Small pupil enlargement during cataract extraction A new method Richard
J.
Mackool, M.D.
Pupils that do not dilate adequately for cataract extraction must be surgically enlarged. Radial iridotomy, sector iridectomy, multiple sphincterotomies,l and/or iris retraction with a spatula2 or suture 3 have been used for this purpose. This report describes a new method of pupil enlargement which is rapid, reversible, and simple to perform. Instruments have been designed to retract the iris, reducing or eliminating the need to incise or suture it.
Two new instruments were designed for this procedure: self-retaining iris retractors and an iris repositor. Self-retaining iris retractors (Figure 1) are small titanium hooks, each of which is attached to a square titanium base. Smooth forceps are used to hold the base during placement of the retractor. After insertion, the square base rests on the limbus and prevents rotation of the retractor. The iris re-
Fig. 1.
Fig. 2.
(Mackool) Self-retaining iris retractor (lateral view).
MATERIALS AND METHODS
(Mackool) Iris repositor (lateral view).
Reprint requests to Richard]. Mackool, M.D., Mackool Eye Institute, 31-27 41st Street, Astoria, New York 11103.
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
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Fig. 3.
(Mackool) Iris repositor engaging iris sphincter.
positor (Figure 2) has a concave titanium tip attached to a narrow shaft. This instrument is used to push the iris sphincter into each retractor; it is also used to release the iris from the retractor after cataract extraction and lens implantation. A lid speculum or other method of lower lid retraction which keeps the lid margin away from the inferior limbus should be used. Self-sealing, 1.5 mm beveled incisions are made at the limbus in each meridian where an iris retractor will be placed. I have used two retractors (at 4:30 and 7 :30 o'clock), three retractors (at 4, 6, and 8 o'clock), four retractors (at 2, 4, 8, and 10 o'clock), or five retractors (at 2, 4, 6, 8, and 10 o'clock). The incision for cataract extraction (limbal incision or scleral tunnel) is then made and the anterior chamber is filled with a viscoelastic. A retractor is held at its base with smooth forceps and inserted through each of the two to five small limbal incisions, then rotated 90 degrees (so the opening of each retractor is oriented posteriorly). The iris repositor is inserted through the cataract incision and advanced to engage the iris sphincter with its concave tip at a position adjacent to one of the retractors (Figure 3). The iris is pushed to the periphery by the repositor (Figure 4) and inserted into the retractor (Figure 5). This is repeated at each retractor. It is important to keep the lower lid from contacting the base of the inferior iris retractor during the procedure, since this may rotate the retractor and produce iris trauma. A widelyopened lid speculum or an additional inferior lid retractor will prevent this (Figure 6). A superior radial iridotomy or sphincterotomy, if necessary, is 524
Fig. 4.
(Mackool) Iris repositor pushing iris sphincter toward iris root.
then performed (Figures 7 and 8). When a scleral tunnel dissection has been performed, the following technique can be used to enlarge the superior pupil. A 30-gauge needle is inserted through the tunnel or the adjacent limbus and used to perforate the iris (Figure 9). A Vannas scissors is used to complete the iris opening (Figure 10). This technique is necessary since the superior iris cannot be withdrawn through the scleral tunnel. If four retractors have been inserted (Figure 11), a superior iridotomy is often unnecessary; however, the inferior pupil will not be as large as that shown in Figures 7 and 8. A fifth retractor may be
Fig. 5.
(Mackool) Iris sphincter within retractor.
J CATARACf REFRACT SURG-VOL 18, SEPTEMBER 1992
(Mackool) Superior iridotomy with 30-gauge needle (bevel down) . Iris retractors at 3, 6, and 9 o'clock.
Fig. 6.
(Mackool) Inferior lid retraction prevents contact of lower lid margin with iris retractors.
Fig. 9.
Fig. 7.
(Mackool) Appearance of pupil with radial iridotomy and retractors at 4:30 and 7:30 o'clock.
Fig. 10.
(Mackool) Superior sphincterotomy with Vannas scissors.
Fig. 8.
(Mackool) Appearance of iris with superior radial iridotomy and retractors at 4, 6, and 8 o'clock.
Fig. 11.
(Mackool) Appearance of pupil with four retractors (2, 4, 8, and 10 o'clock).
] CATARACT REFRACT SURG-VOL 18, SEPrEMBER 1992
525
Fig. 12.
(Mackool) Appearance of pupil with five retractors (2, 4, 6, 8, and 10 o'clock).
added at 6 o'clock (Figure 12) to expose the inferior portion of the posterior chamber. After the capsulotomy, cataract extraction, and lens implantation have been completed, the repositor is used to push the iris out of each retractor. The base of each retractor is then rotated 90 degrees, grasped with a smooth forceps, and removed from the eye. If a superior radial iridotomy was performed, it may now be repaired. DISCUSSION
A small pupil may be enlarged by performing multiple sphincterotomies,l a superior and/or inferior radial iridotomy, or a superior sector iridectomy. If necessary, the superior iris can be easily repaired by suturing. Incision of the inferior iris is often necessary to allow visualization of the inferior capsule and lens during the capsulotomy, hy-
526
drodissection, and removal of inferior nucleus and lens cortex. These incisions are more difficult to repair, however, and failure to repair them can result in disabling postoperative glare or diplopia. 4 I have previously described a technique in which the inferior iris is retracted with a spatula during phacoemulsification. 2 While this is useful, only a relatively small region of the posterior chamber is exposed and the maneuver is somewhat difficult to perform. Care must also be taken to avoid inadvertent retraction and tearing of the anterior lens capsule by the spatula. The method reported here allows the iris to be securely and reversibly retracted in several meridians simultaneously. It is relatively simple to perform and reduces or eliminates the need to incise or suture the iris. Reducing the number of iris incisions can be expected to decrease the incidence and severity of postoperative iritis, iris bleeding, and fibrin transudation into the anterior chamber. I have now used this technique successfully in 50 patients without complication. No instances of iris erosion, sphincter tears, postoperative glare, or iridocyclitis have occurred. There have also been no instances of corneal edema at the sites of iris retractor insertion, indicating that the retractors do not contact the endothelium. REFERENCES 1. Fine IH. Pupilloplasty. In Koch PS, Davison JA, eds, Textbook of Advanced Phacoemulsification Techniques. Thorofare, NJ, Slack Inc, 1991; 91-97 2. Mackool RJ. Stereoatlas of Phacoemulsification and IOL Implantation. Woodbury, NY, Stereo Arts Press, 1990; 80-81 3. Masket S. Preplaced inferior iris suture method for small pupil phacoemulsifiCation. J Cataract Refract Surg 1992; 18:518-522 4. Guzek JP, Holm M, Cotter JB, et al. Risk factors for intraoperative complications in 1000 extracapsular cataract cases. Ophthalmology 1987; 94(5):461-466
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER
1992
J.
Mackool, M.D.
Pupils that do not dilate adequately for cataract extraction must be surgically enlarged. Radial iridotomy, sector iridectomy, multiple sphincterotomies,l and/or iris retraction with a spatula2 or suture 3 have been used for this purpose. This report describes a new method of pupil enlargement which is rapid, reversible, and simple to perform. Instruments have been designed to retract the iris, reducing or eliminating the need to incise or suture it.
Two new instruments were designed for this procedure: self-retaining iris retractors and an iris repositor. Self-retaining iris retractors (Figure 1) are small titanium hooks, each of which is attached to a square titanium base. Smooth forceps are used to hold the base during placement of the retractor. After insertion, the square base rests on the limbus and prevents rotation of the retractor. The iris re-
Fig. 1.
Fig. 2.
(Mackool) Self-retaining iris retractor (lateral view).
MATERIALS AND METHODS
(Mackool) Iris repositor (lateral view).
Reprint requests to Richard]. Mackool, M.D., Mackool Eye Institute, 31-27 41st Street, Astoria, New York 11103.
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
523
Fig. 3.
(Mackool) Iris repositor engaging iris sphincter.
positor (Figure 2) has a concave titanium tip attached to a narrow shaft. This instrument is used to push the iris sphincter into each retractor; it is also used to release the iris from the retractor after cataract extraction and lens implantation. A lid speculum or other method of lower lid retraction which keeps the lid margin away from the inferior limbus should be used. Self-sealing, 1.5 mm beveled incisions are made at the limbus in each meridian where an iris retractor will be placed. I have used two retractors (at 4:30 and 7 :30 o'clock), three retractors (at 4, 6, and 8 o'clock), four retractors (at 2, 4, 8, and 10 o'clock), or five retractors (at 2, 4, 6, 8, and 10 o'clock). The incision for cataract extraction (limbal incision or scleral tunnel) is then made and the anterior chamber is filled with a viscoelastic. A retractor is held at its base with smooth forceps and inserted through each of the two to five small limbal incisions, then rotated 90 degrees (so the opening of each retractor is oriented posteriorly). The iris repositor is inserted through the cataract incision and advanced to engage the iris sphincter with its concave tip at a position adjacent to one of the retractors (Figure 3). The iris is pushed to the periphery by the repositor (Figure 4) and inserted into the retractor (Figure 5). This is repeated at each retractor. It is important to keep the lower lid from contacting the base of the inferior iris retractor during the procedure, since this may rotate the retractor and produce iris trauma. A widelyopened lid speculum or an additional inferior lid retractor will prevent this (Figure 6). A superior radial iridotomy or sphincterotomy, if necessary, is 524
Fig. 4.
(Mackool) Iris repositor pushing iris sphincter toward iris root.
then performed (Figures 7 and 8). When a scleral tunnel dissection has been performed, the following technique can be used to enlarge the superior pupil. A 30-gauge needle is inserted through the tunnel or the adjacent limbus and used to perforate the iris (Figure 9). A Vannas scissors is used to complete the iris opening (Figure 10). This technique is necessary since the superior iris cannot be withdrawn through the scleral tunnel. If four retractors have been inserted (Figure 11), a superior iridotomy is often unnecessary; however, the inferior pupil will not be as large as that shown in Figures 7 and 8. A fifth retractor may be
Fig. 5.
(Mackool) Iris sphincter within retractor.
J CATARACf REFRACT SURG-VOL 18, SEPTEMBER 1992
(Mackool) Superior iridotomy with 30-gauge needle (bevel down) . Iris retractors at 3, 6, and 9 o'clock.
Fig. 6.
(Mackool) Inferior lid retraction prevents contact of lower lid margin with iris retractors.
Fig. 9.
Fig. 7.
(Mackool) Appearance of pupil with radial iridotomy and retractors at 4:30 and 7:30 o'clock.
Fig. 10.
(Mackool) Superior sphincterotomy with Vannas scissors.
Fig. 8.
(Mackool) Appearance of iris with superior radial iridotomy and retractors at 4, 6, and 8 o'clock.
Fig. 11.
(Mackool) Appearance of pupil with four retractors (2, 4, 8, and 10 o'clock).
] CATARACT REFRACT SURG-VOL 18, SEPrEMBER 1992
525
Fig. 12.
(Mackool) Appearance of pupil with five retractors (2, 4, 6, 8, and 10 o'clock).
added at 6 o'clock (Figure 12) to expose the inferior portion of the posterior chamber. After the capsulotomy, cataract extraction, and lens implantation have been completed, the repositor is used to push the iris out of each retractor. The base of each retractor is then rotated 90 degrees, grasped with a smooth forceps, and removed from the eye. If a superior radial iridotomy was performed, it may now be repaired. DISCUSSION
A small pupil may be enlarged by performing multiple sphincterotomies,l a superior and/or inferior radial iridotomy, or a superior sector iridectomy. If necessary, the superior iris can be easily repaired by suturing. Incision of the inferior iris is often necessary to allow visualization of the inferior capsule and lens during the capsulotomy, hy-
526
drodissection, and removal of inferior nucleus and lens cortex. These incisions are more difficult to repair, however, and failure to repair them can result in disabling postoperative glare or diplopia. 4 I have previously described a technique in which the inferior iris is retracted with a spatula during phacoemulsification. 2 While this is useful, only a relatively small region of the posterior chamber is exposed and the maneuver is somewhat difficult to perform. Care must also be taken to avoid inadvertent retraction and tearing of the anterior lens capsule by the spatula. The method reported here allows the iris to be securely and reversibly retracted in several meridians simultaneously. It is relatively simple to perform and reduces or eliminates the need to incise or suture the iris. Reducing the number of iris incisions can be expected to decrease the incidence and severity of postoperative iritis, iris bleeding, and fibrin transudation into the anterior chamber. I have now used this technique successfully in 50 patients without complication. No instances of iris erosion, sphincter tears, postoperative glare, or iridocyclitis have occurred. There have also been no instances of corneal edema at the sites of iris retractor insertion, indicating that the retractors do not contact the endothelium. REFERENCES 1. Fine IH. Pupilloplasty. In Koch PS, Davison JA, eds, Textbook of Advanced Phacoemulsification Techniques. Thorofare, NJ, Slack Inc, 1991; 91-97 2. Mackool RJ. Stereoatlas of Phacoemulsification and IOL Implantation. Woodbury, NY, Stereo Arts Press, 1990; 80-81 3. Masket S. Preplaced inferior iris suture method for small pupil phacoemulsifiCation. J Cataract Refract Surg 1992; 18:518-522 4. Guzek JP, Holm M, Cotter JB, et al. Risk factors for intraoperative complications in 1000 extracapsular cataract cases. Ophthalmology 1987; 94(5):461-466
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER
1992
