1 4/12/2019

Optic chiasm, most important Arrangement of visual fibers Characteristic of visual field

VISUAL DYSFUNCTION Bitemporal defects: IN OPTIC CHIASM SYNDROME Superior Inferior Complete Peripheral, central M.HIDAYAT FACULTY OF MEDICINE, A N DALAS UNIVERSITY /M .DJAMIL HOSPITAL PADANG

AN ATOMY OF CHIASM OPTIC CHIASM

Width : 12 mm 53% fiber from nasal retina crossed to opposite — Length : 8 mmfantero posterior) contra lateral. ■ Inclined : 45 0 Inferior nasal fibers cross anterior loop in to contra lateral (Willbrand's knee) Location : anterior hypothalamus & anterior third Macular fiber cross posterosuperior ventricle 10 mm above sella Vascular supply: Anterior communicating artery Anterior cerebri artery Circle of Willis

ANTERIOR ANGLE OF CHIASM

Compression to anterior angle of chiasm

Small lesion damages the crossing fibers of ipsilaferal eye -> field defect: monocular and temporal Damage of macular crossed fibers: monocular, temporal defects and parasentral scotoma Damage fiber from nasal contralateral, anterior extension : central ipsilateral scotoma and contralateral upper temporal quadrant {"Willbrand’s Knee")

1 4/12/2019

Chiasmal compression from below defects stereotyped pattern : bitemporal defect Example: pituitary adenoma

Peripheral fiber damage, defects begin from superior quadrants of both eyes Can be not similar

Similar defects causes from tubercullum sellae, meningioma, craniopharyngiomas, aneurysm t

Sella or supra sella lesion : damage superior fiber defect bitemporal inferior

Bitemporal Hemianopsia Example: angioma cavernous Compression from below meningioma, craniopharyngioma, (hipophyse adenoma, aneurism, germinioma, glioma, Ro: sella enlargement. If lesion spread to third ventricle papilledema Caused by craniopharyngioma, meningioma, aneurism, (Ro: no sella enlargement)

Neural compression from nasal cavity -^Upper/lower bitemporal 1 | | P hemianopsia

2 4/12/2019

DAMAGE LATERAL OF THE CHIASM

Contralateral Homonim Hemianopsia Hemianopsia binasal caused by sclerotic of internal carotid arteries

If lesion spread from optic nerve or optic tract to chiasm ipsilateral blindness

ETIOLOGY OF OPTIC CHIASM SYNDROME

Damage of optic chiasm :

• Bitemporal field defects: 80% mass lesion

Malformation and congenital anomalies infection and inflammation Encephalocell Chiasmal arachnoiditis Craniopharyngioma Sarcoid Masses Meningitis Pituitary adenomas Sphenoid ridge Vascular Ectopic sinus cavernosus Compression by aneurysm internal carotid artery Glioma Radiation necrosis Supra sella meningioma Dalichoectatic vessels Craniopharyngiomas

3 4/12/2019

COMMON CAUSES

Other 1 Adenoma pituitary Hydrochephalus ■ Mengioma supra sella Dilated third ventricle Craningioma Empty sella syndrome Glioma Internal artery carotid aneurism Multiple sclerosis Trauma Rare Multiple sclerosis Sarcoidosis SIE

UNCOMMON

During pregnancy: Empty sella syndrome : Spreading of subarachnoid to sella tursica, Enlargement of pituitary Gland compressionof spontaneously or arachnoid cyst chiasm - > visual impairment -> recovery after Chiasm disgenesis, achiasm, w ith congenital delivery n is ta g m u s

b. Marked by bitemporal visual field loss with or Adenohipophysitis timphositic without visual acuity and dyschromatopsia Apoplexy pituitary Complete Hemianopsia bitemporal: caused by optic chiasm trauma

IATROGENIC OPTIC CHIASM SYNDROME

Hemianopsia defect, causes by posterior fossa After lesion removal or chiasm infiltration lesion.

Increased Intra Crania! Pressure and compression Radiation from third ventricle enlargement Dopamin Agonist Ventricle compression to posterior inferior chiasm : Bilateral central scotoma Bilateral nasal scotoma Arcuata scotoma Superior hemianopsia scotoma

4 4/12/2019

SIMTOM PS OPTIC CHIASM SYNDROME PATHOPHYSIOLOGY

Chiasm was compressed : initially, lower nasal and later Progressive loss of central acuity the upper nasal Thing suddenly disappearing, tilting, diplopia, loss of depth perception Ischemic ->chiasm infarct: visual acuity decrease and Bitemporal field defect: visual field defect Complete Visual improvement: after compression removal Scotoma

Visual impairment will happen caused by compression (conduction block, demyelination and axon transport loss)

Depth perception impairment Complain : difficulty to do activity with precision Convergence results in crossing of two blind temporal hemifield This produces a completely blind triangular area of field with its apex at fixation

Testing tor stereopsis can also be helpful in patients with suspected chiasmal disorders.

Diplopia or reading difficulty Hemianopsia bitemporal with optic atrophy, Caused by a horizontal or vertical deviation of appearing as a band across the disc (band images atrophy) “ Hemifield slide phenomenon” none ocular motor nerve paresis

Diplopia may be caused by ocular motor paresis in Hemianopsia bitemporal with papilledema caused subarachnoid or sinus cavernosus space by pre and post chiasm tumor (supra chiasmal Pain -> trigeminal affected tumors like compression by third ventricle)

Strabismus) apoplexy of pituitary or process extrinsic of chiasm

5 4/12/2019

6 This is to Certify that

HIDAYAT, MD

Has attended as

SPEAKER

In The 37th Annual Scientific Meeting Of Indonesian Ophthalmologist Association

Wimbo Sasono, MD Prof. Nila F. Maeloek, MD, PhD. Chairman of The Organizing Committee President of Indonesia^ Ophthalmologist Association 2228/PB/A.4/06/20 i 2 : Participant 12 SKP IDI, Speaker/Instructor 12 SKP 1D1, Moderator 4 SKP IDI, Committee 2 SKP IDI

rp-V" ' • ' :