Crystal's MCW Coder HubCYCLODIALYSIS - Medical Keyword Reference
Cyclodialysis is the separation or detachment of the ciliary body from its attachment to the scleral spur, creating a direct communication between the anterior chamber and the suprachoroidal space.[^1][^3][^5]
Short and Long Definitions
Short definition Cyclodialysis is separation of the ciliary body from the sclera, either traumatic or surgical, causing abnormal aqueous drainage and ocular hypotony.
Long definition Cyclodialysis is the disinsertion of longitudinal ciliary muscle fibers from the scleral spur, creating an aberrant pathway (cyclodialysis cleft) for aqueous humor drainage into the suprachoroidal space, dramatically increasing aqueous outflow and predisposing the eye to hypotony (IOP ≤5 mmHg); historically performed intentionally as a surgical procedure to reduce intraocular pressure in refractory open-angle and aphakic glaucoma, but now more commonly encountered as an unintended traumatic or iatrogenic complication following blunt ocular trauma or intraocular surgeries (phacoemulsification, trabeculectomy, IOL procedures); complications include chronic hypotony, hypotony maculopathy, choroidal detachment, optic disc edema, and decreased visual acuity requiring medical or surgical closure.
Etymology
- Cyclo-: Greek kúklos (κύκλος) = “circle” (referring to ciliary body, the circular muscle structure).
- Dialysis: Greek diálysis (διάλυσις) = “separation, dissolution” (from dia- “apart” + lýsis “loosening”).
- Literal: “Separation of the ciliary circle/body.”[^1][^2]
Classification
| Type | Etiology/Mechanism | Context |
|---|---|---|
| Traumatic cyclodialysis | Blunt ocular trauma causing ciliary body tear from scleral spur.[^3][^6] | Associated with hyphema, iris sphincter tears; 2% incidence in hypotony after trauma. |
| Iatrogenic cyclodialysis | Unintended surgical complication during intraocular procedures.[^3][^6] | Post-phacoemulsification, trabeculectomy, IOL placement/removal, goniotomy. |
| Intentional cyclodialysis | Historical surgical glaucoma procedure (rarely performed now).[^3] | Open-angle/aphakic glaucoma; replaced by modern procedures. |
Coding Context
ICD-10-CM:
| Code | Description |
|---|---|
| S05.20XA | Ocular laceration/rupture with prolapse/loss of intraocular tissue (traumatic). |
| H21.89 | Other specified disorders of iris and ciliary body. |
| H44.40 | Hypotony of eye, unspecified eye. |
| H44.41 | Hypotony of right eye / H44.42 left eye. |
| T85.398A | Other mechanical complication of other ocular prosthetic devices (iatrogenic). |
CPT Codes (Repair Procedures):
| Code | Description |
|---|---|
| 66680 | Repair of iris, ciliary body (suture of iris, ciliary body disinsertion). |
| 67255 | Scleral reinforcement (without graft). |
| 0308T | Insertion of ocular telescope prosthesis (experimental cyclodialysis-related). |
Surgical repair techniques (coded under 66680 primarily):[^4][^3]
- Cyclopexy (exocyclopexy): Direct suturing of ciliary body to sclera via ab-externo approach.
- Endocyclopexy: Ab-interno suturing technique.
- Cyclotamponade: Gas/viscoelastic tamponade to close cleft.
- Laser photocoagulation: Argon/diode laser to induce inflammation and closure.
Clinical Features
Pathophysiology:
- Ciliary body detachment → aqueous drains into suprachoroidal space → bypasses trabecular meshwork → hypotony (IOP ≤5 mmHg).[^6][^3]
- Hypotony duration correlates with complications (choroidal folds, maculopathy, vision loss).[^3]
Symptoms:[^6][^3]
- Decreased visual acuity.
- Hypotony (low IOP).
- Shallow anterior chamber.
- Choroidal effusion/detachment.
- Hypotony maculopathy (retinal/choroidal folds).
- Optic disc edema.
- Corneal edema with Descemet folds.
Physical examination findings:[^3][^6]
- Gonioscopy: Cleft visible as abnormal region posterior to scleral spur; iris root/ciliary body displaced posteriorly; appearance white (sclera), black, or gray.
- UBM/OCT: Definitive imaging showing ciliary body separation (gold standard: anterior segment OCT/Visante OCT).
- Associated findings: Hyphema, iris sphincter tears, lens subluxation, vitreous prolapse.
Related Terms
- Cyclodialysis cleft: The gap/opening created by ciliary body separation.[^3]
- Cyclopexy: Surgical repair technique reattaching ciliary body to sclera.[^4][^6]
- Hypotony: IOP ≤5 mmHg (primary consequence).
- Hypotony maculopathy: Macular folds from low IOP causing vision loss.
- Scleral spur: Anatomic landmark where ciliary body attaches.
- Suprachoroidal space: Space between sclera and choroid where aqueous drains abnormally.
- Choroidal detachment: Serous fluid accumulation in suprachoroidal space.
Diagnostic Workup
Clinical suspicion:[^3]
- Hypotony after trauma (especially with hyphema/iris tears) or intraocular surgery.
- Remote history of ocular trauma (cleft may reopen during later surgery).
Diagnostic tools:[^6][^3]
- Gonioscopy: Direct visualization of cleft.
- Anterior segment OCT (Visante OCT): High-resolution imaging of ciliary body position.
- Ultrasound biomicroscopy (UBM): Alternative imaging modality.
- Tonometry: Document hypotony (IOP ≤5 mmHg).
- Fundoscopy: Assess for choroidal folds, maculopathy, disc edema.
Management and Treatment
Conservative/medical therapy (first-line):[^3]
- Atropine cycloplegia: Relaxes ciliary muscle, may promote spontaneous closure.
- Topical steroids: Reduce inflammation.
- Observation: Many clefts close spontaneously (especially small, <2 clock hours).
Interventional procedures (when conservative fails):[^4][^3]
| Technique | Method | Success Rate/Notes |
|---|---|---|
| Argon/Diode laser photocoagulation | Laser to cleft edges induces inflammation/closure. | Low energy; variable success; may need repeat. |
| Direct cyclopexy (ab-externo) | Scleral flap → direct suturing ciliary body to sclera.[^6] | Gold standard; 80-90% success; invasive. |
| Endocyclopexy (ab-interno) | Suturing via internal approach during phaco/vitrectomy.[^4] | Less invasive; good success in pseudophakic/aphakic eyes. |
| Gas/viscoelastic tamponade | SF6/C3F8 gas or viscoelastic injection to tamponade cleft. | Temporary; may need positioning; combined with laser. |
| Transscleral diathermy | Heat application to appose tissues (partial thickness flap).[^3] | Historical; risk of scleral ectasia, lens damage. |
| Cryotherapy | Freeze-thaw to induce closure. | Variable success; inflammatory complications. |
Complications and Prognosis
Untreated cyclodialysis complications:
- Chronic hypotony → phthisis bulbi (shrunken eye).
- Hypotony maculopathy → permanent vision loss.
- Cataract formation.
- Optic atrophy.
Treatment complications:
- Scleral ectasia (diathermy).
- Lens damage.
- Malignant glaucoma (pupillary block post-repair).
- Incomplete cleft closure requiring repeat intervention.
Prognosis:[^3]
- Small clefts (<2 clock hours): High spontaneous closure rate.
- Large/persistent clefts: Require surgical intervention; 80-90% success with direct cyclopexy.
- Vision recovery depends on duration of hypotony and maculopathy severity.
Epidemiology
- Incidence: Rare even after blunt trauma (2-7% of post-traumatic hypotony cases).[^3]
- Iatrogenic: Extremely rare in modern phacoemulsification (<1% reported).
- Historical use: Once common glaucoma surgery (1950s-1970s); now obsolete.
One-Sentence Summary
Cyclodialysis (H44.40/S05.20XA, Greek cyclo-dialysis “ciliary separation”), traumatic/iatrogenic ciliary body detachment from scleral spur creating suprachoroidal aqueous drainage causing hypotony/maculopathy, diagnosed via gonioscopy/OCT, treated conservatively (atropine) or surgically (cyclopexy 66680, laser, tamponade) with 80-90% closure success.[^2][^1][^4][^6][^3]
Document created: February 13, 2026 Medical coding professional reference
Med roots Appendix A Prefixes Appendix B Combining Forms Appendix C Suffixes Appendix D Suffix forms