Fig. 2.1
Traumatic mydriasis
No treatment for traumatic mydriasis is necessary in the absence of visually disturbing or cosmetic symptoms. In symptomatic patients, miotic agents such as 1–2 % pilocarpine eye drops four times daily may be attempted. However, pilocarpine is often ineffective and may induce eye pain and/or headache, myopic shift, miosis, reduction of accommodative amplitude, or retinal detachment in predisposed eyes. The use of competitive α-adrenergic antagonists may be better tolerated, with less effect on accommodation and a less frequent dosing schedule [4].
Failure of pharmacologic treatment in symptomatic patients may warrant the use of opaque, iris-print contact lenses to ease the burden of visual symptoms and provide an acceptable cosmetic appearance. However, in case of contact lens intolerance or unsuitability or in cases in which surgical intervention is planned for coexisting traumatic ocular injuries (e.g., traumatic cataract and/or lens subluxation/dislocation), surgical correction of traumatic mydriasis could be considered. Surgical iridoplasty can be achieved by radially cutting the iris extending from the iris periphery to the pupillary margin at the point of presumed sphincter rupture using a pair of iris scissors, followed by bringing the two ends of the cut pupillary border apposed with a permanent 9–0 or 10–0 polypropylene suture using the Siepser slipknot technique (described below in the Sect. 2.4.3, Fig. 2.2). The procedure is repeated distally along the length of the radial iris cut. A running suture acting as an encircling band may also be weaved through the iris margin in a purse string fashion, tied, and tightened as necessary forming a type of pupillary cerclage [5].
Fig. 2.2
Seipser slipknot technique. Two opposing side ports are made and a 10-0 suture with a CIF-4 needle passed from the first paracentesis through the 2 edges of the iris laceration and externalized out of the second side port incision. The needle is cut and a large loop of suture is pulled out of the entry side port incision intraocularly then out of the second side port incision. A double throw slipknot is made by tying the loop around the free suture end and the knot is slid into the anterior chamber by pulling the 2 suture ends firmly. The process is repeated to form a square knot. The suture ends are trimmed using intraocular scissors
2.4.3 Traumatic Iris Lacerations
Traumatic iris lacerations (Fig. 2.3) can result secondary to penetrating ocular trauma or be iatrogenic (e.g., during cataract surgery where a tuft of iris tissue is caught in the phacoemulsification tip, particularly in cases of floppy iris syndrome). Iris lacerations can result in intraocular bleeding, poor pupillary reaction, mydriasis, poor cosmesis with an eccentric pupil, and visual symptoms similar to those associated with traumatic sphincter rupture and possible associated mydriasis. Large iris lacerations can result in monocular diplopia if traumatic polycoria is present. Iris lacerations may also be associated with other iris deformities (e.g., iridodialysis) and traumatic ocular injuries.
Fig. 2.3
Traumatic iris laceration
Management of traumatic iris lacerations depends on the extent of injury and whether it is symptomatic. Surgical repair of iris lacerations can be achieved by suturing the two cut ends with a Siepser slipknot (Fig. 2.2) using a permanent 9–0 or 10–0 polypropylene suture on a long needle (e.g., CIF-4 needle, Ethicon) [6]. Two side ports are made at either ends of a projected imaginary line perpendicular to the iris laceration along the suture tract. The needle is then introduced into the anterior chamber through a side port, while a 25-gauge cannula is introduced through the opposite side port to provide countertraction necessary for passing the needle into the iris tissue and for docking the needle tip. The needle is then externalized through the second side port, and the needle is cut leaving long suture ends on both sides. A large loop of suture is then pulled inside the eye and pulled out of the entry side port using a hook (i.e., Bonds or Sinskey). A double throw slipknot is formed by tying the externalized loop around the free suture end and then pulling both suture ends gently and securely to form a slipknot inside the anterior chamber. The process is then repeated to form a square knot. The suture ends are then trimmed short using a pair of intraocular microscissors. If the laceration is large and requires multiple knots along its length, the more proximal ends near the pupillary border should be apposed first and the procedure then repeated distally as required along the laceration length.
2.4.4 Iris Prolapse
Iris prolapse occurs secondary to an open globe injury (due to a blunt force or a penetrating trauma) (Fig. 2.4). The iris tissue may prolapse through corneal, limbal, scleral, or corneoscleral lacerations and can be associated with traumatic iris laceration, iridodialysis, or other ocular injuries. Prompt, timely management of iris prolapse is crucial to store the anatomic integrity of the eye. Delayed management may result in iridocorneal adhesions with ischemia and necrosis of the iris tissue, introduction of microorganisms with the secondary occurrence of endophthalmitis, surface epithelialization and epithelial downgrowth, and peripheral anterior synechia (PAS) formation with secondary angle-closure glaucoma. Surgical management is indicated in all cases in which adequate conjunctival and scleral coverage is present. Surgical management of cases in which iris tissue prolapses through a scleral laceration but is covered by the intact conjunctiva should still be considered when the scleral wound is relatively large because of future extension of the scleral wound and progressive uveal prolapse with blunt force, which may also lead to progressive PAS formation and secondary glaucoma.
Fig. 2.4
Iris prolapse
Topical and systemic antibiotics should be considered on presentation depending on the extent, length of time, and other ocular risk factors for infection, including consideration of system risk factors such as a compromised immune system. Intracameral antibiotics may be administered intraoperatively to minimize the risk of endophthalmitis. The surgical technique employed depends on the location of the incarcerated iris tissue, anterior chamber depth, duration of prolapse, and viability of the prolapsed iris tissue. Cases in which the location of iris prolapse is peripheral and the anterior chamber is relatively formed can be managed with intracameral administration of mitotic agents (e.g., acetylcholine) through a side port incision with gentle stroking of the prolapsed iris tissue into the eye. Conversely, intracameral injection of mydriatic agents (e.g., epinephrine) may help relieve a small, central iris prolapse. Such simple maneuvers may reposition the prolapsed iris in situ without unnecessary intraocular manipulation.
The intracameral injection of viscoelastic agents through a paracentesis incision to mechanically dislodge and reposit the prolapsed iris tissue into the anterior chamber with or without the aid of a cyclodialysis spatula can be attempted when pharmacologic agents alone fail. Care should be exercised to not exert undue force on the iris root which can result in iatrogenic iridodialysis.
When iris prolapse is relatively long-standing (e.g., >36–48 h), the prolapsed iris tissue should be carefully examined for signs of necrosis or epithelialization. Any unviable iris tissue should be excised without pulling excessively on viable iris. Closure of the resultant iris defect is usually done to avoid monocular diplopia and can be performed utilizing the technique used for traumatic iris lacerations. Globe integrity is then restored by suturing the corneal, limbal, scleral, or corneoscleral wound closed.
2.4.5 Traumatic Iridodialysis
Iridodialysis represents detachment of the iris root from its ciliary insertion (Fig. 2.5). Iridodialysis can result from blunt or penetrating ocular trauma or be inflicted iatrogenically during intraocular surgery. Small iridodialyses or those adequately covered by the upper eyelid are usually asymptomatic. Symptoms of larger iridodialyses include monocular diplopia, glare, and cosmetic disfigurement. Iridodialysis can coexist with other traumatic ocular injuries, including lens subluxation/dislocation and/or vitreous prolapse.
Fig. 2.5
Iridodialysis
When small, iridodialysis can be managed with frequent instillation of mydriatic eye drops (e.g., atropine) and/or dark sunglasses to reduce light-induced miosis. These measures may result in spontaneous reattachment [7]. Several surgical techniques have been described to correct large iridodialyses. Any vitreous strands prolapsing through the iridodialysis defect should be cut using anterior vitrectomy through a limbal approach prior to suture placement. The most widely used techniques utilize the McCannel technique (Fig. 2.6) [8, 9]. In one modification of the technique, a conjunctival peritomy is made, followed by placing several evenly spaced, full-thickness 1-mm-wide scleral incisions using a microvitreoretinal (MVR) blade, 1 mm behind the limbus along the circumference of the iridodialysis. Viscoelastic agents are injected through a corneal side port incision in order to push the peripheral edge of the iris distally. Iris hooks may be used if the peripheral iris edge has retracted too far centrally. A long needle with a permanent 10–0 polypropylene suture is then passed through one a previously made sclerotomy to catch the peripheral iris edge and is then externalized through a limbal side port incision or another sclerotomy. The 2 suture ends are externalized using a hook (Bonds or a Sinskey) through a third, central side port and tied together extraocularly, cut flush, and then reposited intraocularly. The procedure can be repeated as necessary depending on the size of iridodialysis. All sclerotomies are then sutured closed.
Fig. 2.6
McCannel iris suture technique. (a). Creation of 2 opposing side ports using MVR blade, passage of a single-armed 10-0 suture through the 2 edges of iris, and cutting off needle. (b). Exteriorization of the 2 suture ends (c). Suture ends tied extraocularly and cut flush. (d). Sutured iris ends reposited intraocularly
Another popular technique also involves placing several (at least 2) evenly spaced sclerotomies with the MVR blade 1-mm behind the limbus. A long single-armed needle with a permanent 10–0 polypropylene suture is then passed through a limbal incision across the pupil from the site of iridodialysis to catch the peripheral edge of the iris with the needle tip and exits through a previously made sclerotomy. The other end of the suture is then externalized through the adjacent scleral incision. The needle is subsequently cut, and the two ends of the suture are tied extraocularly over the sclera and trimmed and the knot internalized. The procedure can also be repeated to address the size of iridodialysis, and all sclerotomies are sutured closed.
2.4.6 Traumatic Aniridia
Complete avulsion of the iris may occur in open globe trauma mostly due to a severe blunt trauma but may less frequently occur secondary to penetrating trauma [10]. The avulsed iris may be found retracted in the anterior chamber, occluding the angle, underneath the conjunctiva after escaping through a penetrating wound, or not be found inside or around the eye. Traumatic aniridia may occur alongside other ocular injuries, including lens subluxation/dislocation, anterior chamber angle damage, late PAS formation, and glaucoma (Fig. 2.7).
Fig. 2.7
Traumatic aniridia
Correction of traumatic aniridia depends on whether cataract extraction or lensectomy will be undertaken. If no lens surgery is planned, the use of opaque, iris-print contact lenses is a suitable option. Surgical correction of traumatic aniridia usually involves the placement of an aniridia or a black diaphragm lens after lensectomy or cataract extraction in the sulcus, with the lens haptics placed in the bag or in the sulcus. These lenses may also be sulcus sutured or glued. Although the use of these lenses effectively reduces glare and improves cosmetic appearance, complications such as corneal decompensation, glaucoma, and decentration are commonly encountered [11]. Many other types of prosthetic iris devices (PIDs) are available, including iris-lens diaphragm PIDs, endocapsular capsular tension ring (CTR)-based PIDs, and customized artificial irides [12].
Tattooing of the mid-corneal stroma is a less popular option and, although can eliminate visual disturbances associated with traumatic aniridia, often has a poor cosmetic appearance, and eye color cannot be made to match that of the contralateral iris. It is usually reserved for blind eyes for cosmetic purposes and is rarely indicated in eyes with good visual potential or for elimination of glare symptoms.
2.4.7 Traumatic Ciliary Body Injury
Traumatic ciliary body injury can occur as a result of an open or closed globe injury and may result in iridocyclitis, traumatic hypotony, ciliary body detachment, ciliary body damage, or cyclodialysis cleft. It can also be associated with a range of other ocular injuries, including trauma to the corneoscleral shell, crystalline lens, iris, and/or posterior segment structures.
Ocular hypotony is often thought of as an intraocular pressure (IOP) less than 6.5 mmHg [13]. However, many of the complications of hypotony often do not manifest until the IOP is 4–5 mmHg or less [14]. Complications of ocular hypotony include reduced visual acuity, corneal edema and striae, shallow anterior chamber, cataract formation, choroidal effusion or hemorrhage, exudative retinal detachment (ERD), hypotony maculopathy, optic disk edema, and, eventually, phthisis bulbi [15–17].
The pathophysiology of traumatic hypotony is not completely understood and may at times be difficult to precisely determine. However, traumatic hypotony can generally result secondary to an imbalance between aqueous humor production and filtration and may be transient or persistent [13, 18, 19]. Excessive aqueous drainage can occur secondary to wound leak, ciliary body detachment, or cyclodialysis cleft, while reduced aqueous production may occur in cases of intraocular inflammation/iridocyclitis or ciliary body damage [19].
Wound leak due to open globe injuries secondary to blunt or penetrating injuries is common. It is an important differential diagnosis of traumatic hypotony that should be ruled out before other causes of hypotony are considered. A fluorescein strip Seidel test can be used to confirm the presence of a leak when the source of a presumed leak could not be easily identified. Management of a wound leak involves prompt, timely surgical closure of the wound to restore globe integrity, reverse hypotony, and minimize the risk of endophthalmitis. However, minimally leaking or self-sealing small full-thickness wounds may be managed conservatively with pressure patching or bandage contact lens placement, in addition to topical administration of aqueous suppressants, such as carbonic anhydrase inhibitors (CAIs) and β-blockers. Surgical closure of lacerations that are located far posteriorly (i.e., posterior to the equator) is difficult, and conservative, watchful management should be considered.
When an open globe is ruled out and no wound leak is presumed to be present, other potential causes of hypotony, such as cyclodialysis cleft and ciliary body detachment, should be considered. Traumatic ciliary body detachment usually occurs together with choroidal detachment (ciliochoroidal detachment) and is commonly associated with hypotony, breakdown of the blood-ocular barrier, and iridocyclitis. It may also coexist with a cyclodialysis cleft. Ciliochoroidal detachment is thought to reduce aqueous humor production. However, the reduction in aqueous outflow maybe attributed to concurrent iridocyclitis rather than ciliary body detachment per se [19]. The diagnosis can be made by observation of anterior choroidal detachment using binocular indirect ophthalmoscopy, B-scan ultrasonography, or ultrasound biomicroscopy (UBM). UBM can also precisely determine if a concurrent cyclodialysis cleft exists (Fig. 2.8). Treatment of ciliochoroidal detachment involves:
Fig. 2.8
Cyclodialysis cleft
Topical and systemic corticosteroids to treat concurrent iridocyclitis.
Topical cycloplegic agents (e.g., 1 % atropine two to three times daily).
Systemic carbonic anhydrase inhibitors (CAIs) may help improve suprachoroidal fluid absorption [19].
Surgical treatment if no response to medical regimen for 3–4 weeks, with flat anterior chamber and/or PAS formation.
Surgical treatment of a ciliochoroidal detachment by means of supraciliary/suprachoroidal fluid drainage is achieved by creating a fornix-based conjunctival flap, followed by the dissection of a partial-thickness scleral flap extending over the supraciliary and the suprachoroidal spaces [20]. A stab incision is then made into the supraciliary space, and fluid is subsequently drained. Multiple incisions are usually made. The ciliary body is sutured to the scleral spur using a permanent 10–0 polypropylene or nylon suture, if a cyclodialysis cleft is also identified preoperatively.
A cyclodialysis cleft typically results from a closed globe injury caused by significant blunt shear force trauma and represents disruption of the insertion of meridional ciliary muscle fibers into the scleral spur [21]. The cleft results in the creation of an abnormal aqueous humor drainage pathway into the suprachoroidal space causing hypotony. Cyclodialysis clefts are commonly associated with iridocyclitis and aqueous flare, which may hinder accurate measurement of aqueous production [19]. The earlier concept attributing hypotony associated with cyclodialysis clefts to reduced aqueous humor production is challenged, since eyes with a cyclodialysis cleft and no aqueous flare were shown to have normal aqueous outflow as measured by fluorophotometry [22]. Sudden closure of cyclodialysis clefts may cause a rapid, severe rise in intraocular pressure (IOP) which needs to be observed closely in the acute postoperative period [23]. However, a cleft may reopen upon using miotic agents, and IOP may again fall to hypotonous levels [24].
Clinical diagnosis of cyclodialysis clefts is challenging, given the softness of the eye, associated corneal edema, and occasionally trauma hyphema, which may render gonioscopy very difficult [22, 25]. Ultrasound biomicroscopy (UBM) and anterior segment optical coherence tomography (AS-OCT) have therefore been increasingly utilized in the diagnosis of this condition. Sometimes an occult cleft may be present, and dynamic testing with indentation to open a cleft while imaging a cleft or viewing through a gonioprism is needed to identify the presence and extent of a cleft. Identifying the location and extent of the cleft is crucial to formulating a management plan, since multiple clefts may be present, and overlooking one of them may warrant a secondary therapeutic intervention [25].
Small clefts (less than 2–3 h) may respond to a 6–8-week course of cycloplegic-mydriatic agents (e.g., 1 % atropine twice daily), since cycloplegia relaxes the ciliary muscle, allowing its apposition to the sclera [15, 21, 23]. Reduction or elimination of corticosteroids, when feasible, may also induce an inflammatory reaction that may facilitate ciliary muscle adhesion to the sclera [26].
When pharmacologic treatment fails to achieve closure of the cyclodialysis cleft, a number of minimally invasive, nonsurgical procedures can be tried, including argon and diode laser photocoagulation, transscleral diathermy, and cryotherapy [25–33]. These treatments generate inflammation that may help scar the cleft closed. Although a reemergence of interest in some of these techniques exists, strong evidence of their safety, efficacy, and reproducibility is lacking [25].
Surgical repair is the treatment modality of choice for medium to large-sized clefts after initial less invasive modalities have elicited an insufficient response [34]. Many surgical techniques have been developed to achieve cyclodialysis cleft closure. A commonly used technique involves marking of the preoperatively determined cleft location; creation of peritomy; cutting of a partial-thickness scleral flap, followed by passing a needle with 9–0 or 10–0 polypropylene (Prolene) or nylon suture through the scleral bed to engage; and reattachment of the ciliary body to the sclera to surgically close the cleft (Fig. 2.9).
Fig. 2.9
Surgical repair of cyclodialysis cleft
2.4.8 Traumatic Lens Injury
Mechanical ocular trauma can damage the crystalline lens by inducing loss of transparency (cataract), loss of position (subluxation, dislocation, or extrusion), or both (Fig. 2.10a, b). Traumatic cataract can result secondary to both blunt and penetrating mechanical ocular injuries and demographically affects patients of all ages, with 53 % of patients falling between 7 and 30 years of age [35]. Male patients are four times more often affected than are female patients [35]. Definitive treatment of traumatic cataract or lens subluxation/dislocation, like that of all other forms of crystalline lens pathology, is surgical.
Fig. 2.10
(a) Traumatic lens subluxation and (b) traumatic lens dislocation into the anterior chamber
Although surgical extraction of age-related cataract is relatively simple and carries a great success rate, surgical treatment of traumatic cataract can be more technically challenging, and outcomes are generally less favorable depending on the amount and type of trauma. This is mainly due to:
Reduced visibility: with cloudy media (corneal laceration, intense inflammatory reaction in the anterior chamber, hyphema, intraocular foreign body)
Disruption of globe integrity in open globe injuries
Difficult wound construction: due to loss of anterior chamber volume and uveal prolapse
Difficult capsulorhexis: traumatic capsular injury, loss of contrast due to vitreous hemorrhage, loose zonular support, and poor view with corneal edema
Difficult nucleus disassembly: loose zonular support, lens subluxation, and lens dislocation
Concomitant injury to other anterior segment structures: poor pupil dilation, iris laceration, and iridodialysis
Vitreous prolapse: either preoperatively or as an intraoperative complication
Required use of often unfamiliar devices/instrumentation: iris retractors, capsular tension rings, vitrectomy instrumentation, and iris-fixated or scleral-fixated intraocular lenses (IOLs)
Preoperative evaluation of traumatic cataract should therefore aim at determining:
Globe integrity status: open globe vs. closed globe injury. Determining if there is a corneal, limbal, or scleral laceration (or any combination of these) that must be addressed before management of the traumatic cataract is a critically important step in the evaluation of these cases. Care must be taken to avoid overlooking occult scleral lacerations that may be obscured by subconjunctival hemorrhage or rectus muscle insertions, especially in the presence of conjunctival lacerations.
Visual significance of cataract: this can be difficult to determine in the presence of cloudy media (cornea, anterior chamber, or vitreous) or retinal pathology. Lens opacities that are off the visual axis generally induce less vision loss than do more central opacities.
Intraocular pressure in closed globe injuries.
Anterior chamber status: lost volume, fibrin, hyphema, lens material, or vitreous prolapse.
Anterior capsule: intact vs. injured/torn.
Lens clarity: is the lens clear or cataractous (total, membranous, cortical, white soft, or rosette shaped)? Is a Vossius ring present?
Lens location: in place, anteriorly dislocated in the anterior chamber, posteriorly dislocated in the vitreous cavity, or extruded extraocularly. Posteriorly dislocated crystalline lenses may be surgically treated by pars plana vitrectomy and lens fragmentation.
Lens integrity: is the lens fragmented or one piece? Has the lens capsule been violated?
Posterior capsule integrity. This is very important in surgical planning since cases in which the posterior capsule is breached are generally managed with pars plana lensectomy and vitrectomy. If preoperative determination of posterior capsule integrity is not possible, intraoperative assessment under the surgical microscope can sometimes be achieved.
Zonular support: is the lens held firmly in place or is there iridodonesis/phacodonesis? Location of weak zonular support should be determined when possible.
Status of the iris, angle, and ciliary body: iris laceration, iridodialysis, angle recession, or cyclodialysis.
The presence of an intraocular foreign body (IOFB) or an intralenticular foreign body.
Pupil reaction/dilation.
Retina/vitreous status: vitreous prolapse, vitreous hemorrhage, retinal breaks, retinal hemorrhages, or retinal detachment. If adequate fundus examination cannot be attained, diagnostic B-scan ultrasonography should be performed with extreme care if loss of globe integrity is a concern.
Diagnostic B-scan ultrasonography, computed tomography (CT) scan, and newer imaging technologies such as Scheimpflug imaging can be used in cases in which the status of the lens, posterior capsule integrity, or the presence of an intralenticular foreign body (Fig. 2.11) cannot be determined by slit lamp biomicroscopy due to corneal laceration, corneal edema, anterior chamber fibrin, hyphema, or ineffective pupil dilation [36–39], although their diagnostic accuracy is questioned and certain artifacts can be misleading [40, 41].
Fig. 2.11
Intralenticular foreign body
2.4.8.1 Timing of Surgery
Primary cataract surgery to address traumatic cataract and/or lens subluxation/dislocation has certain advantages over secondary surgery, including:
Faster visual rehabilitation: particularly in children in whom development of amblyopia is a major concern and in patients whose occupations require faster regain of visual acuity
Earlier elimination of lens-induced inflammation: particularly when the anterior lens capsule has been breached
Avoidance or definitive treatment of lens-induced intraocular pressure (IOP) elevation or glaucomas including phacomorphic, phacoanaphylactic, lens particle, or lens subluxation/dislocation-associated (e.g., pupillary block) glaucomas
Elimination of refractive fluctuations resulting from the instability of subluxated lenses
Allowing prompt examination of, or future surgical intervention involving, the posterior segment
Elimination of undue vitreous traction on the retina when vitreous prolapse or traction is present that may lead to a retinal detachment
However, surgery may be deferred until certain surgeon-related or center-related factors are addressed (e.g., availability of a more experienced surgeon able to undertake technically challenging techniques, trained support personnel, or special instrumentation that may not be available to the surgeon in emergent surgeries that are performed outside normal working hours such as vitrectomy, capsular tension rings, or special IOLs). Surgery is also better deferred if the cataract is presumed to be visually insignificant, particularly in the absence of coexisting ocular injuries requiring surgery. However, traumatic cataracts can be stationary or progressive (particularly in the presence of an intralenticular foreign body due to siderosis) [42, 43], and regular follow-up is required to rule out progression of traumatic cataracts initially considered visually insignificant.
2.4.8.2 Type of Surgery/Surgical Technique
Primary closure of globe lacerations (corneal, limbal, scleral, or corneoscleral), when present, is the first step in the management of traumatic cataract, since a formed globe is necessary for safe cataract removal. Constructing a separate incision for the removal of cataract (clear corneal, limbal, scleral, or pars plana) is preferred to utilizing the existing traumatic corneal wound to avoid inflicting damage to the endothelium or inducing Descemet’s detachment [44]. Liberal use of ophthalmic viscoelastic devices (OVDs) or the use of an anterior chamber maintainer should be employed to keep the globe formed at all times and to avoid potentially devastating complications such as suprachoroidal hemorrhage (SCH). The anterior chamber should be washed to remove hyphema to improve the view, and any floating lens particles should be removed. Anterior chamber vitrectomy should also be performed when vitreous strands are visible anterior to the crystalline lens plane. The pupil should be dilated using iris retractors or pupil-dilating (e.g., Malyugin) rings if the pupil is not readily and sufficiently dilated, and capsular staining should be considered to improve the view for capsulorhexis.
Important factors to consider when determining the method of cataract removal are:
- 1.
Amount of zonular support
- 2.
Posterior capsule integrity
- 3.
Density of the cataract
- 4.
View of the cataract
In cases in which zonular support is deemed to be sufficient for safe removal of the cataract through an anterior (limbal) approach, cataract can be removed using manual extracapsular cataract extraction (ECCE), phacoemulsification, or vitrectomy. Capsulorhexis can be challenging in the traumatic cataract. Minimal downward pressure on the lens and compression of the lens should be carried out using a pair of capsulorhexis (e.g., Utrata) forceps or a cystotome needle in order to avoid further weakening of the zonules. The capsulorhexis should start away from the presumed area of zonular weakness. Partial capsulorhexis may be done, followed by, when necessary, insertion of capsule retractors to support the area of zonular loss, before capsulorhexis is safely completed. Capsular tension rings or ring segments can be used either after performing capsulorhexis or prior to nuclear disassembly in phacoemulsification. Capsular microscissors (which insert through a paracentesis) may be used if the anterior capsule is torn and the direction of tear does not allow safe redirection of the capsular flap to achieve a continuous, curvilinear capsulorhexis to avoid extension of the anterior capsule tear. Capsular staining using trypan blue dye under an air bubble should be used in traumatic cataracts where adequate visibility of the capsule cannot be achieved, due to the lack of a contrasting red reflex due to either a hard cataract, vitreous hemorrhage, or milky white traumatic cataract.
Phacoemulsification (with low vacuum and aspiration settings to avoid anterior chamber size fluctuation and prevent further zonular damage) [45] is the preferred technique when the posterior capsule is intact and adequate zonular support is present due to its less traumatic nature and faster visual recovery. Manual ECCE or slow-motion phacoemulsification can be carefully attempted if the status of the posterior capsule cannot be precisely determine in the presence of good zonular support or in the presence of a small posterior capsule rent with no vitreous prolapse. If the chamber is deep enough, supracapsular cataract extraction is also a good approach to remove the lens since this approach, with the partial prolapse of the cataract in the iris plane for phacoemulsification, reduces zonular stress with the lens being fractured outside the capsular bag.
The surgeon needs to be ready to switch to vitrectomy if vitreous prolapse is detected. Posterior-assisted levitation (PAL) using a 1-mm spatula inserted through a pars plana sclerotomy created by a microvitreoretinal (MVR) blade 3.5-mm posterior to the limbus to lift the posterior capsule-lens complex upward and resume phacoemulsification of remaining nuclear fragments may be attempted by experienced surgeons when a rent in the posterior capsule is inadvertently brought about or becomes evident or when further zonular damage is inflicted during nuclear fragmentation [46]. This technique can also be planned preoperatively in subluxated lenses thought to not be adequately fixable using capsular tension rings. Viscoelastic agents should be liberally used to return into the vitreous cavity any vitreous strands attached to the posterior capsule or prolapsing into the bag or anterior chamber if this technique is used. However, the technique is technically challenging and carries a risk of significant complications such as nuclear drop and retinal detachment. Intracapsular cataract extraction (ICCE), while can be employed in cases of significantly severed zonular support, requires the creation of a large incision and carries a high risk of suprachoroidal hemorrhage (SCH) [44].
In the presence of vitreous prolapse or a large rent in the posterior capsule, or if there is an indication of a posterior segment surgery at the time of cataract extraction, pars plana lensectomy/vitrectomy (PPLV), with the possible aid of phacofragmentation in hard nuclei, is the procedure of choice [44]. Lens removal using the vitrector has the advantage of utilizing a small incision and minimizing the risk of suprachoroidal hemorrhage (SCH). The pars plana approach, while requires special expertise and equipment, is preferred to corneal or limbal approaches when vitrectomy is planned, since it maintains corneal clarity and achieves a more complete vitrectomy behind the iris plane [44].
Age of the traumatic cataract patient is also an important determinant of the surgical technique to be employed. In young children, performing primary posterior capsulotomy and anterior vitrectomy is indicated due to the high rate of posterior capsule opacification [47, 48]. Anterior and posterior lens capsules are very elastic in young children, and standard continuous curvilinear capsulorhexis (CCC) is technically challenging. Vitrectorhexis is gaining popularity as an equally effective alternative to anterior and posterior CCC in children, with the added benefit of being faster, more predictable, and reproducible and requiring only a short learning curve [49–51]. The authors prefer using the vitrectomy system for cutting the lens matter through a limbal incision with the aid of an anterior chamber maintainer over the older irrigation/aspiration techniques for soft pediatric cataracts. A separate pars plana port is subsequently created for posterior vitrectorhexis and limited anterior vitrectomy, although suturing the sclerotomy site may be required, even with the use of 23-gauge and 25-gauge vitrectomy systems [49].
The age also determines the vitrectomy settings to be used when cutting the nuclear matter utilizing the vitrectomy system is planned. In children and young adults, using only aspiration without cutting usually suffices, with more cutting required with older patients and harder cataracts.
2.4.8.3 Intraocular Lens (IOL) Implantation
Preservation of anterior and/or posterior capsular support to allow in-the-bag or in-sulcus implantation of IOLs is an important goal of surgery in most traumatic cataract. However, achieving adequate capsular support is not always feasible, especially when the degree of zonular loss is significant or when pars plana lensectomy/vitrectomy is employed, and in some complex cases, it may be better to leave a patient aphakic and take a staged approach for refractive purposes.
When enough anterior and posterior capsular support permissive of in-the-bag IOL implantation is present, it is best to proceed with in-the-bag implantation, since the IOL-capsular bag complex is more resilient and resistant to subsequent trauma [52]. Three-piece foldable IOLs are preferred over single-piece IOLs since three-piece lenses provide more tensile strength, can provide enough support in mild degrees of zonular loss when implanted in the bag, and may afford better resistance to capsular phimosis [53–55]. Moreover, the optic of a three-piece lens can be captured in the bag with placement of the haptics in the sulcus to provide additional tensile support.
Sulcus implantation of a three-piece foldable IOL is indicated when the capsular support available is not enough to permit in-the-bag implantation of the IOL or anterior optic capture. Viscoelastic agents should be injected in the ciliary sulcus between the iris and the remaining capsular support in order to insure proper placement of the IOL optic and haptics in the sulcus. Central polishing or removal of the capsular support tissue is recommended in such cases [56].
If no enough capsular support permissive of IOL implantation in the bag or in sulcus or when such positioning may result in a significant IOL tilt with or without the use of capsular tension rings, the use of an angle-supported anterior chamber IOL, sulcus-sutured or glued posterior chamber IOL, or iris-fixated IOL is indicated following anterior vitrectomy. The visual outcome achieved using these techniques is generally comparable [57].
Angle-supported anterior chamber IOLs are implanted in close proximity to the posterior corneal surface. Therefore, they have the potential for inducing corneal decompensation and precipitating pseudophakic bullous keratopathy (PBK), especially when the older model is used [58, 59]. It is important that the haptics are well seated in the angle to minimize PAS and effects on the cornea. These types of IOLs in younger patients or in patients in whom the axial length and/or anterior chamber depth (ACD) is relatively small may have greater long-term complications.
Various techniques for fixating IOLs to the ciliary sulcus have been described. Sutured scleral fixation of IOLs with specialized haptics harboring suture eyelets can be achieved using double-armed permanent 8-0 or 9-0 polypropylene sutures and long straight or curved hollow needles (Fig. 2.12a–h) [57]. Most techniques utilize scleral flaps, tunnels, or grooves to provide access to the ciliary sulcus, bury the knots, and guard against suture erosion/exposure. However, difficult centration, IOL tilt, and rotational and anteroposterior instability are potential pitfalls of sulcus-sutured IOLs and may warrant secondary surgical intervention. A peripheral iridectomy using the vitrectomy system is recommended to prevent pupillary block glaucoma. This is achieved by introducing the vitrector into the anterior chamber at the 12 or 9 o’clock position with the port facing down, cutting rate initially set to zero, and an aspiration pressure of 300 mmHg. Once occlusion is achieved, the cutting speed is carefully increased until a full, patent iridectomy is made. In cases of traumatic coexisting aniridia, a black diaphragm tinted IOL (Fig. 2.13) may be sutured to the sulcus [60].
Fig. 2.12
(a–h) A 38-year-old man underwent initial vitrectomy for traumatic cataract extraction, IOFB removal, and retinal detachment with C3F8 filling. The BCVA was 0.6 after vitrectomy. The secondary sulcus-fixed foldable IOL implantation through a clear corneal incision with 25-gauge infusion was performed 3 months after initial vitrectomy. The UCVA was 0.5, and BCVA was 0.6 at the final follow-up postoperatively. (a) 25-gauge infusion cannulae were created and fixed 3-mm from the corneal limbus at inferior temporal site firstly. And the infusion was kept turned on until the completion of the surgery. (b) The triangular lamellar scleral flaps were made with the corneal limbus as base (black arrow) at 3 and 9 o’clock, respectively, for protecting the IOL suture. (c) The suture needle (10–0 polypropylene) entered the eye under the sclera flap at 9 o’clock and was relayed into a 1-mL syringe needle in the posterior chamber which entered the eye at 3 o’clock. (d) A 3.0-mm clear corneal incision was made, and the 10–0 polypropylene suture was pulled out through the incision. (e) The foldable lens was put in the IOL injector and was pushed until the front haptic just exposed from the cartridge. Then the front haptic was tied by 10–0 polypropylene for preparing fixation. (f) The foldable lens was pushed into the posterior chamber with the posterior haptic left out of the incision. (g) The posterior haptic was tied by 10–0 polypropylene for preparing fixation. (h) The foldable IOL was fixed by suturing in the sulcus with a well-centered position
Fig. 2.13
A black diaphragm tinted IOL
Sutureless sulcus fixation of IOLs can be achieved with the utility of scleral flaps, limbus parallel tunnels, or both [57]. Sulcus-glued IOLs (Fig. 2.14) are becoming exceedingly popular and are thought to have better stability and fewer postoperative complications than do sulcus-sutured IOLs [61–65]. The technique of the procedure involves insertion of an infusion cannula or an anterior chamber maintainer, creation of two limbal-based, partial-thickness scleral flaps 180° apart, and performing two sclerotomies underneath the flaps 1.5-mm from the limbus [66]. This is followed by limited pars plana or limbal anterior vitrectomy to remove all vitreous strands in the anterior chamber, anterior vitreous cavity, and sclerotomy sites. Two scleral tunnels are then created in the edge of the scleral bed underlying the flaps adjacent and parallel to the limbus and following the curvature of the IOL haptics. These tunnels are created in such a way to allow tucking of the IOL haptics once externalized. The IOL is then introduced through a limbal-based incision and the two haptics externalized through the sclerotomies and tucked into the limbal scleral tunnels. Proper IOL centration is ensured by adjusting the tucked length of each haptic. Fibrin glue is then applied over the haptics underneath the scleral flaps which are subsequently repositioned. The infusion cannula or the anterior chamber maintainer is then removed, and the overlying conjunctiva is closed using the same glue. A glued aniridia IOL may also be used in cases of coexisting aniridia [67].
Fig. 2.14
Sulcus-glued IOLs
Iris-claw lenses (e.g., Artisan/Verisyse “rigid” and Artiflex “foldable” lenses, Ophtec BV, Groningen, the Netherlands) are popular phakic IOLs used in refractive surgery in patients with high degrees of ametropia (Fig. 2.15) [68–70]. They have, however, been widely used for the correction of aphakia in the absence of sufficient capsular support in adults and children [71–73]. The technique of implantation of iris-claw lenses entails creation of an appropriately sized clear corneal incision centered at the 12 o’clock position and two side ports aligned with the enclavation sites, injection of a miotic agent, filling the anterior chamber with a cohesive viscoelastic, and introduction of the lens into the anterior chamber through the main wound. The lens is then rotated 90° so that the iris claws are horizontally placed in line with the side ports. Iris enclavation of the lens claws is then achieved through the two side port incisions, where a knuckle of iris tissue is captured by the claws on either side of the lens. A peripheral iridectomy is then made at the 12 o’clock position using the vitrectomy system as explained above. Although iris-claw lenses are considered effective in achieving the desired refractive outcome, the relatively high rate of endothelial cell loss remains a major concern [71, 74]. The retro-enclavation of these lenses to the posterior surface of the iris in aphakic eyes has thus become an attractive alternative to anterior iris enclavation, achieving a comparable refractive outcome and inducing less endothelial cell loss [75–77]. Other complications that could result from iris-claw lens implantation include trauma to the iris vessels with subsequent intraocular bleeding, interference with pupillary dilation, dyscoria, and peripheral anterior synechiae formation [57, 78, 79].
