Dry Eye (Keratoconjunctivitis Sicca, KCS)


The 2017 International Dry Eye Workshop (DEWS II) has provided the following definition: Dry eye is a multifactorial disease of the ocular surface characterised by
a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and
damage, and neurosensory abnormalities play aetiological roles.

Aetiology: Dry Eye Disease (DED) is divided into aqueous-deficient dry eye and evaporative dry eye, and the two forms can occur together. The lists that follow
are simplified from TFOS DEWS II:

1. Aqueous-deficient Dry Eye (ADDE)

  • Sjögren Syndrome Dry Eye (SSDE)
    • associated systemic diseases, e.g. rheumatoid arthritis, polyarteritis nodosa, systemic lupus erythematosus, granulomatosis with polyangiitis (formerly known as Wegener’s granulomatosis)
  • Non-Sjögren Syndrome Dry Eye (NSDE)
    • intrinsic lacrimal gland deficiency
    • age-related dry eye
    • inflammation or infiltration of lacrimal gland
      • sarcoidosis
      • lymphoma
      • viral infection
      • radiation injury
    • lacrimal gland obstruction
      • cicatricial conjunctivitis
        • Graft Versus Host Disease (GVHD)
        • Stevens-Johnson syndrome (SJS)
        • cicatricial pemphigoid
        • trachoma
        • chemical injury
    • hyposecretory states
      • reflex afferent block
        • topical anaesthesia
        • trigeminal nerve injury
          • refractive surgery
          • neurotrophic keratitis
      • secretomotor block
        • parasympathetic damage
        • pharmacological inhibition (wide range of systemic
          drugs, including antidepressants, anticholinergics,
          antipsychotics, antihistamines, chemotherapeutic
          agents, antihypertensives, anti-arrhythmics,
          antithyroid agents and opioid analgesics)

2. Evaporative Dry Eye (EDE)

Tear deficiency can also be related to tear film dysfunction:

  • meibomian gland dysfunction
  • secondary to local disease
    • anterior blepharitis
    • ocular surface inflammation
  • secondary to systemic disease
    • rosacea
    • seborrhoeic dermatitis
    • atopic dermatitis
    • ichthyosis
    • psoriasis
  • genetically determined meibomian gland disorders
  • lid aperture disorders
    • thyroid eye disease
    • ectropion
    • abnormal blink
    • lagophthalmos
  • ocular surface-related EDE
    • allergic eye disease
    • vitamin A deficiency
    • iatrogenic disease including contact lens wear

Predisposing factors

Wide variation in prevalence worldwide (6.5% to 52.4%); higher prevalence in women in all studies
Wide variation in prevalence by symptom compared to clinical diagnosis
Prevalence rises with age, between 2.0% and 10.5% per decade
Factors that aggravate symptoms:

  • noxious agents (cooking fumes, tobacco smoke)
  • increased evaporation of tears (air conditioning, central heating)
  • digital device use (reduced blink interval)
  • refractive surgery
  • contact lens wear
  • conjunctivitis medicamentosa secondary to long-term topical therapy

Symptoms of dry eye

  • ocular irritation
  • foreign body, gritty or burning sensationp
    presence of a stringy mucous discharge
  • blurring of vision from epithelial disruption or (transiently) from mucus strands
  • symptoms exacerbated by smoke, wind or heat
  • symptoms usually bilateral; may not be described as a feeling of dryness
  • associated symptoms of dry mouth, systemic disease (e.g. arthritis)

Signs of dry eye

  • reduced tear meniscus at inferior lid margin (following the instillation of fluorescein, normal meniscus is not less than 0.2 mm in height)
  • raised tear osmolarity (308 mOsm/l is the most sensitive threshold to distinguish normal from mild/moderate DED, while 315 mOsm/l is the most
    specific cut-off)
  • fluorescein break up time (FBUT) <10 sec
  • Schirmer test (without anaesthesia) ≤ 5mm in 5 min; may be helpful in the diagnosis of Sjögren’s Syndrome, but of limited value in non-Sjögren’s DED
  • punctate epithelial erosions in exposed area of cornea and bulbar conjunctiva (especially in inferior third of palpebral aperture). Stain with vital dye(s) as available. Various grading systems are available (e.g.Oxford staining score)
  • lid wiper epitheliopathy
  • increased mucus strands and other tear film débris
  • filaments (adherent comma-shaped mucus strands)
  • mucus plaques
  • Dellen
  • thinning and (very rarely) perforation
  • reduced corneal sensitivity

Differential diagnosis

Anterior blepharitis
Allergic and infective conjunctivitis
Eyelid abnormality or dysfunction leading to exposure (exposure keratopathy)
Nocturnal lagophthalmos (failure to close eyes at night)

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

GRADE* Level of evidence and strength of recommendation always relates to the statement(s) immediately above

Non pharmacological:

Patient education regarding the condition

Modification of local environment

  • desiccating conditions and environmental pollutants
  • digital device use

(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Oral essential fatty acid supplements (omega-3 and omega-6): a recent high-quality RCT found that patients who were randomly assigned to receive supplements containing 3000mg of omega-3 fatty acids for 12 months did not have significantly better outcomes than those who were assigned to receive placebo
(GRADE*: Level of evidence=moderate, Strength of recommendation=weak)

Tear conservation

  • diminish outflow – punctal plugs

(GRADE*: Level of evidence=moderate, Strength of recommendation=weak)

Lid hygiene for meibomian dysfunction (hot compresses, lid hygiene) (see Clinical Management Guideline on Blepharitis)
(GRADE*: Level of evidence=moderate, Strength of recommendation=strong)

Protection with therapeutic contact lenses
(GRADE*: Level of evidence=low, Strength of recommendation=weak)


Tear supplements (preferably unpreserved) for use during the day ± unmedicated ointment for use at bedtime
(Recent systematic review found no evidence to support the superiority of any particular tear supplement)
Liposomal sprays in evaporative dry eye
(GRADE*: Level of evidence=moderate, Strength of recommendation=strong)

NB Patients on long-term medication may develop sensitivity reactions which may be to active ingredients or to preservative systems (see Clinical Management
Guideline on Conjunctivitis Medicamentosa). They should be switched to unpreserved preparations

Topical steroids (such as fluorometholone or loteprednol) may be considered for short-term use in some cases. The usual precautionary surveillance is required
(GRADE*: Level of evidence=moderate, Strength of recommendation=weak)

Management category

B2: alleviation or palliation; normally no referral
(If idiopathic and not associated with systemic disease)
B1: initial management followed by routine referral if adequate trial of topical treatment or punctal plugs fails, or for secondary complications (vascularisation, corneal scaring, melt, or infection). If lid anatomy or function is abnormal, refer. If the condition is not idiopathic, for example if Sjögren’s syndrome or an unidentified underlying disease are suspected, refer.
A3: if SJS or OCP are suspected, refer urgently (within one week) to ophthalmologist

Possible management by ophthalmologist

  • drug treatment for underlying disease (eg SJS, OCP)
  • ciclosporin eye drops (Ikervis)
  • autologous serum eye drops
  • electrolysis, cryotherapy
  • protection with therapeutic contact lenses of all types
  • permanent (surgical) occlusion of puncta
  • tarsorrhaphy (surgical or botulinum toxin)
  • transplantation of salivary gland/duct

Evidence base

*GRADE*: Grading of Recommendations Assessment, Development and Evaluation (www.gradeworkinggroup.org)

Sources of evidence

Akpek E K, Amescua G, Farid M, Garcia-Ferrer FJ, Lin A, Rhee MK, Varu DM, Musch DC, Dunn SP, Mah FS (American Academy of Ophthalmology Preferred Practice Pattern Cornea and External Disease Panel). Dry Eye Syndrome Preferred Practice Pattern. Ophthalmology. 2019;126(1):P286-P334

Courtin R, Pereira B, Naughton G, Chamoux A, Chiambaretta F, Lanhers C, Dutheil F. Prevalence of dry eye disease in visual display terminal workers: a systematic review and meta-analysis. BMJ Open. 2016;6(1):e009675

Craig JP, Nichols KK, Akpek EK, Caffery B, Dua HS, Joo C-K, Liu Z, Nelson JD, Nichols JJ, Tsubota K, Stapleton F. TFOS DEWS II Definition and Classification Report. Ocul Surf. 2017;15:276-83

Dry Eye Assessment and Management Study Research Group. n-3 Fatty Acid Supplementation for the Treatment of Dry Eye Disease. N Engl J Med. 2018;378(18):1681-90

Ervin A-M, Law A, Pucker AD, Punctal occlusion for dry eye syndrome: summary of a Cochrane systematic review. Br J Ophthalmol. 2019;103:301-6

Jones L, Downie LE, Korb D, Benitez-del-Castillo JM, Dana R, Deng, SX, Dong PN, Geerling G, Yudi Hida R, Liu Y, Yul Seo K, Tauber J, Wakamatsu TH, Xu J, Wolffsohn JS, Craig JP. TFOS DEWS II Management and Therapy Report. Ocul Surf. 2017;15:575-628

Pucker AD, Ng SM, Nichols JJ. Over the counter (OTC) artificial tear drops for dry eye syndrome. Cochrane Database Syst Rev. 2016;2:CD009729

Wolffsohn JS, Arita R, Chalmers R, Djalilian A, Dogru M, Dumbleton K, Gupta PK, Karpecki P, Lazreg S, Pult H, Sullivan BD, Tomlinson A, Tong L, Villani E, Yoon KC, Jones L, Craig JP. TFOS DEWS II Diagnostic Methodology Report. Ocul Surf.2017;15:539-74

Plain language summary

Dry Eye Disease is also known by the medical term Keratoconjunctivitis Sicca, which means inflammation of the conjunctiva (the membrane overlying the white of the eye) and the cornea (the clear window of the eye) caused by dryness resulting from a deficiency or disorder of the tear film (the thin layer of tears covering the surface of the eye). It is a common condition affecting many people in the later decades of life. Most cases have no apparent cause but some are related to various inflammatory conditions, surgical treatment or as a side-effect of drug treatment. Some are caused by abnormalities of the eyelids or blinking, or by disorders of the meibomian (oil) glands of the eyelid margin.

Patients complain of irritation of the eyes, a feeling that there is something in the eye, a discharge from the eye, and sometimes blurred vision. They notice that their symptoms are worse in windy or dry conditions or when irritants such as smoke are in the air. When they are examined in the clinic they may be found to have reduced tear production or increased tear evaporation (sometimes due to lack of normal oil gland secretion). There may be damage to the surface of the eye produced by the increased saltiness of the tears.

Tears can be supplemented with various drops and ointments. It is also possible to conserve natural tears by blocking the openings of the tear ducts, either temporarily with tiny plugs or permanently by surgery. Where the problem relates to a disorder of the oil glands, treatment is directed to the eyelids.

Dry eye (Keratoconjunctivitis Sicca) (KCS)
Version 14
Date of search 21.10.19
Date of revision 21.11.19
Date of publication 23.04.21
Date for review 20.10.21
© College of Optometrists 

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