O , my sustainer! Open my Heart and make my task easy for me and loosen the knot from my tongue so that, they might understand my speech
Surah Taha (16:25-290)____Al Quran DR. FAIZUR RAHMAN Professor of Ophthalmology PESHAWAR MEDICAL COLLEGE LEARNING OBJECTIVES
BY THE END OF THE SESSION THE STUDENTS WOULD BE ABLE TO: Correlate the structure of the lacrimal system with its function and clinical presentation in common clinical disorders. Outline the clinical examination protocol for the
assessment of lacrimal system in patient presenting with epiphora. Lacrimal System Consist of two parts: Tear production
Tear drainage Tear production: *Main Lacrimal gland *Accessory lacrimal glands Glands of Krause Glands of Wolfring
LACRIMAL GLANDS Serous glands Situated at the upper and outer angle of the orbit, just within the orbital margin, in a depression on the orbital plate of the frontal bone (Fossa for the lacrimal gland)
Embryology Lacrimal gland forms as a series of ectodermal buds that grow supero-laterally from the sup. fornix of the conjunctiva into the underlying mesenchyme. These buds then canalize forming the secretary units and multiple ducts of the gland.
Lacrimal sac and NLD develop as a solid cord of ectodermal cells between lat. nasal process & maxillary process of the developing face. LACRIMAL GLANDS-Anatomy. Anteriorly divided by aponeurosis of levator
palpabrae superioris into: Upper orbital part Lower palpabral part Ducts are 12 in number, pass through the palpabral part of the gland and open into the conjunctival sac, 4.5 mm above the upper border of the superior tarsus
Location LACRIMAL GLAND LOCATION LACRIMAL GLAND
LACRIMAL GLAND 12 ducts of the lacrimal gland pass from the orbital part through the palpebral part into the superior conjunctival fornix. In addition to Lacrimal gland, small accessory glands are also present in the conjunctiva.
In case of non functioning of lacrimal gland, these glands keep cornea wet . MICROSCOPIC STRUCTURE Lacrimal gland is lobulated tubulo-acinar structure. On cross section, the acini are seen as round or tube shaped masses of
columnar cells. Acini cells 80% are surrounded by Myoepithelial cells for squeezing out the secreted fluid. RELATIONS Palpebral part of Lacrimal gland lies below the
Aponeurosis of Levator palpebrae superioris. It extends into the upper eye lid. Superiorly=Aponeurosis of Levator Palpabrae Superioris. Inferiorly= Superior fornix- conjunctiva. BLOOD SUPPLY
Is from Lacrimal artery ( a branch of Ophthalmic artery) , and from Infra orbital artery ( a branch of Maxillary artery) VENOUS DRAINAGE Venous drainage is through Sup. Ophthalmic vein into cavernous sinus.
LYMPHATIC DRAINAGE Lymphatic drainage occurs into the superficial Parotid lymph nodes. NERVE SUPPLY Two types of nerve supply that is
Autonomic and sensory nerve supply. Autonomic nerve supply consist of Parasympathetic and sympathetic components. In parasympathatic system, the Nervous intermedius from the secretomotor nucleus of Facial nerve join a
branch of Great petrosal nerve to form nerve of Pterygoid canal which goes to Pterygo palatine ganglion. From here nerve fibers pass through Maxillary , Zygomatic N; Zygomatico temporal and finally Lacrimal nerve. In sympathatic system, superior cervical
sympathatic ganglion,Plexus of nerves around ICA, deep petrosal nerve, nerve of Pterygoid canal, Maxillary nerve, Zygomatic N .Zygomatico temporal nerve & Lacrimal nerve Sensory nerve supply; Lacrimal nerve.
Accessory lacrimal glands Same structure as main lacrimal gland Very small in size Glands of Krause: 20 in number, in the upper lid and 8 in
the lower lid, deeply situated in the conjunctiva near the fornix on lateral side Glands of Wolfring: are few in number, situated near the upper border of the tarsal plate
Physiology Secretes tear, a slightly alkaline serous fluid. Consist of water and minute quantities of sodium chloride, sugar , urea and protein. Contains lysozyme which is bactericidal Starts 3-4 weeks after birth.
Tear drainage system Consist of puncta, ampula, canaculi, lacrimal sac and nasolacrimal duct *Punctum: Situated near the medial end of each eyelid.
Face slightly posterior in normal condition. slightly evert the medial end of the eyelid and the punctum will become visible. *Ampula: (Vertical canaliculus) The most proximal portion of the canaculus, measuring 2 mm.
.Tear drainagecont *Horizontal canaliculus: -8 mm long, in 90% the upper and lower unite to open in the lateral wall of the sac. -In 10% both open separately. -A flap of mucosa (valve of Rozenmuller) prevents regurg from the sac.
.Tear drainagecont *Lacrimal sac: - It is 10 mm long and lies in the lacrimal fossa. - Lacrimal bone and frontal process of Maxilla separate it from middle meatus of nose. *Nasolacrimal duct:
-Passes down medially & posteriorly to open in the inferior meatus. -Opening is gauded by a valve. (valve of Hasner) Physiology Tear drainage:
Tears are drained from conjunctival sac by two mechanisms: 1. Gravity. 2. Active pump mechanism. By gravity: Gravity plays a small part and most of the tears are drained by active pump.
Physiology Active pump (Suction): -70% of the tears are drained through the lower punctum and 30% through the upper punctum -Upper and lower marginal strips of tears go
medially -The tears enter the puncta by capillary action and suction. - Pretarsal orbicularis oculi splits into superficial and deep heads around the ampulae and some fibres are attached to the sac.
Physiology -During closure of the eye: *Ampulae is compressed. *Horizontal canaliculus shortens. *Puncta move medially. *Deep head of the orbicularis (attached to sac) causes dilatation of the sac.
Physiology All these causes a negative pressure in the sac and tears are sucked into the sac. -When the eye closes, the sac goes to its original volume, forcing the tears into the nasolacrimal duct, and the puncta move laterally sucking tear into it.
Canalicular abnormalities: Very rare and often undiagnosed. Absence of punctum: very rarely one or both the puncta may be absent congenitally, usually the site may be visible
(congenital stenosis) .Congenital disorders Congenital NLD blockage: More common condition leading to epiphora in small children (non-canalization of the NLD cord)
Managed by massages and simple antibiotics till the age of 6 months in the hope of spontaneous canalisation If no improvement in 6 months the probing is tried three times till the age of 2 years. Congenital disorders
After the age of 2 years the success of probing decreases and the child may require a DCR when he/she reaches the age of 6 years. EVALUATION History
*watering, discharge, swelling and pain *usually prolonged, usually unilateral Examination *Inspection ectropion, swelling, fistula *Palpation cystic swelling, any stones, regurg test
.EVALUATIONCont *Slitlamp exam *Punctal exam for malposition, stenosis *Press canaliculus for infection *Examine marginal tear strip *Froceful closure of lidspuncta may
evertlids may overlap *Fouroscein disappearance test2 minutes .EVALUATIONCont Clinical tests
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