Blinking and the Mechanics of the Lacrimal Drainage System

Doane, Marshall G.

doi:10.1016/s0161-6420(81)34940-9

Cited by 260 publications

(163 citation statements)

References 9 publications

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“…1, 4). The increase in blink amplitude and frequency reduces tear film breakup by spreading tears and increasing the meibomian oil excreted to stabilize the aqueous component of the tear film (Doane, 1980(Doane, , 1981Nakamori et al, 1997;Bron and Tiffany, 1998). Despite their efficacy in reducing corneal irritation, these adaptive modifications do not alleviate the proprioceptive error signal created by the difference in actual and intended blink amplitude.…”

Section: Two Modes Of Blink Modificationmentioning

confidence: 99%

“…First, the increased drive onto both the palsied and the normal facial nuclei from the trigeminal complex ipsilateral to the palsied lid causes the normal eyelid to make larger and more frequent blinks than necessary to maintain a normal tear film Huffman et al, 1996). This excessive blinking can remove tears too rapidly (Doane, 1980(Doane, , 1981, creating a mild corneal irritation in the unaffected eye (Spiera et al, 1997;Sahlin et al, 2000). The corneal irritation of the unaffected eyelid would initiate hyperexcitability and blink oscillations in the trigeminal complex contralateral to the palsied eyelid.…”

Section: Facial Nerve Palsy and Lid Restraint Produce The Same Blinkmentioning

confidence: 99%

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Lid Restraint Evokes Two Types of Motor Adaptation

Schicatano

Mantzouranis²,

Peshori³

et al. 2002

J. Neurosci.

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Unilateral reduction in eyelid motility produced two modes of blink adaptation in humans. The first adaptive modification affected both eyelids. Stimulation of the supraorbital branch of the trigeminal nerve (SO) ipsilateral to the upper eyelid with reduced motility evoked bilateral, hyperexcitable reflex blinks, whereas contralateral SO stimulation elicited normally excitable blinks bilaterally. The probability of blink oscillations evoked by stimulation of the ipsilateral SO also increased with a reduction in lid motility. The increased probability of blink oscillations correlated with the enhanced trigeminal reflex blink excitability. Thus, the trigeminal complex ipsilateral to the restrained eyelid coordinated an increase in excitability and blink oscillations independent of the eyelid experiencing reduced motility. The second type of modification appeared only in the eyelid experiencing reduced motility. When tested immediately after removing lid restraint, blink amplitude increased in this eyelid relative to the normal eyelid regardless of the stimulated SO. A patient with seventh nerve palsy exhibited the same two patterns of blink adaptation. These results were consistent with two forms of adaptation, presumably because unilateral lid restraint produced two error signals. The corneal irritation caused by reduced blink amplitude generated abnormal corneal inputs. The difference between proprioceptive feedback from the blink and expected blink magnitude signaled an error in blink amplitude. The corneal irritation appeared to drive an adaptive process organized through the trigeminal complex, whereas the proprioceptive error signal drove an adaptive process involving just the motoneurons controlling the restrained eyelid.

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Section: Two Modes Of Blink Modificationmentioning

confidence: 99%

Section: Facial Nerve Palsy and Lid Restraint Produce The Same Blinkmentioning

confidence: 99%

Lid Restraint Evokes Two Types of Motor Adaptation

Schicatano

Mantzouranis²,

Peshori³

et al. 2002

J. Neurosci.

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“…lacrimalia) that lies on the summit of a papilla (papillae lacrimales), situated on the posterior eyelid margin. 5,12 The vertical portion is generally two millimetres long, inclined laterally by five degrees and dilates at its base to form a receptacle for tear collection, called the 'ampulla'. 11,13 The vertical portion is surrounded by the muscle of Riolan or Horner's muscle.…”

Section: Discussionmentioning

confidence: 99%

“…[6][7][8] Expansion of the lacrimal sac during the opening phase of blink causes suction and after opening of the eyelids, the punctal, canalicular and lacrimal sac vacuum breaks to reload with tear fluid. 5,8 There is also thought to be a passive wringing out of the sac because of its medial attachment and helically arranged fibrillar structures. 3 In the above processes, the puncta are usually thought of as only minute orifices through which tears gain entry into the canalicular system.…”

mentioning

confidence: 99%

Punctal function in lacrimal drainage: the ‘pipette sign’ and functional ectropion

Beigi

Gupta

Luo

et al. 2015

Clinical and Experimental Optometry

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Background:The aim was to assess the movements of the inferior punctum during blinking and discuss pertinent clinical applications. Methods: This is a prospective, non-comparative observational case-series examining the function of inferior punctum during blinking using video recordings of the blinking action at the slitlamp with slow-motion analysis and comparison. Results: In all 56 eyes of 28 patents, supero-medial movement of the lower punctum toward the medial canthus, together with a medially directed protrusion of the inferior punctum was noted. It was also noted that the punctum blanched during this projectile movement compared to the rest of the lid margin. Simultaneous posterior rotation of the punctum was also observed in 48 eyes (85.7 per cent; 23 right eyes and 25 left eyes), resulting in apposition of the punctum to the lacus lacrimalis. In eight eyes (14.3 per cent; five right eyes and three left) from six patients, co-existence of medial punctal ectropion led to failure of internal rotation of the punctum during blinking, even though punctal 'pipette formation' was preserved. These six patients all suffered from epiphora in the affected eyes. The presence of 'pipette' formation was calculated to have a sensitivity of 80 per cent and specificity of 100 per cent for punctal ectropion in our series. A two-tailed Fisher exact test showed that based on our 56 eyes, these results were statistically significant (p < 0.0001). Conclusions: The inferior punctum plays an active and important role in the drainage of tears by the mechanism of supero-medial movement and medially directed protrusion ('pipetting action'), failure of which contributes to epiphora. This is a highly specific sign and should be sought in the evaluation of epiphora, even in the absence of frank ectropion. In punctual stenosis where location of the punctal orifice is proving difficult, inducing the pipette sign will help in its identification.

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“…It has been suggested that during eyelid closure the lacrimal sac is distended, creating a suction effect which draws tears from the canaliculi into the sac4 It has alternatively been suggested that eyelid closure is accompanied by sac compression which forces tears down the nasolacrimal duct . 3 However, quantitative lacrimal scintillagraphy studies suggest that once the lacrimal sac has filled, tear drainage down the nasolacrimal duct into the nose is essentially due to In some individuals coloured fluid will drain from the eye in the absence of blinking, and to explain this it has been suggested that gravitational drainage down the nasolacrimal duct creates a siphon effect which produces aspiration of tears along the canalicuk6 There are multiple valve-like projections of the mucosa within the nasolacrimal duct, the distal one forming the valve of Hasner.' These and the valve of Rosenmuller combine to allow one-way tear drainage but prevent retrograde flow from the lacrimal sac and nasolacrimal duct on blowing the nose.…”

Section: Surgical Management Of the Lacrimal Drainage Systemmentioning

confidence: 99%

Surgical Management of the Lacrimal Drainage System

Benger¹

1988

Australian and New Zealand Journal of Ophthalmology

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The physiology of normal tear drainage has been better defined in recent years Some of the refined tech nrques developed in the fields of anaesthesia and surgery have been applied to the lacrimal drainage system The combination of these advances has resulted in more rational and successful treatment of lacrimal drainage abnormalities A review of these advances is presented with a discussion on the treat ment of lacrimal drainage abnormalities

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Blinking and the Mechanics of the Lacrimal Drainage System

Cited by 260 publications

References 9 publications

Lid Restraint Evokes Two Types of Motor Adaptation

Lid Restraint Evokes Two Types of Motor Adaptation

Punctal function in lacrimal drainage: the ‘pipette sign’ and functional ectropion

Surgical Management of the Lacrimal Drainage System

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