Chapter 8 Reconstruction 8 Steven P. Dunn and Lori Stec

Key Points scope and microsurgical instrumentation, were not readily available. Drops, sutures, various lasers, tattoo Surgical Indications pigments, and tinted intraocular lenses are some of the • Decreased visual acuity approaches available today. Th is chapter discusses the • Incapacitating glare surgical anatomy and healing response of the iris as • well as a variety of approaches for use when recon- • struction is necessary. • Cosmesis Instrumentation • Contact 8.2 • Argon laser Iris Anatomy and Wound Healing • Polymethyl methacrylate (PMMA) ring • Intraocular iris prosthesis Th e unique characteristics of the iris, its structure, and • Polypropylene suture response to disease and injury make an appreciation of Surgical Technique iris anatomy and wound healing of particular impor- • Laser iridoplasty tance when contemplating iris repair. • Suture iridopexy Th e structure of the normal human iris consists of • Pupil shaping with PMMA dilating ring two parts, the anterior stroma and the posterior dou- • Insertion of single-piece prosthetic iris with ble-layered pigmented epithelium. Between these lay- intraocular lens (IOL) ers are sandwiched the iris dilator and sphincter mus- • Insertion of multipiece prosthetic iris cles (Fig. 8.1). Th e stroma, in contrast to other ocular Complications structures, has a very loose, discontinuous architec- • ture. Th e anterior surface is made up of stromal cells, • Iritis fi brocytes, and melanocytes. Th ese cells have no de- • Subluxation of IOL fi ned linkage to one another and are separated by very • Decreased vision large intercellular spaces. Th e intercellular space con- • tains a few fi brils, ground substance, and aqueous humor. Within the stroma is a loosely orga- nized mix of melanocytes and iris blood vessels. Th e only continuous cell layer is found at the posterior sur- 8.1 face of the iris, and it is formed by the sphincter muscle Introduction ring, the dilator myofi brils, and the pigment epitheli- um. Th e muscle cells of the iris sphincter form a dense Th e function of the iris as a light-limiting diaphragm mass adjacent to the pupil. Th e dilator muscle origi- has been recognized for several thousand years. Initial nates and is thickest near the iris root and thins as it attempts to modify the iris and pupil were pharmaco- extends toward the pupillary edge (Table 8.1). logic in character. Th e concept of surgically modifying Clinical and pathologic studies indicate that trau- or repairing the iris did not receive much attention un- matic and surgical iris wounds do not heal spontane- til 1917, when Key fi rst wrote about his eff orts at re- ously. When a gap occurs in the iris (i. e., iridotomy), pairing an by suturing the iris edge to the and no bridging scaff old exists for stromal cells, pig- . Iris-to-iris repair was fi rst described by Emm- ment cells, or fi broblasts to migrate across, scarring erich in 1957. Neither of these contributions attracted between the margins of the defect does not occur. signifi cant attention when initially published. In large Clinical observations have raised the question of part this was because suitable equipment to facilitate whether true wound healing occurs or whether a me- surgical reconstruction, namely the operating micro- chanical apposition of the wound margins is all that 72 Steven P. Dunn and Lori Stec

Table 8.1 Standard measurements of the iris takes place. Research in and human patho- Diameter 12 mm logic specimens indicates that iris wounds do not show Circumference 37.5 mm any healing tendency or formation of scar tissue ex- cept in the area immediately surrounding an iris su- Th ickness: region 0.2 mm ture. At the site of the iris suture, there is a faint scar of the iris root with activated fi broblasts, a few plasma cells and mac- Th ickness: region 1.0 mm rophages, but very little collagen deposition. Long- of the collarette term apposition of an iris wound thus appears to be Pupillary diameter 1.2–9.0 mm wholly dependent on the presence of sutures. If a sig- nifi cant fi brinoid reaction occurs, a cyclitic membrane Width of the 0.6–0.9 mm may form, leading to “closure” of an iris defect. Th is, sphincter muscle however, does not lead to the reestablishment of nor- Th ickness of the pigment 12 µm mal iris architecture or to the formation of a collage- epithelium: nous scar, and can result in further pathology. Th ickness of the pigment 50–60 µm epithelium: 8.3 Nonsurgical Approaches

Th is chapter is devoted to the surgical management of iris defects; however, it is worth emphasizing that many iris problems require no treatment or can be managed nonsurgically. Nonsurgical approaches to iris repair include the use of miotics and - es. Miotics such as pilocarpine have minimal eff ect on the pripheral iris. Pupillary margin defects and trau- matic paralytic mydriasis also respond poorly or not at all to strong miotics. For the sphincter muscle to con- strict the pupillary opening, it must be able to pull against another structure. Under normal circumstanc- es, it pulls against itself; however, when it is transected or a portion is missing, there is nothing against which the muscle can work. Alpha-2 agonists such as brimo- nidine have been used to temporarily induce miosis (without signifi cant or brow ache) in post–re- fractive surgery patients suff ering from halos associ- ated with enlarged . Long before contact lenses became a consumer commodity, custom labs were manufacturing them in various materials for therapeutic purposes. Th ey were initially designed with a black pupillary zone and tint- ed periphery to hide corneal scars. Subsequent designs with a clear pupillary zone and opaque periphery be- came available for use in patients with and partial iris loss. Design parameters for these custom lenses are infi nite. In many cases, the pupil diameter can be custom-designed to produce a near-pinhole ef- fect if glare is signifi cant. Th e need for the peripheral opaque portion of the lens to extend to the limbus of- ten necessitates the use of soft and rigid gas-permeable contact lenses with large diameters. Th e greater gas permeability of today’s lens materials has had a major aff ect on the success of these lenses. Whereas most lenses have a paint/tint schema that is concentric in Fig. 8.1 Histologic cross section of pupillary and peripheral nature, focal painting/tinting can be done using trun- portions of the iris. cated lenses. Chapter 8 Iris Reconstruction 73

8.4 the fi rst of which is a detailed history of the condition Surgical Indications causing the iris defect and the various treatments, medical and surgical, that have produced the present Many iris abnormalities, both congenital ( albinism, picture. aniridia, and coloboma) and acquired ( traumatic my- Factors that should be determined preoperatively driasis, aniridia, and iridodialysis) benefi t from surgi- include the amount of iris that is missing, the amount cal intervention aft er nonsurgical options have been of iris that remains, and the specifi c portion of iris that exhausted. remains (i. e., collarette versus midperipheral). Th e Modifi cation or repair of the iris is indicated in character of the iris tissue is important to assess. Are three clinical settings. Th e fi rst of these, and by far the multiple transillumination defects present? Is there most common, is associated with functional diffi cul- schisis or delamination of the iris? Is there fraying of ties such as glare, photophobia, and/or diplopia. Th ese the surface or iris edge? Is rubeosis or abnormal vascu- optical symptoms are caused by an enlarged pupillary larization present? Th e presence or absence of periph- opening secondary to trauma, surgery or a congenital eral anterior ( PAS), lens capsule, iridocapsu- defect. An intact and functioning iris diaphragm de- lar adhesions, or iris or vitreous incarceration in old creases aberrations arising from the periphery of the surgical or traumatic wounds must to be determined lens. Traumatic or congenital aniridia is the ultimate preoperatively. example of pupil enlargement. A symptomatic para- Evaluation of the lens should determine if a central or peripheral iridotomy or iridectomy would is present. If aphakic, it is important to look for a capsu- constitute the opposite extreme. Th e functional diffi - lar ring with maximal dilation. If an intraocular lens is culties that these anatomic distortions present can of- present, the type, placement, and stability of the intra- ten be confi rmed by occlusion with the lid, the strate- ocular lens should be assessed. When the results of slit- gic obstruction of an iridotomy or sector iridectomy lamp examination are inconclusive, the angle, iris thick- with a cotton applicator or the use of an opaque con- ness, and posterior chamber can be evaluated by high tact lens with a small, clear pupillary zone. frequency ultrasound biomicroscopy (UBM) or ante- Th e second indication for repair is restoration of the rior chamber optical coherence tomography (OCT). iris diaphragm as part of a multifaceted surgical recon- Th e overall integrity of the corneal surface, includ- struction. A large iris defect might require closure to ing surface staining, corneal sensation, and Schirmer support an anterior chamber intraocular lens. If a pos- testing, should be determined. Th e clarity of the cor- terior chamber lens is implanted, the edges of an iris nea, the presence or absence of corneal edema or gut- defect might be drawn together in an eff ort to reduce tata, and an endothelial cell count are important fac- postoperative glare or diplopia (either because of the tors to measure when planning a surgical approach. enlarged pupillary opening itself or as a result of light Th e central and peripheral corneal thickness should be striking the lens edge). Th e removal of an iris lesion evaluated by slit-lamp examination and measured ul- might be combined with iris reconstruction if enough trasonically if thinning or thickening is present. iris is left to facilitate a primary repair. Corneal trans- Th e information resulting from these investigations plant surgeons will surgically tighten a loose, fl oppy will oft en illuminate other issues that aff ect the choices iris diaphragm during penetrating keratoplasty to re- available for eff ective surgical management. A thick- duce the risk of the iris shift ing forward, adhering to ened with guttata and signs of epithelial or the endothelial surface and producing broad periph- stromal edema, or a low endothelial cell count suggest eral anterior synechiae and secondary glaucoma. future corneal decompensation and the possible need Th e third clinical situation, and by far the rarest, is for a corneal transplant. A low-grade, chronic repair of an iris defect for cosmetic purposes. Th e risks may not only be the source of some of the patient’s of surgery, the uncertainty of the fi nal operative appear- complaints, but may reduce the intraocular options for ance, and the availability of excellent cosmetic contact the patient and require treatment in advance. lenses make this an uncommon surgical indication. Iris surgery, despite the most thorough preparation, is not always successful. At times one‘s best eff orts may result in a tattered and frayed iris. Even when initially 8.5 successful, the suture may gradually erode through the Surgical Technique: General Considerations iris, resulting in reopening of the defect in part or full. Close attention to the anatomy of the iris (thickest at Th e surgical management of an iris defect may involve the collarette), the preoperative documentation of alterations to the cornea, reconstruction or manipula- atrophic areas and areas of transillumination, careful tion of the iris, or insertion of an opaque barrier in the full-thickness placement of sutures, and awareness of lenticular plane. Th e decision as to which approach the amount of tension that the iris tissue is being sub- may be most benefi cial depends on a variety of factors, jected to is paramount. 74 Steven P. Dunn and Lori Stec

8.6 Goniosynechiolysis with a fl at, blunt-tipped spatula Surgical Technique: Instrumentation may free iris that has been trapped by PAS or captured within a prior wound. Care (and patience) needs to be Monofi lament polypropylene is now considered to be exercised when lysing synechiae, as the instrument tip the best suture material for iris surgery. It has a smooth, is not visible and can easily tear the iris, create a cyclo- snag-resistant fi nish; limited memory; and resists deg- dialysis, or trigger signifi cant bleeding. An intraopera- radation. Th e particular reconstructive technique used tive goniolens for closed-system work or a small-di- will dictate the length, shape, and type of needle point ameter dental mirror for open-system work is to be used. A needle with a cutting tip and a tapered extre mely helpful. Goniosynechialysis is best utilized body (taper cut) is the least destructive as it passes when limited areas of PAS exist and the iris is not through the iris (a BV needle). Th e tapered body does “fl oppy” in character. Large areas of PAS can be lysed; not cause further side cutting of the tissue as the nee- however, the exposed surfaces oft en re-adhere like two dle passes through. Distortion of the iris should be pieces of fl ypaper. avoided even when a tapered needle is used, since it Vitreous on the anterior or posterior surface of the will oft en lead to stretching or tearing of the suture iris, pupil or angle must be removed before surgical tract (see Table 2.2, Chap. 2). A paracentesis, full-entry reconstruction is attempted. Mechanical vitrectomy wound, or partial-thickness scleral fl ap is necessary must carefully and completely remove the vitreous with this needle because of the large amount of force from the iris. Incarceration of vitreous into sutures or necessary to push these needles though the sclera. the wound may result in traction and possible retinal Side-cutting spatula tip needles are necessary for pierc- tears, detachment or in the post opera- ing the cornea or sclera, but are prone to creating a tive period. larger slit rather than a small puncture as they pass Viscoelastic dissection should be used to deepen through the iris. the anterior chamber and to help separate the iris from In many situations, traditional tying techniques can the underlying lens, capsule, or pseudophakos. Th e di- be used to appose the iris. Closed-system repairs, how- rection of instillation is important in that the visco- ever, oft en necessitate the use of alternative tying tech- elastic can be used to the surgeon’s advantage to unfurl niques that involve slipknots, such as that proposed by the iris (or, inadvertently, twist it further if one is not Siepser (see Sect. 8.7.5) or intraocular knot manipula- paying close attention). tion using long fi ne forceps or intraocular lens (IOL) manipulators. Care must be exercised when handling the iris. Th e 8.7 less iris tissue manipulation with forceps, the better. Surgical Approaches Flat, toothless forceps should be used and then only by grasping the full-thickness iris wound edge. Forceps with teeth are likely to tear the iris. Similarly, grasping 8.7.1 the iris on its anterior surface may lead to shredding of the surface because of the loose linkage of stromal cells with one another. Corneal tattooing has been used for centuries to treat cosmetically objectionable corneal leukomas. Th e original technique involved imbedding India ink or carbon particles in the anterior and midstroma by a process similar to corneal stromal puncture (Fig. 8.2). Oft en the procedure had to be repeated in order to achieve the desired distribution and density of pig- ment. Over time the pigment tended to migrate from the puncture wounds, and the procedure needed re-

Fig. 8.2 Corneal tattooing: micropuncture and lamellar Fig. 8.3 Corneal tattooing before (left ) and aft er (right) the technique procedure. (Photo courtesy of Mark Mannis, M.D.) Chapter 8 Iris Reconstruction 75 peating. Given these problems, an alternative method dilator as well as bimanual stretching of the pupil using was developed involving the creation of a lamellar a push-pull technique provides temporary intraopera- pocket or fl ap into/under which pigment is instilled. tive enlargement of a miotic pupil. Mechanical pupil Th is technique is easily adapted to almost any type, dilatation is oft en required when the above measures size, and shape of iris defect. Th e density and color dis- are ineff ective, a very large papillary opening is re- tribution of the pigment can be varied according to the quired, or a prolonged procedure is anticipated. Mul- demands of the case. tiple iris-retraction hooks can be rapidly and easily One drawback of corneal tattooing is that the pig- placed providing adequate exposure and pupil stability ment (particularly when a densely pigmented, dis- for lengthy operative procedures. Th e Morcher poly- cretely edged tattoo is applied) oft en appears to be methyl methacrylate (PMMA) pupil-dilator ring or “stuck on” the surface of the cornea. Th is lack of depth the Greather 2000 pupil expander can enlarge an oth- is not a major problem when functional issues are the erwise-small pupil to 7.5 mm by acting as a “collar,” primary concern, but may be signifi cant when cosmet- maintaining a fi xed pupillary opening throughout the ic issues are paramount (Fig. 8.3). case ([4]; Fig. 8.4). Th e pupil dilator ring and iris hooks are both tempo- rary in nature. Perhaps, some variation of one or both of 8.7.2 these will fi nd clinical use as a permanent means of me- Laser Iridoplasty chanically enlarging a miotic pupil in the future.

Since its introduction in 1958, the argon laser has been used to treat a variety of ocular diseases and disorders. 8.7.4 Cleasby was one of the fi rst to describe how the argon Iridopexy for Coloboma Repair laser could be used eff ectively to alter the size, shape, and position of the pupil in cases of miosis, up-drawn Suture closure of iris defects can be handled in a num- pupil, or cyclitic membrane [1]. Most techniques ad- ber of ways. vocate the application of laser spots at the pupillary A small coloboma, as might occur following remov- margin or overlying the region of the collarette, caus- al of a 1- to 2-mm lesion at the pupillary margin, can ing destruction to the sphincter either physically or usually be drawn together with either one or two full- functionally (through denervation) [2]. thickness sutures placed through the iris sphincter. Laser iris sphincterotomy by linear incision was One suture should be placed close to the edge to limit promoted by Wise in 1985 to permanently alter the the amount of nicking that might develop postopera- size, shape, and location of the pupil. Less of the iris tively, the other suture within the sphincter itself. If the required treatment, and as a consequence, less energy coloboma extends toward the iris root, then additional was required as compared with earlier techniques. Th e sutures may be required (Fig. 8.5a). argon laser (0.02-s exposure, 50-µm spot size, 800– Th e management of a larger coloboma that extends to 1,500 mW) can be used to cut across the iris sphincter the iris root is much more diffi cult. A sector iridecto- fi bers in a radial line. Laser spots should be confi ned to my may be closable at the pupil margin by one or two the stroma, allowing the deep pigment epithelium to carefully placed sutures. It is rare, however, that the be pulled apart by iris tension. Treatment of the deeper more peripheral portions can be pulled together com- stromal layers with a reduced exposure time of 0.01 s can minimize damage to the lens. Th e radial pull of the dilator muscle fi bers are normally countered by the contracted sphincter muscles. Linear cuts with the la- ser across the sphincter leave the dilator fi bers unap- posed, facilitating pupillary mydriasis [3].

8.7.3 Intraoperative Pupil Dilators and Maintainers

Th e miotic pupil that fails to respond to mydriatics preoperatively creates a number of signifi cant techni- cal diffi culties for the ophthalmic surgeon planning cataract or vitreoretinal surgery. An increased inci- dence of intraoperative complications is associated Fig. 8.4 Intraoperative pupil enlargement. Iris hooks (top), with this problem. Th e three-pronged Beehler pupil Morcher pupil expander (bottom) 76 Steven P. Dunn and Lori Stec

pletely. If there is too much tension at the pupillary border, multiple small sphincterotomies evenly placed along the inner circumference of the pupil may be needed. Ignoring excess iris tension will usually lead to cheese-wiring of the suture and the production of a

a secondary iris defect. A circumferential incision at the root of the iris, to either side of the coloboma, will help to mobilize the iris (Fig. 8.5b). Th e pupillary edges of Inc ise d the coloboma may then be brought together, leaving a basal, -shaped coloboma in the periphery. A rotational fl ap of iris tissue can also be used to help bridge a large coloboma (Fig. 8.5c). Th ickened capsu- lar remnants can sometimes be used to bridge a gap or simply as a backing material to give the reconstruction

b more stability. As yet, there is no artifi cial iris material that can be use for this purpose. Various open- and closed-system suturing tech- A niques can be adapted for repairing a large coloboma if B B adequate tissue is present. Wound tension (and indi-

A rectly the presence of suffi cient tissue) is oft en the critical issue aff ecting ones ability to surgically repair an iris defect.

c 8.7.4.1 Closed-System, Single-Armed, Peripheral Approach Fig. 8.5 Iridopexy techniques: a Basic closure technique, b circumferential incision technique, and c rotating segment technique A popular closed-system approach ( McCannel tech- nique) involves the creation of two paracenteses at the limbus at either end of a projected line that is perpen- dicular to the edge of the iris defect. A long, thin needle with a 10-0 polypropylene suture is then introduced through the entry site (Fig. 8.6a). Th e anterior chamber is fi lled with hyaluronic acid or viscoelastic introduced through the other paracentesis. If the hyaluronate is in- jected posterior to the iris edge, the uveal tissue can be

a b “nudged” toward the tip of the needle. Th e needle is then passed through the iris edge on both sides of the wound, assisted by gentle counterpressure from the blunt tip of the hyaluronic acid cannula (Fig. 8.6b). Th e tip of the needle may be lodged in the open bore of the cannula— using it as a guide to both penetrate the iris and remove the needle via the opposite paracentesis. A full-thickness stab incision is made through the peripheral portion of the cornea between the paracenteses sites. A small hook c d is introduced through this incision, and both ends of the suture are brought out, tied together, cut fl ush, and then reposited (Fig. 8.6c–e). Th is can be repeated as many times as needed to properly close an iris defect [9]. Shin modifi ed McCannel’s technique using a 1.6- cm 25-gauge hypodermic needle attached to a tuber- culin syringe instead of a long thin needle. Th e hypo- dermic needle tip should pierce the proximal iris wound margin from anterior to posterior, and the dis- e tal wound edge from posterior to anterior before exit- Fig. 8.6 An iridopexy technique: closed-system, single- ing through the opposite limbus (Fig. 8.7a). A 10-0 armed, peripheral approach ( McCannel technique) polypropylene suture can be threaded into the lumen Chapter 8 Iris Reconstruction 77 of the 25-gauge needle and passed through to its bevel end is then passed through clear limbal cornea adja- (Fig. 8.7b). Th e 25-gauge needle is then removed, leav- cent to the iris base. A long needle with a moderate ing the polypropylene suture in place. Retrieval of the curve to it (such as the CIF-4 or bent straight needle) suture with hooks and closure of the iris coloboma is needed to accomplish this without excessive distor- through a third incision is similar to the standard Mc- tion of the cornea. A paracentesis and cannula or a Cannel technique [10]. needle with open bore can greatly assist in the passage Siepser further modifi ed McCannel’s technique by of the needle through the peripheral cornea. Retrieval using only two paracentesis and a slipknot (see Fig. 5.3, of the suture with hooks and closure of the iris colo- Chap. 5). Th e 10-0 polypropylene suture is passed ac- boma through the corneal incision is similar to the cording to the technique described above. A large loop standard McCannel technique (Fig. 8.8c). Th is proce- of suture is left externally at either end. A Bonds or sim- dure can be repeated as needed distal to the pupillary ilar microhook is then introduced; a loop of suture is border for complete closure of the iris defect [13]. taken from the opposite side of the anterior chamber and brought out through the entry paracentesis. A dou- 8.7.4.3 ble-throw slipknot is then placed, and both suture ends Lasso Technique are pulled outwards, drawing the knot back into the and apposing the iris edges. A second knot is made in a Th is last technique is a lasso suture with three entry/ similar fashion to lock the fi rst knot in place. Th e suture manipulation “ports” and can be used for postopera- ends are trimmed with fi ne intraocular scissors [11]. tive atonic pupils or traumatic mydriasis. Th ree 1.0- Th is procedure can be repeated along the length of the mm limbal or clear corneal stab incisions are made at iris defect if necessary. 9, 5, and 1 o’clock (termed nos. 9, 5, and 1). Aft er fi lling the anterior chamber with viscoelastic, a PC-7 needle 8.7.4.2 (or similar) with a 10-0 polypropylene suture is insert- Closed-System, Double-Armed, Peripheral Approach ed through no. 9. Forceps usually used for peeling are inserted through no. 1. Th e iris An iris coloboma can be closed via a single limbal inci- is grasped with the forceps at 10 o’clock and pulled sion, using a double-armed suture technique. Pallin centrally. Th e fi rst bite is placed peripheral to the pu- described an approach in which a stab incision is made pillary edge. Th is is repeated, making a continuous in the clear cornea peripheral to, but overlying, an iris row of three to four suture bites in the lower part of the defect. Each needle of a double-armed 10-0 polypro- iris toward no. 5 (Fig. 8.9a, b). Th e forceps are with- pylene suture is passed through the corneal stab inci- drawn, and a blunt cannula is inserted into the anterior sion and then through opposite edges of the sector iris chamber at no. 5 to act as a guide to smoothly with- defect at the pupillary border (Fig. 8.8a, b). Each needle draw the needle tip from the anterior chamber. Th e

a a b

b c Fig. 8.7 An iridopexy technique: closed-system, single- Fig. 8.8 An iridopexy technique: closed-system, double- armed, peripheral approach (Shin modifi cation) armed, peripheral approach ( Pallin technique) 78 Steven P. Dunn and Lori Stec

above steps are repeated to make a continuous loop from no. 5 to 1 and then from no. 1 to 9 (Fig. 8.9c, d). At the conclusion of these maneuvers, the ends of the suture will be coming out of no. 9. Th e suture tension can be adjusted for the desired pupil size prior to tying the fi nal knot (Fig. 8.9e; [14]). A special situation exists in keratoplasty cases where the free edge of a coloboma or a fl oppy, atonic iris may become adherent to the posterior edge of the graft – host junction. Peripheral anterior synechiae in the keratoplasty patient may become broader and “zipper” the angle, causing secondary glaucoma. Although the mechanism for this problem is not fully understood, progressive PAS is a rare fi nding when the iris dia- phragm is intact, underscoring the importance of re- pairing iris colobomas in this group of patients. Th e techniques described above are easily adapted to an open-sky approach. In addition, iris fl aps hinged at Fig. 8.10 Large iridodialysis the collarette can be fashioned from the edge of the col- oboma and used to bridge the gap. Th e end result should be a tight iris diaphragm with little anterior–posterior movement. One cautionary remark: If mobilization of the iris requires dissecting the iris off the endothelial surface peripherally or goniosynechialysis, then the raw

a b

#1 #1

#9 #9

#5 #5 a b c d

#1 #1

#9 #9

#5 #5

c d e f

g h

e Fig. 8.11 An iridodialysis technique: closed-system, single- Fig. 8.9 Lasso technique armed, cross-pupil approach Chapter 8 Iris Reconstruction 79 surfaces produced have a tendency to act like two adhe- whether the needle crosses the pupil. While simple in sive surfaces—attracting one another and re-apposing concept, they oft en turn out to be more challenging themselves, oft en with even more extensive adhesions. than thought at fi rst glance. Th is may relate as much to where the iridodialysis is (i. e., inferior or nasal) or to diffi culties “spearing” the iris or suture tear-out (pull- 8.7.5 ing through the iris tissue). A bimanual approach is Iridopexy for Iridodialysis Repair oft en necessary in order to stabilize the iris enough for the needle to pass through it. A fl oppy iris edge has a Small iridodialyses rarely require repair unless they tendency to “run away” from the needle point. One occur in the horizontal meridian and cause disabling must keep in mind that the anatomy of these may glare or diplopia. When surgery is required, a single be altered as a consequence of the process (oft en trau- suture is oft en adequate to reduce symptoms. More matic) that led to the iridodialysis. than one suture, however, may be required to ensure Th e following are a summary of some of the surgi- full closure. Larger iridodialyses are frequently re- cal approaches used to repair an iridodialysis. paired for cosmetic as well as optical reasons. In these cases, refi xation of the iris at two or more peripherally 8.7.5.1 points is necessary. Th e presence of vitreous in the an- Closed-System, Single-Armed, Cross-Pupil Approach terior chamber or in the vicinity of the iris defect must be recognized preoperatively and removed prior to A 17-mm single-armed straight needle with 10-0 poly- suture placement. propylene suture is passed through a paracentesis site Numerous techniques have been proposed to cor- located 180° away from the iridodialysis. Th e needle is rect large iridodialyses (Fig. 8.10). Many are slight passed across the chamber, through the torn iris edge, variations of one another. Techniques vary according and out through the sclera at the point of normal iris to whether they are closed chamber in character and insertion. Th e needle exits beneath a large preplaced scleral fl ap (Fig. 8.11a, b). A second paracentesis site is then created just above the suture exit site (beneath the fl ap). An iris hook is then passed through this second entry site and used to retrieve the other end of the polypropylene suture (Fig. 8.11c–g). Th e suture is tied, buried, and the fl ap re-apposed (Fig. 8.11h). Addition- al fl aps and exit–entry sites need to be created if addi- tional sutures are to be placed [5]. Th is technique has more incisions than other techniques; however, it does a b

a b c d

e c Fig. 8.12 An iridodialysis technique: closed-system, thread- Fig. 8.13 An iridodialysis technique: closed-system, double- ed needle, cross-pupil approach ( Bardak technique) armed, cross-pupil approach 80 Steven P. Dunn and Lori Stec

allow for a bimanual approach if counter pressure is hind the limbus. A long, thin needle with 10-0 poly- needed to spear the iris edge. As with the double- propylene is passed through a scleral incision, catching armed suture approach discussed below, a needle has the edge of the incision as one enters the eye. Th e iris to be passed over the unprotected pupil. edge is then caught with the point of the suture, and the Bardak describes a modifi cation of this technique needle is then passed out of the eye through the cornea using a 22.0-mm, 26-gauge hypodermic needle or a second scleral incision (Fig. 8.14). An iris hook is through which a 9-0 or 10-0 suture can be thread aft er then passed through the fi rst incision, and the suture it has been passed through the iris edge and out be- caught and drawn out. Th e suture is tied to itself aft er neath the opposite scleral fl ap. (Fig. 8.12a–e; [6]). An drawing the iris edge to the posterior scleral edge. Th is MVR blade modifi ed with a 0.4- to 0.6-mm hole at the can be repeated as many times as needed to properly tip can also function similarly [7]. reposition the iris [9]. A variation of this using a double armed suture has also been described (Fig. 8.15). 8.7.5.2 A variation of the above technique is worth consid- Closed-System, Double-Armed, Cross-Pupil Approach ering if the peripheral iris edge has not retracted very far centrally. Aft er entering the eye with a MVR blade Th is technique involves performance of a peritomy in and creating a 1.0- to 1.5-mm opening, viscoelastic is the area of the iridodialysis and a paracentesis 180° instilled on either side of the iris. An iris hook or fi ne away. A 17-mm double-armed straight needle with 10- retinal forceps are carefully advanced beneath the iris, 0 polypropylene suture is used. One needle is passed catching the iris edge and drawing it out through the through the paracentesis, engaging the peripheral, opening. A 10- polypropylene suture is then passed torn iris root before exiting the sclera at a distance of through the edge of the scleral incision, through the 1.0- to 1.25-mm peripheral to the surgical limbus (Fig. iris, and then through the opposite scleral edge. Th e 8.13a, b). Th e other needle of this double-armed suture iris is then reposited in the anterior chamber and the engages the iris 1.0- to 1.5-mm lateral to the fi rst su- wound closed. Care should be taken not to incarcerate ture and exits the in the same plane as the fi rst, the iris in the wound in order to avoid formation of a but 1.5- to 2.0-mm laterally (Fig. 8.13c). Th e two su- fi stula tract in the postoperative period. Grasping the tures are tied, and the knots are rotated into the needle iris and drawing it into the paracentesis site may be tract. Alternatively, the needles may be brought out in more diffi cult than one might expect. the base of a previously made groove, and the knots A second variation involves the creation of one large cut short [8]. Th e principal risks/diffi culties of this ap- or multiple small scleral fl aps in the region of the iri- proach relate to the need for good control of the needle dodialysis. A 30-gauge straight needle threaded with a when passing the tip of the needle across the pupil. 10-0 polypropylene is passed through the bed of the scleral fl ap and through the peripheral edge of the iris. 8.7.5.3 Twenty-fi ve–gauge retinal forceps entering from a Closed-System, Single-Armed, Peripheral Approach more lateral paracentesis can be used to unfurl the iris and assist in passage of the needle through the iris (Fig. A second closed-system approach ( McCannel tech- nique) involves the creation of a peritomy in the quad- rant of the iridodialysis. A number of full-thickness incisions measuring 1.0-mm wide are placed equidis- tant along the length of the iridodialysis, 1.0 mm be-

a b

c Fig. 8.14 An iridodialysis technique: closed-system, single- Fig. 8.15 An iridodialysis technique: closed-system, double- armed, peripheral approach ( McCannel technique) armed, peripheral approach Chapter 8 Iris Reconstruction 81

8.16a). Once the suture is through the iris, the forceps black diaphragm lenses specifi cally for use in patients grasp the suture, allowing the needle to be withdrawn. with congenital or acquired aniridia (partial or com- A second 25-gauge forceps or iris hook is then ad- plete), traumatic mydriasis and albinism [16]. Th ese vanced through a paracentesis adjacent to the initial pseudophakic lenses have gone through a number of entry site, and the suture is withdrawn. Th e suture is modifi cations and are available in diff erent aperture then tied and the knot buried beneath the scleral fl ap (3.5, 4, and 5 mm) and optic diameters (7 × 10-mm (Fig. 8.16b). Th is approach can be repeated as many elliptical, 8, 9.64, and 10 mm). Th e lenses can be cap- times as necessary to properly reposition the iris [10]. sular supported or sewn in, using haptic loops provid- One advantage of this approach is that the needle is ed for this purpose (Fig. 8.17a–c). not passed over the pupil/lens. A disadvantage is that Morcher black diaphragm lenses have not been the surgeon needs to reach into the eye with forceps or Food and Drug Administration (FDA)-approved; an iris hook to grasp the suture, iris edge, or both. however, they are available from Morcher on a case- by-case basis with approval of an investigational re- 8.7.5.4 view board. Th ere are several case series in the litera- Open-System, Peripheral Approach ture with long-term follow-up [17–19]. Ophtec BV is currently doing FDA trials with a Th e fi nal approach is an open-system approach in similar lens. Th is is a single piece, non-foldable poste- which a full-thickness scleral incision is made in the rior chamber aniridic lens with a brown, blue, or green quadrant of the iridodialysis. Forceps or an iris hook is peripheral diaphragm [20, 21]. Ophtec is also evaluat- then used to grasp or “snag” the iris edge and draw it to ing a multipiece iris prosthetic system with compo- the wound edge to be sutured to the sclera. Th e princi- nents that can be inserted through a small incision and pal disadvantage of this approach is the large wound assembled inside the eye. that is necessary (oft en 90–180°), the greater risks as- Th ese lenses have signifi cantly reduced postopera- sociated with an open eye, longer wound healing, tive glare dysfunction in aniridic patients and, as a wound instability, and increased postop- consequence, have been associated with improvement eratively. in visual function. Low-grade intraocular infl amma- tion and glaucoma are problems that have been re- ported with these lenses. It is unclear, however, if these 8.7.6 problems are related to the lens, or to the underlying Intraocular Prostheses conditions and circumstances that have lead to the need for these specialized intraocular lenses. Th e concept of implanting an anterior chamber lens A segmented opaque capsular tension ring is also with an optic surrounded by a colored diaphragm was available from Morcher and can be used to selectively fi rst described in 1959 by Choyce [15]. Since then, block peripheral iris defects (areas of atrophy or an old Sundmacher (in cooperation with Morcher GmbH of peripheral iridectomy/iridotomy) (Fig. 8.18). Th ese Germany) has developed a series of posterior chamber rings can be implanted into the capsular bag at the time of cataract extraction, or into the sulcus in an eye al- ready containing a posterior chamber intraocular lens. Th e rings come in diff erent confi gurations and can be combined to achieve even greater eff ect: Two rings can be rotated against one another to form a complete pe- ripheral ring if required. Osher described six cases of combined with implantation of a vari- ety of Morcher aniridia devices. Black iris diaphragm rings or iris segments were inserted through a small a b incision and assembled inside the capsule along with a posterior chamber intraocular lens [22].

8.8 Complications

Surgical complications during or following suture iri- doplasty are not distinctly diff erent from those of other Fig. 8.16 An iridodialysis techniques: closed-system, single- types of intraocular surgery. Hemorrhage, though, is a armed, peripheral approach frequent complication. All patients should stop aspi- 82 Steven P. Dunn and Lori Stec

Fig. 8.17 Aniridic intraocular lenses (IOLs) (Morcher GmbH) Preoperative photo of an aniridic eye prior to placement of the IOL. Postoperative photo of the same aniridic aft er placement of the IOL

choroidal hemorrhages may occur. Hyphemas and vit- reous hemorrhage may develop within the fi rst 24–48 h aft er surgery, even when bleeding was minimal (or easily brought under control) at the time of surgery. Cyclodialysis cleft s may be present as a result of the original problem and should be looked for preopera- tively. Excessive traction on the iris or eff orts at releas- ing PAS may result in the formation of a cyclodialysis cleft at the time of surgery. Th is oft en occurs in an area 180° away from the original iridodialysis. Failure to recognize the presence of vitreous in the area requiring reconstruction can have devastating consequences. Intraoperatively, vitreous may interfere with suture passage and knot tying. Postoperatively, the resultant vitreous traction may result in chronic intraocular infl ammation, or . Th e vast majority of patients who require iris recon- struction have either a congenital abnormality of the iris or have sustained some form of surgical or trau- matic injury to their eye. Th ese eyes are abnormal in both obvious and not-so-obvious ways. Contact lenses may induce old blood vessels to recannalize. Th e tissue overlying peripheral tattooing may break down or be- come vascularized; the pigment may gradually dimin- ish in density. A good understanding of the diapha- nous nature of the tissue, the full extent of the injury, Fig. 8.18 Iris occlusive segments for correction of sector iris and the limitations that these impose on reconstruc- defects at or following cataract surgery. tion is paramount to successful surgery. Complications associate with specifi c techniques are discussed in the various sections above. As emphasized in the surgical rin, nonsteroidal antiinfl ammatory drugs (NSAIDs) techniques section, the surgeon who is unprepared is and other anticoagulants at least 7 days prior to sur- likely to be extremely frustrated during surgery and gery. Th e peripheral iris (fortunately) does not contain disappointed with the result. It is not unusual for even many large blood vessels; however, the iris root and the well-prepared surgeon to have to modify his or her are quite vascular and prone to bleeding. plans in the middle of surgery. A clear and detailed A fi ne-tip intraocular cautery is very helpful when in- discussion between the surgeon and patient is very im- creasing the (with air, saline, or portant in this group of patients where surgical objec- viscoelastics) fails to halt the bleeding. Epinephrine in tives may not always be achieved and the potential for the irrigating solution may be of some benefi t. Supra- operative and postoperative problems are high. Chapter 8 Iris Reconstruction 83

7. Erakgun, T., Kayikcioglu, O., Akkin, C., MVR knife with 8.9 a hole at the tip for secondary IOL implantation. Journal Future Challenges of Cataract and Refractive Surgery, 2000. 26: p. 1700– 1701 Advances in contact lens and intraocular lens technol- 8. Wachler, B., Krueger, R., Double-armed McCannell su- ture repair of traumatic iridodialysis. American Journal ogy will certainly aff ect the development of lenses for of , 1996. 122(1): p. 109–110 use in the area of iris repair and reconstruction. It is 9. McCannel, M., A retrievable suture idea for anterior conceivable that these lenses may contain threshold uveal problems. Ophthalmic Surgery, 1976. 7: p. 98– triggered, photoreactive pigments that vary the size of 103 10. Chang, S., Coll, G., Surgical techniques for repositioning the pupil according the amount and intensity of avail- a dislocated intraocular lens, repair of iridodialysis, and able light. Th e development of a biocompatible iris re- secondary intraocular lens implantation using innovat- placement material and rapid acting, long-lasting ad- ing 25-gauge forceps. American Journal of Ophthalmol- ogy, 1995. 119: p. 165–174 hesives for use within the eye will lead to greater 11. Siepser, S.B., Th e closed chamber slipping suture tech- fl exibility and surgical innovation at the time of iris re- nique for iris repair. Annals of Ophthalmology, 1994. 26: construction. A rapidly polymerizing material might p. 71–72 be injected into the eye to create a spider web–like 12. Shin, D.H., Repair of sector iris coloboma. Archives of Ophthalmology, 1982. 100: p. 460–461 scaff old over which fi broblasts and pigment cells might 13. Pallin, S.L., Closed chamber iridoplasty. Ophthalmic be stimulated to grow. Similarly a fi ne, folded mesh Surgery, 1981. 12: p. 213–214 containing a tissue-specifi c growth factor might be in- 14. Behndig, A., Small incision single-suture-loop pupillo- serted into the anterior chamber, unfolded, and clipped plasty for postoperative atonic pupil. Journal of Cataract and Refractive Surgery, 1998. 24: p. 1429–1431 to iris remnants or other ocular structures. Iris repair 15. Choyce, P., Intraocular lenses and implants. 1964, Lon- and reconstruction is an area rife for innovation. Th e don: HK Lewis. 27–32, 162–178 increased number of articles on this subject over the 16. Sundmacher, R., Reinhard, T., Althaus, C., Black-dia- past few years suggests many new approaches will be phragm intraocular lens for correction of aniridia. Oph- thalmic Surgery, 1994. 24(3): p. 180–185 available to assist us in the future. 17. Reinhard, T., Engelhardt, S., Sundmacher, R., Black dia- phragm aniridia intraocular lens for congenital aniridia: long-term follow-up. Journal of Cataract and Refract Surgery, 2000. 26: p. 375–381 References 18. Th ompson, C.G., Fawzy, K., Bryce, I.A., et al., Implanta- 1. Cleasby, G.W., Photocoagulation coreplasty. Archives of tion of a black diaphragm intraocular lens for traumatic Ophthalmology, 1970. 83(2): p. 145–151 aniridia. Journal of Cataract and Refractive Surgery, 2. L’Esperance, F.A.J., James, W.A., Jr., Argon laser photo- 1999. 25: p. 808–813 coagulation of iris abnormalities. Transactions of the 19. Burk, S.E., DaMata, A.P., Snyder, M.E., et al., Prosthetic American Academy of Ophthalmology and Otolaryn- iris implantation for congenital, traumatic, or functional gology, 1975. 79(2): p. 321–339 iris defi ciencies. Journal of Cataract and Refractive Sur- 3. Wise, J.B., Iris sphincterotomy, iridotomy, and synechio- gery, 2001. 27: p. 1732–1740 tomy by linear incision with the argon laser. Ophthal- 20. Esquenazi, S., Amador, S., Bilateral cataract surgery mology, 1985. 92: p. 641–645 combined with implantation of a brown diaphragm in- 4. Akman, A., Yilmaz, G., Oto, S., et al., Comparison of traocular lens aft er for congenital an- various pupil dilatation methods for phacoemulsifi ca- iridia. Ophthalmic Surgery & Lasers, 2002. 33(6): p. tion in eyes with a small pupil secondary to pseudoexfo- 514–517 liation. Ophthalmology, 2004. 111: p. 1693–1698 21. Price, M., Price, F.W. Jr., Chang, D.F., et al., Ophtec iris 5. Nunziata, B., Repair of iridodialysis using a 17-millime- reconstruction lens United States clinical trial phase I. ter straight needle. Ophthalmic Surgery, 1993. 24: p. Ophthalmology, 2004. 111: p. 1847–1852 627–629 22. Osher, R.H., Burk, S.E., Cataract surgery combined with 6. Bardak, Y., Ozerturk, Y., Durmus, M., et al., Closed implantation of an artifi cial iris. Journal of Cataract and chamber iridodialysis repair using a needle with a distal Refractive Surgery, 1999. 25: p. 1540–1547 hole. Journal of Cataract and Refractive Surgery, 2000. 26: p. 173–176