Relative Canalicular Tear Flow as Assessed by Dacryoscintigraphy

White, William L.; Glover, A. Tyrone; Buckner, Arthur B.; Hartshorne, Michael F.

doi:10.1016/s0161-6420(89)32918-6

Cited by 50 publications

(17 citation statements)

References 7 publications

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“…Linberg 8c Moore (1988) reported that a single functioning canaliculus was usually suflticient to drain basal or minimally stimulated tear secretion, 50% of the time it was not sufficient to drain reflex secretions. White (1989) objectively evaluated tear drainage in 11 volunteers by dacriyoscintigraphy after occluding the canaliculus with collagen im-They found no statistical difference in tear flow between the upper and lower canalicular systems. Meyer et al (1989), using fluorescein dye disappearence, confirmed that monocandicular obstruction generally results in minimal or no impairment in tear drainage in the vast majority of patients.…”

Section: Discussionmentioning

confidence: 99%

“…To solve this problem numerous studies using various methods have been done. Primary Jones-dye-test (Jones et al 1972;Zappia 8c Milder 1972), the frequence of cilia impaction in the lacrimal puncta (Nagashima & Kid0 1984), lacrimal scintillography (White 1989;von Denffer 1984) and clinical evaluation of pa-tients who have sustained lacrimal system injuries (Canavan & Archer 1979;Saunders et al 1978;Ortiz & Kraushar 1975) have all been used. Nagashima & Kido (1984) assessed the tear drainage after canalicular obstruction with the impaction of the eyelashes into the lacrimal puncta and found that lower lacrimal punctum plays a major role in normal tear drainage.…”

mentioning

confidence: 99%

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Assessment of tear drainage by fluorescein dye disappearance test after experimental canalicular obstruction

Öğüt

Bavbek

Kazokoğlu

1993

Acta Ophthalmologica

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Controversy exists about the role of upper and lower canaliculi in tear drainage. Fluorescein dye disappearance test was used to evaluate tear drainage after experimental obstruction of upper, lower, neither or both canaliculi in 18 subjects by hydroxypropil cellulose rods. When both canaliculi were occluded marked impairment was noted in all subjects (p < 0.05). Monocanalicular obstruction (either upper or lower) generally resulted in minimal impairment in most of the cases. Only 11% of upper canalicular obstruction and 20% of lower canalicular obstruction resulted in marked impairment. There was no significant difference between upper and lower canalicular obstruction (p < 0.05). In this study it is concluded that both upper and lower canaliculus have equal importance in tear drainage.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Assessment of tear drainage by fluorescein dye disappearance test after experimental canalicular obstruction

Öğüt

Bavbek

Kazokoğlu

1993

Acta Ophthalmologica

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“…Tears are moved into the lacrimal puncta by negative pressure created within the lacrimal drainage system during a blink 42 . The majority of tears drain through the lower puncta; 43,44 however, if drainage is impaired in the lower puncta, sufficient drainage can be obtained through the upper puncta 42,45,46 . Finally, tears move via gravity from the upper tear meniscus to the lower one.…”

Section: Tear Film Dynamicsmentioning

confidence: 99%

“…42 The majority of tears drain through the lower puncta; 43,44 however, if drainage is impaired in the lower puncta, sufficient drainage can be obtained through the upper puncta. 42,45,46 Finally, tears move via gravity from the upper tear meniscus to the lower one. In the presence of impaired drainage, reduced tear production has been observed.…”

Section: Tear Film Drainagementioning

confidence: 99%

Osmolality and tear film dynamics

Stahl

Willcox

Stapleton

2012

Clinical and Experimental Optometry

133

102

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The tear film is a nourishing, lubricating and protecting layer that bathes the ocular surface. It is continuously replenished through cycles of production and elimination via evaporation, absorption and drainage. These processes are often referred to as tear film dynamics. Osmolality is an objective clinical measurement that provides insight into the balance of these complex tear film dynamics. Balanced tear production and elimination is vital for tear film integrity, stability and normal osmolality. Imbalances cause alterations of the tear film structure and composition, ultimately leading to tear film instability and measurable tear film hyperosmolality. Elevated tear film osmolality is considered a core mechanism in dry eye, forming the basis of dry eye symptoms and leading to ocular surface damage. Despite its immense potential in the diagnosis of dry eye, tear film osmolality is not commonly assessed. This review will focus on the current knowledge of tear film dynamics and tear film osmolality. The pre-ocular tear film is the outermost layer of the eye and is of critical importance to the health of the ocular surface. A continuous cycle of production, evaporation, absorption and drainage leads to a dynamic equilibrium in the pre-ocular tear film. Tear film osmolality or tear saltiness can be considered a consequence of these various factors in tear film dynamics.1 Homeostatic balance leads to tear film stability, enabling the tear film to fulfil its vital functions such as lubrication, nourishment and protection of the ocular surface.2,3 Homeostatic imbalance causes alteration of the tear film structure and composition, ultimately leading to tear film instability and tear film hyperosmolality.2 Measurement of tear film osmolality has been suggested as a gold standard in the diagnosis of dry eyes as elevated tear film osmolality is considered a core mechanism in symptoms and ocular surface damage in dry eye. 2,4,5 Despite its immense potential in the diagnosis of dry eye, measurement of tear film osmolality has not been amenable to in-office use and is largely confined to use in research. Newly available technology might increase its uptake by clinicians. This review focuses on the current knowledge of tear film dynamics and the relevance and clinical implications of tear film osmolality. TEAR FILM STRUCTURE AND FUNCTIONThe classical description of the tear film is a three-layered structure, with a predominant aqueous phase, a superficial thin oily layer, which interfaces with the environment, and a deep mucous layer at the base. 6,7 The thickness of the tear film was originally estimated to be 4 to 8 mm, with the aqueous layer being the thickest

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“…8,9 In the setting of a normal eye, a trial with a punctual plug on the proposed donor eyelid could be used to investigate the possible postoperative outcomes on the donor lacrimal system. Finally, a monocanilicular silicone stent, as opposed to the described bicanalicular stent, could function as an acceptable alternative technique during transplantation.…”

mentioning

confidence: 99%