NMH 14 : missing stuff : part 2

Question 1

Where does ciliary body sit compared to ciliary muscle

Answer 1

Medially

Question 2

How is aqeous reabsorbed

Answer 2

passive= uveal-scleral outflow Active= TM canal of schlemm (80%)

Question 3

What does pressure have to do with glaucoma

Answer 3

Sustained Raised Intraocular Pressure is risk factor

Question 4

Which glaucoma could be symptomatic

Answer 4

Primary asymptomatic until late stages, closed angle- sudden painful red eye, and drop in vision.

Question 5

Differnetiate what an arteriole looks like vs venule on fundoscopy

Answer 5

venules more dilated

Question 6

Highly sensitive part of the retina

Answer 6

Fovea of Macula

Question 7

More rods or cones

Answer 7

much more rods``

Question 8

T.F Rods have multiple peak light sensitivity and cones have just one

Answer 8

F- there are 3 cone photopigment subtypes: S-blue M-green L-red S for small waves (short wavelength is blue) M for medium and L for large (long wavelength is red!) only one rod (with peak sensitivity at 498nm, between cone S and M)

Question 9

What is Deuteranomaly

Answer 9

caused by the shifting of the M-cone sensitivity peak towards that of the L-cone curve, causing red-green confusion.

Question 10

What is Anomalous Trichromatism (i.e. deuteranomaly)

Answer 10

Colour Vision Deficiencies due to shifting of photo-pigment peak sensitivity

Question 11

What are dichromatism and monochromatism

Answer 11

In Dichromatism, only two cone photo-pigment sub-types are present. In Monochromatism, there is complete absence of colour vision.

Question 12

Differentiate blue and red cone monochromatism

Answer 12

blue- normal day light visual acuity red- no functional day vision

Question 13

What happens to rod function in light adaptation

Answer 13

Suppressed, and cone function takes over within one minute.

Question 14

What is visual acuity

Answer 14

clarity of vision

Question 15

4 types of optical correction

Answer 15

1. Spectacle lens (monofocal or multifocal) 2, Contact lenses (higher quality of optical image and less influence on the size of retinal image than spectacle lenses ) 3. Intraocular lenses (cataract crystalline lens) 4. Surgical correction Keratorefractive surgery or Intraocular surgery : clear lens extraction (with or without IOL), phakic IOL

Question 16

What is clear lens extraction + IOL

Answer 16

like removing opaque lens in cataracts, except lens is clear (just not bending light well), so means takoing out clear lens and putting in IOL (intraocular lens)

Question 17

Problem with clear lens extraction woith IOL

Answer 17

Lose accommodation (patient will need reading glasses).

Question 18

Which structures pass through:( 1.Sup. orbital fissure 2. Optic foramen 3. Supraorbital notch 4.Infraorbital fissure 5. Infraorbital groove 6. Infraorbital foramen)

Answer 18

1. Trochlear, abducens, oculomotor (superior and inferior division) and ophthalmic (lacrimal, frontal and nasociliary branches of ophthalmic) cranial nerves, opthalmic vein (supoerior and inferior division) 2.Optic nerve and ophthalmic artery 3. supraorbital nerve (from frontal from opthalmic) and vessels (supraorbital artery and supraorbital vein.) 4. Zygomatic branch of the maxillary nerve and the ascending branches from the pterygopalatine ganglion. Infraorbital vessels pass from here. Inferior division opthalmic vein 5. Infraorbital vessels (infraorbital artery from the maxillary artery from external carotid) (through infraorbital groove, canal, and out via infraorbital foramen) 6. Infraorbital vessels emerge and infraorbital nerve (branch of V2)