Ocular Physiology - Eyelid

Sherrington's law of reciprocal innervation states that when one muscle is activated, its antagonist muscle is inhibited. This means that the muscles that work together in opposite directions are coordinated to prevent them from contracting at the same time, allowing for smooth and coordinated movement. This reciprocal innervation helps to maintain balance and control in the body.

Hering's law of equal innervation states that the muscles that are yoked together, meaning they work together to perform a certain movement, receive equal innervation from the nervous system. This means that when one muscle is activated, its yoked muscle will also be activated to the same extent. This ensures smooth and coordinated movement.

The purpose of treatments for GPC (Giant Papillary Conjunctivitis) is to suppress the immune response, not eradicate it. This means that the goal of the treatments is to reduce the symptoms and inflammation caused by the immune response, rather than completely eliminating the immune response itself. By suppressing the immune response, the treatments can provide relief for the patient and improve their overall eye health.

Pseudo Von Graefe's sign: Remember that CN III is capable of regeneration, Levator and MR are typically affected. In Adducted gaze - ptosis will disappear due to lid retraction.

Orbicularis Oculi - is the major protractor of the eyelids (closing) it is innervated by CNVII as well

Option D; fusion of the lids/ risk no orbit is present behind the lids

The palpebral fissure refers to the opening between the upper and lower eyelids. Option B states that the palpebral fissure is elliptical in children and already completely developed at birth. However, this statement is incorrect as the palpebral fissure is actually narrower and more rounded in children, and it continues to grow and develop until adulthood.

Collier's sign: The increased tonus is due to a lesion of CN III at the posterior commissure. Unlike Von Graefe's is is NOT a result of thyroid disease. We also see nucleus damage at the intersitial nucleus of Cajal and Darkschewitz (spelling ?).

Von Graefe's sign is the correct answer. This sign refers to the retraction of the upper eyelid due to excessive sympathetic stimulation of Muellers muscle. It is commonly seen in patients with Graves' disease, an autoimmune disorder that affects the thyroid gland. The excessive sympathetic stimulation causes the eyelid to retract, resulting in a widened palpebral fissure. This sign is named after the German ophthalmologist, Carl Ferdinand von Graefe, who first described it. Collier's sign refers to a different condition, which is the absence of the upper eyelid crease. Pseudo Von Graefe's sign is not a recognized term.

Option B: Only non-metastatic option listed. Make up 95% of lid carcinomas
He also showed the cutaneous horns in lecture but that was purely a cosmetic issue.

Option A; Correct but in addition CNV also controls the facial reflex
Option B: CNVIII - is solely responsible for auditory reflex

Areas of oily tissue are adjacent to the duct (acini)

Option A; Refers to Dermatochalasis
Option C: refers to congenital ptosis
Option D: Refers to Blepharophimosis

Neostigmine: is given to patients with acquired ptosis from MG. It enhances the activity of the LPS

Option C - refers to the Dazzle reflex
Additional information for the corneal reflex = CL patients adapt to this reflex

Option C: Cicatrial = scar tissue that results in ptosis

Blink suppression affects all of the above options: low spatial frequency, high temporal frequency, and luminance information. Blink suppression refers to the phenomenon where the visual system suppresses the perception of visual information during eye blinks. This suppression can affect the perception of low spatial frequency information, which refers to the perception of coarse details in an image. It can also affect high temporal frequency information, which refers to the perception of rapid changes or motion in an image. Additionally, blink suppression can also affect the perception of luminance information, which refers to the perception of brightness or intensity of light.

Correct: Meibomitis = chronic, painful, bilateral inflammation of the meibomian glands
Marginal blepharitis = bilateral inflammation of the lid margins
Option C = aka chalazion

The "contact lens stare" is significant because it demonstrates that blink characteristics can be altered. This suggests that wearing contact lenses can affect the natural blinking reflex, potentially leading to dry eyes or other discomfort. The stare may indicate that contact lens wearers tend to blink less frequently or have altered blink patterns compared to those who do not wear contact lenses.

Normal patients can withhold the Facial Reflex. Myerson's sign refers to the inability to withhold the Glabellar Reflex, which is a repetitive blinking response to tapping on the forehead. Therefore, the correct answer is B.