Glaucoma (Adjunctive)
Investigational adjunctive use in primary open-angle glaucoma; weak case-series evidence. Not a substitute for IOP-lowering eye drops or surgery.
Patient Summary
- Is this FDA-cleared for this use?
- Not FDA-cleared for glaucoma. FDA cleared medicinal leeches only for venous congestion in microsurgical reconstruction (K040187, 2004). Use for glaucoma is investigational and not endorsed by ophthalmology guideline bodies.
- What evidence exists?
- Tier C (investigational). Two small uncontrolled case series (Sharifian 2014 n=18; Khan 2020 n=24) report modest IOP reductions of 2-4 mmHg. There are no randomized controlled trials. Glaucoma is a sight-threatening, progressive optic neuropathy — evidence-based first-line therapy is prostaglandin analogs, beta-blockers, selective laser trabeculoplasty (SLT), or trabeculectomy. Leech therapy is NOT a substitute, and undertreated glaucoma causes irreversible blindness.
- Main risks
- Bleeding from bite sites for 6 to 24 hours after detachment (peri-orbital location)
- Bruising around the temple and behind the ear for 5 to 10 days
- Itching and irritation near sensitive periocular skin
- Local skin infection or, rarely, Aeromonas infection
- Catastrophic harm if leech is mistakenly applied to the eyelid, conjunctiva, or orbit (NEVER do this)
- Allergic reaction to leech saliva (uncommon)
- Delayed presentation to ophthalmology if used as substitute for evidence-based care, leading to irreversible vision loss
- Small permanent scars at bite sites
- Who should not consider this
- Patients on blood thinners (warfarin INR >2.0, DOACs, heparin)
- Patients with hemophilia or other bleeding disorders
- Patients with severe anemia (Hb <10 g/dL)
- Patients with acute angle-closure glaucoma (ophthalmologic emergency)
- Patients whose IOP is not yet controlled by prescribed therapy
- Patients considering this INSTEAD OF prescribed glaucoma drops or surgery
- Patients with recent ocular surgery or active ocular infection
- What to ask your clinician
- Will I continue all prescribed glaucoma medications and ophthalmology follow-up?
- What evidence supports leech therapy for glaucoma specifically, and what is the realistic IOP-lowering effect?
- How will leeches be kept off the eyelid, conjunctiva, and orbit?
- What is the practitioner's experience treating glaucoma with leech therapy?
- How will IOP be monitored before and after sessions?
- What is the cost, and is it covered by insurance? (typically not)
- What red flags require me to seek urgent ophthalmologic care?
- When to seek urgent care
- Sudden severe eye pain, eye redness, halos around lights, nausea/vomiting (possible acute angle-closure — go to ER)
- Sudden vision loss, new floaters or flashes, or curtain across vision
- Bleeding from a bite site lasting more than 24 to 48 hours
- Spreading redness or pus near the eye (orbital cellulitis is sight- and life-threatening)
- Fever above 38.0 C / 100.4 F or chills
- Hives, throat tightness, or breathing difficulty
What this does NOT mean
- This is not FDA-cleared for glaucoma.
- Two small uncontrolled case series do NOT establish that leech therapy lowers IOP meaningfully or durably.
- Glaucoma causes irreversible blindness if undertreated — leech therapy is NOT a substitute for prescribed drops, SLT, or surgery.
- Mechanism rationale (episcleral venous drainage) does NOT establish clinical efficacy.
- Leech therapy must NEVER be applied near the eyelid or orbit; periocular placement carries cosmetic risk.
Safety cross-references
Clinical Profile
- Category
- ophthalmologic
- ICD-10
- H40.10, H40.11, H40.20
- Safety tier
- high
Evidence Summary
Historical Russian and Iranian texts describe periocular leech application for glaucoma, but no controlled trial or quantified case series supports an effect on intraocular pressure; the proposed mechanism (improved episcleral venous drainage) is speculative. Ophthalmology consensus does NOT endorse leech therapy as glaucoma treatment, and it is not a substitute for prostaglandin analogs, beta-blockers, selective laser trabeculoplasty, or trabeculectomy. ASH position: not recommended outside research protocols; use is investigational and historical only.
Treatment specifics
How many leeches, where they are placed, how long a session lasts, and whether to repeat are clinical decisions made by a qualified provider under institutional protocol — not something to self-administer. Discuss the specifics with a clinician experienced in medicinal leech therapy. (Clinicians: switch the audience selector in the top bar to “Clinician” to view protocol detail.)
Key Trials
- Sharifian B et al. (2014), n=18
Contraindications
- Active anticoagulant therapy (warfarin INR >2.0, DOACs, heparin)
- Hemophilia or other bleeding disorder
- Severe anemia (Hb <10 g/dL)
- Active bacteremia or sepsis
- Known hypersensitivity to leech salivary proteins
- Pregnancy (relative — first/third trimester)
- Immunocompromised state with severe neutropenia
- Acute angle-closure glaucoma (emergency)
- Recent (<3 months) eye surgery
- Active uveitis or scleritis
Related Conditions
Dry Eye Syndrome
Investigational use for dry eye disease; mechanism via reduction of meibomian gland inflammation. Weak case-series evidence.
Thyroid Eye Disease (Investigational Periocular Adjunct)
Highly investigational periocular adjunct for stable thyroid eye disease; ocular risk is critical; teprotumumab and orbital decompression remain primary.