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