D/D OF IRIS LESIONS

D/D OF IRIS LESIONS

Iris neovascularization
(always look at the posterior segment for cause, the first two on the list are the commonest causes)

· PDR

· CRVO

· carotid artery disease

· BRVO

· CRAO

· BRAO

· chronic uveitis

· RD (chronic).

· malignant melanoma

· CCF

· ROP

Iris transillumination
Diffuse

· Albinism

· FHU

· previous acute glaucoma

· post-cataract surgery

· diabetic mellitus

Sectorial

· HZV

· HSV

· ICE

· ICD

· PPD

· Leprosy

· iridoschisis

· previous acute glaucoma

· post-cataract surgery

Peripupillary

PXS

Marfan Syndrom

DM

Sickle cell anemia (extends to collarete)

Mid-periphery

· PDS

· PC IOL sulcus fixated with iris chafing

· Female carrier of ocular albinism

Localized- PI

· Superiorly: PI-laser or surgical (isolated or with SST)

· Inferiorly: post-vitrectomy with silicone oil (Ando's procedure)

Heterochromia

Refers to differences in the iris colour. The differences are best seen in day light; the abnormal eye may be hypochromic or hyperchromic.

In the examination, most common conditions: FHU, siderosis bulbi and congenital Horner's syndrome.

Cases of iris transillumination mentioned above may also give rise to heterochromia if there is significant pigment loss

1) Causes of hypochromia

· Congenital isolated

· Waardenburg's syndrome – (hypertelorism, white forelock, white eyelashes, leukoderma and cochlear deafness)

· Congenital Horner's syndrome

· Fuch's heterochromic cyclitis

· Chronic uveitis

· Post-cataract surgery

2) Causes of hyperchromia

· congenital isolated

· naevus of Ota

· siderosis bulbi

· diffuse iris naevus / melanoma

· Sturge-Weber's syndrome

· rubeosis iridis (differences in iris colour can become obvious if the blood vessels are extensive)

· drug-induced latanoprost

· paradoxical FHU

Corectopia

· congenital (including coloboma)

· iris naevus / iris melanoma

· ectropia uvae

· ciliary body tumours

· ICD

· ICE

· PPD

· post-cataract surgery (especially with vitreous loss or the haptic is displaced)

· post-trabeculectomy

Polycoria + correctopia + glaucoma:

ICD: bilatreral/hereditary/posterior embryotoxon/normal endothelium

ICE: unilateral with corneal endothelial changes

Iris Nevus Syndrome: diffuse nevus (now considered a separate entity from Cogan Reese)

Posterior Polymorphous Dystrophy

Chronic anterior uveitis

Diffuse melanoma

post-cataract surgery (especially with vitreous loss or the haptic is displaced)

post-trabeculectomy

Ectropin uvae:

· Isolated

· With NF

· Rubeosis iridis

Iris mass

Melanotic mass

· Nevus

· Indeterminate melanocytic lesion

· Malignant melanoma

· Adenoma of the pigmented epithelium

· Iris cyst (Primary epithelial)

· Metastases from the SKIN

· FB

Amelanotic mass

· Malignanat melanoma

· Metastases

· Leiomyoma: Iris cyst: (1ry stromal or 2ry)

· JXG

· Inflammatory ganuloma (TB or Sarcoid)

D/D OF PUPIL PHYSICAL SIGNS

D/D OF PUPIL PHYSICAL SIGNS

Relative afferent pupillary defect
(RAPD is caused by unequal light conduction of the afferent visual pathway. It is best examined in the dim light with distant fixation. The lesion can be anywhere from the retina to the optic tract before the lateral geniculate body. In the clinical examination, the most common case would be optic nerve lesion due to either optic neuritis or ischaemic causes)

· Retina lesions- if extensive

vascular causes (central retinal artery or vein occlusion)

advanced glaucoma

extensive chorioretinitis as in toxoplasmosis, retinitis such as cytomegalovirus infection or acute retinal necrosis)

total retinal detachment

· Optic nerve lesions

optic neuritis

ischaemic optic neuropathy (non-arteritic or arteritic due to giant cell arteritis)

tumours (primary such as glioma and meningioma or secondary)

trauma (traumatic optic neuropathy or optic nerve avulsion) congenital (unilateral optic nerve hypoplasia)

· Chiasmal lesions- can cause more damage to one optic nerve than the other resulting in RAPD

tumours (primary such as pituitary tumours and craniopharyngioma or secondary from metastasis)

vascular lesions (internal carotid artery aneurysm)

inflammatory (granuloma such as sarcoidosis and TB or idiopathic such as Tolosa-Hunt syndrome)

· Optic tract lesions- RAPD occurs if more visual field in one eye is affected more than the other

vascular lesions (ischaemic or haemorrhagic stroke)

tumours (primary such as meningioma and astrocytoma or secondary)

Paradoxical pupillary reaction (the pupil dilates instead of constriction in swinging flash test)

CSNB

Cone dystrophy

Leber’s amarousis

Optic neuritis

Dominnt optic atrophy

Amlyopia (rarely)

Anisocoria

(The most common cases in the clinical examination are Horner's syndrome, Adie's pupil and third nerve palsy. The first step in your examination is to determine which is the abnormal eye and this is helped greatly by the associated sign especially ptosis. In less obvious cases, the increase in anisocoria in bright light suggest the large pupil to be abnormal whereas such increase in dim light suggest the small pupil to be abnormal)

· Abnormaly small pupil:

congenital (essential)

Horner's syndrome

drug-induced (parasympathomimetic)

previous uveitis resulting in posterior synechiae

traumatic miosis

· Abnormaly large pupil:

congenital (essential)

Adie's pupil

third nerve palsy

damage to the iris (traumatic or inflammation)

drug-induced (anticholinergic blockage or adrenergic stimulation)

Light-near dissociation

( The condition occurs when the near response is stronger than the light response. It is true to say that all light-near dissociation is due to abnormal light response with sparing of the near response. The commonest case in clinical examination is Adie's pupil. As the light response has an afferent and efferent pathway, the lesions can be thus classified)

· Lesions of the afferent pathway

in the retina (occurs when both eyes are blind as in diabetic retinopathy resulting in absent light response)

in the optic nerves (if both optic nerves are damaged as in giant cell arteritis)

in the midbrain (lesion involving the pretectal region, the classical one being Parinaud's syndrome from pinealoma)

in the Edinger-Westphal nucleus (classical one being Argyll-Robertson's pupil)

· Lesions of the efferent pathway
(this is usually caused by aberrant regeneration of the damaged nerve resulting in better near reaction)

in the ciliary ganglion (typified by Adie's pupil)

other peripheral neuropathies for example Charcot-Marie-Tooth syndrome, amyloidosis, alcoholism

· Unknown aetiology

myotonic dystrophy

D/D OF CORNEAL LESIONS:

D/D OF CORNEAL LESIONS:

The cornea provides a variety of signs for the slit-lamp examination. These signs are easy to detect provided you examine each layer in turn and know how to use the various slit-lamp techniques. Usually more than one sign is present in the cornea. The following provide lists of differential diagnosis of common corneal signs seen in the examination.

Ferritin lines
(This seldom occurs in isolation in the examination. It is either a coincidental finding or associated with the corneal problem.)

· Hudson-Stahli's line (occurs in elderly and is found at the junction between the upper 2/3 and lower 1/3 of the cornea)

· Ferry's line (found anterior to a filtering bleb)

· Stocker's line ( found anterior to a pterygium)

· Fleischer's ring ( found at the base of keratoconus)

· foreign body (Rust ring).

· others ( diseases which distort the surface of the cornea as recurrent erosion syndrome, radial keratotomy)

Vortex keratopathy
(Also known as cornea verticillata; it is characterized by epithelial deposition which is arranged in a vortex fashion and usually begins just below the pupil and radiate outward. Like ferritin lines it is unlikely to be the only signs, if there is no other physical signs in the cornea ask to examine the posterior segment. For example, you may be given vortex keratopathy with tamoxifen deposition in the macula or vortex keratopathy with bull-eye maculopathy due to chloroquine toxicity.)

· Fabry's disease

· Drug-induced

amiodarone
chloroquine/hydroxychloroquine
tamoxifen
chlorpomazine
indomethacin

Keratoconus:

Marfan

Ehler danlos

Down Syndrom

Turner Syndrom

RP

Leber’s amourosis

Atopic eye disease

Contact lens use

Aniridia

Corneal neovascularization
(These may be superficial or deep in stroma. In the examination, the most common cases are phthisical eye, trauma, herpes simplex keratopathy, chemical burn and ocular cicatricial pemphigoid.)

· Trauma:

alkali burns

contact lens wear

· Infections

bacteria such as chlamydia, staphylococcus, pseudomonas
viruses such as herpes simplex and herpes zoster
protozoa such as onchocerca volvulus, leishmania brasiliensis

· Immunologic diseases

Steven-Johnson's syndrome
graft rejection
cicatricial ocular pemphigoid

Mooren’s ulcer

· Degenerative disorders

Pterygium
Terrien's marginal degeneration

Band keratopathy
(It is found in the palpebral fissure. Although it may occur singly, in the examination you are likely to be given one with underlying ocular diseases for example chronic uveitis, interstitial keratic, phthsical eye or silicone oil in the anterior chamber)

· Ocular causes

Chronic uveitis esp in paediatrics
interstitial keratitis
phthsical eye
Silicone oil in the AC

· Systemic disease

hypercalcaemia /hyperphosphatemia

hyperuricemia

Hereditary-dystrophic band keratopathy

Idiopathic- in eldery

Ghost vessels (Interstititial keratitis)
(These usually occur in deep stroma in patients with interstitial keratitis. The chronic inflammation usually leaves a thin cornea and possibly anterior or posterior synechiae. Although interstitial keratitis classically occurs in congenital syphilis in which case the condition is invariably bilateral, it can also occur in a variety of infection. The most likely case in the examination is congenital syphilis and the patient may have the typical facial features of saddle nose, deafness and Hutchinson's teeth or may be normal. Avoid using words like syphilis (in front of the patient) when asked about the diagnosis or investigation instead used terms like St. Louis's disease or serology for Treponema pallidum).

· Bacterial disease

congenital syphilis
tuberculosis
leprosy

· Viral disease

herpes simplex
herpes zoster
measles
mumps
rubella

· Parasitic disease

leishmaniasis
onchocerciasis
cysticerosis

· Unknown aetiology

Cogan's syndrome

Breaks in Descemet's membrane
(This is a common sign in the examination and the most common cause in the examination is bulphthalmos. Therefore, look out for differences in corneal size. )

Advanced keratoconus (Vogt).

Congenital glaucoma: curvilinear or Horizontal rupture (Haab)

Trauma (for example forcep delivery); vertical or oblique

Peripheral corneal thinning:
(In the clinical examination, the most common cases will include rheumatoid arthritis, Mooren's ulcer and Terrein's marginal degeneration. However, in your differential diagnosis do not forget to mention more common condition such as bacterial infection or recurrent marginal keratitis.)

Local causes:

Any where

dellen

marginal keratitis
phylyctenulosis
Mooren's ulcer

vernal keratoconjunctivitis …

Superior

superior limbic keratoconjunctivitis

Terrien's marginal degeneration

Furrow degeneration…

Inferior

atopic dermatits

neurotropic/exposure

dry eye

pellucid marginal degeneration

Collagen vascular diseases

rheumatoid arthritis
systemic lupus erythematosus
relapsing polychondritis
Wegener's granulomatosis

Dermatologic conditions= acne rosacea

Inflammatory bowel diseases

Blood disorders= leukaemia

Corneal oedema
(Another common sign in the examination. The sign may be missed if subtle unless you look at the corneal thickness and the present of clear spaces in the stroma. You must look for the underlying cause. The most common case ispseudophakic bullous keratopathy.)

· Acute increase in IOP

acute glaucoma- epithelial edema

Endothelium decompensation- stromal edema

inherited

congenital hereditary endothelial dystrophy
posterior polymorphous dystrophy
Fuch's dystrophy

trauma
post-operative: PBK√√

mechanichal trauma

instruments

IOL esp during periods of AC shallowness esp after the wash of VES

US- AC phaco

Toxicity (TASS): limbal – limbal edema + dilated fixed pupil + severe glaucoma

DM detachment

blunt blades

IOL insertion through a small wound

infectious
corneal ulcer
endopthalmitis

inflammation

chronic uveitis

graft rejection

others-

chronic rise in IOP- chronic glaucomas

ICE

DM rupture:

advanced keratoconus

congenital glaucoma

trauma (for example forcep delivery)

Cloudy cornea in a child: STUMPED

S= Sclerocornea

T= Trauma: Birth

U=

M= Metabolic: cystinosis/MPS

P= Peters Anomly

E=

D= Dystrophy: CHED/CHSD/PPD

Buphtalmos

Pigments on the endothelium
(The typical case in the examination is Krukenberg's spindle in patient with pigment dispersion syndrome. However, pigments can also occur in various conditions and a detailed examination of the anterior segment may provide the clues.)

pigment dispersion syndrome

pseudoexfoliation syndrome

post-cataract surgery

previous corneal performation in which the iris was incarcerated in the wound

trauma

iris melanoma

idiopathic

Keratic precipitates in the endothelium
(The most common case is Fuch's heterochormic cyclitis in which there are multiple discrete KP evenly distributed in the endothelium. Occasionally you may be given a patient with mutton fat KP and asked to give a differential diagnosis. Possible cases include sarcoidosis (look for nodules on the iris), toxoplasmosis (there may be chorioretinitis scar in the posterior segment) and rarely sympathetic ophthalmia (look for signs of ocular damage in the opposite eye)

Dendritc epithelial lesion:

HSV

HZV

Acanthamoeba

CL

Healing abrasion

Prominent corneal nerves (D/D: ghost vessels & Lattice dystrophy)

· Corneal dystrophies (Fuchs’, keratoconus)

· NF I

· Buphthalmos

· leprosy

· Ichthyosis

· After corneal grafts

· Multiple endocrine neoplasia.

· Refsum disease

· trauma

Filamentary keratitis:

· dry eye

· Exposure keratopathy

· Neuroparalytic keratitis

· Recurrent erosions

· prolonged patching

· SLK

· Midbrain strokes

· Blepharospasm

· HZV

Pigment Epithelial Erosions (PEE):

Superior: Spring catarrh/SLK/floppy lid/poor CL fitting

Middle: dry eye/ NP keratitis/ UV (welding arc).

Inferior: lid margin dis/ rosacea/ exposure/ toxicity

Kayser Fleisher ring:

Wilson’s diseases

Primary biliary cirrhosis

Chronic active hepatitis

Multiple myeloma