Trabeculotomy ab externo, cataract extraction, and intraocular lens implantation: Preliminary report

T rabeculotomy ab externo, cataract extraction, and intraocular lens implantation: Preliminary report Megumi Honjo, MD, Hidenobu Tanihara, MD, Akira Negi, MD, Masanori Hangai, MD, Tomoko Taniguchi, MD, Yoshihito Honda, MD, Takanori Mizoguchi, MD, Miyo Matsumura, MD, Makoto Nagata, MD

ABSTRACT Purpose: To compare the results of a triple procedure using either extracapsular cataract extraction (ECCE) or one of two phacoemulsification techniques combined with trabeculotomy ab externo and intraocular lens (IOL) implantation. Setting: Kyoto University Hospital, Kyoto, Japan, and Nagata Eye Hospital, Nara, Japan Methods: In this comparative study, 25 eyes with primary open-angle glaucoma had ECCE combined with trabeculotomy ab externo and IOL implantation and 22 had the same procedure using phacoemulsification instead of ECCE. Of the eyes that had phacoemulsification, 10 had a single-flap and 12 had a double-flap procedure. Results: All 22 eyes that had phacoemulsification had a postoperative lOP of 21 mm Hg or less, as did all ECCE eyes except 2. Although the self-sealing incision might have caused the higher incidence of lOP spikes in the immediate postoperative period, lOPs in the phacoemulsification groups were lower after 3 months. Results were similar in the single-flap and double-flap phacoemulsification groups. There were no significant complications. Conclusion: Cataract extraction by phacoemulsification or ECCE combined with IOL implantation and trabeculotomy ab externo is a safe, effective treatment for patients with coexisting glaucoma and cataract. J Cataract Refract Surg 1996; 22: 601-606

T

rabeculotomy is thought to relieve the resistance to aqueous outflow by mechanical cleavage of the trabecular meshwork and the inner layer of Schlemm' s ca-

From the Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, japan (Honjo, Tanihara, Negi, Hangai, Taniguchi, Honda), and Nagata Eye Hospital, Nara, japan (Mizoguchi, Matsumura, Nagata). Reprint requests to Hidenobu Tanihara, MD, Department ofOphthalmology and Visual Sciences, Kyoto University Graduate School ofMedicine, Kyoto 606-01, japan.

nal. i ,2 Trabeculotomy effectively controls intraocular pressure (lOP) in eyes with certain forms of glaucoma, including primary open angle, developmental, primary angle closure, and combined mechanism, and in eyes with pseudoexfoliation. 3- 6 In a previous paper, 3 we described our modification of the trabeculotomy ab externo procedure and have reported that combined trabeculotomy and extracapsular cataract extraction (ECCE) is beneficial in treating primary open-angle glaucoma and pseudoexfoliation. 5

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n

It is possible, however, that modifications in the trabeculotomy technique for use in combination with cataract extraction may lead to surgical effects and complications different from those of single-procedure surgery. We describe our triple procedure of trabeculotomy, cataract extraction, and intraocular lens (IOL) implantation, and discuss the possible advantages and disadvantages of our modifications.

o A

Subjects and Methods Surgical Techniques Our trabeculotomy ab externo technique, a modification of the procedure described by Harms and Dannheim,l-9 has been previously described. 3- 5 The following additional modifications were made for its use in combination with cataract extraction and IOL implantation (Figure O. Extracapsular cataract extraction, lOL implantation, and trabeculotomy. Mter placement of superior 4-0 silk bridle sutures and creation of the limbal-based conjunctival incision, a 4 X 4 mm flap of four-fifths thickness is made in the upper region (Figure lA) to allow identification of Schlemm's canal and the scleral spur by the contrast in color. After the canal is located, its outer wall is cut with a razor blade and excised with fine scissors, if indicated. A scleral incision for the ECCE is created at the superior limbus, and six 8-0 silk sutures are preplaced. The scleral incision is perforated with a razor blade or slit knife, after which viscoelastic is injected through the incision into the anterior chamber and a capsulotomy (or capsulorhexis) performed. A U-shaped probe (Trabeculotome®, Handaya Inc.) is inserted into the opened Schlemm's canal under the scleral flap and the probe is rotated (Figure 2A) as described previously.3 The scleral flap is closed with five to seven 10-0 nylon sutures until the wound is watertight, after which hydrodissection, nucleus removal, cortex aspiration, and posterior chamber IOL implantation are performed as in a routine ECCE (Figure 2B). In most cases, a peripheral iridectomy is done to prevent pupillary block glaucoma secondary to fibrin exudation. The scleral incision at the limbus is closed with the preplaced sutures. In some cases, a surgical keratometer is used to reduce surgically induced astigmatism. The 602

or

o VB a

o c

Figure 1. (Honjo) Scleral flap and incision designs. A: Trabeculotomy ab externo, ECCE, and IOL implantation. B: Trabeculotomy ab externo, phacoemulsification, and IOL implantation of an intraocular lens, single-flap method. C: Trabeculotomy ab externo, phacoemulsification, and IOL implantation, double-flap method.

conjunctival flap is closed with 8-0 silk sutures, and topical antibiotics are applied. Phacoemulsification, lOL implantation, and trabeculotomy: single flap. After routine creation of the 4 X 4 mm scleral flap and identification of Schlemm's canal, another scleral incision for phacoemulsification is made (Figure 1B), after which a routine continuous curvilinear capsulorhexis (CCC) is done. A U-shaped probe (Trabeculotome) is inserted into the opened Schlemm's canal under the scleral flap and then rotated. 3 The flap is closed with five to seven 10-0 nylon sutures; routine phacoemulsification and IOL implantation are per-

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B

A

Figure 2. (Honjo) Triple procedure using ECCE. A: After the probe is inserted into Schlemm's canal, it is rotated 90 degrees against the trabecular meshwork. B: Nucleus removal, cortex aspiration, and posterior chamber IOL implantation are done in a routine fashion.

formed. As an option, the probe can be inserted and rotated after the IOL is implanted. The self-sealing property of the scleral tunnel and resultant intraoperative lOP stability enable safe probe rotation. Phacoemulsification, lOL implantation, and trabeculotomy: double flap. A 5 X 4 mm scleral flap of one-half thickness is created at the upper or temporal upper limbus as a self-sealing incision (Figures 1 C and 3A). A second flap, 4 X 3 mm and four-fifths thickness, is created inside the initial flap for identification of the canal (Figure 3B). A routine CCC is done through the paracentesis. A probe is inserted into the opened Schlemm's canal under the scleral flap and then rotated as described above (Figure 3 C). The second flap is closed with two 10-0 nylon sutures. Routine phacoemulsification and IOL implantation are performed through the scleral tunnel under the scleral flap. At the end of the procedure, the initial scleral flap is closed with six to eight 10-0 nylon sutures. Small pupil management. A small pupil can be managed by dilating the pupil with iris retractors (two eyes in this study) or by an incision of the sphincter muscle (two eyes).

Study Group This study comprised 47 eyes (33 patients) with cataract and primary open-angle glaucoma that had one of the triple procedures described above as follows: Group A-ECCE, IOL implantation, trabeculotomy (n = 25); Group B-phacoemulsification, IOL implan-

tation, trabeculotomy, single flap (n = 10); Group C-phacoemulsification, IOL implantation, trabeculotomy, double flap (n = 12). Mean age of the 11 men and 22 women was 71.4 years:±: 8.5 (SD). Mean follow-up was 28.7 :±: 22.4 months (range 3 to 76 months).

Results All 22 eyes that had the combined procedure with phacoemulsification (Groups B and C) had a postoperative lOP of 21 mm Hg or less, as did all ECCE eyes (Group A) except 2 (Table l). Table 2 shows mean lOP preoperatively and at six follow-up visits. Mean preoperative lOP was 26.6 :±: 4.5 mm Hg on a mean of 2.4 :±: 1.1 glaucoma medications in Group A and 25.4 :±: 4.3 mm Hg on a mean of 2.2 :±: 1.0 medications in Groups Band C (combined). The means at the final follow-up were 17.0 :±: 2.7 mm Hg on 1.2 :±: 1.1 medications and 16.2 :±: 2.0 mm Hg on 1.1 :±: 1.2 medications, respectively. In Group A, lOP tended to be lower during the first postoperative month than at 3 to 6 months. In Groups B and C, lOP decreased with time (Table 2); the amount of decrease was similar. Table 3 shows the intraoperative and early postoperative complications. No eye developed a filtering bleb lasting longer than 1 month, a shallow anterior chamber, endophthalmitis, or malignant glaucoma. Fibrin exudate in the anterior chamber was significantly greater in

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Table 1. Success rates. Number of Eyes (%) Group A

Group B

Group

8 (32) 15 (60) >21 mm Hg 0 Required additional glaucoma surgery 2 (8)

4(40) 6 (60) 0 0

6 (50) 6 (50) 0 0

Criteria lOP $21 mm Hg, no medication $21 mm Hg, medication

C

Table 2. Mean preoperative and postoperative lOP and mean

A

glaucoma medications used. Mean ± SO

n Group A Preoperative 2 wks 1 month 3 months 6 months 1 year Last visit Group B Preoperative 2 weeks 1 month 3 months 6 months 1 year Last visit Group Preoperative 2 weeks 1 month 3 months 6 months 1 year Last visit

B

e

c Figure 3. (Honjo) A: A 5 x 4 mm scleral flap, one-half thickness, is created at the upper limbus. B: A second flap, 4 x 3 mm and four-fifths thickness, is created inside the initial flap for identification of the canal. G: After GGe, the probe is inserted and rotated and the second flap for the trabeculotomy is closed with two 10-0 nylon sutures.

Group A (P < .001, chi-square test). Although transient lOP elevation occurred more commonly in Groups B and C (combined) than in Group A, the difference was 604

lOP

(mmHg)

Medication

25 25 25 25 25 23 25

26.6 14.4 15.6 16.1 16.7 17.0 17.0

± ± ± ± ± ± ±

4.5 4.4 4.8 3.6 3.4 2.7 2.7

2.4±1.1 1.1 ± 0.9 1.2 ± 1.0 1.0 ± 1.0 1.1 ± 1.0 1.1 ± 1.0 1.2 ± 1.1

10 10 10 10 8 8 10

23.9 15.4 16.1 14.7 14.3 16.5 16.8

± ± ± ± ± ± ±

2.2 2.8 3.4 3.2 3.2 1.3 2.3

1.9 1.2 1.2 0.6 0.5 0.6 1.3

12 12 12 12 8 5 12

26.6 17.3 17.1 16.0 15.6 15.0 15.8

± 5.3 ± 3.1 ±4.7 ± 2.6 ± 2.5 ± 1.4 ± 1.8

± ± ± ± ± ± ±

0.7 1.0 0.8 1.0 1.1 1.1 1.3

2.5±1.1 1.3 ± 1.1 1.1 ± 1.0 1.0 ± 1.0 1.1 ± 0.8 1.4 ± 0.5 0.9 ± 1.1

not significant (P = .3759, chi-square test). In all nine eyes that had phacoemulsification and in four of the seven ECCE eyes that had a pressure spike, the elevation occurred within 3 days after surgery. Table 4 shows visual acuity results. Only one eye (Group B) had a decrease in visual acuity (more than two lines), the result of complicated epiretinal membrane. Most surgeries were considered an overall success; that is, visual field and optic nerve status remained stable and final lOP was lower than preoperatively (Table 5).

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Table 3. Intraoperative and early postoperative complications. Number of Eyes (%) Complication

Total

Intraoperative Early anterior chamber perforation by probe Descemet's membrane detachment Posterior capsule rupture Angle recession Choroidal hemorrhage Early (51 month) Fibrin exudation Transient lOP elevation greater than preop lOP Prolonged hyphema (> 1 week)

0

1 (8)

4 (16)

0

0

2 (4)

1 (4)

0

1 (8)

(2)

(4)

0

0

(2)

(4)

0

0

17 (36)

15 (60)

16 (34)

7 (28)

0 4 (40)

5 (42)

5 (11)

3 (12)

1 (10)

1 (8)

Group B

Group C

20 (80)

8 (80)

10 (83)

5 (20)

1 (10)

2 (17)

0

1 (10)

0

Table 5. Overall success rates. Number of Eyes (%)

Overall success (stable lOP, visual field, optic nerve) Overall failure Visual field and/or optic nerve deterioration Additional glaucoma surgery

Group C

2 (8)

Group A

Category

B

4 (9)

Number of Eyes (%)

Improved Unchanged Decreased

Group

3 (6)

Table 4. Visual acuity results.

Visual Acuity

Group A

Group A

Group B

Group C

19 (76)

9 (90)

12 (100)

6 (24)

1 (10)

0

4 (16)

1 (10)

0

2 (8)

0

0

Only 2 eyes (both in Group A) required further filtering surgery.

Discussion Trabeculotomyab externo effectively controls lOP in eyes with certain types of glaucoma. 3,4,6 In eyes with glaucoma and cataract, combined trabeculotomy ab externo and cataract extraction can be used to treat the glaucoma. 5,10-15 Although there are many reports on the usefulness of combined trabeculotomy and intracapsular cataract extraction (ICCE), 10-13 ICCE is no

2 (17)

longer the procedure of choice; most surgeons now use phacoemulsification and IOL implantation. We reviewed our preliminary results of procedures using either ECCE or phacoemulsification combined with IOL implantation and trabeculotomy. Intraocular pressure was well controlled at 21 mm Hg or less at the final examination in all 47 eyes with primary open-angle glaucoma. This success rate is much higher than that of previous reports on trabeculotomy alone. 3- 6,16,17 One year postoperatively, mean lOP decreased from 23.9 to 16.5 mm Hg after phacoemulsification using the singleflap method and from 26.6 to 15.0 mm Hg after phacoemulsification using the double-flap method. Several reports on combined trabeculotomy and modern phacoemulsification have been published. For example, Gimbel and Meyer14 reported on 50 eyes that had small incision trabeculotomy combined with phacoemulsification and IOL implantation in which Schlemm's canal could be identified under the scleral tunnel with four-fifths depth. Schwenn and Grehn 15 reported on combined trabeculotomy, phacoemulsification using a corneal incision, and IOL implantation. Although both reports showed the usefulness of combined trabeculotomy and phacoemulsification, the study by Gimbel and Meyer had a follow-up of only 3 months. In addition, we believe it is difficult for general surgeons to identifY Schlemm's canal in small incision trabeculotomy. In Schwenn and Grehn's study, a small trabeculectomy was added to one third of the cases that had trabeculotomy combined with phacoemulsification or ECCE because of difficulty in identifYing Schlemm's canal.

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The overall success rate,18 based on the stability of visual field, optic nerve status, and lOP, was about 85% (95% after phacoemulsification and 76% after ECCE). F rom these preliminary results, we conclude that all three of our triple procedures are safe and useful for treating coexisting cataract and glaucoma in elderly patients, which agrees with the findings in a previous report. s Using phacoemulsification rather than ECCE in the triple procedure has advantages: 1. The incidence of fibrin exudate is lower. 2. Blood reflux is often less, and hyphemas disappear faster. 3. The small incision results in less scar tissue. Many of the advantages of phacoemulsification stem from the self-sealing incision and the lower level of postoperative inflammation. Although the self-sealing incision might have caused the higher incidence ofIOP spikes in the immediate postoperative period, lOPs in the phacoemulsification groups were lower after 3 months. Transient aqueous leakage from the ECCE incision might nullify the lOP-elevating effect of postoperative inflammation, but the leakage would decrease as the wound healed. Also, the more intense inflammation after ECCE might inhibit aqueous humor production, another effect that would dissipate over time, perhaps causing increased lOP. Because the results in the two phacoemulsification groups in our study were similar, at this time we cannot conclude whether it is best to use a single- or a doubleflap method. One possible advantage of the double-flap method is less conjunctival scarring, which would be beneficial in eyes that require additional filtering surgery. Further long-term studies should be done to confirm our findings.

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3. Tanihara H, NegiA, Akimoto M, et al. Surgical effects of trabeculotomy ab externo on adult eyes with primary open angle glaucoma and pseudoexfoliation syndrome. Arch Ophthalmol1993; 111:1653-1661 4. Akimoto M, Tanihara H, Negi A, Nagata M. Surgical results of trabeculotomy ab externo for developmental glaucoma. Arch Ophthalmol 1994; 112: 1540 -1544 5. Tanihara H, Negi A, Akimoto M, Nagata M. Long-term surgical results of combined trabeculotomy ab externo and cataract extraction. Ophthalmic Surg 1995; 26:316324 6. Tanihara H, Negi A, Akimoto M, Nagata M. Long-term results of non-filtering surgery for the treatment of primary angle-closure glaucoma. Graefes Arch Clin Exp Ophthalmol1995; 233:563-567 7. Harms H, Dannheim R. Epicritical consideration of 300 cases of trabeculotomy" ab externo". Trans Ophthalmol Soc UK 1969; 89:491-499 8. Harms H, Dannheim R. Trabeculotomy-results and problems. Adv Ophthalmol1970; 22:121-131 9. Dannheim R. T rabeculotomy. Trans Am Acad Ophthalmol OtolaryngoI1972; 76:375-383 10. Sautter H, Demeler U, Naumann G. Zur simultanen Trabekulotomie und intrakapsularen Kataraktextraktion. Klin Monatsbl Augenheilkd 1974; 164:65-71 1l. McPherson SO Jr. Combined trabeculotomy and cataract extraction as a single operation. Trans Am Ophthalmol Soc 1977; 74:251-260 12. Dannheim R, HetzingerA. T rabekulotomie undKataraktextraktion-simultan oder sukzessiv? Klin Monastbl Augenheilkd 1978; 173:542-549 13. Mackensen G, Orsoni GJ. Mit Trabekulotomie kombinierte Kataraktextraktion. Klin Monastbl Augenheilkd 1978; 173:756-760 14. Gimbel HV, Meyer D. Small incision trabeculotomy combined with phacoemulsification and intraocular lens implantation. J Cataract Refract Surg 1993; 19:92-96 15. Schwenn 0, Grehn FTI. Cataract extraction combined with trabeculotomy. Ger J Ophthalmol1995; 4:16-20 16. Chihara E, Nishida A, Kodo M, et al. Trabeculotomy ab externo: an alternative treatment in adult patients with primary open-angle glaucoma. Ophthalmic Surg 1993; 24:735-739 17. Wada Y, Nakatsu A, Kondo T. Long-term results of trabeculotomy ab externo. Ophthalmic Surg 1994; 25:317320 18. Roth SM, Spaeth GL, Starita RJ, et al. The effects of postoperative corticosteroids on trabeculectomy and the clinical course of glaucoma: five-year follow-up study. Ophthalmic Surg 1991; 22:724-729

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