Gross Anatomy of Vision

Introduction

• Lecturer: Carlos Andres Aresquian
• Main Theme: Importance of vision and its anatomical structures
• Key Objective: Understand various aspects of the eye and its anatomy

Overview of the Senses

• Five primary senses: touch, taste, smell, hearing, and vision
• Sight is considered one of the most critical senses

Objectives of the Lecture

1. Location of the Orbit:
   • Bony walls of the orbit
   • Surface anatomy of the eye
2. Extrinsic Muscles of the Eye:
   • Movement and positioning
3. Nerves and Blood Supply:
   • Accommodative functions
   • Blood supply to the eye

Anatomy of the Orbit

• Contents: Eyeballs, muscles, nerves, vessels, fat
• Shape: Pyramidal
• Walls: Medial and lateral walls
  • Medial walls are parallel and susceptible to fractures

Orbital Wall Features

• Medial Wall: Extends further anteriorly
• Lateral Wall: More exposed and preferred for surgical entry

Surrounding Structures and Impact

• Accidents can involve penetration through:
  • Roof: Anterior cranial fossa
  • Floor: Maxillary sinus
  • Medial wall: Ethmoidal sinuses

Case Examples

• Nail gun incidents
• Historical case: Phineas Gage

Bones of the Orbit

• Six bones: Frontal, sphenoid, zygomatic, maxillary, lacrimal, ethmoid
• Medial Wall: Lamina papyracea, very thin

Blowout Fractures

• Occur due to increased pressure in the orbit
• Types: Enophthalmos and exophthalmos

Surface Anatomy of the Eye

• Eyelid Features:
  • Palpebral fissure, commissures, and canthi
• Eye Components:
  • Cornea, iris, pupil, sclera

Eyelid Anatomy

• Tarsus: Dense connective tissue
• Glands: Tarsal and ciliary glands
• Muscles: Orbicularis oculi, levator palpebrae superioris

Injuries to Surface Anatomy

• Periorbital Ecchymosis:
  • Results from trauma
• Subconjunctival Hemorrhage:
  • Typically benign causes

Lacrimal Apparatus

• Location: Lateral margin of the orbit
• Function: Tear drainage and nasal involvement

Muscles of the Eye

• Primary Muscles: Superior, inferior, lateral, medial rectus and obliques
• Innervation Formula: LR6 (abducens), SO4 (trochlear), all others by 3 (oculomotor)

Eye Movement and Muscles

• Adduction/Abduction: Medial/lateral rectus
• Elevation/Depression: Superior/inferior rectus and obliques
• Rotation: Intorsion/extorsion

Eye Conditions

• Strabismus: Misalignment of eyes
• Esotropia/Exotropia: Inward/outward deviation
• Hypertropia/Hypotropia: Vertical deviations

Nerve Supply of the Eye

• Optic Nerve: Visual pathway
• Oculomotor Nerve: Five muscles, parasympathetic functions
• Trochlear and Abducens: Single muscle focus

Nerve Conditions

• Diplopia: Double vision due to nerve damage
• Horner's Syndrome: Sympathetic disruption causing meiosis, ptosis, anhidrosis

Blood Supply

• Ophthalmic Artery: Primary blood source
• Veinous Return and Danger Zone: Risk of meningitis

Conclusion

• Understanding anatomy is crucial for diagnosis and treatment of ocular conditions
• Emphasizes the importance of knowing the detailed anatomy for medical professionals

Additional Resources

• Recommended YouTube videos for further study on eye anatomy and nerve tests.