p.10
Ocular Symptoms and Examination Techniques
What specific aspect of Figs. 3.5 and 3.7 needs to be checked?
The appropriateness of their captions.
p.10
Ocular Symptoms and Examination Techniques
What is required for Figs. 3.3–3.5, 3.7, and 3.8?
Captions need to be provided.
p.11
Ocular Symptoms and Examination Techniques
What is the significance of examining the eye in ophthalmology?
It can often confirm a diagnosis without further blood tests or scans.
p.3
Colour Blindness and Detection
How does red-green trichromatism affect perception?
It causes a spectral shift in either red or green hues, making it difficult to distinguish between the two.
p.2
Visual Cortex and Neural Pathways
What is the location of the synapse prior to the occipital cortex?
Within the lateral geniculate nucleus of the thalamus.
p.16
Colour Vision Mechanisms
What visual acuity is required for the Ishihara test?
A minimum visual acuity of 6/36.
p.3
Visual Fields and Binocular Vision
What is the visual field?
A representation of the receptive area of each eye.
p.19
Ocular Symptoms and Examination Techniques
What should be done to enhance fundal examination?
Use dilating drops to enable a larger field of view.
p.14
Ocular Symptoms and Examination Techniques
What is the purpose of the 50 useful means mentioned?
To rapidly screen for major defects and neglect.
p.1
Photoreceptor Function
What unique ability do photoreceptors have compared to other neural cells?
They can transmit a localized, graded action potential.
p.5
Refraction and Optics in the Eye
What is an emmetropic eye?
A normal eye where focusing is sufficient without corrective lenses.
p.15
Visual Fields and Binocular Vision
What is helpful for the patient to do when testing confrontational visual fields?
Look directly into the examiner’s eye.
p.21
Lid Anatomy and Conditions
What is the role of the levator complex?
To elevate the upper lid.
p.10
Ocular Symptoms and Examination Techniques
What should be checked regarding the figures in Chapter 3?
The appropriateness of the inserted citation for all figures.
p.14
Ocular Symptoms and Examination Techniques
What is the significance of using a white pin in screening?
To trace the periphery of a field.
p.17
Ocular Symptoms and Examination Techniques
What does RAPD stand for?
Relative Afferent Pupillary Defect.
p.19
Ocular Symptoms and Examination Techniques
What is the systematic approach for examining the globe and adnexal structures?
Inspect from afar, move closer, and finish with fundoscopy.
p.15
Visual Fields and Binocular Vision
What should the examiner and patient do during confrontational visual field testing?
Compare the patient's visual field with that of the examiner.
p.1
Photoreceptor Function
What is the role of the retinal pigment epithelium in relation to retinal?
It degrades the remainder of retinal as waste and helps convert some back to 11-cis retinal.
p.21
Lid Anatomy and Conditions
Which cranial nerve innervates the orbicularis oculi muscle?
The seventh cranial nerve.
p.15
Visual Fields and Binocular Vision
From whose perspective is the visual field documented?
From the perspective of the patient looking out onto the environment.
p.8
Anterior Segment Physiology
What is the primary route for aqueous humor drainage in the eye?
The conventional route through Schlemm’s Canal.
p.1
Visual Cortex and Neural Pathways
How do ganglion cells contribute to visual discrimination?
They allow for activation and nearby inhibition, improving object discrimination and increasing contrast.
p.21
Lid Anatomy and Conditions
What is blepharitis?
Inflammation of the lid margins.
p.13
Ocular Symptoms and Examination Techniques
How is Snellen visual acuity documented?
Distance Patient Is from Chart/Number of the Lowest Correctly Visualised Line.
p.19
Ocular Symptoms and Examination Techniques
What signs are tested to assess eyelid laxity?
Tone of the lids and ability to resist forced opening.
p.11
Ocular Symptoms and Examination Techniques
What do posterior segment conditions affect?
The ocular contents behind the lens, as well as vascular and neurological problems.
p.1
Visual Cortex and Neural Pathways
What are the two main types of ganglion cells?
On-centre and off-centre cells.
p.1
Visual Cortex and Neural Pathways
What is the function of off-centre ganglion cells?
They have a central inhibitory zone and a surrounding excitatory area.
p.2
Colour Vision Mechanisms
What theory forms the basis of colour vision?
The trichromatic theory of vision.
p.1
Image Formation in Vision
What is the role of bipolar cells in image processing?
They perform summation and further modulation of the image.
p.16
Pupil Size and Response
What is a Relative Afferent Pupillary Defect (RAPD)?
A test to check for impaired optic nerve function.
p.16
Visual Cortex and Neural Pathways
What is assessed during funduscopy?
The appearance of the optic nerve, including colour, contour, and presence of haemorrhages.
p.4
Visual Fields and Binocular Vision
How does the brain interpret depth perception?
By processing two images with disparity to derive a three-dimensional structure.
p.12
Anterior Segment Physiology
What increases the risk of infection in patients wearing contact lenses?
Poor lens hygiene and specific lens-wearing habits.
p.11
Ocular Symptoms and Examination Techniques
How can symptoms be categorized in ophthalmology?
Into anterior segment conditions and posterior segment conditions.
p.5
Refraction and Optics in the Eye
What is refractive error?
When light is not brought to a focal point on the retina.
p.3
Visual Fields and Binocular Vision
What limits the shape of the visual field?
The shape of the eye and the bony aspects of the orbit.
p.19
Ocular Symptoms and Examination Techniques
What is checked first during direct ophthalmoscopy?
The red reflex in both eyes.
p.7
Anterior Segment Physiology
What type of lens can correct presbyopia?
An additional convex lens.
p.1
Image Formation in Vision
What is the initial step in image formation after light is received by photoreceptors?
An initial impulse is generated.
p.21
Lid Anatomy and Conditions
What conditions are associated with blepharitis?
Seborrhea, staphylococcal infection, and meibomian gland dysfunction.
p.7
Anterior Segment Physiology
What happens if the endothelial pump in the cornea fails?
The stroma becomes oedematous and cloudy, adversely affecting vision.
p.16
Colour Vision Mechanisms
What does the Ishihara test primarily detect?
Inheritable colour vision deficiency.
p.1
Visual Cortex and Neural Pathways
How do on-centre ganglion cells respond to stimuli?
They produce an excitatory response to stimuli in the central field and an inhibitory response to surrounding light.
p.3
Visual Fields and Binocular Vision
Where is the visual field most limited?
Nasally (by the nose) and superiorly (by the frontal bone).
p.16
Pupil Size and Response
What is the acceptable physiological variant for anisocoria?
Up to 1 mm of difference.
p.5
Refraction and Optics in the Eye
What happens to light in a myopic eye?
Light focuses in front of the retina.
p.3
Visual Fields and Binocular Vision
What are the two types of eye movements?
Saccadic movements (sudden jerky) and smooth pursuit (tracking).
p.7
Anterior Segment Physiology
What is the function of aqueous humour?
It maintains intraocular pressure and provides nutrients to the endothelium and lens.
p.4
Visual Fields and Binocular Vision
What is binocularity and its significance?
Binocularity allows for true stereopsis, enabling depth perception from two slightly different images.
p.14
Ocular Symptoms and Examination Techniques
How can the screening for defects be performed?
Grossly, focusing on quadrants, or more formally using a white pin to trace the periphery of a field.
p.5
Refraction and Optics in the Eye
What can affect the eye's ability to focus?
Corneal pathology or natural aging of the lens.
p.17
Ocular Symptoms and Examination Techniques
What is the effect of shining light in the right eye of a patient with optic neuropathy?
The right eye has a RAPD, and the pupil may dilate when light is swung back to it.
p.5
Refraction and Optics in the Eye
What is myopia?
Nearsightedness, where light focuses in front of the retina.
p.19
Ocular Symptoms and Examination Techniques
What features can be examined with a direct ophthalmoscope?
Major macular vasculature, optic nerve, macular retina, and peripheral retina.
p.7
Anterior Segment Physiology
What is the structure of the cornea?
A five-layered structure composed predominantly of collagen.
p.8
Anterior Segment Physiology
What is the consequence of untreated acute angle closure?
Rapid glaucomatous optic neuropathy.
p.7
Anterior Segment Physiology
How does the epithelium contribute to corneal health?
It provides a water-tight barrier to prevent dehydration of the stroma.
p.12
Anterior Segment Physiology
What questions should be asked to assess anterior segment symptoms?
Site, onset, character, radiation, associated symptoms, timing, exacerbating/relieving factors, and severity.
p.6
Refraction and Optics in the Eye
What is hypermetropia?
A condition where the length of the eye is too short or the focusing power is too weak, causing light rays to focus behind the retina.
What should be included in the drug history for posterior segment conditions?
Particular attention to eye drops, especially for glaucoma or ocular surface disease.
p.17
Ocular Symptoms and Examination Techniques
What indicates a RAPD when light swings back to the affected eye?
The pupil dilates due to reduced optic nerve input.
p.2
Visual Cortex and Neural Pathways
Where does the visual pathway extend to in the brain?
The visual cortex in the occipital lobe.
p.7
Anterior Segment Physiology
What is presbyopia?
A part of the natural aging process related to the loss of the lens's ability to change shape for accommodation.
p.16
Pupil Size and Response
What is anisocoria?
A difference in pupil size between the two eyes.
p.3
Visual Fields and Binocular Vision
What is essential for determining if binocular vision can be achieved?
The central portion of overlapping visual fields from each eye.
p.16
Pupil Size and Response
What does a small pupil that does not dilate in the dark indicate?
It is generally the abnormal side.
p.16
Pupil Size and Response
What does the acronym PERLA stand for?
Pupils Equal and Reactive to Light and Accommodation.
p.13
Ocular Symptoms and Examination Techniques
What does 'Counting Fingers' (CF) indicate in visual acuity testing?
The ability to count presented fingers, starting at 1 m.
p.12
Anterior Segment Physiology
What are common symptoms of anterior segment conditions?
Pain, localized redness, watering/discharge, photophobia, blurring of vision, and foreign body sensation.
p.2
Colour Blindness and Detection
What is the spectrum of colour deficiency?
It ranges from an absolute inability to distinguish any colours to a weakness in perceiving one particular colour.
p.18
Ocular Symptoms and Examination Techniques
How can you differentiate between monocular and binocular diplopia?
Monocular diplopia occurs with one eye covered, while binocular diplopia occurs only when both eyes are uncovered.
p.4
Visual Cortex and Neural Pathways
Why is screening for amblyopia important in children?
To detect and treat suppression early, preventing long-term weakness in one eye.
p.4
Refraction and Optics in the Eye
What is refraction?
The bending of light by a surface.
p.17
Ocular Symptoms and Examination Techniques
Which nucleus is stimulated by the afferent signal in the pupillary light response?
The Edinger-Westphal nucleus.
p.11
Ocular Symptoms and Examination Techniques
What do anterior segment conditions affect?
The lids, ocular surface, and anterior segment of the globe.
p.21
Lid Anatomy and Conditions
What are the main components of the eyelid structure?
Skin, orbicularis oculi muscle, tarsal plate, septum, fat pads, lid retractors, and conjunctiva.
p.1
Photoreceptor Function
What happens to 11-cis retinal during phototransduction?
It changes to all-trans retinal and detaches from the opsin.
p.3
Colour Blindness and Detection
Why does red-green trichromatism primarily affect men?
Because it is X-linked, affecting men more commonly than women.
p.19
Ocular Symptoms and Examination Techniques
What is the purpose of fluorescein 2% eye drops?
To stain epithelial defects on the conjunctiva and cornea.
p.13
Ocular Symptoms and Examination Techniques
What are the main modalities examined in optic nerve assessment?
Visual Acuity, Visual Fields, Colour Vision, Pupillary Reaction, Fundoscopy.
p.5
Refraction and Optics in the Eye
What is hyperopia?
Farsightedness, where light focuses behind the retina.
p.15
Visual Fields and Binocular Vision
What can careful examination of visual fields detect?
Gross field defects leading to important neurological diagnoses.
p.2
Colour Vision Mechanisms
What are the three main photoreceptor types responsible for colour vision?
Blue (440 nm), green (541 nm), and red (566 nm).
p.12
Anterior Segment Physiology
What factors can help identify the source of anterior segment problems?
History of foreign body entry or chemical exposure.
p.6
Refraction and Optics in the Eye
What is myopia?
A condition where the length of the eye is too long or the focusing power is too strong, causing light rays to focus in front of the retina.
p.4
Visual Fields and Binocular Vision
What is parallax in vision?
The difference in apparent position of an object viewed through two different lines of sight, helping to determine distance.
p.6
Refraction and Optics in the Eye
How is hypermetropia corrected?
Using a converging (convex) lens.
p.18
Ocular Symptoms and Examination Techniques
What is a common symptom of a trochlear palsy?
Diagonal diplopia that may worsen on adduction of the affected eye.
p.18
Ocular Symptoms and Examination Techniques
How is corneal sensation tested?
By touching a fine piece of cotton to the peripheral cornea to elicit a blink reflex.
p.16
Colour Vision Mechanisms
What indicates a potential underlying optic nerve problem during the Ishihara test?
More than three mistakes or a slow reading speed compared to the fellow eye.
p.13
Ocular Symptoms and Examination Techniques
How is distance visual acuity commonly assessed?
Using a Snellen chart or a logMar chart at a distance of 6 m.
p.8
Anterior Segment Physiology
What can cause a dramatic rise in intraocular pressure?
Blockage of the conventional drainage pathway.
p.19
Ocular Symptoms and Examination Techniques
Why should topical anesthetic not be given to take home?
Prolonged use may lead to corneal toxicity and failure of the corneal epithelium.
p.2
Colour Blindness and Detection
What is the most common method of detecting colour deficiency?
Testing with similar hues or using Ishihara plates.
p.6
Refraction and Optics in the Eye
How is myopia corrected?
Using a diverging (concave) lens.
What is a key difference in symptoms between anterior and posterior segment conditions?
Posterior segment conditions often cause fewer pain symptoms but can lead to varied visual symptoms, including loss of vision.
p.15
Visual Fields and Binocular Vision
Why is documentation of visual fields important in patients with possible optic nerve damage?
It is essential as part of the assessment.
p.21
Lid Anatomy and Conditions
What types of glands are found in the lid margin?
Meibomian glands, Glands of Zeis, and Glands of Moll.
p.13
Ocular Symptoms and Examination Techniques
What does an improvement in visual acuity with a pinhole test suggest?
A focusing/refractive problem with the eye.
p.3
Visual Fields and Binocular Vision
What can affect the visual field?
Structural or neurological abnormalities from the eyelids to the occipital cortex.
p.21
Lid Anatomy and Conditions
What can the glands in the eyelid margin lead to?
Cysts, masses, or occasionally tumor formation.
p.18
Ocular Symptoms and Examination Techniques
Which cranial nerves control the extraocular muscles?
Oculomotor, Trochlear, and Abducens Nerves.
p.18
Ocular Symptoms and Examination Techniques
What is the significance of testing extraocular movements?
It provides information on movement deficits and restrictions, important for diagnosing orbital pathology.
p.7
Anterior Segment Physiology
What are the two methods of aqueous outflow?
Conventional and unconventional outflow.
p.6
Refraction and Optics in the Eye
What is astigmatism?
A condition where there is more than one refractive power within the eye, typically occurring in the lens or cornea.
p.18
Ocular Symptoms and Examination Techniques
What does the trigeminal nerve supply?
Sensation to the eyelid skin and cornea.
p.4
Refraction and Optics in the Eye
Which part of the eye provides the greatest focusing power?
The corneal surface due to the difference in refractive indices.
p.7
Anterior Segment Physiology
How does the lens change with aging?
It stiffens and becomes unable to increase in power through the movement of the ciliary processes.
p.13
Ocular Symptoms and Examination Techniques
What should a patient wear before assessing distance visual acuity?
Any distance prescription corrective lens.
p.7
Anterior Segment Physiology
What is the role of the cornea in vision?
It maintains clarity through homeostatic mechanisms and a balance of hydration.
p.8
Anterior Segment Physiology
What condition can result from blockage of the meshwork by the iris?
Acute angle closure glaucoma.
p.5
Refraction and Optics in the Eye
What happens to light in a hypermetropic eye?
Light focuses behind the retina.
p.13
Ocular Symptoms and Examination Techniques
What does 'Hand Movements' (HM) signify in visual acuity testing?
The ability to detect a hand moving in front of the eye in a well-lit room.
p.4
Visual Fields and Binocular Vision
What role does the vestibular system play in vision?
It stabilizes head positioning, allowing eye movements to adjust accordingly.
p.8
Anterior Segment Physiology
How does fluid drain in the uveoscleral route?
Fluid passes posteriorly into the space around the choroid and drains through the surface of the eye.
p.12
Anterior Segment Physiology
What conditions may recur with distinct flare episodes in the anterior segment?
Anterior uveitis and Herpes simplex keratitis.
p.4
Visual Fields and Binocular Vision
How do rabbits compensate for their lack of depth perception?
By moving their heads side to side to utilize parallax for identifying prey.
p.6
Refraction and Optics in the Eye
How can regular astigmatism be characterized?
The two meridians are separated by 90°.
p.12
Ocular Symptoms and Examination Techniques
What forms the basis of all ophthalmic examinations?
Cranial nerve examination of cranial nerves II–VII.
p.4
Refraction and Optics in the Eye
How does the lens change shape to adjust focus?
By the contraction or relaxation of the ciliary processes.
p.3
Visual Fields and Binocular Vision
What is the role of muscular control in binocular vision?
It ensures that the eyes move in sync and complementary directions.
p.8
Anterior Segment Physiology
What can block the trabecular meshwork besides the iris?
Blood or dense inflammation in the anterior chamber.
p.13
Ocular Symptoms and Examination Techniques
What does 'Perception of Light' (PL) mean in visual acuity testing?
The ability to perceive if a bright light is shone in the eye.
p.13
Ocular Symptoms and Examination Techniques
What does 'No Perception of Light' (NPL) indicate?
The inability to perceive any light shone in the affected eye.
p.13
Ocular Symptoms and Examination Techniques
Why is formal visual field testing useful?
To monitor optic nerve function and assess fitness to drive.
p.18
Ocular Symptoms and Examination Techniques
What is a common cause of binocular diplopia?
An imbalance or weakness in one of the extraocular muscles.
p.4
Visual Cortex and Neural Pathways
What is amblyopia?
A condition where the brain suppresses one eye due to two separate retinal images, leading to chronic suppression.
p.6
Refraction and Optics in the Eye
What is a sphero-cylinder lens?
A lens used to correct both myopia or hypermetropia and astigmatism in one pair of glasses.
p.18
Ocular Symptoms and Examination Techniques
What does the presence of diplopia indicate?
It may indicate a problem with eye movement or muscle imbalance.
p.18
Ocular Symptoms and Examination Techniques
What is the typical appearance of a third nerve palsy?
A 'down and out' eye with possible ptosis.
p.18
Ocular Symptoms and Examination Techniques
What is the role of the facial nerve in eye function?
It supplies the orbicularis oculi, important for lid tone and closure.
p.4
Visual Cortex and Neural Pathways
What is strabismus?
A condition where a single visual stimulus does not fall on corresponding retinal points, leading to misalignment of the eyes.
What family history may provide clues to ocular conditions?
Conditions with strong family links such as glaucoma and squints.
p.18
Ocular Symptoms and Examination Techniques
What happens in an abducens palsy?
Worsening diplopia on abduction of the affected eye, with horizontal images.
p.4
Refraction and Optics in the Eye
What is the primary function of refraction in vision?
To bring environmental light to focus on the retina.
