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PubMed This is a summary of 16 peer-reviewed journal articles Updated
Ophthalmology · HSV Stromal Keratitis

Subtypes of Stromal Keratitis: Immune vs. Necrotizing

At a Glance

HSV stromal keratitis has two subtypes: immune (non-necrotizing) and necrotizing. Immune keratitis causes cloudiness from inflammation, while necrotizing is an active viral infection that can dangerously thin or "melt" the cornea. Both require prompt treatment to protect your vision.

While all herpes eye infections are serious, doctors categorize HSV stromal keratitis into two distinct “personalities”: Immune (Non-Necrotizing) and Necrotizing. Understanding which type you have is vital because it changes the treatment strategy and the long-term outlook for your vision.

Immune (Non-Necrotizing) Stromal Keratitis: The “Cloudy” Type

This is the most common form of stromal keratitis [1]. It is primarily an “immune overreaction” where your T-cells are attacking the middle layer of the cornea because they detect leftover viral fragments [2][3].

  • Appearance: The eye typically looks hazy or cloudy. The surface of the cornea is usually smooth and intact [4][5].
  • The Mechanism: The damage isn’t caused by the virus eating away at the eye, but by the inflammation your own body creates.
  • Treatment: The main goal is to calm the immune system. Doctors use topical corticosteroids (steroid drops) to reduce the haze, while also providing a low dose of antivirals to make sure the virus doesn’t “wake up” while the immune system is suppressed [6][7].
  • Prognosis: If caught early, the outlook for vision is generally good, though repeated episodes can lead to permanent scarring [5][8].

Necrotizing Stromal Keratitis: The “Melting” Type

This is a much more aggressive and dangerous, but rare, form of the disease. In this subtype, the virus is actively replicating inside the stroma, causing direct tissue death while the immune system also attacks the area [6][9].

  • Appearance: Unlike the immune type, this involves the active breakdown or “melting” of the deep corneal tissue, which is often accompanied by an overlying surface ulcer [5][8]. This deep tissue damage distinguishes it from superficial, standard epithelial infections. The cornea may appear cloudy and structurally weakened as the tissue begins to break down.
  • The Mechanism: This is a dual-attack: the virus is directly destroying the tissue, and the immune system is causing massive inflammation in response.
  • The Danger: The cornea can physically thin, leading to perforation (a hole in the eye) [10][11].
  • Treatment: This requires intensive medical management. Standard protocol involves initiating high-dose therapeutic antivirals (oral or topical) alongside cautious, concurrent use of topical steroids. This dual approach simultaneously fights the active virus and suppresses the immune inflammation to prevent the cornea from melting [12][9].
  • Prognosis: This type carries a higher risk of permanent vision loss and scarring [5][1]. Frequent doctor visits are designed to catch this early and prevent severe complications.

Summary of Differences

Feature Immune (Non-Necrotizing) Necrotizing
Surface Ulcer Usually absent (surface is smooth) Present (open sore + deep damage)
Main Cause Immune system overreaction Active virus + Immune attack
Risk of Hole (Perforation) Low High
Pain Level Dull ache / Blurry Often severe / Sharp
Primary Treatment Steroids + Preventative Antivirals High-dose Antivirals + Concurrent Steroids
Visual Outlook Good if managed early Poorer; high risk of scarring

Monitoring for “Melting”

If you are diagnosed with the necrotizing type, your doctor will monitor your corneal thickness very closely. If the cornea becomes dangerously thin (a condition called a descemetocele), you may need surgical interventions like amniotic membrane transplantation or a corneal patch graft to physically reinforce the eye and prevent it from rupturing [10][13][14]. Even in severe cases, catching structural weakening early can save the eye through these specialized surgical techniques [15][16].

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Common questions in this guide

What is the difference between immune and necrotizing stromal keratitis?
Immune stromal keratitis is an inflammatory reaction to leftover viral particles, causing a cloudy but smooth cornea. Necrotizing stromal keratitis involves an active viral infection that physically breaks down or "melts" the corneal tissue, often presenting with an open sore.
Can a herpes eye infection cause a hole in my cornea?
Yes, the necrotizing subtype of stromal keratitis can cause severe corneal thinning, which can eventually lead to a hole in the eye called a perforation. If this structural weakening occurs, you may need surgical interventions like a corneal patch graft to reinforce the eye.
Why are steroid eye drops used to treat stromal keratitis?
Steroid eye drops are used to calm the severe inflammation and cloudiness caused by your immune system's overreaction to the virus. To ensure the virus does not actively spread while your immune system is suppressed, doctors always prescribe antivirals alongside the steroids.
How do I know if my cornea is thinning or melting?
Signs of a thinning or melting cornea can include severe sharp pain, sudden worsening of your vision, or a sensation that your eye is leaking fluid or changing shape. Because thinning isn't always easy to feel, your eye doctor will measure your corneal thickness during checkups.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Do I have an active ulcer on the surface of my cornea, or is the inflammation contained inside the stromal layer?
  2. 2.Based on my subtype, should I be on a 'therapeutic' (high) dose of antivirals or a 'preventative' (low) dose?
  3. 3.Am I at immediate risk for corneal 'melting' or perforation?
  4. 4.Is it safe to start or increase my steroid drops, or is there still active virus that needs to be cleared first?
  5. 5.How often do you need to check the thickness of my cornea to monitor for thinning?

Questions For You

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References

References (16)
  1. 1

    Herpes simplex virus keratitis: electronic medical records driven big data analytics report from a tertiary eye institute of South India.

    Das AV, Satyashree G, Joseph J, Bagga B

    International ophthalmology 2023; (43(12)):4669-4676 doi:10.1007/s10792-023-02866-0.

    PMID: 37668848
  2. 2

    Recurrence of Herpetic Keratitis after COVID-19 Vaccination: A Report of Two Cases.

    Fard AM, Desilets J, Patel S

    Case reports in ophthalmological medicine 2022; (2022()):7094893 doi:10.1155/2022/7094893.

    PMID: 35601874
  3. 3

    Pathogenesis and virulence of herpes simplex virus.

    Zhu S, Viejo-Borbolla A

    Virulence 2021; (12(1)):2670-2702 doi:10.1080/21505594.2021.1982373.

    PMID: 34676800
  4. 4

    Analysis of clinical characteristics and factors influencing herpes simplex virus keratitis.

    Zhang S, Mi J, Ge S, et al.

    Frontiers in medicine 2023; (10()):1267783 doi:10.3389/fmed.2023.1267783.

    PMID: 38293295
  5. 5

    Herpes simplex keratitis in central India: Clinical types, treatment patterns, and outcome measures.

    Chatterjee S, Agrawal D, Malik M

    Indian journal of ophthalmology 2025; (73(7)):1050-1054 doi:10.4103/IJO.IJO_2233_24.

    PMID: 40586190
  6. 6

    Infectious keratitis: A review.

    Cabrera-Aguas M, Khoo P, Watson SL

    Clinical & experimental ophthalmology 2022; (50(5)):543-562 doi:10.1111/ceo.14113.

    PMID: 35610943
  7. 7

    Hypopyon after Periocular Corticosteroid Injection: A Case Series.

    Li F, Zhang Q

    Ocular immunology and inflammation 2023; (31(5)):955-960 doi:10.1080/09273948.2022.2073237.

    PMID: 35852938
  8. 8

    Clinical Pattern And Visual Impairment Associated With Herpes Simplex Keratitis.

    Shah A, Joshi P, Bhusal B, Subedi P

    Clinical ophthalmology (Auckland, N.Z.) 2019; (13()):2211-2215 doi:10.2147/OPTH.S219184.

    PMID: 31814705
  9. 9

    Clinical efficacy of oral and topical acyclovir in herpes simplex virus stromal necrotizing keratitis.

    Dutt S, Acharya M, Gour A, et al.

    Indian journal of ophthalmology 2016; (64(4)):292-5 doi:10.4103/0301-4738.182940.

    PMID: 27221681
  10. 10

    Potential Role and Significance of Ocular Demodicosis in Patients with Concomitant Refractory Herpetic Keratitis.

    Hung KH, Lan YH, Lin JY, et al.

    Clinical ophthalmology (Auckland, N.Z.) 2020; (14()):4469-4482 doi:10.2147/OPTH.S282059.

    PMID: 33380781
  11. 11

    Real-time polymerase chain reaction for the diagnosis of necrotizing herpes stromal keratitis.

    Ma JX, Wang LN, Zhou RX, et al.

    International journal of ophthalmology 2016; (9(5)):682-6 doi:10.18240/ijo.2016.05.07.

    PMID: 27275421
  12. 12

    Role of Intravenous Acyclovir in Treatment of Herpes Simplex Virus Stromal Keratitis with Ulceration: A Review of 2 Cases.

    Pisitpayat P, Jongkhajornpong P, Lekhanont K, Nonpassopon M

    The American journal of case reports 2021; (22()):e930467 doi:10.12659/AJCR.930467.

    PMID: 34133412
  13. 13

    Clinical and surgical outcomes of tectonic corneal patch grafts : insights from a tertiary referral hospital.

    Asfuroğlu Y, Karaca EE, Orman C, Evren Kemer Ö

    BMC ophthalmology 2024; (24(1)):516 doi:10.1186/s12886-024-03782-2.

    PMID: 39614205
  14. 14

    Amniotic Membrane Transplantation in the Management of Corneal Ulceration Following Infectious Keratitis.

    Lamas-Francis D, Navarro D, Moreno C, et al.

    Ocular immunology and inflammation 2024; (32(7)):1261-1267 doi:10.1080/09273948.2023.2228901.

    PMID: 37418657
  15. 15

    Amniotic Membrane as a Main Component in Treatments Supporting Healing and Patch Grafts in Corneal Melting and Perforations.

    Krysik K, Dobrowolski D, Wylegala E, Lyssek-Boron A

    Journal of ophthalmology 2020; (2020()):4238919 doi:10.1155/2020/4238919.

    PMID: 32148944
  16. 16

    Case Report: Conservative management of herpes simplex keratitis with corneal perforation and anterior chamber collapse.

    Xie W, Tian T, Ying L

    Frontiers in medicine 2026; (13()):1749225 doi:10.3389/fmed.2026.1749225.

    PMID: 41704682

This page explains HSV stromal keratitis subtypes for educational purposes and does not replace professional medical advice. Always consult your ophthalmologist immediately for diagnosis and treatment of eye infections.

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