5.14 Keratitis, Viral, Herpes Simplex

eyes.nhs.scot/
Eyecare Guidelines/
Section 5 - Cornea/
5.14 Keratitis, Viral, Herpes Simplex

Date of last review:

19/12/2025

Date of next review:

19/12/2027

Date of publication:

19/1/2026

This is a GOS Specialist Supplementary condition and should be managed by community optometrists in line with national guidance⁽⁸⁾. This guideline should be read in conjunction with ‘Supporting information’ guidance [link to Supporting Information page]

Differential diagnosis ⁽¹⁾

Herpes zoster keratitis
Bacterial, fungal, or amoebic keratitis (consider Acanthamoeba in contact lens wearers)
Healing epithelial defects (e.g. abrasions)
Other causes of pseudodendrites

Possible management by optometrist

Advice

Sunglasses for symptom relief ⁽¹⁾
Dendritic keratitis in a contact lens wearer may indicate Acanthamoeba infection rather than viral keratitis. Such cases require specialist assessment and should not be treated within community settings – see further management options for referral guidance ⁽⁷⁾
Exclude viral retinitis following pupil dilatation (especially in immunocompromised patients - requires same-day referral) ⁽¹⁾
- Signs of viral retinitis include ⁽¹⁾:
  - Peripheral infiltrates
  - Vasculitis
  - Intra-retinal haemorrhages
  - Vitreous inflammation
HSK is a potentially blinding disease
- Apply low threshold for referral ⁽¹⁾

Treatment

Acute epithelial HSK (non-contact lens wearing adults, classic dendritic ulcer)
- Topical antivirals ⁽¹⁾
Recurrent epithelial HSK
- Topical antivirals ⁽¹⁾ if:
  - Clear history of recurrence
  - Diagnosis is certain
  - No stromal involvement
Monitor closely within first 72 hours (where appropriate ⁽⁷⁾) to evaluate healing, but refer urgently to ophthalmology if epithelium has not healed after 7 days ⁽¹⁾ (consult local guidance as they may vary on review timescales e.g. 7 days for first review, or 14 days for referral ⁽⁷⁾)
Stromal HSK:
- The College of Optometrists Clinical Management Guideline (CMG) recommends that stromal involvement should be referred as an emergency same day referral to ophthalmology ⁽¹⁾

NB Some local Health Boards have specific guidance for treating HSK in the community. Local guidance can be found within the clinical and referral protocols section of their host Board page on eyes.nhs.scot ⁽⁷⁾

NB Oral antivirals decrease the recurrence of stromal HSK by 50% when used prophylactically at low dose. There is no indication for prophylactic use for epithelial HSK, apart from for those patients with multiple recurrence ⁽¹⁾

Typical adult dosage/duration

(Blue text = IP, black text = non-IP)

Ganciclovir 0.15% eye gel ^(1,5) (POM): One drop 5 times daily until healing complete, then 3 times daily for a further 7 days (consult local guidance as they may vary on tapering ⁽⁷⁾), treatment does not usually exceed 21 days ^(2,3)

Regimens should be adjusted according to severity and patient factors (e.g. age, weight, pregnancy, renal function). Prescribing should follow local formulary and local/national guidance where available ⁽⁷⁾.

In cases of known sensitivities, please consult local formularies for alternative options ⁽⁷⁾.

Further management options

GOS Specialist Supplementary Stage 1 to assess and establish presence of HSK* ⁽⁸⁾
If HSK present (no stromal involvement), GOS Specialist Supplementary Stage 2* treatment should be provided by a local IP optometrist/OMP who is registered and qualified to carry out GOS Specialist Supplementary Stage 2 management; intra-referral (practice to practice) should take place to facilitate this ⁽⁸⁾
- Urgent referral if no healing after 7 days ⁽¹⁾ (local guidance may vary on timescales ⁽⁷⁾)
Stromal involvement, children, contact lens wearers, or bilateral cases ⁽¹⁾
- Consider emergency same-day referral ^(1,7)
Treatment may be provided within available locally enhanced schemes, or by community IP optometrists/OMPs, as appropriate (outwith GOS Specialist Supplementary) ⁽⁷⁾

*Treatment should be provided in line with “Annex C of the Statement” ⁽⁸⁾ https://www.eyes.nhs.scot/for-professionals/legislation/

Possible management in secondary care or local/community pathways where available ^(1,8)

See Further management options
Diagnostic confirmation via swab, PCR or viral culture⁽¹⁾
Topical and/or systemic antivirals (e.g. aciclovir, famciclovir) reduce recurrence risk⁽¹⁾
Topical steroids for stromal/endothelial disease⁽¹⁾
Anti-glaucoma agents for raised IOP⁽¹⁾
Epithelial debridement⁽¹⁾
Corneal transplant (keratoplasty) for scarring in quiescent cases⁽¹⁾

College of Optometrists Clinical Management Guideline⁽¹⁾

Herpes simplex keratitis (HSK) - College of Optometrists *

*With special thanks to The College of Optometrists for providing the evidence framework for diagnosis and management from the Clinical Management Guidelines (CMGs) for this condition. All references to the College/CMGs are included where appropriate and form the basis of the Community Eyecare Guidelines.

Guidance is informed by the following sources

College of Optometrists Clinical Management Guidelines Clinical Management Guidelines - College of Optometrists
Advisory alignment with the College of Optometrists Formulary Optometrists' Formulary - College of Optometrists
Advisory alignment with the BNF BNF (British National Formulary) | NICE
Advisory alignment with the Summary Product Characteristics taken from the EMC Home - electronic medicines compendium (emc)
Advisory alignment with Scottish Health Board formularies (where a clear majority is present) *
Advisory alignment with expert consensus (CEGG), informed by sources 2-5 above
Advisory alignment with expert consensus (CEGG)
“Annex C of the Statement” https://www.eyes.nhs.scot/for-professionals/legislation/

* Scottish formularies should be available within the Prescribing section of your Health Board pages on the eyes.nhs.scot website. If unavailable, contact your local Health Board for further information; Health Boards landing page

If you have a query relating to this page, please email NSS.ComEyecareGuidelineGroup@nhs.scot

Disclaimers

CEG disclaimer for guidelines awaiting update:

The Eyecare Guidelines area of the eyes.nhs.scot website (“Website”) is intended as a reference source for education and clinical decision support and is intended for use by ophthalmic healthcare professionals working in Scotland.

As such, the Eyecare Guidelines are not intended for use by the general public and do not replace the advice of a healthcare professional. Members of the public should seek advice directly from their optometrist.

Before reading the Eyecare Guidelines or making any management decisions based upon them, all users should read the ‘supporting information’ page which gives more detail around the content of the Guidelines and useful website links [link to Supporting Information page].

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Users should note that that the Eyecare Guidelines guidance is not mandatory. The guidelines will not be suitable for every situation and they are not intended to be a substitute for specialist expertise and clinical judgement. Users assume all responsibility for using/interpreting the information within the Eyecare Guidelines section of the website. Users should also note that the Eyecare Guidelines should not be adhered to in isolation and should be considered in conjunction with other national and locally available guidance/pathways. 

Updating the Eyecare Guidelines requires a continuous process; the date of the last review for each guideline will be clearly noted on each guideline. Users must consider these dates before using the guidance.

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