- Email: [email protected]
Vitrectomy-assisted phacoemulsification for lenticular coloboma
156
TECHNIQUE
Vitrectomy-assisted phacoemulsification for lenticular coloboma Ashvin Agarwal, MS, Priya Narang, MS, Amar Agarwal, MS, FRCS, FRCOphth
We describe a technique to prevent continuous vitreous hydration during phacoemulsification in eyes with lenticular coloboma. The hydration results from communication between the anterior and posterior chambers from the edges of the colobomatous defect. To avoid this, a valved trocar is placed at the pars plana site around the area of the lenticular defect, which allows a limited dry vitrectomy during phacoemulsification. Intermittent vitrectomy with a moderate cutting rate and low vacuum parameters accompanied by temporary halting of
C
ataract surgery in eyes with lenticular coloboma can present preoperative and intraoperative technical challenges because of the higher risk for complications.1–6,A The failure of zonular fibers to develop in the area of coloboma increases the risk for vitreous loss and poor pupillary dilation, which is often compounded by an eccentric pupillary aperture that makes phacoemulsification more complex. Phacoemulsification is often performed with the profuse use of a dispersive ophthalmic viscosurgical device (OVD) to tamponade the zonular defect, and the machine parameters are set at low fluid flow to prevent the excess fluid around the edges of coloboma from seeping into the vitreous.7 In cases of lenticular coloboma associated with cataract, we propose an intermittent vitrectomy-assisted phacoemulsification technique to prevent vitreous hydration and prolapse from the edges of the coloboma into the anterior chamber, thereby limiting the complication rate and facilitating the phacoemulsification procedure (Figure 1). SURGICAL TECHNIQUE The extent of lenticular coloboma is assessed (Figure 2, A) and in the area of maximum defect, a valved 23-gauge trocar is introduced (Figure 2, B) from the pars plana site at 3.0 mm from the limbus. A 2.8 mm corneal tunnel incision is framed followed by side-port incisions and placement of iris retractors that permit the enlargement of an eccentric nondilating pupillary aperture. Trypan blue is injected to stain the anterior capsule, and capsulorhexis is
the phacoemulsification procedure prevents vitreous herniation into the anterior chamber and limits the extension of zonular compromise, facilitating safe phacoemulsification with appropriate capsule expansion and fixation devices and implantation of an intraocular lens. J Cataract Refract Surg 2017; 43:156–161 Q 2017 ASCRS and ESCRS Online Video
performed (Figure 2, C) followed by gentle hydrodissection. Because of the zonular absence in some quadrants, use of low-flow rate parameters and a reduced infusion bottle height are preferred along with a chopping technique, avoiding maneuvers that could strain the remaining zonular fibers near the lenticular defect. A limited dry vitrectomy is performed with a 25-gauge vitrectomy probe introduced from the pars plana site to reduce the vitreous bulge if noted before the phacoemulsification procedure begins. During phacoemulsification (Figure 2, D), as the fluid surges into the posterior chamber after crossing the lenticular defect, the vitreous swells from the hydration and the anterior chamber depth decreases. The phacoemulsification probe is withdrawn, the vitrectomy probe is introduced again (Figure 2, E) from the pars plana site, and a limited dry vitrectomy is performed with a moderate cutting rate and low vacuum in a way to ensure that the tip of the cutter is constantly seen and at no time goes beneath the lens and inadvertently creates a capsule opening. Post-vitrectomy, as the relative depth of the anterior chamber increases, the vitrector is withdrawn (Figure 2, F), the valve is placed on the trocar, and the phacoemulsification probe is reintroduced. This step of alternative phacoemulsification with vitrectomy is repeated until the entire nuclear fragment is completely emulsified. A standard capsular tension ring (CTR) (Figure 3, A) is placed in the capsular bag and irrigation/aspiration (I/A) performed (Figure 3, B). An intermittent vitrectomy is performed if the anterior chamber shallows again and a vitreous bulge occurs during the surgical
Submitted: July 8, 2016 | Final revision submitted: October 10, 2016 | Accepted: October 10, 2016 From Dr. Agarwal's Eye Hospital & Research Centre (Ashvin Agarwal, Amar Agarwal), Chennai, and the Narang Eye Care & Laser Centre (Narang), Ahmedabad, India. Corresponding author: Amar Agarwal, MS, FRCS, FRCOphth, Dr. Agarwal's Eye Hospital and Eye Research Centre, 19, Cathedral Road, Chennai-600 086, India. E-mail: [email protected]. Q 2017 ASCRS and ESCRS Published by Elsevier Inc.
0886-3350/$ - see frontmatter http://dx.doi.org/10.1016/j.jcrs.2016.10.028
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
157
Figure 1. A: A case of lens coloboma with absence of zonular fibers in 1 quadrant. B: Valved trocar is introduced in the area of zonular absence. C: Regurgitation of fluid into the posterior chamber during phacoemulsification due to anteroposterior communication in the area of lens coloboma. D: Swelling of the vitreous body due to constant hydration pushing the lens diaphragm anteriorly. E: Dry vitrectomy places the lens iris diaphragm into position. F: Phacoemulsification procedure resumed.
procedure (Figure 3, C). A 3-piece foldable intraocular lens (IOL) (Figure 3, D) is placed in the capsular bag with the haptics directed along the axis of maximum zonular instability (Videos 1 and 2, available at http://jcrsjournal.org). The iris retractors are removed, and pupilloplasty is performed with a modified McCannel suture technique to reduce the glare and prevent diplopia (Figure 4). A 100 polypropylene (Prolene) suture is passed from limbus to limbus through the anterior chamber, engaging the edges of the iris coloboma. The suture end of the needle is cut and a Sinskey hook or an end-opening forceps is used to pull the suture ends that are then retracted out of the anterior chamber from the corneal incision. Both ends are tied,
and a knot is created that results in approximation of the iris margins. Stromal hydration is done to seal all the corneal incisions, and the trocar is removed. In cases of large lenticular colobomas, capsular hooks can be used to stabilize the capsular bag during phacoemulsification and a Cionni ring or a capsular tension segment (CTS) can be placed to fixate the bag depending on the surgical scenario. Results
The technique was performed in 9 eyes that had a preoperative corrected distance visual acuity (CDVA) of hand movements close to the face with accurate projection of
Figure 2. A: A case of right eye lenticular coloboma associated with an iris coloboma in the inferior quadrant. B: Introduction of valved trocar into the inferotemporal quadrant area. C: Creation of superotemporal corneal incision. Use of iris hooks to dilate the pupil and creation of capsulorhexis. D: Performance of phacoemulsification. E: Pause in phacoemulsification procedure due to shallowing of the anterior chamber; performance of dry vitrectomy. F: Resumption of phacoemulsification as the anterior chamber deepens.
Volume 43 Issue 2 February 2017
158
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
Figure 3. A: Placement of CTR in the capsular bag. B: Irrigation/aspiration. C: Performance of dry vitrectomy to handle the vitreous hydration. D: Placement of a 3-piece foldable IOL in the bag.
light (Table 1). Vitreous hydration was successfully managed by an intermittent limited vitrectomy done from the pars plana site. No incidence of zonular defect extension into the anterior chamber due to vitreous herniation was noted, and phacoemulsification was performed and completed in all eyes. No intraoperative complications related to the vitrectomy procedure were noticed. The IOL was placed in the capsular bag in all eyes, but the final CDVA was suboptimal in 2 eyes because of the presence of associated fundal coloboma.
Postoperatively, all eyes achieved the expected level of CDVA consistent with the preexisting retinal pathology (Table 2). Pupilloplasty was performed, and all eyes had a centrally positioned pupillary aperture. DISCUSSION Congenital coloboma is a rare eye disorder,8 and any study of surgical outcome in eyes with cataract and congenital coloboma is limited. Studies highlighting the management of lens coloboma have been published,9–11
Figure 4. A: Pupilloplasty with a modified McCannel suturing technique. Engagement of tip of 10-0 polypropylene needle and iris tissue edges. B: Suture ends retracted from the anterior chamber through the main corneal incision. C: The knots are tied and the ends of the knots approximated. D: Knot in place in anterior chamber. Both edges of the iris margins are well approximated.
Volume 43 Issue 2 February 2017
159
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
Table 1. Patient demographics. Case
Age (Y)
Type of Coloboma with Cataract
Associated Features
1
41
Iris, lens
None
2
53
Iris, lens
None
3
47
Iris, lens
None
4
35
Iris, lens
None
5
49
Iris, lens
None
6
56
Iris, lens
None
7
45
Iris, lens, choroid
Microphthalmos
8
48
Iris, lens
None
9
39
Iris, lens, choroid
Nystagmus
and the development of phacoemulsification techniques and CTRs have improved the surgical results in eyes with lenticular coloboma.1–6 In cases of coloboma, it is recommended that phacoemulsification be performed at low fluid settings to prevent a surge of fluid into the vitreous cavity.7 Isolated lenticular colobomas are rare to spot and are usually associated with an iris coloboma.12 The presence of an iris defect adds to the tendency of fluid to surge into the vitreous cavity, which would otherwise act as a restricting factor. Tamponading the zonular defect is often performed with a dispersive OVD because it exhibits superior retention and prevents vitreous prolapse from around the edges of the coloboma. In eyes with a crowded anterior segment and positive pressure, a pars plana vitreous tap with an automated vitrectomy has been suggested to facilitate phacoemulsification.13 A prior pars plana vitreous tap has also been recommended to create adequate working space for cataract surgery in cases of lens coloboma and microphthalmia.A This maneuver initially deepens the anterior chamber, but when the phacoemulsification
procedure is being performed, vitreous prolapse or herniation occurs intraoperatively. All these issues are obviated with our technique in which performing an intermittent vitrectomy prevents the buildup of pressure in the posterior cavity due to vitreous hydration. The issue of vitreous herniation into the anterior chamber and subsequent extension of zonular dialysis were not encountered in any of our cases with the vitrectomy-assisted phacoemulsification technique because the intermittent vitrectomy was done from the pars plana site. However, it is essential to note that aggressive vitrectomy was avoided because it could make the lens more mobile and deepen the anterior chamber, making later maneuvers more difficult. In the vitrectomy-assisted phacoemulsification technique, we recommend placing a valved trocar because the valve seals the cannula opening and prevents inadvertent egress of fluid from the eye, which indirectly facilitates the phacoemulsification procedure. The placement of the trocar is also critical as it must be appropriately placed in the area of the lenticular defect. This enables the surgeon to clearly visualize the tip of the vitrectomy probe and prevents inadvertent damage to the posterior capsule. Triamcinolone can be injected into the anterior chamber to ascertain the presence of vitreous strands around the area of lenticular defect, and adequate vitrectomy can then be done. A CTR was placed in our 9 cases to distend the capsular bag and limit the passage of excessive fluid behind the lens, expanding the capsular bag on the vitreous.14 It also helps to reestablish the contour of the bag for proper IOL rotation and centration.3 Zonular absence in colobomata tends to be localized and can typically be managed with a CTR, usually without the need for a sutured device.A Placement of a Cionni CTR or a CTS can be considered in cases with extensive zonular compromise, although we did not find it necessary to use these sutured devices in our cases. To prevent vitreous hydration from around the subluxated
Table 2. Visual profile and other results. Preop Snellen Acuity
4-Mo Postop CDVA
Pupilloplasty
CTR
Intraop/Postop Complication
Intermittent Vitrectomy (n)*
FU (Mo)
1
CFNF
20/40
Performed
Implanted
None
2
6
2
HM
20/40
Performed
Implanted
None
3
10
3
CFNF
20/30
Performed
Implanted
None
3
6
4
CF 1 m
20/20
Performed
Implanted
None
2
6
5
CF 2 m
20/20
Performed
Implanted
None
3
9
6
CF 1 m
20/60
Performed
Implanted
None
3
6
7
HM
20/400
Performed
Implanted
None
4
7
8
CFNF
20/60
Performed
Implanted
None
2
9
9
HM
20/200
Performed
Implanted
None
3
5
Case
CDVA Z corrected distance visual acuity; CF Z counting fingers; CFNF Z counting fingers near face; CTR Z capsular tension ring; FU Z follow-up; HM Z hand movements *Number of times performed
Volume 43 Issue 2 February 2017
160
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
quadrant of the lens, surgical techniques have been described in which an iris hook holds the iris tissue along with the anterior capsule, preventing seepage of fluid into the vitreous cavity.15 Lenticular colobomas are often associated with iris colobomas, and in these cases our technique of vitrectomy-assisted phacoemulsification offers optimal results. During phacoemulsification, capsular hooks can be used to support the capsulorhexis margin, but we did not find them necessary because in lenticular colobomas, the remaining zonular fibers are intact and provide stability to the capsular bag. This is not true in cases of subluxation, in which the residual zonular fibers can be compromised due to varied etiology, although capsular hooks can be used per the surgeon's preference. A 3-piece foldable IOL was placed in the capsular bag with the haptics oriented along the direction of zonular involvement to facilitate maximum distension of the bag with the hard haptics. Although with a CTR the direction of the haptic placement might not be significant, orienting the haptics along the axis of zonular defect might be beneficial. All these measures prevented episodes of capsular fornix aspiration into the I/A probe. Positive pressure from microphthalmos and excess fluid transition into the vitreous increases the risk for intraoperative malignant glaucoma.A In 1 of our 9 cases, microphthalmia was an associated feature of lens coloboma. As microphthalmia itself increases the surgical challenge to performing safe phacoemulsification, preoperative injection of mannitol 20% that acts as a hyperosmotic agent and dehydrates and reduces the vitreous volume was infused intravenously in a dose of 1g/kg body weight over a period of 30 minutes. We believe that microphthalmic eyes that have a high vitreous pressure will benefit from an intermittent vitrectomy that reduces the positive pressure and subsequent shallowing of the anterior chamber. In these eyes, we recommend placing the trocar 1.5 mm from the limbus because of the overall shorter length of the pars plana. In cases with associated iris defect, it is essential to reconstruct the pupil to prevent photophobia and glare and various surgical techniques to reconstruct the pupil have been described.16–20 In studies that adopted a modified McCannel suture technique,18,21 a well-centered pupillary aperture was created in the postoperative period. We think the vitrectomy-assisted phacoemulsification technique can also be used in cases of a subluxated lens because a similar sequence of events and challenges from vitreous hydration and pressure increase in the posterior chamber will be present in these cases. A pars plana intermittent vitrectomy without irrigation sufficiently expanded the anterior chamber in all cases of lenticular colobomata, facilitating a good capsulorhexis, uneventful phacoemulsification, and safe foldable IOL implantation and pupilloplasty while maintaining the advantages and safety of small-incision cataract surgery. In summary, our technique facilitates the phacoemulsification procedure and subsequent maneuvers in eyes with Volume 43 Issue 2 February 2017
lens coloboma, limiting further vitreous prolapse through the existing defect in the contour of the lens and simultaneously maintaining the integrity of the remaining zonular fibers.
WHAT WAS KNOWN There is an increased risk for intraoperative complications in eyes with lens coloboma. Fluid from the phacoemulsification procedure surges in the vitreous cavity because of the open communication from around the edges of the lenticular defect, facilitating vitreous herniation into the anterior chamber and leading to further zonular instability and zonular compromise. This often necessitates abandoning the phacoemulsification procedure.
WHAT THIS PAPER ADDS Phacoemulsification with intermittent vitrectomy from the pars plana site effectively decompresses the posterior chamber and resolves the issue of vitreous hydration and its subsequent prolapse into the anterior chamber with the associated complications. Vitrectomy-assisted phacoemulsification facilitates the phacoemulsification procedure with the effective placement of an IOL in the capsular bag along with the performance of additional procedures such as placement of a CTR, Cionni ring, or CTS as necessary.
REFERENCES 1. Nordlund ML, Sugar A, Moroi SE. Phacoemulsification and intraocular lens placement in eyes with cataract and congenital coloboma: visual acuity and complications. J Cataract Refract Surg 2000; 26:1035– 1040 2. Chaurasia S, Ramappa M, Sangwan VS. Cataract surgery in eyes with congenital iridolenticular choroidal coloboma. Br J Ophthalmol 2012; 96:138–140 3. Mizuno H, Yamada J, Nishiura M, Takahashi H, Hino Y, Miyatani H. Capsular tension ring use in a patient with congenital coloboma of the lens. J Cataract Refract Surg 2004; 30:503–506 4. Goel R, Kamal S, Khurana B, Kumar S, Malik KPS, Bodh SA, Singh M. Manual small incision cataract surgery for subluxated cataract with lens coloboma. Cont Lens Anterior Eye 2012; 35:89–91 5. Hernadez-Camarena JC, Ayup-Arguijo E, Chavez-Mondragon E, RamirezMiranda A. Surgical management and Scheimpflug analysis of an atypical lens coloboma. Case Rep Ophthalmol 2012; 3:317–320. Available at: http:// www.ncbi.nlm.nih.gov/pmc/articles/PMC3493002/pdf/cop-0003-0317.pdf. Accessed December 18, 2016 6. Kim J-H, Kang M-H, Kang S-M, Song B-J. A modified iris repair technique and capsular tension ring insertion in a patient with coloboma with cataracts. Korean J Ophthalmol 2006; 20:246–249. Available at: http://www.ncbi.nlm. nih.gov/pmc/articles/PMC2908861/pdf/kjo-20-246.pdf. Accessed December 18, 2016 € 7. Solmaz N, Onder F. Cataract surgery in a case with bilateral iridolenticular coloboma associated with microphthalmos and relative anterior microphthalmos. JCRS Online Case Rep 2014; 2:e41–e43. Available at: http:// www.jcrscasereports.com/article/S2214-1677(14)00005-2/pdf. Accessed December 18, 2016 8. Bermejo E, Martinez-Frias ML. Congenital eye malformations: clinical– epidemiological analysis of 1,124,654 consecutive births in Spain. Am J Med Genet 1998; 75:497–504 €lcker HE, Tetz MR, Daus W. Cataract surgery in eyes with colobomas. 9. Vo Dev Ophthalmol 1991; 22:94–100 10. Nixseaman DH. Cataract extraction in a case of congenital coloboma of the iris. Br J Ophthalmol 1968; 52:625–627. Available at: https://www.ncbi. nlm.nih.gov/pmc/articles/PMC506655/pdf/brjopthal00344-0049.pdf. Accessed December 18, 2016 11. Jaffe NS, Clayman HM. Cataract extraction in eyes with congenital colobomata. J Cataract Refract Surg 1987; 13:54–58
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
12. Weilder WB. Concerning congenital coloboma of the lens. Am J Ophthalmol 1922; 6:465–467 13. Chang DF. Pars plana vitreous tap for phacoemulsification in the crowded eye. J Cataract Refract Surg 2001; 27:1911–1914. Available at: http:// www.changcataract.com/pdfs/Vit_tap.pdf. Accessed December 18, 2016 14. Hasanee K, Ahmed K II. Capsular tension rings: update on endocapsular support devices. Ophthalmol Clin North Am 2006; 19:507–519 15. Sethi HS, Mayuresh NP, Gupta VS. Intraoperative intracameral pilocarpine after capsular tension ring and capsule/iris hook insertion in pediatric eyes with subluxated cataract. J Cataract Refract Surg 2016; 42:190–193 16. Watt RH. Inferior congenital iris coloboma repair and IOL implantation [letter]. J Cataract Refract Surg 1993; 19:669–671 17. Burk SE, Da Mata AP, Snyder ME, Cionni RJ, Cohen JS, Osher RH. Prosthetic iris implantation for congenital, traumatic, or functional iris deficiencies. J Cataract Refract Surg 2001; 27:1732–1740 18. McCannel MA. A retrievable suture idea for anterior uveal problems. Ophthalmic Surg 1976; 7 (2):98–103 19. Worst JGF, Los JRLI. Iris reconstruction by coloboma repair. Ophthalmic Surg 1989; 20:790–793 20. Cionni RJ, Karatza EC, Osher RH, Shah M. Surgical technique for congenital iris coloboma repair. J Cataract Refract Surg 2006; 32:1913–1916 21. Blackmon DM, Lambert SR. Congenital iris coloboma repair using a modified McCannel suture technique. Am J Ophthalmol 2003; 135:730–7322
161
OTHER CITED MATERIAL A. Miller KM, Snyder ME, Tam DY, Varma DK, Ahmed II K. Coloboma of the iris, retina, optic nerve and lens. Cataract & Refractive Surgery Today October 2010, pages 47–51. Available at: http://bmctoday.net/crstoday/pdfs/ crst1010_catsurg_complex.pdf. Accessed December 18, 2016
Disclosure: None of the authors has a financial or proprietary interest in any material or method mentioned.
First author: Ashvin Agarwal, MS Dr. Agarwal's Eye Hospital & Research Centre, Chennai, India
Volume 43 Issue 2 February 2017
TECHNIQUE
Vitrectomy-assisted phacoemulsification for lenticular coloboma Ashvin Agarwal, MS, Priya Narang, MS, Amar Agarwal, MS, FRCS, FRCOphth
We describe a technique to prevent continuous vitreous hydration during phacoemulsification in eyes with lenticular coloboma. The hydration results from communication between the anterior and posterior chambers from the edges of the colobomatous defect. To avoid this, a valved trocar is placed at the pars plana site around the area of the lenticular defect, which allows a limited dry vitrectomy during phacoemulsification. Intermittent vitrectomy with a moderate cutting rate and low vacuum parameters accompanied by temporary halting of
C
ataract surgery in eyes with lenticular coloboma can present preoperative and intraoperative technical challenges because of the higher risk for complications.1–6,A The failure of zonular fibers to develop in the area of coloboma increases the risk for vitreous loss and poor pupillary dilation, which is often compounded by an eccentric pupillary aperture that makes phacoemulsification more complex. Phacoemulsification is often performed with the profuse use of a dispersive ophthalmic viscosurgical device (OVD) to tamponade the zonular defect, and the machine parameters are set at low fluid flow to prevent the excess fluid around the edges of coloboma from seeping into the vitreous.7 In cases of lenticular coloboma associated with cataract, we propose an intermittent vitrectomy-assisted phacoemulsification technique to prevent vitreous hydration and prolapse from the edges of the coloboma into the anterior chamber, thereby limiting the complication rate and facilitating the phacoemulsification procedure (Figure 1). SURGICAL TECHNIQUE The extent of lenticular coloboma is assessed (Figure 2, A) and in the area of maximum defect, a valved 23-gauge trocar is introduced (Figure 2, B) from the pars plana site at 3.0 mm from the limbus. A 2.8 mm corneal tunnel incision is framed followed by side-port incisions and placement of iris retractors that permit the enlargement of an eccentric nondilating pupillary aperture. Trypan blue is injected to stain the anterior capsule, and capsulorhexis is
the phacoemulsification procedure prevents vitreous herniation into the anterior chamber and limits the extension of zonular compromise, facilitating safe phacoemulsification with appropriate capsule expansion and fixation devices and implantation of an intraocular lens. J Cataract Refract Surg 2017; 43:156–161 Q 2017 ASCRS and ESCRS Online Video
performed (Figure 2, C) followed by gentle hydrodissection. Because of the zonular absence in some quadrants, use of low-flow rate parameters and a reduced infusion bottle height are preferred along with a chopping technique, avoiding maneuvers that could strain the remaining zonular fibers near the lenticular defect. A limited dry vitrectomy is performed with a 25-gauge vitrectomy probe introduced from the pars plana site to reduce the vitreous bulge if noted before the phacoemulsification procedure begins. During phacoemulsification (Figure 2, D), as the fluid surges into the posterior chamber after crossing the lenticular defect, the vitreous swells from the hydration and the anterior chamber depth decreases. The phacoemulsification probe is withdrawn, the vitrectomy probe is introduced again (Figure 2, E) from the pars plana site, and a limited dry vitrectomy is performed with a moderate cutting rate and low vacuum in a way to ensure that the tip of the cutter is constantly seen and at no time goes beneath the lens and inadvertently creates a capsule opening. Post-vitrectomy, as the relative depth of the anterior chamber increases, the vitrector is withdrawn (Figure 2, F), the valve is placed on the trocar, and the phacoemulsification probe is reintroduced. This step of alternative phacoemulsification with vitrectomy is repeated until the entire nuclear fragment is completely emulsified. A standard capsular tension ring (CTR) (Figure 3, A) is placed in the capsular bag and irrigation/aspiration (I/A) performed (Figure 3, B). An intermittent vitrectomy is performed if the anterior chamber shallows again and a vitreous bulge occurs during the surgical
Submitted: July 8, 2016 | Final revision submitted: October 10, 2016 | Accepted: October 10, 2016 From Dr. Agarwal's Eye Hospital & Research Centre (Ashvin Agarwal, Amar Agarwal), Chennai, and the Narang Eye Care & Laser Centre (Narang), Ahmedabad, India. Corresponding author: Amar Agarwal, MS, FRCS, FRCOphth, Dr. Agarwal's Eye Hospital and Eye Research Centre, 19, Cathedral Road, Chennai-600 086, India. E-mail: [email protected]. Q 2017 ASCRS and ESCRS Published by Elsevier Inc.
0886-3350/$ - see frontmatter http://dx.doi.org/10.1016/j.jcrs.2016.10.028
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
157
Figure 1. A: A case of lens coloboma with absence of zonular fibers in 1 quadrant. B: Valved trocar is introduced in the area of zonular absence. C: Regurgitation of fluid into the posterior chamber during phacoemulsification due to anteroposterior communication in the area of lens coloboma. D: Swelling of the vitreous body due to constant hydration pushing the lens diaphragm anteriorly. E: Dry vitrectomy places the lens iris diaphragm into position. F: Phacoemulsification procedure resumed.
procedure (Figure 3, C). A 3-piece foldable intraocular lens (IOL) (Figure 3, D) is placed in the capsular bag with the haptics directed along the axis of maximum zonular instability (Videos 1 and 2, available at http://jcrsjournal.org). The iris retractors are removed, and pupilloplasty is performed with a modified McCannel suture technique to reduce the glare and prevent diplopia (Figure 4). A 100 polypropylene (Prolene) suture is passed from limbus to limbus through the anterior chamber, engaging the edges of the iris coloboma. The suture end of the needle is cut and a Sinskey hook or an end-opening forceps is used to pull the suture ends that are then retracted out of the anterior chamber from the corneal incision. Both ends are tied,
and a knot is created that results in approximation of the iris margins. Stromal hydration is done to seal all the corneal incisions, and the trocar is removed. In cases of large lenticular colobomas, capsular hooks can be used to stabilize the capsular bag during phacoemulsification and a Cionni ring or a capsular tension segment (CTS) can be placed to fixate the bag depending on the surgical scenario. Results
The technique was performed in 9 eyes that had a preoperative corrected distance visual acuity (CDVA) of hand movements close to the face with accurate projection of
Figure 2. A: A case of right eye lenticular coloboma associated with an iris coloboma in the inferior quadrant. B: Introduction of valved trocar into the inferotemporal quadrant area. C: Creation of superotemporal corneal incision. Use of iris hooks to dilate the pupil and creation of capsulorhexis. D: Performance of phacoemulsification. E: Pause in phacoemulsification procedure due to shallowing of the anterior chamber; performance of dry vitrectomy. F: Resumption of phacoemulsification as the anterior chamber deepens.
Volume 43 Issue 2 February 2017
158
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
Figure 3. A: Placement of CTR in the capsular bag. B: Irrigation/aspiration. C: Performance of dry vitrectomy to handle the vitreous hydration. D: Placement of a 3-piece foldable IOL in the bag.
light (Table 1). Vitreous hydration was successfully managed by an intermittent limited vitrectomy done from the pars plana site. No incidence of zonular defect extension into the anterior chamber due to vitreous herniation was noted, and phacoemulsification was performed and completed in all eyes. No intraoperative complications related to the vitrectomy procedure were noticed. The IOL was placed in the capsular bag in all eyes, but the final CDVA was suboptimal in 2 eyes because of the presence of associated fundal coloboma.
Postoperatively, all eyes achieved the expected level of CDVA consistent with the preexisting retinal pathology (Table 2). Pupilloplasty was performed, and all eyes had a centrally positioned pupillary aperture. DISCUSSION Congenital coloboma is a rare eye disorder,8 and any study of surgical outcome in eyes with cataract and congenital coloboma is limited. Studies highlighting the management of lens coloboma have been published,9–11
Figure 4. A: Pupilloplasty with a modified McCannel suturing technique. Engagement of tip of 10-0 polypropylene needle and iris tissue edges. B: Suture ends retracted from the anterior chamber through the main corneal incision. C: The knots are tied and the ends of the knots approximated. D: Knot in place in anterior chamber. Both edges of the iris margins are well approximated.
Volume 43 Issue 2 February 2017
159
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
Table 1. Patient demographics. Case
Age (Y)
Type of Coloboma with Cataract
Associated Features
1
41
Iris, lens
None
2
53
Iris, lens
None
3
47
Iris, lens
None
4
35
Iris, lens
None
5
49
Iris, lens
None
6
56
Iris, lens
None
7
45
Iris, lens, choroid
Microphthalmos
8
48
Iris, lens
None
9
39
Iris, lens, choroid
Nystagmus
and the development of phacoemulsification techniques and CTRs have improved the surgical results in eyes with lenticular coloboma.1–6 In cases of coloboma, it is recommended that phacoemulsification be performed at low fluid settings to prevent a surge of fluid into the vitreous cavity.7 Isolated lenticular colobomas are rare to spot and are usually associated with an iris coloboma.12 The presence of an iris defect adds to the tendency of fluid to surge into the vitreous cavity, which would otherwise act as a restricting factor. Tamponading the zonular defect is often performed with a dispersive OVD because it exhibits superior retention and prevents vitreous prolapse from around the edges of the coloboma. In eyes with a crowded anterior segment and positive pressure, a pars plana vitreous tap with an automated vitrectomy has been suggested to facilitate phacoemulsification.13 A prior pars plana vitreous tap has also been recommended to create adequate working space for cataract surgery in cases of lens coloboma and microphthalmia.A This maneuver initially deepens the anterior chamber, but when the phacoemulsification
procedure is being performed, vitreous prolapse or herniation occurs intraoperatively. All these issues are obviated with our technique in which performing an intermittent vitrectomy prevents the buildup of pressure in the posterior cavity due to vitreous hydration. The issue of vitreous herniation into the anterior chamber and subsequent extension of zonular dialysis were not encountered in any of our cases with the vitrectomy-assisted phacoemulsification technique because the intermittent vitrectomy was done from the pars plana site. However, it is essential to note that aggressive vitrectomy was avoided because it could make the lens more mobile and deepen the anterior chamber, making later maneuvers more difficult. In the vitrectomy-assisted phacoemulsification technique, we recommend placing a valved trocar because the valve seals the cannula opening and prevents inadvertent egress of fluid from the eye, which indirectly facilitates the phacoemulsification procedure. The placement of the trocar is also critical as it must be appropriately placed in the area of the lenticular defect. This enables the surgeon to clearly visualize the tip of the vitrectomy probe and prevents inadvertent damage to the posterior capsule. Triamcinolone can be injected into the anterior chamber to ascertain the presence of vitreous strands around the area of lenticular defect, and adequate vitrectomy can then be done. A CTR was placed in our 9 cases to distend the capsular bag and limit the passage of excessive fluid behind the lens, expanding the capsular bag on the vitreous.14 It also helps to reestablish the contour of the bag for proper IOL rotation and centration.3 Zonular absence in colobomata tends to be localized and can typically be managed with a CTR, usually without the need for a sutured device.A Placement of a Cionni CTR or a CTS can be considered in cases with extensive zonular compromise, although we did not find it necessary to use these sutured devices in our cases. To prevent vitreous hydration from around the subluxated
Table 2. Visual profile and other results. Preop Snellen Acuity
4-Mo Postop CDVA
Pupilloplasty
CTR
Intraop/Postop Complication
Intermittent Vitrectomy (n)*
FU (Mo)
1
CFNF
20/40
Performed
Implanted
None
2
6
2
HM
20/40
Performed
Implanted
None
3
10
3
CFNF
20/30
Performed
Implanted
None
3
6
4
CF 1 m
20/20
Performed
Implanted
None
2
6
5
CF 2 m
20/20
Performed
Implanted
None
3
9
6
CF 1 m
20/60
Performed
Implanted
None
3
6
7
HM
20/400
Performed
Implanted
None
4
7
8
CFNF
20/60
Performed
Implanted
None
2
9
9
HM
20/200
Performed
Implanted
None
3
5
Case
CDVA Z corrected distance visual acuity; CF Z counting fingers; CFNF Z counting fingers near face; CTR Z capsular tension ring; FU Z follow-up; HM Z hand movements *Number of times performed
Volume 43 Issue 2 February 2017
160
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
quadrant of the lens, surgical techniques have been described in which an iris hook holds the iris tissue along with the anterior capsule, preventing seepage of fluid into the vitreous cavity.15 Lenticular colobomas are often associated with iris colobomas, and in these cases our technique of vitrectomy-assisted phacoemulsification offers optimal results. During phacoemulsification, capsular hooks can be used to support the capsulorhexis margin, but we did not find them necessary because in lenticular colobomas, the remaining zonular fibers are intact and provide stability to the capsular bag. This is not true in cases of subluxation, in which the residual zonular fibers can be compromised due to varied etiology, although capsular hooks can be used per the surgeon's preference. A 3-piece foldable IOL was placed in the capsular bag with the haptics oriented along the direction of zonular involvement to facilitate maximum distension of the bag with the hard haptics. Although with a CTR the direction of the haptic placement might not be significant, orienting the haptics along the axis of zonular defect might be beneficial. All these measures prevented episodes of capsular fornix aspiration into the I/A probe. Positive pressure from microphthalmos and excess fluid transition into the vitreous increases the risk for intraoperative malignant glaucoma.A In 1 of our 9 cases, microphthalmia was an associated feature of lens coloboma. As microphthalmia itself increases the surgical challenge to performing safe phacoemulsification, preoperative injection of mannitol 20% that acts as a hyperosmotic agent and dehydrates and reduces the vitreous volume was infused intravenously in a dose of 1g/kg body weight over a period of 30 minutes. We believe that microphthalmic eyes that have a high vitreous pressure will benefit from an intermittent vitrectomy that reduces the positive pressure and subsequent shallowing of the anterior chamber. In these eyes, we recommend placing the trocar 1.5 mm from the limbus because of the overall shorter length of the pars plana. In cases with associated iris defect, it is essential to reconstruct the pupil to prevent photophobia and glare and various surgical techniques to reconstruct the pupil have been described.16–20 In studies that adopted a modified McCannel suture technique,18,21 a well-centered pupillary aperture was created in the postoperative period. We think the vitrectomy-assisted phacoemulsification technique can also be used in cases of a subluxated lens because a similar sequence of events and challenges from vitreous hydration and pressure increase in the posterior chamber will be present in these cases. A pars plana intermittent vitrectomy without irrigation sufficiently expanded the anterior chamber in all cases of lenticular colobomata, facilitating a good capsulorhexis, uneventful phacoemulsification, and safe foldable IOL implantation and pupilloplasty while maintaining the advantages and safety of small-incision cataract surgery. In summary, our technique facilitates the phacoemulsification procedure and subsequent maneuvers in eyes with Volume 43 Issue 2 February 2017
lens coloboma, limiting further vitreous prolapse through the existing defect in the contour of the lens and simultaneously maintaining the integrity of the remaining zonular fibers.
WHAT WAS KNOWN There is an increased risk for intraoperative complications in eyes with lens coloboma. Fluid from the phacoemulsification procedure surges in the vitreous cavity because of the open communication from around the edges of the lenticular defect, facilitating vitreous herniation into the anterior chamber and leading to further zonular instability and zonular compromise. This often necessitates abandoning the phacoemulsification procedure.
WHAT THIS PAPER ADDS Phacoemulsification with intermittent vitrectomy from the pars plana site effectively decompresses the posterior chamber and resolves the issue of vitreous hydration and its subsequent prolapse into the anterior chamber with the associated complications. Vitrectomy-assisted phacoemulsification facilitates the phacoemulsification procedure with the effective placement of an IOL in the capsular bag along with the performance of additional procedures such as placement of a CTR, Cionni ring, or CTS as necessary.
REFERENCES 1. Nordlund ML, Sugar A, Moroi SE. Phacoemulsification and intraocular lens placement in eyes with cataract and congenital coloboma: visual acuity and complications. J Cataract Refract Surg 2000; 26:1035– 1040 2. Chaurasia S, Ramappa M, Sangwan VS. Cataract surgery in eyes with congenital iridolenticular choroidal coloboma. Br J Ophthalmol 2012; 96:138–140 3. Mizuno H, Yamada J, Nishiura M, Takahashi H, Hino Y, Miyatani H. Capsular tension ring use in a patient with congenital coloboma of the lens. J Cataract Refract Surg 2004; 30:503–506 4. Goel R, Kamal S, Khurana B, Kumar S, Malik KPS, Bodh SA, Singh M. Manual small incision cataract surgery for subluxated cataract with lens coloboma. Cont Lens Anterior Eye 2012; 35:89–91 5. Hernadez-Camarena JC, Ayup-Arguijo E, Chavez-Mondragon E, RamirezMiranda A. Surgical management and Scheimpflug analysis of an atypical lens coloboma. Case Rep Ophthalmol 2012; 3:317–320. Available at: http:// www.ncbi.nlm.nih.gov/pmc/articles/PMC3493002/pdf/cop-0003-0317.pdf. Accessed December 18, 2016 6. Kim J-H, Kang M-H, Kang S-M, Song B-J. A modified iris repair technique and capsular tension ring insertion in a patient with coloboma with cataracts. Korean J Ophthalmol 2006; 20:246–249. Available at: http://www.ncbi.nlm. nih.gov/pmc/articles/PMC2908861/pdf/kjo-20-246.pdf. Accessed December 18, 2016 € 7. Solmaz N, Onder F. Cataract surgery in a case with bilateral iridolenticular coloboma associated with microphthalmos and relative anterior microphthalmos. JCRS Online Case Rep 2014; 2:e41–e43. Available at: http:// www.jcrscasereports.com/article/S2214-1677(14)00005-2/pdf. Accessed December 18, 2016 8. Bermejo E, Martinez-Frias ML. Congenital eye malformations: clinical– epidemiological analysis of 1,124,654 consecutive births in Spain. Am J Med Genet 1998; 75:497–504 €lcker HE, Tetz MR, Daus W. Cataract surgery in eyes with colobomas. 9. Vo Dev Ophthalmol 1991; 22:94–100 10. Nixseaman DH. Cataract extraction in a case of congenital coloboma of the iris. Br J Ophthalmol 1968; 52:625–627. Available at: https://www.ncbi. nlm.nih.gov/pmc/articles/PMC506655/pdf/brjopthal00344-0049.pdf. Accessed December 18, 2016 11. Jaffe NS, Clayman HM. Cataract extraction in eyes with congenital colobomata. J Cataract Refract Surg 1987; 13:54–58
TECHNIQUE: VITRECTOMY-ASSISTED PHACOEMULSIFICATION FOR LENS COLOBOMA
12. Weilder WB. Concerning congenital coloboma of the lens. Am J Ophthalmol 1922; 6:465–467 13. Chang DF. Pars plana vitreous tap for phacoemulsification in the crowded eye. J Cataract Refract Surg 2001; 27:1911–1914. Available at: http:// www.changcataract.com/pdfs/Vit_tap.pdf. Accessed December 18, 2016 14. Hasanee K, Ahmed K II. Capsular tension rings: update on endocapsular support devices. Ophthalmol Clin North Am 2006; 19:507–519 15. Sethi HS, Mayuresh NP, Gupta VS. Intraoperative intracameral pilocarpine after capsular tension ring and capsule/iris hook insertion in pediatric eyes with subluxated cataract. J Cataract Refract Surg 2016; 42:190–193 16. Watt RH. Inferior congenital iris coloboma repair and IOL implantation [letter]. J Cataract Refract Surg 1993; 19:669–671 17. Burk SE, Da Mata AP, Snyder ME, Cionni RJ, Cohen JS, Osher RH. Prosthetic iris implantation for congenital, traumatic, or functional iris deficiencies. J Cataract Refract Surg 2001; 27:1732–1740 18. McCannel MA. A retrievable suture idea for anterior uveal problems. Ophthalmic Surg 1976; 7 (2):98–103 19. Worst JGF, Los JRLI. Iris reconstruction by coloboma repair. Ophthalmic Surg 1989; 20:790–793 20. Cionni RJ, Karatza EC, Osher RH, Shah M. Surgical technique for congenital iris coloboma repair. J Cataract Refract Surg 2006; 32:1913–1916 21. Blackmon DM, Lambert SR. Congenital iris coloboma repair using a modified McCannel suture technique. Am J Ophthalmol 2003; 135:730–7322
161
OTHER CITED MATERIAL A. Miller KM, Snyder ME, Tam DY, Varma DK, Ahmed II K. Coloboma of the iris, retina, optic nerve and lens. Cataract & Refractive Surgery Today October 2010, pages 47–51. Available at: http://bmctoday.net/crstoday/pdfs/ crst1010_catsurg_complex.pdf. Accessed December 18, 2016
Disclosure: None of the authors has a financial or proprietary interest in any material or method mentioned.
First author: Ashvin Agarwal, MS Dr. Agarwal's Eye Hospital & Research Centre, Chennai, India
Volume 43 Issue 2 February 2017