A 26-year-old, otherwise healthy man was referred to our center with a corticonuclear cataract and decrease of BCVA in his right eye.
His ocular history included congenital nystagmus, strabismus surgery at 6 years of age, and tractional retinal detachment unsuccessfully repaired by vitrectomy and silicone tamponade in the left eye. Subsequently, the patient experienced corneal decompensation and phthisis bulbi, and finally an ocular prosthesis was implanted to replace his left eye at 9 years of age.
The patient came to us for consultation with a medical report of nystagmus, iris coloboma, subluxation of the crystalline lens, and superficial keratopathy in his right eye. He had a visual acuity of 20/200 that did not improve with optical correction.
The patient reported increasing sensitivity to light, decreasing visual acuity, and loss of functional visual acuity. His BCVA was counting fingers, the eye was quiet, and a rotational nystagmus was observed.
Examination at the slit-lamp biomicroscope revealed a dull and irregular reflex of the corneal epithelium, which varied in thickness and transparency; an ingrowth of thickened fibrovascular pannus at the limbus; and chronic keratitis. A sectoral defect in the iris and deficiency of zonular support along the inferonasal quadrant with severe phacodonesis were observed (Figure 1). There was no corneal nodular degeneration or stromal opacity. A corticonuclear cataract (NO 3.0, C 3.0 using the LOCS III classification system1) was observed. No significant alterations were seen in the ocular fundus examination. The tear film breakup time and Schirmer test were severely diminished.
In the context of congenital partial aniridia with an irregularly enlarged pupil, limbal stem cell deficiency, and subluxated cataract, how would one proceed with this patient? What are the surgical options to improve this situation, and in which order would the surgeon proceed? Two of our colleagues offer their solution to our case.
MARK PACKER, MD, FACS
In a paper reporting results of implantation of the Black Iris Diaphragm IOL (Morcher GmbH, Stuttgart, Germany) for congenital aniridia, Reinhard, Engelhardt and Sundmacher note that, "In addition to the lack of an iris diaphragm, other reasons exist for the reduction in visual acuity that is common in congenital aniridia. These include hypoplasia of the macula, optic nerve, or both; glaucoma; conjunctivalization of the cornea; and cataract."2 These lesions are thought to be related to mutations in the PAX6 gene.3 The long-term prognosis for these eyes, with or without surgical intervention, is extremely guarded.4
In the case described by Drs. Güell and Elies, it appears likely that the recent reduction in visual function is related to the development of cataract. We are not told about the intraocular pressure, status of the macula, or condition of the optic nerve. However, given the patient's poor visual acuity, it is possible that cataract surgery will improve matters. I would plan phacoemulsification (preferably biaxial microincision cataract surgery [MICS]) with implantation of a capsular tension ring (CTR) to stabilize the capsule during surgery. Following extraction of the lens, I would implant an aniridia ring segment to cover the iris defect and place an IOL in the capsular bag. (The aniridia ring segment is not approved by the US Food and Drug Administration [FDA], and so I would require a compassionate-use exemption from the FDA to use this in the United States.) Limbal stem cell transplantation or penetrating keratoplasty may be considerations in the future, depending on the outcome of cataract surgery. Management of glaucoma, if present, will be an ongoing process for this patient.
BORIS MALYUGIN, MD, PHD
This case presents a challenge for even the most experienced ophthalmologist. The main question to be answered is, "What is the principal cause of the visual acuity decrease?" Differential diagnosis should try to determine whether the cause is progression of the corneal degeneration or development of cataract. In some doubtful cases, the medical history of the patient supplied by the referring ophthalmologist is helpful.
Because the corneal stroma is clear, we can assume that cataract progression is the main reason for vision degradation, and a surgical approach should be considered as a primary option.
Several techniques can be used to improve the likelihood of a successful outcome. The surgical algorithm includes three main considerations: (1) the optimal lens removal technique and whether additional instruments (eg, iris hooks, capsular supporting devices) are necessary; (2) proper management of the pupillary defect (eg, iris suturing, pupillary prosthetic devices); and (3) selection of an IOL design and fixation method to achieve stable long-term lens centration.
My primary surgical plan in this case would be ultrasound phacoemulsification with suturing of the capsular bag to the sclera, in-the-bag posterior chamber IOL implantation, and pupilloplasty.
The incision should be located in the meridian away from the missing zonules. I would then inject two ophthalmic viscosurgical devices (OVDs): first, a highly dispersive OVD, such as Viscoat (sodium hyaluronate 3.0%, chondroitin sulfate 4.0%; Alcon Laboratories, Inc.), over the area of the zonular defect to prevent anterior displacement of vitreous strands during lens removal; then, a highly cohesive OVD over it to completely fill the anterior chamber and facilitate anterior capsulorrhexis.
I would then assess the exact extent of the zonular defect. A Lester hook or similar instrument can be used to retract the iris if necessary and displace the lens in different directions to determine the degree of lens mobility.
Tearing of the capsule during anterior capsulorrhexis should be performed toward the area of missing zonules. I would initiate the capsular tear with a sharp instrument (eg, bent needle, scissors) at the 11-o'clock position. To avoid excessive traction on the zonules during capsulorrhexis, I would create a tear with two capsular flaps. The first flap would be grasped with capsulorrhexis forceps and would proceed clockwise toward the zonular defect; the other would extend the tear counterclockwise. If necessary, I would stabilize the lens with a second instrument (eg, spatula, Bechert nucleus rotator) inserted through a corneal paracentesis. Both tears would meet at the 4-o'clock position, creating a round anterior capsulorrhexis opening.
I would then insert a Cionni modified CTR (Morcher GmbH) and suture it to the sclera in the inferonasal quadrant with 9-0 polypropylene. This approach would achieve 360° expansion of the capsular equator and stabilization of the bag. Another option would be to suture an Ahmed capsular tension segment (Morcher GmbH) in place.
Before inserting the ring, I would inject OVD under the anterior capsulorrhexis rim to create a path for the CTR between the lens and the capsule. After implanting the ring, I would secure it to the sclera with a suture. Next, I would perform hydrodissection and hydrodelineation.
After the ring is sutured in place, I would remove the nucleus with coaxial MICS, using a combined vertical and horizontal chop technique in situ with minimal nucleus rotation. Phaco parameters would be as low as possible to avoid hydration of the vitreous, excessive fluctuation of the anterior chamber, and overstretching of the remaining zonules. If the capsular bag is unstable during the final steps of fragment removal, I would continue phacoemulsification at the iris plane or even in the anterior chamber.
With the CTR in place, cortical fibers are usually compressed at the equator of the capsular bag, and their removal is hampered. If this were the case, a bimanual irrigation and aspiration technique with tangential traction movements of the aspiration handpiece would be helpful. If the capsular bag retains its integrity, I would place the IOL in the bag.
My preferred IOL would have an optic of 6 mm or larger. In this patient, there are two main concerns regarding the IOL: centration and long-term stability. Both would be achieved with suturing of the CTR–capsular-bag complex and in-the-bag IOL placement. If a posterior capsular tear occurs during surgery but the anterior capsulorrhexis remains intact, I would implant a three-piece IOL, position the haptics in the ciliary sulcus, and capture the optic within the anterior capsulorrhexis opening. If the anterior capsule edge is also torn, I would remove the CTR and suture the posterior chamber IOL to the sclera.
At the completion of the case, I would inject a miotic into the anterior chamber. After assessing the pupil diameter, I would make a decision regarding pupilloplasty.
With the extent of iris coloboma (about 2.5 clock hours) and young age of the patient (with therefore elastic iris tissue), it should be possible to perform iris reconstruction using a modified Siepser suturing technique with 10-0 polypropylene. Two sutures are usually enough to close the defect. If after this maneuver the pupil is slightly decentered in the direction of the sutures, a vitrector or wet-field cautery can be used to make it round and centered.
Rather than pupilloplasty, one can choose to implant an iris prosthetic device. I usually reserve them for cases with more profound iris defect (more than 3 clock hours).
Final visual acuity of this patient will greatly depend on the extent of the coloboma into the choroid and retina, and whether or not it reached the macular region. Despite of this, the approach described should lead to a successful outcome with the highest possible functional visual result.
THE AUTHORS' CHOSEN APPROACH
Management options for this case may include the following approaches:
- Clear corneal phacoemulsification with insertion of a CTR with or without scleral fixation or with a modified CTR, followed by in-the-bag IOL implantation;
- In-the-bag implantation of an aniridia ring segment or iris reconstruction with an iris suture;
- Pars plana lensectomy and implantation of an iris-fixated IOL (Artisan/Verisyse lens; Ophtec BV, Groningen, Netherlands);
- Limbal allograft or amniotic membrane transplantation to protect the cornea against surgical trauma and/or autologous serum eye drops before any intraocular surgery.
After considering these options, we decided to treat this patient by performing pars plana lensectomy as a primary procedure. Depending on the outcome of the primary surgery, we would implant an aphakic iris-supported Artisan IOL as a secondary refractive procedure and/or we would repair the limbal stem cell deficiency in case severe ocular surface damage was observed.
At 2 months after the primary procedure, the eye is quiet and aphakic, with a stable superficial keratopathy that does not require limbal repair or amniotic membrane transplantation. The patient's BCVA is 20/200 with a refraction of 12.00 D, and the ocular surface is not getting worse. We are waiting for the next medical examination, 3 or 4 months after primary surgery, before performing the secondary procedure of Artisan IOL implantation.
José Luís Güell, MD, is Chairman of the Cornea and Refractive Surgery Unit in private practice at the Instituto de Microcirugía Ocular and is Clinical Associate Professor of Ophthalmology at the Universitat Autonoma de Barcelona, Hospital del Valle d'Hebron, Barcelona, Spain. Dr. Güell states that he has no financial interest in the products or companies mentioned.
Daniel Elies, MD, is in private practice in the Cornea and Refractive Surgery Unit at the Instituto de Microcirugía Ocular. Dr. Elies states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +34 93 253 15 00; fax: +34 93 417 13 01; e-mail: danielies@hotmail.com.
Boris Malyugin, MD, PhD, is the Chief of the Department of Cataract and Implant Surgery and Deputy Director General at the S. Fyodorov Eye Microsurgery Complex, Moscow, Russia. Dr. Malyugin states that he has no financial interest in the products or companies mentioned. Dr. Malyugin is a member of the CRST Europe Editorial Board. He may be reached at tel: +7 495 488-8511; fax: +7 495 905-8051; e-mail: boris.malyugin@gmail.com.
Mark Packer, MD, FACS, is a Clinical Associate Professor at the Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, and is in private practice at Drs. Fine, Hoffman & Packer, LLC, Eugene, Oregon. He states that he is a consultant to Advanced Medical Optics, Inc., Bausch & Lomb, Advanced Vision Science, Carl Zeiss Meditec AG, Carl Zeiss, Inc., Celgene Corp., Ista Pharmaceuticals, Gerson Lehman Group, iTherapeutix, Vistakon, Leerink Swann & Company, Transcend Medical, Visiogen, Vision Care, WaveTec Vision Systems, and TrueVision. Dr. Packer may be reached at tel: +1 541 687 2110; e-mail: mpacker@finemd.com.
