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. LACRIMAL SYSTEM: CLINICAL ANATOMY, PHYSIOLOGY, CONGENITAL DISORDERS AND EVALUATION. DR. FAIZUR RAHMAN
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O , my sustainer! Open my Heartandmake my task easy for meand loosen the knot from my tongueso that, they might understand my speechSurahTaha (16:25-290)____Al Quran
DR. FAIZUR RAHMAN
Professor of Ophthalmology
PESHAWAR MEDICAL COLLEGE
BY THE END OF THE SESSION THE STUDENTS
WOULD BE ABLE TO:
*Main Lacrimal gland
*Accessory lacrimal glands
Glands of Krause
Glands of Wolfring
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.
Upper orbital part
Lower palpabral part
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 .
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.
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
Inferiorly= Superior fornix- conjunctiva.
Is from Lacrimal artery ( a branch of Ophthalmic artery) ,
and from Infra orbital artery ( a branch of Maxillary
Venous drainage is through Sup. Ophthalmic vein into
Lymphatic drainage occurs into the superficial Parotid lymph nodes.
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.
20 in number, in the upper lid and 8 in the lower lid, deeply situated in the conjunctiva near the fornix on lateral side
are few in number, situated near the upper border of the tarsal plate
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.
-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.
- 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.
-Passes down medially & posteriorly to open in the inferior meatus.
-Opening is gauded by a valve. (valve of Hasner)
Tears are drained from conjunctival sac by two mechanisms:
2. Active pump mechanism.
Gravity plays a small part and most of the tears are drained by active pump.
-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.
-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.
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.
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.
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.
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.
*watering, discharge, swelling and pain
*usually prolonged, usually unilateral
ectropion, swelling, fistula
cystic swelling, any stones, regurg test
*Punctal exam for malposition, stenosis
*Press canaliculus for infection
*Examine marginal tear strip
*Froceful closure of lids—puncta may
evert—lids may overlap
*Fouroscein disappearance test—2
Upper passages obstruction or
Lipoidal in water or lipoidal with olive oil