LPS stands for:

Levator Palpebrae Superioris

In Horner’s syndrome, enophthalmos is apparent, not real

It cannot be demonstrated using an exophthalmometer

Mechanism:

The underlying cause is damage to sympathetic nerves (cervical sympathetic trunk or central sympathetic pathway)
The upper lid drops down (ptosis) – due to paralysis of muller’s muscle (a part of levator palpebrae superioris)
Lower lid is pulled up – due to paralysis of smooth muscle responsible for retraction of lower lid
This causes narrowing of palpebral fissure causing an apparent enophthalmos

Horner’s syndrome is a condition caused by damage to the sympathetic nervous system (cervical sympathetic chain or central pathways)
Clinical features:

Ptosis (paralysis of muller’s muscle – part of levator palpebrae superioris)
Miosis (constricted pupil – sympathetic supply is responsible for dilation of pupil)
Anhidrosis (decreased sweating on affected side of face)
Enophthalmos (appearance of a sunken eyeball – apparent rather than real) – Read Mechanism of enophthalmos in Horner’s syndrome
Loss of ciliospinal reflex

Diagnosis

Can be easily diagnosed by clinical signs
In case of doubtful cases, it can be confirmed by instilling 4% cocaine eyedrops

Cocaine acts by blocking uptake of adrenaline
In …

Distichiasis is a condition in which an extra row of eyelashes occupy the usual site of meibomian glands
It is of 2 types

Congenital distichiasis

The meibomian glands open into the hair follicles of the extra row of eyelashes as ordinary sebaceous glands
The eyelashes are directed backwards and may require epilation if they rub on the cornea

Acquired distichiasis (metaplastic lashes)

The meibomian glands undergo metaplasia to form hair follicles
It is seen in conditions like late stage of cicatrizing conjunctivitis due to chemical injury, Stevens-Johnson syndrome, ocular cicatricial pemphigoid

Uniocular diplopia refers to the appearance of an object in double even when viewing it through one eye. The causes of uniocular diplopia are:

Subluxated clear lens
Subluxated intraocular lens
Keratoconus (irregular refraction from corneal surface)
Double pupil (congenital / large iridectomy / iridodialysis)
Incipient cataract (this usually causes polyopia – due to irregular refraction due to multiple water clefts within the lens)

Amaurosis is the complete loss of vision in one or both eyes in the absence of ophthalmologic or other objective signs
Amblyopia is the partial loss of vision in  one or both eyes in the absence of ophthalmologic or other objective signs

It is a ophthalmological condition in which the person can see only moving (kinetic) objects
Static objects are invisible to the patient
The colour or shape of the the objects cannot be visualised, only the perception of motion is present
It is seen in lesions of occipital nerve

Night blindness (nyctalopia) is a condition in which there is impaired vision in dim light. The causes of night blindess are:

Conditions affecting the functioning of rods (as rods are involved in night / scotopic vision)

Vitamin A deficiency
Retinitis pigmentosa (and other tapetoretinal degenerations)
Oguchi disease (congenital stationary night blindness)
Congenital high mypoia
Familial congenital night blindness

Certain conditions affecting transparency of visual media

In dim light, the pupils dilate so as to allow more light to reach the retina
In case of peripheral corneal opacities and paracentral lenticular opacities, there is obstruction to the passage of light when …

Anterior Ischemic Optic Neuropathy is a condition in which there is segmental or total infarction of the anterior part of the optic nerve

Etiology:

AION occurs due to blockage of Short posterior ciliary arteries which supply the optic nerve
The different types of AION are:

Idiopathic – most common – thought to be due to atherosclerotic changes in the vessels
Arteritic – associated with giant cell arteritis
Miscellaneous – associated with various conditions like

Severe anemia
Malignant hypertension
Papilledema
Migraine
Massive haemorrhage
Collagen vascular disorders

Clinical features:

Sudden visual loss

involving the upper or lower (more common) half of the visual field – altitudinal hemianopia

Fundus …

AION stands for:

Anterior Ischemic Optic Neuropathy