CATARACT

CATARACT IS LOSS OF TRANSPARENCY OF LENS IN THE EYE.

LENS TRANSPARENCY DEPENDS ON THE REGULAR ARRANGEMENT OF THE LENS FIBRES AND TIGHT PACKING OF PROTEIN.

TYPES OF CATARACT BASED ON ETIOLOGY:

1.CONGENITAL CATARACT
2.ACQUIRED CATARACT
a.AGE RELATED CATARACT
b.TOXIC-
     i.SMOKING
     ii.ALCOHOL
    iii.DRUG-CHLORPROMAZINE,ALLOPURINOL,AMIODARONE,CHLOROQUINE,MIOTICS
c.RADIATION
d.SYSTEMIC DISEASES
e.TRAUMA
f.METABOLIC-
        i.GALACTOSEMIA
        ii.HYPOCALCEMIA
        iii.DIABETES
        iv.LOWE'S SYNDROME
G.OCULAR DISEASES-
        i.GLAUCOMA
        ii.HIGH MYOPIA
        iii.UVEITIS
        iv.INFECTION

TYPES OF CATARACT BASED ON LOCATION:

THREE PRINCIPAL TYPES OF AGE RELATED CATARACT EXIST.HOWEWVER VARIOUS COMBINATIONS OF THESE THREE FORMS OF CATARACT CAN OCCUR IN A SINGLE LENS.

1.NUCLEAR CATARACT

2.CORTICAL CATARACT

3.POSTERIOR SUBCAPSULAR CATARACT

CONGENITAL CATARACT -CAUSES INCLUDES
1.INTRAUTERINE INFECTIONS-
A.TOXOPLASMOSIS
B.RUBELLA
C.RUBEOLA
D.CYTOMEGALOVIRUS
E.HERPES SIMPLEX
F.HERPES ZOSTER
G.EPSTEIN BARR VIRUS
H.SYPHILIS

2.FAMILIAL

3.METABOLIC CAUSES


MECHANISM OF CATARACT FORMATION;

1.OXIDATIVE STRESS-CAUSED BY SMOKING,ALCOHOL,HYPERGLYCEMIA,AGEING

2.RADIATIONS HAVE EFFECT ON GERMINAL EPITHELIUM LYING AT LENS EQUATOR

3.TEARING APART OF LENS FIBRES AS IN TRAUMA

SYMPTOMS INCLUDE:

1.DEFECTIVE VISION
2.GLARE
3.HALOS
4.POLYOPIA


TREATMENT : SURGERY IS THE TREATMENT OF CHOICE.THE OPTIONS ARE:

1.EXTRA CAPSULAR CATARACT EXTRACTION
2.SMALL INCISIONAL CATARACT SURGERY
3.PHACO EMULSIFICATION
4.LASER REFRACTIVE CATARACT SURGERY

SOME COMMON POST CATARACT SURGERY COMPLICATIONS INCLUDE:

1.CYSTOID MACULAR EDEMA
2.POSTERIOR CAPSULAR OPACIFICATION
3.APHAKIA

STYE EYE AND CHALAZION

HORDEOLUM OR STYE EYE

Hordeolum is an acute purulent inflammation of glands of the eyelid.It ususally presents as elevated ,painful erythematous nodule.The most common organism causing is staphylococcus aureus.

It is of two types:1.Hordeolum Externum(glands of zeis is involved)

                            2.Hordeolum internum(meibomian gland is involved)


STRUCTURE OF EYELID

Usually it is self limiting.Treatment includes warm compresses,rapid drainage can be done at out patient department

CHALAZION


Chalazion appears as a firm erthymatous nodule in the eyelid that results from obstruction in the  meibomian gland or it may follow a Hordeolum.If larger in size it can compress cornea and cause blurry vision.

Treatment:

Smaller chalazion disappears usually with warm compresses.If large enough incision and curettage is advised.Recurrent chalazion at the same place needs a biopsy.