
<h2 id="lacrimal-gland">Lacrimal Gland</h2>
<ul>
  <li>Lobulated tubuloacinar gland</li>
  <li>Embryology: derived from surface ectoderm</li>
</ul>
<HotTopic>
  <p>
    The gland is divided into a larger orbital (superior) lobe and smaller palpebral lobe separated
    by the aponeurosis of levator
  </p>
</HotTopic>
<ul>
  <li>Situated within the zygomatic process of the frontal bone</li>
  <li>Possibly partially enclosed in periorbital connective tissue, but no true capsule</li>
</ul>
<ClinicalCorrelate>
  <p>
    The pre-aponeurotic fat does not extend to cover the gland (so important not to mistake gland
    for fat during blepharoplasty or other upper lid surgery).
  </p>
</ClinicalCorrelate>
<ul>
  <li>12 ducts secrete from orbital part into palpebral part then into superior fornix</li>
  <ul>
    <li>Ductules drain into the superotemporal fornix above the tarsus</li>
  </ul>
</ul>
<HotTopic>
  <p>
    The palpebral lobe contains secretory ducts for both portions. Therefore biopsy of the palpebral
    lobe is more likely to impair tear production
  </p>
</HotTopic>
<ul>
  <li>The ducts comprise secretory epithelial cells surrounded by myoepithelial cells</li>
  <ul>
    <li>
      Conical shaped columnar/cuboidal epithelial bilayer: with apices facing the central lumen
    </li>
    <li>Apical microvilli</li>
    <li>Basally located nuclei</li>
    <li>Rich in ER, Golgi, mitochondria</li>
    <li>Larger ducts have a double layer of lining cells</li>
    <li>Membrane bound secretory granules</li>
    <li>Histology is similar to salivary glands</li>
  </ul>
  <li>
    &ldquo;Basal&rdquo; tear film secretion is the result of light or temperature stimulation (plus
    proprioceptors in lids)
  </li>
  <li>
    Note: the lacrimal gland primarily performs <strong>reflex tear production</strong>
  </li>
</ul>
<h2 id="arterial-supply">Arterial supply</h2>
<ul>
  <li>Lacrimal artery, branch of the ophthalmic (from internal carotid)</li>
  <li>Infraorbital artery, branch of maxillary (from external carotid)</li>
  <li>Ophthalmic vein drains</li>
  <li>Lymph drains to superficial parotid nodes</li>
</ul>
<h2 id="nerve-supply">Nerve supply</h2>
<ul>
  <li>Higher control from reticular formation via descending autonomic pathways</li>
  <li>
    Secretomotor parasympathetic supply derives from superior salivatory nucleus (aka lacrimatory
    nucleus) of CNVII (facial nerve)
  </li>
  <ul>
    <li>Preganglionic fibres travel with nervus intermedius through middle ear</li>
    <li>Becomes the greater petrosal nerve</li>
    <li>Enters pterygopalatine fossa to synapse at pterygopalatine ganglion</li>
    <li>
      Postganglionic fibres hitch-hike with branches of maxillary nerve (zygomaticotemporal) and the
      lacrimal nerve (branch of ophthalmic).
    </li>
    <li>
      This innervation is responsible for <strong>reflex tearing</strong>
    </li>
  </ul>
</ul>
<ul>
  <li>
    Sensory innervation derives from trigeminal nerve: sensory ganglion, ophthalmic nerve and
    lacrimal branch
  </li>
</ul>
<ul>
  <li>
    Sympathetic innervation derives from T1 level sympathetic chain and superior cervical ganglion.
    These affect tear production by altering blood flow to the gland
  </li>
  <ul>
    <li>
      Post-ganglionic fibres from superior cervical ganglion travel in internal carotid plexus
    </li>
    <li>Join deep petrosal nerve</li>
    <li>
      Joins the vidian nerve and meets the pterygopalatine ganglion (but does not synapse here)
    </li>
    <li>
      Branches of the maxillary nerve become the zygomatic and zygomaticotemporal nerves and finally
      the lacrimal nerve
    </li>
  </ul>
  <li>
    Note: sympathetic and parasympathetic neurones both pass through the pterygopalatine ganglion
  </li>
</ul>
<h2 id="drainage">Drainage</h2>
<ul>
  <li>Punctum lacrimale sits upon the papillae lacrimalis, in line with tarsal glands</li>
  <ul>
    <li>The upper punctum sits medial to the lower punctum</li>
  </ul>
</ul>
<HotTopic>
  <p>
    The canaliculi have 2mm vertical portion and 10mm horizontal portion with dilation at the
    junction (ampulla)
  </p>
</HotTopic>
<ul>
  <li>Lower canaliculus is slightly longer (10mm compared to 8mm)</li>
  <li>Both have approximately equal diameter (0.5mm)</li>
  <li>Canaliculi are lined by stratified squamous epithelium</li>
  <li>
    Common canaliculus enters nasolacrimal sac at 2.5mm from its apex (which histologically is a
    diverticulum of the sac called the sinus of Maier)
  </li>
  <ul>
    <li>
      Valve of Rosenmuller: where the superior and inferior canaliculi join to form the common
      canaliculus
    </li>
  </ul>
  <li>Medial palpebral ligament lies anteriorly</li>
</ul>
<HotTopic>
  <p>
    Orbicularis oculi lies posterior but its pretarsal fibres surround the canaliculi: pumping
    action compresses canaliculi and dilates sac causing tears to be sucked into sac
  </p>
</HotTopic>
<ul>
  <li>Nasolacrimal sac is 12mm long</li>
  <ul>
    <li>Double layer of columnar epithelium</li>
    <li>Lies within lacrimal fossa: formed by lacrimal bone and frontal process of maxilla</li>
    <li>
      Enclosed in periorbita (fascia) but <strong>anterior to the orbital septum </strong>despite
      lying within the orbit
    </li>
    <li>Below the medial canthal tendon the sac is not enclosed in fascia and so is weaker</li>
    <li>Not covered in orbital fat</li>
    <li>Venous plexus lies between fascia and sac itself</li>
  </ul>
</ul>
<HotTopic>
  <p>The angular vein crosses the sac anteriorly</p>
</HotTopic>
<ul>
  <li>Nasolacrimal duct is continuous with sac</li>
  <ul>
    <li>Membranous structure</li>
    <li>18mm long</li>
    <li>Thicker wall than the sac</li>
    <li>
      Travels within osseous nasolacrimal canal formed by a groove in the maxillary bone and
      laterally, by the lacrimal bone above and inferior nasal concha below
    </li>
  </ul>
</ul>
<ClinicalCorrelate>
  <p>The duct is the most common site for acquired obstruction of the lacrimal system</p>
</ClinicalCorrelate>
<ul>
  <li>Contains a venous plexus along two-thirds of its length</li>
  <li>Enters inferior meatus of nasal cavity</li>
  <li>Plica lacrimalis guards the opening (aka the valve of Hasner) into the inferior meatus</li>
</ul>
<ClinicalCorrelate>
  <p>The valve of Hasner is the most common site for congenital obstruction</p>
</ClinicalCorrelate>
<ul>
  <li>
    Accessory lacrimal glands (in conjunctiva) are histologically identical to the lacrimal gland
    and produce identical secretions
  </li>
</ul>
<h2 id="lacrimal-carucle">Lacrimal caruncle</h2>
<ul>
  <li>Has colourless hair</li>
  <li>Contains accessory lacrimal glands</li>
  <li>Supplied by the infratrochlear nerve (branch of the nasociliary)</li>
  <li>Supplied by the superior medial palpebral artery: highly vascular</li>
  <li>Drains to the submandibular nodes</li>
</ul>


Orbit and ocular adnexae

Lacrimal Glands

Intro

FRCOphth Part 2 Study Notes

Tumours, masses and neoplasia

Tumours overview

Uveitis

Uveitis background

Anterior uveitis

Intermediate uveitis

Uveitis in JIA

Uveitis with JIA

Retinal vasculitis

Sarcoidosis

Behcet's disease

Toxoplasmosis

Strabismus

Overview

Viral uveitis

Esotropia

Fungal uveitis

Mycobacterial uveitis

Adnexal masses

Exotropia

Spirochaetal uveitis (including Syphilis)

Melanoma

Nematode uveitis

Retinoblastoma

Retinoblastoma (for Part 2)

Incomitent

Voyt-Koyanagi-Harada syndrome

Conjunctival intraepithelial neoplasia

Vertical deviations

Orbit

Sympathetic ophthalmia

AV Malformations and hamartomas

Arteriovenous malformations and hamartomas

Restriction syndromes

Paediatrics

Leucocoria

Congenital Cataract

Paediatric Glaucoma

Retinopathy of prematurity

Retinopathy of Prematurity

ROP-like disorders

Congenital nasolacrimal duct obstruction

White dot syndromes

Aniridia: Short Arm 11 Deletion (11p13)

Choristomas

Management Of Amblyopia

Alphabet patterns

Iris Nodules

Scleritis

Meningioma

Strabismus surgery

Optic nerve glioma

Lymphoma

Extraocular Muscles

Rhabdomyosarcoma

Idiopathic orbital inflammation

Orbital neuroblastoma

Anterior Persistent Foetal Vasculature

Lacrimal system

Metastatic lesions

Surgical Retina

Retinal Detachment

Vitreoretinal Interface And Macular Hole

Epiretinal Membrane

Medical Retina

Diabetic Eye Disease

Orbital Blood Vessels

Retinal Vascular Disease

Macular Degeneration

Central Serous Chorioretinopathy (CSCR)

Sickle Cell Retinopathy

Retinitis Pigmentosa

Albinism

Retinal Telangiectasias

Miscellaneous Retinopathies

Atropine And Myopia Progression

Pharmacology

Side Effects Of Systemic Drugs

Foetal Alcohol Syndrome

Neuro-ophthalmology

Optic Neuropathy

Papilloedema

Idiopathic Intracranial Hypertension

Chiasmal Disorders

Retrochiasmal Disorders

Migraine

Paranasal Sinuses

Supranuclear Motility Disorders

Third Nerve Palsies

Fourth Nerve Palsies

Sixth Nerve Palsies

Seventh Nerve Palsies

Anisocoria

Myasthenia Gravis

Myopathies

Blepharospasm

Functional Visual Loss

Phakomatoses

Developmental diseases

Tear Film

Eyelids

Blinking

Lid Malpositions

Anterior segment - ocular surface

Conjunctiva

Conjunctivitis

Sclera

Pigmented Conjunctival Lesions

Squamous Cell Carcinoma Of The Conjunctiva

Ocular Cicatricial Pemphigoid

Cornea

Corneal Structure And Development