Iridoschisis: high frequency ultrasound imaging. Evidence for a genetic defect?

Iridoschisis: Spectrum of Presentation

PURPOSE:

The purpose of the study was to report a small case series of patients with iridoschisis seen at our hospital over a period of 5 years.

METHODS:

Retrospective review of all those files over the past 5 years whereby the diagnosis of iridoschisis/iris atrophy/iris fibrils in anterior chamber (AC) was made.

RESULTS:

In our case series, the average age at presentation was 49 years (range: 23–85 years). The pathology was bilateral in 57% of patients in our series. Our most common presentations were angle closure glaucoma and cataract. Younger individuals can also manifest iridoschisis.

CONCLUSION:

The iridoschisis can be an incidental finding, and gonioscopy should be performed in all the cases, as occludable or synechiael angle closure may be present in these cases.

Iridoschisis-A Systematic Review

Iridoschisis is a rare condition defined as a separation of the anterior iris stroma from the posterior stroma and muscle layers. In this paper, we review current data about the epidemiology, pathophysiology, clinical characteristics and differential diagnoses of this condition and discuss the specificity of surgical treatment of concomitant ocular diseases in iridoschisis patients. Iridoschisis may pose a challenge for both an ophthalmologist in an outpatient setting and an ophthalmic surgeon. Glaucoma, primarily angle-closure glaucoma, is the most often described condition concomitant to iridoschisis. Other ocular abnormalities found relatively often in iridoschisis patients include cataract, lens subluxation and corneal abnormalities. Special attention has been paid to potential complications of cataract surgery and prevention thereof. Beside addressing the practical aspects, we point to discrepancies and suggest topics for further investigation.

Iridoschisis: visual outcome in treated versus untreated eye

A 67-year-old man was referred for iris color change. He was noted to have narrow angles with atrophic iris appearance and visually significant cataracts. The iris findings were consistent with iridoschisis. The patient was recommended to have cataract surgery. Unfortunately, he was lost to follow-up. One year later, he presented with chronic angle closure glaucoma on the right eye with very high pressure and very poor remaining vision. Left-eye vision was also compromised with cataract. Despite the presence of small pupil, abnormal iris stroma, and dense cataract, the patient underwent successful cataract surgery and achieved 20/20 vision post-operatively. Iridoschisis can cause substantial ocular morbidity if not treated timely.

Descemet membrane endothelial keratoplasty for corneal decompensation due to iridoschisis

Purpose

To report a case of bilateral iridoschisis with cataracts and corneal decompensation in a patient who underwent cataract extraction and superficial iridectomy followed by Descemet membrane endothelial keratoplasty (DMEK).

Observations

A 58-year-old man with previously diagnosed iridoschisis, cataracts, and diabetes mellitus experienced progressive vision loss bilaterally due to corneal decompensation. Slit lamp examination revealed iridoschisis with iris fibrils contacting the corneal endothelium, stromal edema, and mild guttate changes bilaterally. Corneal findings were more severe in the right eye, including the presence of bullous keratopathy at the time of presentation. Cataract extraction with intraocular lens implantation and superficial iridectomy were performed in the right eye, followed by DMEK. These same procedures were performed subsequently in the left eye. Postoperatively, the patient had significant improvement in visual acuity and corneal edema.

Conclusions and importance

DMEK can be performed safely and successfully after staged cataract surgery with superficial iridectomy in eyes with endothelial decompensation caused by iridoschisis.

Iridoschisis associated with nanophthalmos and bullous keratopathy

Iridoschisis is a rare condition in which the iris stroma splits into anterior and posterior layers. Iridoschisis is associated with anterior segment abnormalities including keratoconus, lens subluxation and angle-closure glaucoma. We describe the first case in which iridoschisis has occurred in association with nanophthalmos. We also report the rare complication of irido-corneal touch and subsequent corneal decompensation. Nanophthalmos and irido-corneal touch are sight-threatening associations of iridoschisis and should be excluded in all patients with this rare condition.

A case of cataract surgery without pupillary device in the eye with iridoschisis

Purpose

To introduce a case of iridoschisis patient who underwent cataract surgery successfully without pupil device.

Methods

A 64-year-old female who showed iridoschisis of her both eyes underwent cataract operation at her right eye without a pupillary device. The preoperative and postoperative ophthalmologic examinations including visual acuity, intraocular pressure, reaction of anterior chamber, and degree of damage on iris was evaluated respectively.

Results

Cataract surgery was performed under topical anesthesia through a clear corneal incision. Iris fibrils were held in place by ophthalmic viscosurgical device (OVD, sodium hyaluronate 3%-sodium chondroitin sulfate 4%, Viscoat®) that was injected into the anterior chamber. A small capsulorrhexis was made and the nucleus was delivered with low-power phacoemulsification, most of which was performed under the anterior capsule. The iris came into contact with the OVDs only and received no mechanical trauma. There were no intraoperative complications such as tear of the iris, hyphema, loss of mydriasis, or rupture of the posterior lens capsule. The edema of corneal stroma and inflammation of anterior chamber was shown at immediate-postoperative period, but completely subsided 2 weeks later. The visual acuity showed improvement from 20/400 to 20/30.

Conclusions

In iridoschisis patients, there is a risk of aspiration of iris fibers during cataract surgery. With adequate use of OVD and careful modulation of surgical devices, cataract surgery was successfully performed without using extra pupil-supporting device.

[Iridoschisis and angle-closure glaucoma: a case report]

INTRODUCTION

Iridoschisis is a rare condition where a localized area of iris stroma is cleaved in two, with the anterior atrophic portion disintegrating into fibrils. It is frequently associated with angle closure glaucoma and with cataract.

CASE REPORT

A 70-year-old male presented with reduction of visual acuity in the left eye. Visual acuity was 20/25 OD and 20/70 OS. He had suffered acute angle-closure glaucoma in the right eye 10 years before, treated with laser iridotomy and topical antiglaucomatous therapy. Intraocular pressure was 12 mmHg OD and 46 mmHg OS. Slit lamp biomicroscopic examination revealed bilateral shallow anterior chamber, iris atrophy, and leaf degeneration of the iris stroma. A-scan and B-scan standardized echography in both eyes showed shortening of the anterior chamber, a thickened and more anteriorly located lens, the presence of a few hyperechogeneous flocculated masses floating in the vitreous, and optic disc excavation.

CONCLUSION

The mechanism by which iridoschisis causes angle closure is unclear. A pupillary block could be favored by the thickening and anteriorization of the lens and the ciliary processes. Both the presence of strings of iris stroma occluding the trabecula and pupillary block could cause an elevation in intraocular pressure.

Avoiding iris trauma from phacoemulsification in eyes with iridoschisis

Iridoschisis is a rare condition frequently associated with age-related cataract. Phacoemulsification can be difficult to perform in these eyes, as the detached iris fibrils that are typically present free float in the anterior chamber and are attracted to the phaco tip and the irrigation/aspiration handpiece port. We describe a technique for performing phacoemulsification in eyes with iridoschisis. In this technique, iris fibrils are held in place by 2 ophthalmic viscosurgical devices (OVDs) that are injected into the inferior portion of the anterior chamber. An elliptical capsulorhexis is made and limited to the superior half of the pupil for additional stability of the anterior chamber during surgery. The nucleus is chopped with a phaco chopper and a bent-tip, 22-gauge needle. Most of the phacoemulsification is performed under the anterior capsule. The iris comes into contact with the OVDs only and has no mechanical trauma.

Iridoschisis

Iridoschisis is a rare condition in which a localised area of iris stroma is cleaved in two with the anterior atrophic portion disintegrating into fibrils. The most common presentation of iridoschisis is as an age-related iris atrophy in association with glaucoma. The association includes angle-closure glaucoma, angle-recession glaucoma and open-angle glaucoma. A finding of iridoschisis is a warning to the clinician to assess the patient for pre-existing glaucoma and to monitor for glaucomatous changes as it is unclear if iridoschisis is a cause or an effect of raised intraocular pressure (IOP).