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The lacrimal system and tear film
Published in Mary E. Shaw, Agnes Lee, Ophthalmic Nursing, 2018
The upper and lower puncta are small round or slightly oval apertures situated on the lid margin on a slight elevation called the lacrimal papilla. This is a pale area, due to the presence of few blood vessels, about 6 mm from the inner canthus. Both puncta are normally turned inwards towards the bulbar conjunctiva so tears can drain into them. Fibres of the orbicularis muscle surround them.
Head and Neck
Published in Rui Diogo, Drew M. Noden, Christopher M. Smith, Julia Molnar, Julia C. Boughner, Claudia Barrocas, Joana Bruno, Understanding Human Anatomy and Pathology, 2018
Rui Diogo, Drew M. Noden, Christopher M. Smith, Julia Molnar, Julia C. Boughner, Claudia Barrocas, Joana Bruno
The external anatomy of the orbital region (Plate 3.32) includes the eyelashes (cilia), palpebral fissure (opening between eyelids, or rima), medial and lateral palpebral commissures (joining of upper and lower eyelids), medial and lateral angles (canthi) of the eye, lacrimal caruncle bump and the lacrimal lake surrounding it, the lacrimal papilla bump and the lacrimal puncta opening at its apex. The anterior aspect of the eyeball includes the sclera, cornea, iris, and pupil. The sclera and lids are lined by the bulbar conjunctiva and palpebral conjunctiva, forming the superior and inferior conjunctival fornices and conjunctival sac of the eye.
Sensory organs
Published in Aida Lai, Essential Concepts in Anatomy and Pathology for Undergraduate Revision, 2018
Lacrimal apparatus– lacrimal gland → excretory ductules → superior fornix of conjunctival sac → sup./inf. lacrimal papilla → punctum → sup./inf. lacrimal canaliculi → lacrimal sac → nasolacrimal duct → inf. meatus of nose
Routine punctoplasty: isn’t it time we preserved the integrity of the punctum?
Published in Orbit, 2022
Mohammad Javed Ali, Raman Malhotra, Bhupendra C Patel
The punctum is an anatomical structure representing the beginning of the lacrimal drainage system. It lies on a fibrous mound, the ‘lacrimal papilla.’ Although routinely believed to measure 0.2–0.4 mm, there are wide variations in its dimensions, which are influenced by several factors such as age, gender, race, and ethnicity.14,15 Studies assessing the natural evolution of punctal parameters from the 1st to 8th decade in a normal population have shown differences between genders as well as between the upper and lower puncta.16 From childhood to old age, typical changes have been documented in size, punctal papilla, density of peri-punctal fibrous layers, peri-punctal vascularity, and the white punctal zones.16
Ketamine versus fentanyl as an adjuvant to local anesthetics in the peribulbar block for vitreoretinal surgeries: Randomized controlled study
Published in Egyptian Journal of Anaesthesia, 2018
Sameh Abdelkhalik Ahmed, Mohamad Gamal Elmawy, Mohammed Awd
Once, the patients were admitted to the operating room, an intravenous access was established using 20 gauge venous cannula, then, patients were attached to monitor of three leads ECG, noninvasive blood pressure, and pulse oximetry. The peribulbar block was performed with the use of 25 gauge 16mm bevel disposable needles for all blocks with a limitation of injection site by inferior lacrimal canaliculus superiorly, inferior orbital margin inferiorly, lateral nasal margin medially, an imaginary line from the inferior orbital margin and inferior lacrimal papilla laterally [13]. Injection of 10ml of previously prepared solution over a period of 30 s was done which was followed by a transient fullness of the upper and lower eye lids. Careful closure of the eye, padding and intermittent compression with the use of Honan ball for 10 min to exert a pressure of 20mmHg. The intermittent compression was relieved after 1min, 3min, 5min, 7min, 9min, and 10min from injection to assess the corneal anesthesia, lid and globe akinesia. Corneal anesthesia was assessed with evaluation of corneal reflex to the application of a piece of cotton. While the lid akinesia was evaluated by asking the patient to open and squeeze his eye. Moreover, globe akinesia was evaluated by detecting the ability of the patients move his eye globe in the four cardinal directions superior, inferior, nasal, and temporal. The onset of anesthesia was defined as time interval between performing the block and loss of corneal sensation, while, onset of lid akinesia was the elapsed time between the peribulbar injection and partial loss of lid movement, also, onset of globe akinesia was the time interval from initiating the injection and partial loss of globe movement (loss of globe movement into at least two directions).
Human Lacrimal Drainage System Reconstruction, Recanalization, and Regeneration
Published in Current Eye Research, 2020
Mohammad Javed Ali, Friedrich Paulsen
The lacrimal drainage system is an organization of tear-conduit channels that drain the used tears (tear film) from the ocular surface to the inferior meatus of the nasal cavity.1–3 It begins on the eyelid margin with an opening termed “punctum,” which lies on a fibrous mound called the lacrimal papilla. The punctum is 0.2–0.3 mm in diameter with the inferior punctum lying 0.5 to 1 mm more temporally as compared to the superior. Each punctum continues into the lacrimal canaliculus which has approximately a 2-mm vertical portion and a 10 mm horizontal portion.1,2 The canalicular epithelium is of the non-keratinized, stratified squamous type. The upper and the lower canaliculi normally (>95%) unite to form a common canaliculus which empties itself into the sinus of Maier within the lacrimal sac.1–3 The lacrimal sac is 10–15 mm in length and in most cases has a fundus that towers the entrance area of the common canaliculus or the openings of the two canaliculi (if they open separately). The body of the lacrimal sac is housed in the bony lacrimal sac fossa. Its mucosal lining consists of the stratified columnar epithelium composed of single goblet cells or a group of characteristic intra-epithelial mucous glands. The epithelial cells are lined by the microvilli.3 The mucosa often forms protrusions and invaginations into the lumen of the lacrimal sac and the nasolacrimal duct (NLD) that could possibly have been termed valves (of Foltz, Bochdalek, Rosenmüller, Huschke, Aubaret, Krause, Taillefer and Hasner) in the past but are likely to be based on the different swelling states of the cavernous body surrounding the lacrimal sac and the NLD and which is densely innervated.2,3 The lacrimal sac continues as the NLD, which has a comparable epithelial lining as that of the sac but with denser goblet cells and microvilli.1 Absorption studies in animals have indicated that probably reabsorption of tear fluid components also takes place from the human NLDs, supporting the idea of a feedback mechanism for tear fluid production.1–3 The NLD traverses its bony canal in the maxilla and opens in the inferior meatus of the nasal cavity, close to the head of the inferior turbinate. The current review examines in detail the reconstructive and recanalization strategies for the canalicular stenosis, canalicular obstructions, canalicular trauma, NLD stenosis as well as obstructions.