Opthalmology - Passmed

A 54-year-old man with type 2 diabetes mellitus is found on annual review to have new vessel formation at the optic disc. Visual acuity in both eyes is not affected (6/9). Blood pressure is155/84 mmHg.

HbA1c 8.4%

What is the most important intervention to preserve vision in this patient?

Optic neuritis usually occurs

The most common causes of a sudden painless loss of vision are as follows:

Ischaemic optic neuropathy fxs

Ischaemic optic neuropathy is associated with

Central retinal vein occlusion fxs

which is more common central retinal artery or vein occlusion

define polycythemia

difference b/w polycythemia and erythrocytosis

tx for polycythemia

different types of polycythemia

1o polycythemia is due to

examples of 1o polycythemia

Polycythemia vera is classified as a

2o polycythemia is caused by either

2o polycythemia due to natural increase in EPO production aka

Conditions which may result in a physiologically appropriate polycythemia include:

pathological causes of 2o polycythemia

Central retinal artery occlusion fxs

Differentiating posterior vitreous detachment, retinal detachment and vitreous haemorrhage

A 63-year-old man presents to his GP complaining of pain in his right eye. On examination the sclera is red and the pupil is dilated with a hazy cornea. What is the most likely diagnosis?

Red eye - glaucoma or uveitis?

Red eye differentials

Acute angle closure glaucoma fxs

Anterior uveitis fxs

Scleritis fxs

AS is associated with

Conjunctivitis fxs

Subconjunctival haemorrhage fxs

A 71-year-old man presents with a burning sensation around his right eye. On examination an erythematous blistering rash can be seen in the right trigeminal distribution. What is the most likely diagnosis?

Herpes zoster ophthalmicus definition

Herpes zoster ophthalmicus fxs

Herpes zoster ophthalmicus mgmt

Herpes zoster ophthalmicus complications

Conjunctivitis is the most common

bacterial conjunctivitis fxs

Viral conjunctivitis fxs

Allergic conjunctivitis fxs

mgmt of infective conjunctivitis

with regards to infective conjunctivitis - whats done about contact lens, towels, and school

mgmt of allergic conjunctivitis

Fundoscopy reveals a number of yellow deposits in the left eye consistent with drusen formation. Similar changes but to a lesser extent are seen in the right eye. What is the most likely diagnosis?

Drusen =

Age related macular degeneration

inV and dx

Age related macular degeneration key is

Traditionally two forms of macular degeneration are seen:

updated classfication of age related macular degen

Age related macular degeneration risk factors

Age related macular degeneration fxs

in age related macular degeneration is central or peripheral vision lost first

general mgmt of age related macular degeneration

Dry macular degeneration tx

Wet macular degeneration tx

Which one of the following is the most common ocular manifestation of rheumatoid arthritis?

Keratoconjunctivitis sicca is characterised by

Ocular manifestations of rheumatoid arthritis are common, with 25% of patients having eye problems

Ocular manifestations of RA

RA drugs can cause what eye problems

diabetic retinopathy there are 2 types

diabetic retinopathy - non proliferative type has 2 classfications, an old and a new one - describe the OLD one

diabetic retinopathy - non proliferative type has 2 classfications, an old and a new one - describe the NEW one

Proliferative retinopathy

DIABETIC RETINOPATHY associated maculopathy fxs

Which one of the following is not a risk factor for primary open-angle glaucoma?

primary open-angle glaucoma is associated with

Acute angle closure glaucoma is associated with

Glaucoma is a group disorders characterised by optic neuropathy due, in the majority of patients,

Primary open-angle glaucoma (POAG, also referred to as chronic simple glaucoma) risk factors

Primary open-angle glaucoma fxs

age related macular degeneration vs primary open angle glaucoma

Horner's syndrome fxs:

A patient of yours has been diagnosed with Horner's syndrome. Which of the following is most likely to be seen?

heterochromia (difference in iris colour) is seen in congenital Horner's

Distinguishing between causes for horners based on anhydrosis

mgmt principle for 1o open angle glaucoma

medical tx of 1o open angle glaucoma

Prostaglandin analogues (e.g. Latanoprost) moa

Prostaglandin analogues (e.g. Latanoprost) AE

Beta-blockers (e.g. Timolol) moa

Beta-blockers (e.g. Timolol) CI

Sympathomimetics (e.g. brimonidine, an alpha2-adrenoceptor agonist) moa

Sympathomimetics (e.g. brimonidine, an alpha2-adrenoceptor agonist) CI

Sympathomimetics (e.g. brimonidine, an alpha2-adrenoceptor agonist) AE

Carbonic anhydrase inhibitors (e.g. Dorzolamide) moa

Carbonic anhydrase inhibitors (e.g. Dorzolamide) AE

Miotics (e.g. pilocarpine, a muscarinic receptor agonist) moa

Miotics (e.g. pilocarpine, a muscarinic receptor agonist) AE

Primary open-angle glaucoma: management if refractory cases

Radioiodine treatment may lead to the development / worsening of

An 84-year-old man presents with loss of vision in his left eye since the morning. He is otherwise asymptomatic and of note has had no associated eye pain or headaches. His past medical history includes ischaemic heart disease but he is otherwise well. On examination he has no vision in his left eye. The left pupil responds poorly to light but the consensual light reaction is normal. Fundoscopy reveals a red spot over a pale and opaque retina. What is the most likely diagnosis?

Papilloedema

The following features may be observed during fundoscopy:

Causes of papilloedema

Malignant hypertension is

Colours, especially red, seem 'washed-out'. dx

Optic neuritis classic sxs

key fx with optic neuritis

Optic neuritis causes

Optic neuritis fxs

Optic neuritis mgmt

Optic neuritis prognosis

Pituitary tumour associated visual field defect:

Primary open angle glaucoma in right eyeassociated visual field defect:

Patient who has had an extensive stroke with right-sided hemiplegiaassociated visual field defect:

the homonymous hemianopia is always on what side as paresis

Eyelid problems commonly encountered include:

Different types of stye are recognised:

STYE mgmt

A chalazion (Meibomian cyst) is

A 35-year-old man presents with visual problems. He has had very poor vision in the dark for a long time but is now worried as he is developing 'tunnel vision'. He states his grandfather had a similar problem and was registered blind in his 50's. What is the most likely diagnosis?

px developoing night blindness + tunnel vision - dx

Retinitis pigmentosa mainly affects the

Retinitis pigmentosa fxs

Retinitis pigmentosa is associated with other diseases - which ones

Bitemporal hemianopia fxs

Homonymous hemianopia fxs

Visual field defects

The main points for the exam are:

incongruous defects = optic tract lesion;

congruous defects = optic radiation lesion or occipital cortex

Smoking is the most important modifiable risk factor for the development of

A 35-year-old female who has recently being diagnosed with Grave's disease presents for review 3 months after starting a 'block and replace' regime with carbimazole and thyroxine. She is concerned about developing thyroid eye disease. What is the best way that her risk of developing thyroid eye disease can be reduced?

mgmt of thyroid eye disease

Thyroid eye disease affects between 25-50% of patients with Graves' disease.

Anterior uveitis mgmt

Anterior uveitis is one of the important differentials of a red eye. It is also referred to as iritis.

its associated with

diagnosis of acute glaucoma. Which of the following should be the aims of treatment?

difference b/w anterior uveitis and acute glaucoma in relation to the meds used to manage the pupil

In acute angle closure glaucoma (AACG) there is a rise in IOP secondary

Factors predisposing to acute angle closure glaucomaAACG include

Acute angle closure glaucoma fxs

Acute angle closure glaucoma mgmt

normal range for intraocular pressure?

A 45-year-old woman with Graves' disease comes for review. She has recently been diagnosed with thyroid eye disease and is being considered for radiotherapy. Over the past three days her right eye has become red and painful. On examination there is proptosis and erythema of the right eye. Visual acuity is 6/9 in both eyes. What complication is she most likely to have developed?

Exposure keratopathy due to

Ptosis + dilated pupil =

ptosis + constricted pupil =

A 64-year-old woman presents with bilateral sore eyelids. She also complains of her eyes being dry all the time. On examination her eyelid margins are erythematous at the margins but are not swollen. Of the given options, what is the most appropriate initial management?

Blepharitis is

Blepharitis causes

Blepharitis is also more common in patients with rosacea

The meibomian glands secrete

Any problem affecting the meibomian glands (as in blepharitis) can hence cause drying of the eyes which in turns leads to

Blepharitis fxs

Blepharitis mgmt

A 67-year-old man presents as he has developed a painful blistering rash around his right eye. On examination a vesicular rash covering the right trigeminal nerve dermatome is seen. Currently he has no eye symptoms or signs. Which one of the following is most likely to predict future eye involvement?

A 43-year-old man with a history of chronic back pain presents to his GP complaining of pain in his left eye and photophobia. On examination the pupil is small, oval shaped and associated with ciliary congestion. What is the most likely diagnosis?

Red eye - glaucoma or uveitis?

A 68-year-old man with a history of type 2 diabetes mellitus presens with worsening eye sight. Mydriatic drops are applied and fundoscopy reveals pre-proliferative diabetic retinopathy. A referral to ophthalmology is made. Later in the evening whilst driving home he develops pain in his left eye associated with decreased visual acuity. What is the most likely diagnosis?

Mydriatic drops are a known precipitant of

Mydriatic drops are applied and fundoscopy reveals pre-proliferative diabetic retinopathy

he develops pain in his left eye associated with decreased visual acuity

dx

A 60-year-old woman who has recently started treatment for polymyalgia rheumatica presents with a five day history of headaches and reduced vision on the right side since this morning There is no eye pain but the there is a 'large, dark shadow' covering the superior visual field on the right side. On examination she has a tender, palpable right temporal artery. What is the most likely explanation for the reduced vision?

Temporal arteritis is large vessel vasculitis which overlaps with

Temporal arteritis histology findings

with temporal arteritis you can get visual disturbances how

A 6-year-old boy is brought to surgery as mum has noticed redness of his right eye. When assessing the child which one of the following features would be most associated with a viral aetiology?

A 54-year-old woman presents with a persistent watery left eye for the past 4 days. On examination there is erythema and swelling of the inner canthus of the left eye. What is the most likely diagnosis?

Dacryocystitis definition

Dacryocystitis fxs

Dacryocystitis mgmt

Congenital lacrimal duct obstruction

Lacrimal duct problems

At what age would the average child be expected to have visual acuity similar to that of an adult?

vision tests which may be performed when assessing children:

A 24-year-old man presents to the emergency department complaining of left eye pain. He has not been able to wear his contact lenses for the past 24 hours due to the pain. He describes the pain as severe and wonders whether he has 'got something stuck in his eye'. On examination there is diffuse hyperaemia of the left eye. The left cornea appears hazy and pupillary reaction is normal. Visual acuity is reduced on the left side and a degree of photophobia is noted. A hypopyon is also seen. What is the most likely diagnosis?

Keratitis describes

Keratitis causes

keratitis fxs

Infective causes for keratitis

enviro causes of keratitis

Hypertensive retinopathy

Keith-Wagener classification of hypertensive retinopathy

A 31-year-old man presents with a painful swelling of his right upper eyelid for the past 3 days. On lifting the eyelid a yellow head pointing at the lid margin can be seen. What is the most appropriate management?

A 35-year-old man presents with right eye pain which is worse on movement. Examination reveals a relative afferent pupillary defect. Which one of the following is the most likely cause of his problems?

eye pain which is worse on movement

relative afferent pupillary defect.

dx

A 64-year-old woman with type 2 diabetes mellitus presents as she has started to bump into things since the morning. Her medications include metformin, simvastatin and aspirin. Over the previous two days she had noticed numerous 'dark spots' over the vision in her right eye. Examination reveals she has no vision in her right eye. The red reflex on the right side is difficult to elicit and you are unable to visualise the retina on the right side during fundoscopy. Examination of the left fundus reveals changes consistent with pre-proliferative diabetic retinopathy. What is the most likely diagnosis?

Darth Vader is from the Dark Side

A 54-year-old man is noted to have papilloedema on examination. Which one of the following may be responsible?

A 40-year-old man presents with bilateral dry, gritty eyes. A diagnosis of blepharitis is considered. Which one of the following is least likely to be associated with blepharitis?

Whats the most likely cause of optic neuritis

Which one of the following is least likely to be associated with blepharitis?

A 23-year-old female presents with recurrent headaches. Examination of her cranial nerves reveals the right pupil is 3 mm whilst the left pupil is 5 mm. The right pupil constricts to light but the left pupil is sluggish. Peripheral neurological examination is unremarkable apart from difficult to elicit knee and ankle reflexes. What is the most likely diagnosis?

Holmes-Adie pupil

Holmes-Adie pupil

Holmes-Adie pupil fxs

Holmes-Adie pupil

Holmes-Adie pupil fxs

Holmes-Adie syndrome

association of

A 65-year-old man with a history of primary open-angle glaucoma presents with sudden painless loss of vision in his right eye. On examination of the right eye the optic disc is swollen with multiple flame-shaped and blot haemorrhages. What is the most likely diagnosis?

Central retinal vein occlusion - fxs

Adverse effects include brown pigmentation of the iris

Adverse effects include brown pigmentation of the iris

Should be avoided in patients taking MAOI drugs

Causes pupillary constriction, blurred vision and headaches

A mother brings her 8-week-old child in for review. Since birth his right eye has been watering. His symptoms have got worse over the past few days after he picked up a mild viral illness. Clinical examination is unremarkable. What is the most appropriate action?

A mother brings her 8-week-old child in for review. Since birth his right eye has been watering. His symptoms have got worse over the past few days after he picked up a mild viral illness. Clinical examination is unremarkable. What is the most appropriate action?

Nasolacrimal duct obstruction

Most common cause of

Nasolacrimal duct obstruction

Most common cause of

Nasolacrimal duct obstruction

Most common cause of

Management for Nasolacrimal duct obstruction

A 70-year-old man is investigated for blurred vision. Fundoscopy reveals drusen, retinal epithelial and macular neovascularisation. A diagnosis of age related macular degeneration is suspected. What is the most appopriate next investigation?

A 25-year-old woman presents with a one-day history of a painful and red left eye. She describes how her eye is continually streaming tears. On examination she exhibits a degree of photophobia in the affected eye and fluorescein staining demonstrates a small, feathery area of abnormal uptake. Visual acuity is 6/6 in both eyes. What is the most appropriate management?

A 25-year-old woman presents with a one-day history of a painful and red left eye. She describes how her eye is continually streaming tears. On examination she exhibits a degree of photophobia in the affected eye and fluorescein staining demonstrates a small, feathery area of abnormal uptake. Visual acuity is 6/6 in both eyes. What is the most appropriate management?

This patient may have a corneal abrasion or a dendritic corneal ulcer, particularly given the photophobia. The feathery pattern however points more towards a herpes simplex keratitis. Such a patient should be reviewed immediately by an ophthalmologist. Giving a topical steroid in this situation could be disastrous as it may worsen the infection.

Herpes simplex keratitis most commonly presents with a

Herpes simplex keratitis most commonly presents with a

Herpes simplex keratitis

Fxs

Herpes simplex keratitis

Management

A 54-year-old female presents to the Emergency Department concerned about double vision. She is noted to have exophthalmos and conjunctival oedema on examination and a diagnosis of thyroid eye disease is suspected. What can be said regarding her thyroid status?

A 69-year-old man presents with blurred vision. His GP suspects a diagnosis of primary open-angle glaucoma (POAG). Which one of the following features would be most consistent with a diagnosis of POAG?

A 39-year-old woman with a history of rheumatoid arthritis presents with a two day history of a red right eye. There is no itch or pain. Pupils are 3mm, equal and reactive to light. Visual acuity is 6/5 in both eyes. What is the most likely diagnosis?

Scleritis is painful, episcleritis is not painful

Ocular manifestations of RA

Ocular manifestations of RA

A 65-year-old man presents with an acute, painful red eye. Which one of the following features would not support a diagnosis of acute angle closure glaucoma?

Ocular manifestations of RA

A 65-year-old man presents with an acute, painful red eye. Which one of the following features would not support a diagnosis of acute angle closure glaucoma?

A 70-year-old woman presents with loss of vision in her left eye. For the past two weeks she has painful frontal headaches and has been feeling generally lethargic. On examination visual acuity is 6/9 in the right eye but on the left side only hand movements can be made seen. Fundoscopy of the left side reveals a pale and oedematous optic disc. What is the most likely diagnosis?.

Ocular manifestations of RA

A 65-year-old man presents with an acute, painful red eye. Which one of the following features would not support a diagnosis of acute angle closure glaucoma?

A 70-year-old woman presents with loss of vision in her left eye. For the past two weeks she has painful frontal headaches and has been feeling generally lethargic. On examination visual acuity is 6/9 in the right eye but on the left side only hand movements can be made seen. Fundoscopy of the left side reveals a pale and oedematous optic disc. What is the most likely diagnosis?.

A 22-year-old man is referred to urology with possible urinary retention. He is passing huge amounts of urine. Post void bladder ultrasound is normal.

diagnosis of herpes zoster ophthalmicus is made and an urgent referral to ophthalmology is made. What treatment is she most likely to be given?

Which one of the following conditions would most predispose you to developing anterior uveitis?

A 65-year-old woman presents with visual problems. She suffers from rheumatoid arthritis, depression and takes medication to control her blood pressure. Over the past few days she has been getting troublesome headaches and blurred vision but today has noted a marked reduction in vision in the right eye. On examination her right eye is red, has a sluggish pupil and a corrected visual acuity 6/30. Her medication has recently been changed. Which one of the following drugs is most likely to have precipitated this event?

Drugs which may precipitate acute glaucoma include

Drugs which may precipitate acute glaucoma include

dry age-related macular degeneration is reviewed. Unfortunately her eyesight has deteriorated over the past six months. She has never smoked and is taking antioxidant supplements. What is the most appropriate next step?

A 34-year-old woman presents complaining of headaches. Examination of her pupils using a light shone alternately in each eye reveals that when the light is shone in the right eye both pupils constrict but when the light source immediately moves to the left eye both eyes appear to dilate.

What is the most likely diagnosis?

Relative afferent pupillary defect aka

Relative afferent pupillary defect aka

Relative afferent pupillary defect causes

Relative afferent pupillary defect aka

Relative afferent pupillary defect causes

Pathway of pupillary light reflex

Relative afferent pupillary defect aka

Relative afferent pupillary defect causes

Pathway of pupillary light reflex

A 74-year-old man presents with a severe throbbing headache on the right side of his head. He has now had this pain for around 6-7 days but reports no obvious trigger. There have been no visual disturbances or episodes of limb weakness. Neurological examination is unremarkable. The right side of his head is tender to touch but he cannot remember falling. Given the likely diagnosis what is the most important initial step?

Each one of the following is a cause of a mydriatic pupil, except:

Relative afferent pupillary defect aka

Relative afferent pupillary defect causes

Pathway of pupillary light reflex

A 74-year-old man presents with a severe throbbing headache on the right side of his head. He has now had this pain for around 6-7 days but reports no obvious trigger. There have been no visual disturbances or episodes of limb weakness. Neurological examination is unremarkable. The right side of his head is tender to touch but he cannot remember falling. Given the likely diagnosis what is the most important initial step?

Each one of the following is a cause of a mydriatic pupil, except:

Argyll-Robertson pupil is one of the classic pupillary syndrome. It is sometimes seen in neurosyphilis and is often said to be the prostitute's pupil - accommodates but doesn't react. Another mnemonic used for the Argyll-Robertson Pupil (ARP) is Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA)

Relative afferent pupillary defect aka

Relative afferent pupillary defect causes

Pathway of pupillary light reflex

A 74-year-old man presents with a severe throbbing headache on the right side of his head. He has now had this pain for around 6-7 days but reports no obvious trigger. There have been no visual disturbances or episodes of limb weakness. Neurological examination is unremarkable. The right side of his head is tender to touch but he cannot remember falling. Given the likely diagnosis what is the most important initial step?

Each one of the following is a cause of a mydriatic pupil, except:

Argyll-Robertson pupil is one of the classic pupillary syndrome. It is sometimes seen in neurosyphilis and is often said to be the prostitute's pupil - accommodates but doesn't react. Another mnemonic used for the Argyll-Robertson Pupil (ARP) is Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA)

Causes of mydriasis (large pupil)

Relative afferent pupillary defect aka

Relative afferent pupillary defect causes

Pathway of pupillary light reflex

A 74-year-old man presents with a severe throbbing headache on the right side of his head. He has now had this pain for around 6-7 days but reports no obvious trigger. There have been no visual disturbances or episodes of limb weakness. Neurological examination is unremarkable. The right side of his head is tender to touch but he cannot remember falling. Given the likely diagnosis what is the most important initial step?

Each one of the following is a cause of a mydriatic pupil, except:

Argyll-Robertson pupil is one of the classic pupillary syndrome. It is sometimes seen in neurosyphilis and is often said to be the prostitute's pupil - accommodates but doesn't react. Another mnemonic used for the Argyll-Robertson Pupil (ARP) is Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA)

Causes of mydriasis (large pupil)

Drug causes of mydriasis

Which one of the following is associated with heterochromia in congenital disease?

A 45-year-old man presents with a two week history of a painless lump in his left lower eyelid. A small lump is noted on examination which is more obvious when the eyelid is everted. There is no erythema or discharge. A diagnosis of a meibomian cyst is suspected. What is the most appropriate management?

A 54-year-old man with type 2 diabetes mellitus is found on annual review to have new vessel formation at the optic disc. Visual acuity in both eyes is not affected (6/9). Blood pressure is155/84 mmHg.

HbA1c 8.4%

What is the most important intervention to preserve vision in this patient?

A 54-year-old man with type 2 diabetes mellitus is found on annual review to have new vessel formation at the optic disc. Visual acuity in both eyes is not affected (6/9). Blood pressure is155/84 mmHg.

HbA1c 8.4%

What is the most important intervention to preserve vision in this patient?

This man presents with unilateral visual loss. On examination he has a relative afferent pupillary defect. Fundoscopy shows the following:

What is the most likely diagnosis?

This man presents with unilateral visual loss. On examination he has a relative afferent pupillary defect. Fundoscopy shows the following:

What is the most likely diagnosis?

Which one of the following best describes the action of latanoprost in the management of primary open-angle glaucoma?

Which one of the following is least associated with the development of optic atrophy?

This man presents with unilateral visual loss. On examination he has a relative afferent pupillary defect. Fundoscopy shows the following:

What is the most likely diagnosis?

Which one of the following best describes the action of latanoprost in the management of primary open-angle glaucoma?

Which one of the following is least associated with the development of optic atrophy?

Optic atrophy is seen as pale, well demarcated disc on fundoscopy. It is usually bilateral and causes a gradual loss of vision*.

Causes may be acquired or congenital

This man presents with unilateral visual loss. On examination he has a relative afferent pupillary defect. Fundoscopy shows the following:

What is the most likely diagnosis?

Which one of the following best describes the action of latanoprost in the management of primary open-angle glaucoma?

Which one of the following is least associated with the development of optic atrophy?

Optic atrophy is seen as pale, well demarcated disc on fundoscopy. It is usually bilateral and causes a gradual loss of vision*.

Causes may be acquired or congenital

Optic atrophy is seen as pale, well demarcated disc on fundoscopy. It is usually bilateral and causes a gradual loss of vision*. Causes may be acquired or congenital

A 61-year-old woman presents with bilateral tinnitus. She reports no change in her hearing or other ear-related symptoms. Ear and cranial nerve examination is unremarkable. Which medication is she most likely to have recently started?

A 71-year-old man presents with two year history of intermittent problems with swallowing. His wife has also noticed he has halitosis and is coughing at night. He has a past medical history of type 2 diabetes mellitus but states he is otherwise well. Of note his weight is stable and he has a good appetite. Clinical examination is unremarkable. What is the most likely diagnosis?

A 61-year-old woman with a history of cardiac problems develops hearing loss after a prolonged admission in hospital. Drug toxicity is suspected.

A 71-year-old man presents with two year history of intermittent problems with swallowing. His wife has also noticed he has halitosis and is coughing at night. He has a past medical history of type 2 diabetes mellitus but states he is otherwise well. Of note his weight is stable and he has a good appetite. Clinical examination is unremarkable. What is the most likely diagnosis?

A 61-year-old woman with a history of cardiac problems develops hearing loss after a prolonged admission in hospital. Drug toxicity is suspected.

A 37-year-old cello player complains of a three month history of vertigo and hearing loss on the left side. On examination he has an absent corneal reflex on the left eye.

is diagnosed with Bell's palsy. What is the current evidenced base approach to the management of this condition?

A 42-year-old man with a 3 month history of chronic cough presents with a persistent headache

does optic neuritis cause SUDDEN PAINLESS LOSS OF VISION

what is Ischaemic optic neuropathy