Transcript 4._Ocular_Manifestations_of_Systemic_Diseases

OCULAR MANIFESTATIONS OF SYSTEMIC DISEASES
The eye is intimately linked not only with the
adjacent structures but also with the remote
organs of the body. Ocular manifestations are so
common in many systemic diseases that the
ophthalmoscope is an essential part of the of every
competent physician. No medical examination is
really thorough or complete without examination
of the fundus.
METABOLIC DISORDERS
DIABETES MELLITUS
Ocular complications are common in diabetes, but bear
little relation to the severity of the disease. They depend
much more on the duration of the diabetes and
commonly occur in long-standing cases.
Lesions of the lids.—Diabetes lowers the resistance of the patient to
pyogenic infections and predisposes to recurrent styes.
Lesions of the Conjunctiva and the Cornea.—Conjunctivitis and
keratitis are possible complications.
Lesions of the Iris.—The iris may exhibit the following lesions :
Rubeosis lridis
Edema and Vesiculation of the Pigment Epithelium. — This leads to
easy scattering of the iris pigment by mild trauma.
Transient Visual Disturbances;
Transient Refractive Changes.
Accommodation Disorders.—Weakness of accommodation
may result when the ciliary muscle becomes weakened by
peripheral neuritis involving its nerve supply.
Subjective Visual Disturbances. — Amaurosis may occur in
severe cases of diabetes. Disturbances of the visual cortex
may lead to misty vision and to lashes of light which
patients may experience after an overdose of insulin. .
Diabetic Cataract.
Diabetic Retinopathy.
Intra-Ocular Haemorrhage. This is due to rubeosis
iridis.
Retrobulbar Optic Neuritis.—Diabetic optic neuritis is
usually bilateral, rapid in onset and often painless.
Ocular Tension.—Hypotony may occur in cases of diabetic
coma.
Extra-Ocular Muscle Palsies.—Paralysis of one or more of
the extrinsic ocular muscles may occur.
DISTURBANCES OF CALCIUM METABOLISM
Hypocalcemia
Cataract.
Myopia.
VITAMIN DEFICIENCIES
VITAMIN A DEFICIENCY
The chief ocular manifestations of Vitamin A deficiency are
defective night-vision and xerophthalmia. Blepharitis, recurrent
chalaiza and styes, chronic conjunctivitis and keratomalatia are also
common
VITAMIN B DEFICIENCY
Vitamin B1 Deficiency
Conjunctivitis.
Nystagmus. Papilloedema.
Retinal haemorrhages.
Extra-ocular muscle paralysis.
Vitamin B2 (Riboflavine) Deficiency
Photophobia together with itching and burning sensations.
Conjunctivitis is a typical manifestation.
Peripheral vascularization of the cornea is often present.
Cataract can be produced experimentally in riboflavin deficiency.
Fundus changes consist of hyperaemia of the disc, papilloedema,
VITAMIN C DEFICIENCY
Orbital haemorrhage.
Conjunctival and palpebral haemorrhages.
Keratoconjunctivitis. Cataract. Retinal hemorrhages.
VITAMIN D DEFICIENCY
Lamellar cataract.
High myopia, spring catarrh, phlyctenular keratoconjunctivitis and
conical cornea
DISEASES OF THE ENDOCRINE GLAND
PITUITARY GLAND
Headache— It is often bitemporal and of a "bursting" type.
Visual Field Defects. —The loss of fields to colours is always more
extensive than to white.
Typically, the field defect commences in the periphery of the upper temporal
quadrant and extends downwards to produce the typical bitemporal
hemianopia.
Optic Atrophy but occasionally papilladema.
Ocular Palsy due to the pressure effects by a laterally growing tumour on the
oculomotor, trochlear or abducent nerves.
Slight Exophthalmos may occur as a result of a disturbed production of
thyrotropic hormone.
PINEAL GLAND
Severe headache and papilloedema are early
manifestations, caused by the blockage of cerebrospinal fluid circulation at the aqueduct of Sylvian
Ocular palsies and ptosis often occur.
Failure of the pupillary light response may develop
as a result of pressure on the pathway of the
pupillar
light reflex.
THYROID GLAND
Manifestations of Thyroid Hypofunction (Myxoedema)
Puffiness of the eyelids.
Loss of hairs of the outer half of the eyebrows.
Bilateral Manifestations of Thyroid Hyperfunction (thyrotoxicosis retrobulbar
neuritis and optic atrophy may occur.
Exophthalmos which may lead to exposure keratitis.
Lid retraction and lid lag of the upper eyelid.
Odema of the eyelids.
Pigmentation of the eyelids.
Congestion of the conjunctiva vessels.
Ocular palsies, especially affecting the superior rectus muscles leading to diplopia.
Convergence insufficiency.
Fundus changes include visible arterial pulsation, papilloedcma, partial optic
atrophy, exudates in the posterior pole and degeneration of the macula.
Rarely, retrobulbar neuritis.
DISEASES OF THE KIDNEYS
Renal Retinopathy The retinopathy occurs typically in
type II nephritis and sometimes after type 1 nephritis.
Ophthalmoscopic Signs of Renal (Hypertensive)
Retinopathy
Constriction of the Retinal Arteriols.
Generalized Retinal Edema with Edema of the Optic Disc.
Numerous Cotton-Wool Patches.
Retinal Haemorrhages.
Hard White Exudates
Exudative Retinal Detachment.
Crystalline Retinal Deposits
TEMPORAL ARTERITIS.
Ocular manifestations are present in about 50% of cases. The eye
signs include temporary incomplete external ophthalmoplegia, serve
optic neuritis and unilateral, but sometimes bilateral, occlusion of the
central retinal artery leading to complete blindness.
PERIARTERTTIS NODOSA
Periarteritis nodosa is an inflammatory disease of the coats of the
small and medium-sized arteries of the body with inflammatory
changes around the vessels. Ocular manifestations include
angiospastic retinopathy, central retinal artery occlusion, iritis,
keratitis, ring ulcer of the cornea, scleritis and extra-ocular muscle
palsy. Systemic corticosteroids are of some values but the prognosis
is usually bad.
RHEUMATOID ARTHRITIS
The ocular manifestations of rheumatoid arthritis include
commonly iridocyclitis, but rarely scleromalcia performs.
Ankylosing spondylitis.—The disease affects the joints of
the spine and is associated with recurrent iridocyclitis.
CHRONIC GRANULOMATOUS DISEASES
TUBERCULOSIS
Conjunctivitis.
Phlyctenular keratoconjunctivitis.
Interstitial keratitis.
Sclerosing keratitis.
Anterior uveitis. Nodules on the iris.
Miliary tuberculosis. Choroiditis (tuberculoma)
Perivasculitis retina(Eales' disease). Optic neuritis.
Dacryoadenitis. Dacryocystitis.
SYPHILIS
Chancre of the lid.
Gumma of the tarsal plate.
Gumma of the lacrimal gland.
Chancre of the conjunctiva.
Interstitial keratitis.
Iridocyditis.
Congenital (lamellar) cataract.
Choroido-retinitis.
Optic neuritis.
Primary optic atrophy.
Paralysis of the extrinsic ocular muscles.
LEPROSY
Nodules on eyelids or anesthetic patches.
Nodules on the conjunctiva or sclera.
Interstitial keratitis,
Superficial punctate keratitis,
Leprotic pannus.
Iritis,
Secondary glaucoma
SARCOIDOSIS
Sarcoid nodules on the eyelids.
Painless nodular enlargement of the lacrimal glands
which may be unilateral or bilateral.
Episcleral nodules.
Nodular iritis.
Nodular choroido-retinitis.
DISEASES OF THE MUSCLES
MYASTHENIA GRAVIS
Myasthenia gravis is a chronic neuromuscular disease
characterised by fatigue and exhaustion of the muscular
system marked by progressive paralysis of muscles without
sensory disturbance or motor nerve paralysis, The disease
is presumably due to a curare-like block, interfering with
the normal action of acetylcholine at the myoneural
junction. the disease generally commences the levator
palpebrae superioris muscle leading to ptosis. Later, the
disease involves the extra-ocular muscles, Diplopia.
Convergence insufficiency.
Weakness of accommodation.
References
Parson’s diseases of the eye