

Removal of the pterygium involves surgical excision of the

head, neck and body of the pterygium. The body and base of

the pterygium are dissected with conjunctival scissors, while

the head and neck of the pterygium that has invaded the

cornea is often removed with a surgical blade. An attempt is

made to identify the plane of dissection, which facilitates

removal of the pterygium while keeping the underlying

corneal surface smooth. Remnant stromal attachments may be

smoothed out with the blade.

The surgical options available include the use of conjunctival

autograft, amniotic membrane transplant, and use of fibrin

glue.12

11

2.3.9. Prevention

Minimizing exposure to ultraviolet radiation should reduce

the risk of development of pterygia in susceptible individuals.

Patients are advised to use a hat or a cap with a brim, in addition to

ultraviolet-blocking coatings on the lenses of glasses/sunglasses to

be used in areas of sun exposure. This precaution is even more

important for those patients living in tropical or subtropical areas

or for those patients who are engaged in outdoor activities with a

high risk of ultraviolet exposure.6

2.3.10. Prognosis

The visual and cosmetic prognosis following excision of

pterygia is good. The procedures are well tolerated by patients,

and, aside from some discomfort in the first few postoperative

days, most patients are able to resume full activity within 48 hours

of their surgery.12

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CHAPTER III

CASE

1. Patient identity

Name : Mr. K

Sex : Male

Age : 46 years old

Address : A. Yani 2 street Sungai Raya Kubu Raya

Ethnic : Melayu

Job : Laborer

Religion : Moslem

Patient was examined on Mei 23th, 2011

2. Anamnesis

a. Main complaint: blurry vision in right eye.

b. History of disease :

Patient complains blurry vision in right eye since 3 months ago, the left

eye did not. Both eyes red, itchy and watery. Patient work as a laborer for

construction of builing. He worked under the hot sun. His eyes are often

exposed to the splashes of cement.

c. Past clinical history: Patient claims that there is no history of the same

symptoms before.

d. Family history : There are no one of her family have the same complaint.

3. General Physical Assessment

General condition : good

Awareness : compos mentis

Vital Signs:

Heart Rate : 80x/minute

Respiration freq. : 18x/minute

Blood Pressure : 110/70 mmHg

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Temperature : 36,5oC

4. Ophthalmological status

Visual acuity:

a. OD : 6/20F S – 0.75 C – 1.50 x 90o 6/6F

b. OS : 6/15 S – 0.75 C – 1.25 x 90o 6/6

OD OS

Right eye Left eye

ortho Eye ball position Ortho

ptosis (-), lagoftalmos

(-), edema (-)

Palpebra ptosis (-), lagoftalmos

(-), edema(-)

Redness (+),wing-like

growth from nasal

through limbus about 3

mm across the cornea.

Conjungtiva Redness (+), wing-like

growth from nasal

through limbus about 1

mm across the cornea.

Clear, edema (-) Cornea Clear, edema (-)

clear, deep COA clear, deep

Iris colour : brown

Pupil: circular, 3mm,

isokor, reactive to light

Iris and pupil Iris colour : brown

Pupil: circular, 3mm,

isokor, reactive to light

Clear Lens Clear

14

Clear Vitreous Clear

C/D ratio 0,4 Fundus C/D ratio 0,4

Eye ball movement

• Intraocular pressure (tonometry) : OD 13 mmHg, OS 14 mmHg

• Visual field test (confrontation) : normal

5. Resume

Patient complains of blurry vision in right eye since 3 months ago, the

left eye did not. Both eyes red, itchy and watery. Patient work as a laborer for

construction of builing. He worked under the hot sun. His eyes are often

exposed to the splashes of cement.

Vital signs of this patient are in normal range. Visual acuity of OD is

6/20F, after correction with S – 0.75 C – 1.50 x 90o 6/6F. Visual acuity of OS

is 6/15, after correction with S – 0.75 C – 1.25 x 90o 6/6. Conjunctiva of OD,

redness (+), wing-like growth from nasal through limbus about 3 mm across

the cornea. Conjunctiva of OS, redness (+), wing-like growth from nasal

through limbus about 1 mm across the cornea.

15

++

+

+

+

+

+

+

++

+

+

+

+

+

+

OD OS

6. Diagnose

Working Diagnose:

OD : Pterygium stage 3, myopia, pterygium induced astigmatism

OS : Pterygium stage 2, myopia, pterygium induced astigmatism

7. Plan for examination

- No plan for further examination.

8. Treatment:

- Non medicamentous: using of protective glasses, wear hat.

- Medicamentous: OC

o artificial tear 1-2 gtt prn, naphazoline eyedrop 0,1% 2-4 x 1gtt.

- Surgery: OD pterygium excision with conjunctival autograph.

9. Prognosis

OD

Ad vitam : bonam

Ad functionam : bonam

Ad sanactionam : dubia ad malam

OS

Ad vitam : bonam

Ad functionam : bonam

Ad sanactionam : dubia ad malam

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CHAPTER IV

DISCUSSION

Mr. K, 46 years old, complains blurry vision in right eye since 3 months

ago, the left eye did not. Both eyes red, itchy and watery. Patient work as a laborer

for construction of builing. He worked under the hot sun. His eyes are often

exposed to the splashes of cement.

Abnormalities found in examination is redness and wing-like growth from

nasal through limbus in both eye. There is myopia and astigmatism in both eye

too. Working diagnose for this patient is pterygium based on the apparance of the

growth in conjunctiva, OD is pterygium grade 3, OS is pterygium grade 2. The

pterygium caused astigmatism in both eye.

Recomended therapy for this patient includes nonmedicamentous such as

wearing protective glasses and hat to protect from ultraviolet light and dust.

Medicamentous therapy for this patient is with artificial tear to lubricate the ocular

surface and to fill in defects in the tear film and topical vasoconstrictor to reduce

eye redness. Surgery is indicated for OD since the pterygium is grade 3.

17

CHAPTER V

CONCLUSION

Male, 46 years old, complaint blurry vision in right eye. Examination

reveal redness and wing-like growth in both eye. Working diagnose for this

patient is pterygium. The therapy include wearing protective glasses and hat,

artificial tear, topical vasoconstrictor and surgery.

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