Cataract surgery in patients with small pupils is always challenging. Small pupils can be due to pseudoexfoliation syndrome, posterior synechia, pupillary atrophy, and other conditions.1–7 Iridoschisis presents with 2 or more layers of iris tissue that usually show iris fibers flowing in the anterior chamber (AC). Cataract surgery in these cases may result in aspiration of iris tissue.6 Dilating the pupil with iris retractors or stretching the iris with various instruments does not alleviate the danger of contact with the iris tissue and aspiration of fibers.
The Perfect Pupil system (Milvella Pty. Ltd.) is a tension ring for the pupillary margin that can be inserted through the phacoincision. The first peer-reviewed article about this device was published by Kershner5 in 2002. The Perfect Pupil device is a sterile, disposable polyurethane ring with an integrated arm that allows easy insertion into the eye and removal at the end of surgery. The ring is open for 45 degrees to allow introduction of instruments and the phaco tip. There is a 1.6 mm tab at the top of the device and five 4.0 mm fenestrations in the ring for positioning. The iris is held firmly for 315 degrees by an integrated 0.24 mm flanged groove throughout the length of the ring. The material is biocompatible and flexible, allowing it to be passed easily through a corneal incision. The device can be inserted with forceps or an injector (Geuder). Once in place, the device expands the pupillary opening to 6.0 to 8.0 mm.5
Three eyes with iridoschisis of 2 patients were operated on using the Perfect Pupil pupil-dilating device. Institutional review board approval was not required because the device was approved for use in Germany. The device is also approved in the United States by the Food and Drug Administration. All procedures were performed by the same surgeon (G.U.A.).
Cases 1 and 2
The first patient was an 83-year-old man who presented with iridoschisis in both eyes (Figure 1). Additional ophthalmic findings were nuclear cataract, pseudoexfoliation syndrome, and a preoperative best corrected visual acuity (BCVA) of 0.05 in the right eye and 0.08 in the left eye. Intraocular pressure (IOP) was 10 mm Hg in both eyes. Systemic conditions included Parkinson disease and insufficiency of mitral and tricuspedal heart valves. In addition, the patient was having systemic anticoagulation therapy. Cataract surgery was first performed in the left eye, and then 1 week later, in the right eye.
Topical anesthesia was applied using lidocain gel, and 2 paracentheses were done at 3 o'clock and 9 o'clock. A 2.8 mm clear corneal incision was performed using the soft-shell technique. A dispersive ophthalmic viscosurgical device (OVD) (Viscoat, Alcon) was combined with a cohesive OVD (Provisc, Alcon) to stabilize the anterior chamber and protect the corneal endothelium. In both eyes, the Perfect Pupil device was introduced into the AC through the clear corneal phacoincision using forceps (Figure 2).
The device was placed in the AC and laid on the iris. It was then attached to the pupillary margin in a circular manner, resulting in a pupillary opening approximately 7.0 mm wide (Figure 2, B). Capsulorhexis was performed using a Utrata forceps (Bausch & Lomb). Hydrodissection and hydrodelineation were performed with unpreserved lidocaine 1% until the nucleus could be moved inside the capsular bag. Phacoemulsification was done using a modified chopping technique and bimanual irrigation; aspiration was used to clean residual cortical fibers from the capsular bag (Figures 2, C and D). The capsular bag was then filled with the cohesive OVD, the clear corneal incision was enlarged from 3.0 to 3.2 mm, and an Alcon AcrySof (model MA60BM) foldable intraocular lenses (IOLs) of 23 diopters (D) (right eye) and 21 D (left eye) were safely implanted in the capsular bag using forceps. Then the Perfect Pupil device was loosened from the pupillary margin and laid on the iris, using a conventional phaco spatula. This system was removed from the AC through the clear corneal incision and careful bimanual irrigation. Aspiration was performed to remove the residual OVD. At this point, occasional aspiration of iris fibers occurred without damage (Figure 2, E). After the OVD was removed, the clear corneal incision was hydrated and closed with balanced salt solution (BSS).
On the first postoperative day, both eyes presented with minor cell and flare in the AC; the pupillary margin was undamaged and the IOL well centered. The patient received local antibiotic and steroid treatment as well as low-dose systemic steroids for 4 days. One week postoperatively, visual acuity was 0.5 with a spherical correction of −1.5 in the right eye and 0.4 with a spherical correction of −1.0 in the left eye with a spherical correction was −1.5 D 0.5 in the right eye and −1.0 D 0.4 in the left eye.
The second patient was a 73-year-old mentally retarded man who had had surgery in the left eye, resulting in a BCVA of 0.3. The right eye presented with a brunescent cataract and BCVA of 0.1.
Because of the patient's mental condition, cataract surgery was performed under general anesthesia. After application of 2 paracentheses at 9 o'clock and 3 o'clock, a 2.8 mm clear corneal incision was made. Intraoperative pupil size was 3.5 mm. A dispersive OVD (Viscoat) was injected into the AC; the Perfect Pupil device was then injected into the AC using a special injector that was not available at the time the previous patient had surgery. The pupillary rim was hooked onto the device, and the pupil was dilated to 5.0 to 6.0 mm. A cohesive OVD (Provisc) was then injected into the AC to flatten the anterior capsule. Capsulorhexis was performed using a Utrata forceps, allowing visualization of a lentodonesis. After hydrodissection and hydrodelineation, careful phacoemulsification was performed. After complete removal of the lens nucleus, a zonolulysis from 3 to 6 o'clock was observed. A capsular tension ring (Morcher) was inserted into the capsular bag for stabilization. Bimanual irrigation and aspiration was then performed to remove residual cortical fibers. The capsular bag was inflated with a cohesive OVD, and an AMO Sensar (model AR 40e; AMO) foldable acrylic IOL was inserted using the Emerald injector (AMO). The IOL was safely placed in the capsular bag and centered, then the Perfect Pupil ring was loosened from the pupillary margin and drawn from the AC. The remaining OVD was removed with bimanual irrigation and aspiration. At the end of the procedure, the pupil was round, the IOL was centered, and the paracentheses were closed using BSS. Postoperatively, the inflammatory response in the AC was moderate, some Descemet folds were seen, the pupil was round and undamaged, and the iris was as preoperatively. One week after surgery, uncorrected visual acuity was 0.3. Visual acuity testing was limited because of the patient's mental condition.
Iridoschisis is a rare condition resulting in 1 or more additional layers of the anterior iris surface. These sometimes-long iris fibers tend to compromise cataract surgery and make it more challenging.6 Pupil dilation in these patients is also poor because this condition may be associated with pseudoexfoliation syndrome or atrophy of the pupillary margin. Stretching the iris is not advisable in these cases. The use of iris retractors is possible, but the possibility that longer iris fibers may be aspirated during cataract surgery remains.
With the Perfect Pupil device, the iris rim is safely fixed in the silicone ring and the iridoschisis is pushed back to the periphery of the iris during phacoemulsification. In our cases, no aspiration of iris fibers occurred. After the device was removed, the remaining iris fibers were occasionally aspirated with the OVD without further damage. Application of this device is not as easy as using iris retractors. It requires a learning period but seems to be a useful tool for the cataract surgeon.
Patients with small pupils are always challenging in cataract surgery. Glaucoma patients under miotic therapy and patients with pseudoexfoliation syndrome or other conditions require the use of pupil-dilating devices. Stretching the pupil with special instruments, viscomydriasis with high viscosity OVDs such as Healon5 (OVD), and the use of iris retractors have been recommended.3,4,7–15 Stretching sometimes leads to an unstable iris, which can compromise cataract surgery. Iris retractors produce a rectangular pupillary opening, sometimes leading to defects in the pupillary margin or to an atonic pupil.
Strategies for pupil enlargement depend on surgical techniques and surgeon skill, as well as on the patient's situation. There is no general recommendation or solution. The device presented here is another method to facilitate cataract surgery and make it safer in special situations.
1. Auffarth GU, Blum M, Faller U, et al. Relative anterior microphthalmus; morphometric analysis and its implications for cataract surgery. Ophthalmology 2000; 107:1555-1560
2. Drolsum L, Haaskjold E, Davanger M. Results and complications after extracapsular cataract extraction in eyes with pseudoexfoliation syndrome. Acta Ophthalmol (Copenh) 1993; 71:771-776
3. Fine IH. Pupilloplasty for small pupil phacoemulsification. J Cataract Refract Surg 1994; 20:192-196
4. Gimbel HV. Nucleofractis phacoemulsification through a small pupil. Can J Ophthalmol 1992; 27:115-119
5. Kershner RM. Management of the small pupil for clear corneal cataract surgery. J Cataract Refract Surg 2002; 28:1826-1831
6. Smith GT, Liu CSC. Flexible iris hooks for phacoemulsification in patients with iridoschisis. J Cataract Refract Surg 2000; 26:1277-1280
7. Vasavada A, Singh R. Phacoemulsification in eyes with a small pupil. J Cataract Refract Surg 2000; 26:1210-1218
8. Auffath GU. Viskoelastische Substanzen in der Ophthalmochirurgie. Bremen, Germany, Unit-Med, 2001; 40–43
9. Birchall W, Spencer AF. Misalignment of flexible iris hook retractors for small pupil cataract surgery: effects on pupil circumference. J Cataract Refract Surg 2001; 27:20-24
10. Dinsmore SC. Modified stretch technique for small pupil phacoemulsification with topical anesthesia. J Cataract Refract Surg 1996; 22:27-30
11. Graether JM. Graether pupil expander for managing the small pupil during surgery. J Cataract Refract Surg 1996; 22:530-535
12. Mackool RJ. Small pupil enlargement during cataract extraction; a new method. J Cataract Refract Surg 1992; 18:523-526
13. Masket S. Avoiding complications associated with iris retractor use in small pupil cataract extraction. J Cataract Refract Surg 1996; 22:168-171
14. Oetting TA, Omphroy LC. Modified technique using flexible iris retractors in clear corneal cataract surgery. J Cataract Refract Surg 2002; 28:596-598
15. Pham DT, Volkmer C, Leder K, Wollensak J. Partielle Sphinkterektomie in der Kataraktchirurgie; Klinische und pathohistologische Ergebnisse. Ophthalmologe 1998; 95:635-638