Aqueous deficiency is a contributor to evaporation-related dry eye disease

Abstract Dry eye disease aetiologies can be classified dichotomously into aqueous deficient and evaporative types although many cases involve combinations of both. Differential diagnosis can be confounded by some features of dry eye disease being common to both aetiologies. For example, short tear b...

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Main Author: Charles W. McMonnies
Format: Article
Language:English
Published: BMC 2020-02-01
Series:Eye and Vision
Subjects:
Online Access:https://doi.org/10.1186/s40662-019-0172-z
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author Charles W. McMonnies
author_facet Charles W. McMonnies
author_sort Charles W. McMonnies
collection DOAJ
description Abstract Dry eye disease aetiologies can be classified dichotomously into aqueous deficient and evaporative types although many cases involve combinations of both. Differential diagnosis can be confounded by some features of dry eye disease being common to both aetiologies. For example, short tear break-up times are prime diagnostic findings of tear instability due to lipid and/or mucin deficiencies, but thin tear layers in aqueous deficient eyes also shorten tear break-up times, even at normal range rates of evaporation in eyes without lipid and/or mucin deficiencies. Because tear instability and short tear film break-up times due to thin tear layers can be independent of lipid and/or mucin deficiency, aqueous deficiency can be another form of evaporation-related dry eye. Conversely, tear layers which are thickened by punctal occlusion can be less susceptible to tear break-up. An inflamed lacrimal gland producing reduced quantities of warmer tears can be a basis for thin tear layers and tear instability demonstrated by shorter tear break-up times. Commonly used clinical tests for aqueous deficiency can be unreliable and less sensitive. Consequently, failure to detect or confirm aqueous deficiency as a contributor to short tear break-up times could result in too much weight being given to a diagnosis of meibomian gland deficiency. Less successful treatment outcomes may be a consequence of failing to detect aqueous deficiency. Refining disease classification by considering aqueous deficiency as a contributor to, or even a form of evaporation-related dry eye, could be the basis for more comprehensive and appropriate treatment strategies. For example, some treatment methods for evaporation-related dry eye might be appropriate for aqueous and mucin-deficient as well as lipid-deficient dry eyes. Anti-inflammatory treatment for the lacrimal gland as well as the conjunctiva, may result in increased aqueous production, reduced tear temperature, tear instability and evaporation rates as well as lower osmolarity.
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spelling doaj.art-64ed4f0892a24bf08781f16e938079c72022-12-21T18:15:36ZengBMCEye and Vision2326-02542020-02-01711610.1186/s40662-019-0172-zAqueous deficiency is a contributor to evaporation-related dry eye diseaseCharles W. McMonnies0Honorary Professor, School of Optometry and Vision Science, University of New South WalesAbstract Dry eye disease aetiologies can be classified dichotomously into aqueous deficient and evaporative types although many cases involve combinations of both. Differential diagnosis can be confounded by some features of dry eye disease being common to both aetiologies. For example, short tear break-up times are prime diagnostic findings of tear instability due to lipid and/or mucin deficiencies, but thin tear layers in aqueous deficient eyes also shorten tear break-up times, even at normal range rates of evaporation in eyes without lipid and/or mucin deficiencies. Because tear instability and short tear film break-up times due to thin tear layers can be independent of lipid and/or mucin deficiency, aqueous deficiency can be another form of evaporation-related dry eye. Conversely, tear layers which are thickened by punctal occlusion can be less susceptible to tear break-up. An inflamed lacrimal gland producing reduced quantities of warmer tears can be a basis for thin tear layers and tear instability demonstrated by shorter tear break-up times. Commonly used clinical tests for aqueous deficiency can be unreliable and less sensitive. Consequently, failure to detect or confirm aqueous deficiency as a contributor to short tear break-up times could result in too much weight being given to a diagnosis of meibomian gland deficiency. Less successful treatment outcomes may be a consequence of failing to detect aqueous deficiency. Refining disease classification by considering aqueous deficiency as a contributor to, or even a form of evaporation-related dry eye, could be the basis for more comprehensive and appropriate treatment strategies. For example, some treatment methods for evaporation-related dry eye might be appropriate for aqueous and mucin-deficient as well as lipid-deficient dry eyes. Anti-inflammatory treatment for the lacrimal gland as well as the conjunctiva, may result in increased aqueous production, reduced tear temperature, tear instability and evaporation rates as well as lower osmolarity.https://doi.org/10.1186/s40662-019-0172-zAqueous deficientEvaporativeDry eyesTear break-up
spellingShingle Charles W. McMonnies
Aqueous deficiency is a contributor to evaporation-related dry eye disease
Eye and Vision
Aqueous deficient
Evaporative
Dry eyes
Tear break-up
title Aqueous deficiency is a contributor to evaporation-related dry eye disease
title_full Aqueous deficiency is a contributor to evaporation-related dry eye disease
title_fullStr Aqueous deficiency is a contributor to evaporation-related dry eye disease
title_full_unstemmed Aqueous deficiency is a contributor to evaporation-related dry eye disease
title_short Aqueous deficiency is a contributor to evaporation-related dry eye disease
title_sort aqueous deficiency is a contributor to evaporation related dry eye disease
topic Aqueous deficient
Evaporative
Dry eyes
Tear break-up
url https://doi.org/10.1186/s40662-019-0172-z
work_keys_str_mv AT charleswmcmonnies aqueousdeficiencyisacontributortoevaporationrelateddryeyedisease