Conservative Management
Tinted contact lenses (cosmetic CL)
Spontaneous reduction with mydriatics (for iris capture: attempt spontaneous reduction in supine position)
Observation (for mild pupillary distortion with minimal symptoms)
Iris Repair (Iris Suture and Pupilloplasty)
1. What is Iris Repair Surgery?
Section titled “1. What is Iris Repair Surgery?”Iris repair surgery is a general term for surgical procedures that repair congenital, traumatic, or postoperative iris defects and damage. This article focuses on suture and reconstruction techniques (pupilloplasty, iridoplasty) that preserve the patient’s own iris tissue.
The choice between iris repair surgery and artificial iris devices depends on the amount and quality of remaining iris tissue. If sufficient iris tissue remains, autologous iris suture is selected; for extensive iris damage or atrophy where suturing is not possible, artificial iris devices (see separate article) are indicated. Iris-fixated IOLs and artificial irises are not yet approved in Japan, and pupil reconstruction using iris suture, which does not require special instruments, is a relatively easy procedure to choose.
Classification of iris injury by site (AAO PPP) 1):
- Pupillary margin (sphincter damage): Fixed dilated pupil, irregular pupil
- Mid-peripheral defects: Defects peripheral to the sphincter but not reaching the root
- Root (iridodialysis): Detachment from the iris root
Epidemiology
Section titled “Epidemiology”Independent epidemiological data do not exist. Cataract surgery is performed on approximately 1.6 million eyes per year in Japan, and the exact frequency of iris injury complications is unknown, but the prevalence of IFIS is reported to be about 1–2% of all cataract surgeries.
Q
What is the difference between iris repair and artificial iris devices?
A
Iris repair is a surgery that reconstructs the pupil by suturing and shaping the patient’s own remaining iris tissue. It is indicated when sufficient iris tissue remains, does not require special instruments, and can be performed without using artificial devices that require regulatory approval in Japan. On the other hand, artificial iris devices are indicated for cases with extensive iris damage or iris atrophy where suturing is impossible (including aniridia). Forcing sutures may only cause iris rupture and unnecessary trauma, so the appropriate indication is important.
2. Main symptoms and clinical findings
Section titled “2. Main symptoms and clinical findings”Subjective symptoms
Section titled “Subjective symptoms”- Photophobia and near vision impairment: Due to iris defects or irreversible mydriasis, external light enters directly, reducing patient satisfaction.
- Monocular diplopia: Dispersion of light paths due to irregular pupil.
- Pupil deformation and fixed mydriasis: Also becomes a cosmetic problem after cataract surgery.
- Visual acuity decrease: If the pupil is too large, higher-order aberrations and glare increase, and contrast sensitivity may decrease 5).
Clinical findings (by cause)
Section titled “Clinical findings (by cause)”| Cause | Typical Findings | Complications |
|---|---|---|
| Congenital coloboma | Inferior (inferotemporal) iris defect, widest at pupillary margin | Microphthalmia, cataract, choroidal coloboma, glaucoma, retinal detachment |
| Traumatic | Iris laceration/iridodialysis, hyphema | Lens dislocation, angle recession, cataract |
| Post-cataract surgery | Pupil distortion/poor transillumination, iris capture | IOL decentration, corneal endothelial damage |
| IFIS sequelae | Iris atrophy, transillumination iris defect | Paralytic mydriasis, increased higher-order aberrations |
Q
What happens if iris injury symptoms are left untreated?
A
Photophobia and glare persist, reducing quality of daily life. An excessively large pupil tends to cause higher-order aberrations and decreased contrast 5). Additionally, irregular pupil leads to persistent monocular diplopia. Difficulty in dilating the pupil during fundus examination may delay early detection of macular and retinal diseases. In congenital coloboma, retinal tears or detachment may occur within the choroidal defect, making regular fundus examinations important.
3. Causes and Risk Factors
Section titled “3. Causes and Risk Factors”Congenital Factors
- Failure of closure of the optic fissure (embryonic developmental abnormality). Since the optic cup surrounds the ocular contents from above and closes inferiorly, typical defects are located inferiorly (inferonasal).
- May be found as a symptom of CHARGE syndrome (Coloboma, Heart defects, Atresia choanae, Retarded growth, Genital/urinary anomalies, Ear anomalies).
- Complications: microphthalmia, microcornea, optic nerve coloboma, cataract, lens dislocation, glaucoma, retinal detachment.
Acquired Factors
- Traumatic: blunt trauma (ocular contusion), perforating trauma causing iridodialysis, sphincter rupture.
- Surgery-related 1):
- Iris aspiration (iris entrapment around phaco tip).
- Iris prolapse into the incision (during IFIS or poor wound construction).
- Excessive stretching or laceration from pupil expansion devices (iris hooks, rings).
- Sphincterotomy.
- Iris capture: IOL prolapses anterior to the iris, causing pupil deformation.
- Drug-induced IFIS: α₁-blockers (tamsulosin is representative) → atrophy and degeneration of the iris dilator muscle (irreversible). Cannot be prevented even with preoperative discontinuation.
- Post-inflammatory: Iris atrophy and posterior synechiae after uveitis.
4. Diagnosis and Examination Methods
Section titled “4. Diagnosis and Examination Methods”The following examinations are necessary for preoperative evaluation of iris suture surgery.
| Examination | Purpose | Details |
|---|---|---|
| Slit-lamp microscopy | Evaluation of iris defect | Location, size, and shape of the defect. Presence of transillumination defects. |
| Anterior segment OCT (AS-OCT) | Detailed evaluation of iris structure and anterior chamber angle | Confirmation of iris thickness, defect extent, and IOL position. |
| Fundus examination | Evaluation of complications | Confirmation of choroidal coloboma, retinal coloboma, and optic nerve coloboma (in congenital cases). |
| Corneal endothelial cell examination | Preoperative baseline | Measurement of corneal endothelial cell density by specular microscopy |
| Intraocular pressure measurement | Confirmation of glaucoma comorbidity | Risk assessment of postoperative intraocular pressure elevation |
| Medication history taking | Identification of drugs causing IFIS | History of α₁-blocker (tamsulosin, etc.) use is most important |
| Systemic examination | Confirmation of congenital syndromes | Evaluation of related diseases such as CHARGE syndrome (heart disease, choanal atresia, hearing loss) |
Preoperative simulation: Using the iris cerclage as a landmark, confirm the location of suture placement and preoperatively assess whether the iris can be brought together without tension during ligation.
5. Standard treatment
Section titled “5. Standard treatment”This section is the core of this article and details the technique of iris suturing.
5-A. Treatment Algorithm
Section titled “5-A. Treatment Algorithm”Iris Suturing (Pupilloplasty)
Indications: Partial iris defect, paralytic mydriasis (sequelae of IFIS or after glaucoma attack), sufficient remaining iris tissue
Suture material: 10-0/9-0 polypropylene (Prolene) suture
Features: No special instruments required, easily selected in Japan
Artificial Iris Device (→ separate article)
Indications: Extensive iris damage, iris atrophy precluding suturing, congenital aniridia
Note: Artificial iris and iris-fixated IOLs are not yet approved in Japan (as of 2024)
Forced suturing risks iris rupture; consider artificial iris devices for extensive damage cases
5-B. Iris Suturing Technique
Section titled “5-B. Iris Suturing Technique”Suture Materials
Section titled “Suture Materials”- Use polypropylene (Prolene) suture (less degradation)
- 10-0 or 9-0 Prolene: MANI IOL suturing needle-attached suture, Alcon PAIR PAK
- For intraocular iris suturing, use a non-absorbable suture with a fine needle to minimize intra-anterior chamber manipulation and avoid contact with the corneal endothelium and lens1)2)
Step 1: Iris stretching
Section titled “Step 1: Iris stretching”- After forming the anterior chamber with OVD (ophthalmic viscosurgical device), stretch the iris toward the pupil center using forceps that can be inserted into the anterior chamber
- Recommended forceps: Kawai-style anterior capsule forceps (flat grasping surface → minimal iris damage), MAXGRIP® (Alcon) vitreous forceps
- Forceps with holes (e.g., Ikeda-style anterior capsule forceps) are unsuitable as they tend to cause iris damage
- Simulate the suture position and confirm that the iris can be approximated without tension during ligation
- Caution against excessive tension on the iris root: risk of angle recession
- In cases of paralytic mydriasis, stretching the iris circumferentially itself has a miotic effect
Step 2: Passing the suture
Section titled “Step 2: Passing the suture”Choose from the following three methods depending on the situation.
- Long needle method: Insert a long needle through a side port and puncture the proximal then distal edge of the iris
- Pick-up needle method (30-gauge thin-wall needle): Corneal puncture → iris puncture → lock with long needle → pull out. Good maneuverability and high accuracy. Minimizes needle hole size
- Intraocular method (fine needle): Insert a fine needle through a side port into the anterior chamber and directly suture the iris margin. Keep needle manipulation within the anterior chamber brief and avoid contact with the corneal endothelium and lens1)2)
Step 3: Knot Tying
Section titled “Step 3: Knot Tying”| Knotting Method | Principle | Features |
|---|---|---|
| Siepser slipknot technique2) | Performed only through side ports. The suture on the iris is pulled out with a hook/forceps to form a loop, then the end is passed through the loop twice and tied outside the eye. | High flexibility in knot placement. Care is needed as pulling the suture carelessly can damage the iris. |
| McCannel method3) | A long needle is passed through the main incision to puncture both ends of the iris and the limbus, then a double knot is tied outside the eye. | Easy to perform when the incision and knot placement are close. Simple procedure. |
| SFT method (single-pass four-throw)4) | The end is passed through the loop four times and tied in one go. | Efficient as the knotting operation inside and outside the anterior chamber is completed in one step. |
Number of Sutures and Target Pupil Diameter
Section titled “Number of Sutures and Target Pupil Diameter”- Partial iris defect: 1 to 2 sutures at the defect site.
- Paralytic miosis: First suture at 6 and 12 o’clock (easier to pass the suture), then add more if the effect is insufficient.
- Target pupil diameter: approximately 4 mm or slightly less
- If the pupil is too large, higher-order aberrations and decreased contrast are likely to become problematic, so adjust the diameter to balance symptoms and ease of fundus examination5).
- Traumatic eye or retinal detachment eye: May be set to approximately 5 mm considering postoperative fundus examination.
5-C. Repair of Iris Coloboma
Section titled “5-C. Repair of Iris Coloboma”Conventional methods (incision of the superior healthy pupillary margin or simple suture below the coloboma) often leave pupillary irregularity or deviation. The following are improved techniques.
- Cionni method6): Incise the pupillary sphincter within the coloboma, then suture the adjacent healthy iris. Improves pupil roundness.
- Ogawa method7): Resect the pupillary sphincter within the coloboma, then suture the healthy iris. Less pupillary irregularity or deviation.
5-D. IOL-Related Iris Repair
Section titled “5-D. IOL-Related Iris Repair”- Pupillary capture or capsular capture: Can be repositioned with a hook or spatula through a side port.
- Iris capture: If the iris and IOL are not adherent, attempt spontaneous repositioning with mydriasis and supine position. If unsuccessful, perform surgical repositioning.
- Recurrent pupillary capture: If reverse pupillary block is involved, iridectomy is effective.
- If recurrence occurs even after iridectomy: There is also a method of passing a suture from the sclera to the opposite sclera as a restraint.
5-E. Decision for Simultaneous Surgery
Section titled “5-E. Decision for Simultaneous Surgery”- If after IOL insertion, with miotics and iris traction, a mydriasis of approximately 6 mm or more remains, consider simultaneous pupilloplasty.
- When multiple surgeries complicate the procedure or when decision-making is difficult: consider two-stage pupilloplasty
- In post-traumatic cases, simultaneous PEA + IOL insertion + iris suture may be performed approximately 2 weeks after injury
5-F. Non-indications for iris suture
Section titled “5-F. Non-indications for iris suture”In cases with extensive iris damage or atrophic iris, forced suturing may only cause iris rupture and unnecessary trauma. Such cases are indications for prosthetic iris devices; refer to the Prosthetic-Iris-Devices article.
Q
Can cataract surgery be performed simultaneously with iris suture?
A
If mydriasis of approximately 6 mm or more remains after IOL insertion despite using miotics and iris traction, simultaneous pupilloplasty is indicated. In post-traumatic cases, simultaneous PEA + IOL + iris suture may be performed approximately 2 weeks after injury. However, if the surgery becomes complicated or decision-making is difficult, it is safer to choose a two-stage procedure.
Q
What happens if iris suture is unsuccessful?
A
In cases with extensive iris damage or severe iris atrophy, suturing itself may be difficult or impossible. Forced suturing may cause iris rupture and further damage to iris tissue. In such cases, implantation of a prosthetic iris device is an option. In Japan, prosthetic iris devices are currently not approved, so management at specialized facilities is necessary.
6. Pathophysiology and detailed mechanisms
Section titled “6. Pathophysiology and detailed mechanisms”Mechanism of congenital iris coloboma
Section titled “Mechanism of congenital iris coloboma”The optic cup surrounds the tissue that will become the ocular contents by folding in from above, finally closing at the bottom. If this closure is incomplete during the embryonic period, a typical iris coloboma occurs inferiorly (inferonasally). It may be accompanied by ciliary body coloboma, choroidal coloboma, and optic nerve coloboma. If congenital iris coloboma is associated with zonular deficiency, the lens becomes unstable, making cataract surgery difficult.
Mechanism of traumatic iris injury
Section titled “Mechanism of traumatic iris injury”In blunt trauma, iridodialysis and sphincter rupture occur due to globe deformation. In penetrating trauma, direct iris damage and prolapse occur.
Mechanism of iatrogenic iris injury 1)
Section titled “Mechanism of iatrogenic iris injury 1)”- Iris aspiration in shallow anterior chamber, iris agitation due to phaco tip vibration
- Iris prolapse due to poor wound construction
- Excessive stretching of pupil dilation device → sphincter tear
- Sphincter necrosis: can occur with endophthalmitis, TASS, or acute intraocular pressure elevation
Pathophysiology of IFIS
Section titled “Pathophysiology of IFIS”α₁-adrenergic receptor blockers (e.g., tamsulosin) induce atrophic degeneration of the iris dilator muscle. This degeneration is irreversible and cannot be prevented by preoperative discontinuation of the drug. The degenerated iris is fragile, increasing the risk of intraoperative damage, which may lead to postoperative pupil deformity.
7. Complications and Prognosis
Section titled “7. Complications and Prognosis”Intraoperative Complications
Section titled “Intraoperative Complications”- Excessive traction on the iris root → bleeding (often self-limiting) and angle recession
- Iris tear (if remaining tissue is too short to hold sutures)
- Corneal endothelial cell damage (due to manipulation of a long needle in the anterior chamber)
Postoperative Complications
Section titled “Postoperative Complications”- Residual or recurrent pupil deformity
- Elevated intraocular pressure
- Decreased corneal endothelial cell count
- Anterior chamber inflammation
- Suture exposure or degradation (long-term)
Prognostic data from case reports
Section titled “Prognostic data from case reports”- Case 1 (ocular contusion, 74-year-old male): Underwent PEA + IOL + iris suture. At 4 months, visual acuity 0.8 (corrected 1.2), pupil diameter approximately 5 mm, pupil nearly centered, no photophobia. Corneal endothelial cell loss rate 1.8%.
- Case 2 (traumatic mydriasis, 57-year-old male): Underwent PEA + IOL + synechiolysis + iridotomy + iris suture. At 6 months, corrected visual acuity 1.0, pupil round and nearly centered.
Prognosis of congenital iris coloboma
Section titled “Prognosis of congenital iris coloboma”Visual acuity is often good, but if the coloboma extends to the macula, visual acuity becomes poor. Retinal detachment may occur due to retinal tears within or at the edge of the choroidal coloboma, often leading to poor prognosis. When cataract is associated with congenital coloboma, surgery is often difficult due to microphthalmos, zonular deficiency, and poor dilation. Improved surgical techniques for iris coloboma (Cionni method, Ogawa method) have been reported to improve pupil roundness and centration 6)7).
Q
How much does visual acuity improve after iris repair surgery?
A
Case reports have reported good outcomes with postoperative corrected visual acuity of 1.0 to 1.2. However, the degree of visual improvement depends on the cause and extent of iris damage and concomitant ocular diseases (e.g., retinal disease, corneal endothelial disorders). The main therapeutic effects of iris repair are often reduction of photophobia and glare, elimination of monocular diplopia, and cosmetic improvement rather than visual acuity improvement. In congenital coloboma involving the macula, there is a limit to visual improvement.
8. References
Section titled “8. References”- Foster GJL, Ayres B, Fram N, et al. Management of common iatrogenic iris defects induced by cataract surgery. J Cataract Refract Surg. 2021;47(4):522-532. doi:10.1097/j.jcrs.0000000000000411. PMID:32925648.
- Siepser SB. The closed chamber slipping suture technique for iris repair. Ann Ophthalmol. 1994;26(3):71-72. PMID:7944159.
- Alpar JJ. Use of the Ethicon 1713 suture for McCannel suturing. J Am Intraocul Implant Soc. 1985;11(3):296-298. PMID:4008325.
- Narang P, Agarwal A, Agarwal A, et al. Twofold technique of nonappositional repair with single-pass four-throw pupilloplasty for iridodialysis. J Cataract Refract Surg. 2018;44(12):1413-1420. doi:10.1016/j.jcrs.2018.08.006. PMID:30292471.
- Oshika T, Tokunaga T, Samejima T, Miyata K, Kawana K, Kaji Y. Influence of pupil diameter on the relation between ocular higher-order aberration and contrast sensitivity after laser in situ keratomileusis. Invest Ophthalmol Vis Sci. 2006;47(4):1334-1338. PMID: 16565365. doi:10.1167/iovs.05-1154.
- Cionni RJ, Karatza EC, Osher RH, Shah M. Surgical technique for congenital iris coloboma repair. J Cataract Refract Surg. 2006;32(11):1913-1916. PMID: 17081895. doi:10.1016/j.jcrs.2006.08.017.
- Ogawa T, Inatani M, Takihara Y, et al. Congenital iris coloboma repair with excision of colobomatous sphincter muscle. J Cataract Refract Surg. 2021;47(8):1088-1091. PMID: 32947385. doi:10.1097/j.jcrs.0000000000000440.