Phacoemulsification and modified trabeculectomy for managing combined cataracts and glaucoma Fred M. Gregg, M.D. ABSTRACT Seven eyes in four patients who had combined cataract extraction, intraocular lens implantation, and glaucoma filtering surgery were examined retrospectively. A phacoemulsification technique was use4 with trabeculectomy performed under a modified limbal flap. All patients achieved a final visual acuity of 20/40 or better and intraocular pressure ofless than 20 mm Hg without medication. The techniques .are descrihedand the management of combined cataracts and glaucoma is discussed. Key Words: cataract, glaucoma, intraocular lens implantation, phacoemulsification, trabeculectomy

The surgical management of patients with cataracts and glaucoma can be difficult. Performing surgery for both conditions simultaneously has obvious advantages but is considered more risky by some. Varieties of approaches have been described, usually in conjunction with an extracapsular cataract removal method. I - 5 These techniques traditionally incorporate a broad scleral flap approaching 4 mm posterior to the corneal limbus. Combining glaucoma surgery and small incision cataract surgery has not been extensively discussed. This paper presents our results in seven eyes of four patients who had cataract removal by phacoemulsification, intraocular lens (IOL) implantation, and trabeculectomy through a modified limbal flap.

Table 1. Preoperative findings in patients treated by combined phacoemulsification and trabeculectomy.

Patient Eye LB

Visual Acuity

Visual Field Loss

lOP Medications 23 Betaxolol Rei Advanced Dipivefrin Rei

R

20(70

L

20/60

20

Betaxolol Rei Advanced Dipivefrin Rei

IG

R L

20/60 20/60

None None

Early Early

PR

R

24

Betaxolol Rei Betaxolol Rei

Moderate

MR

L L

20/60 20/60

30 26 26 42

None

20/80

Moderate Advanced

MATERIALS AND METHODS Seven eyes in four consecutive patients were considered for cataract surgery based on best corrected visual acuity of 20/60 or worse and slitlamp diagnosis of cataract formation consistent with the reported acuity. Concomitant filtering surgery for glaucoma was considered for elevated intraocular pressure (lOP) and/or visual field loss consistent with glaucoma (Table 1). Preoperatively, each eye was maximally dilated and the lOP lowered with a mercury weighted bag.

Anesthesia was achieved with facial and peribulbar nerve blocks using 4% lidocaine and 0.75% bupivacaine equally mixed. A4 mm to 6 mm superior fornix-based conjunctival flap was made in each case and the scleral surface cleaned and cauterized. A paracentesis track was then made through the temporal limbus with a micro-knife. II;! patients one and four (three eyes) , a 6 mm curvilinear scleral groove was made (Figure 1A) . In patients two and three (four eyes), a 4.5 mm straight scleral groove

Robert G. Martin, M.D., Donald P. McCurdy, M.D., George W . Tate, M.D., and Spencer P. Thornton, M.D. , provided invaluable support. Reprint requests to Fred M. Gregg, M.D., 725 Glenwood Drive, Chattanooga, Tennessee 37404. 362

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Fig. lAo (Gregg) Initial scleral incision in 6.0 mm technique.

Fig. lB .

was made (Figure 2A). With both techniques the incision was placed 2.0 mm to 2.5 mm behind the corneal limbus, and entry into the anterior chamber was made with a 3.2 mm keratome underneath the constructed flap. This was followed by the creation of a circular-tear caps ulotomy under sodium hyaluronate (Healon®). The lens nucleus was emulsified using a 30-degree bevel tip, and the cortical remnants aspirated through a 0.3 mm port. The viscoelastic was again

introduced to maintain the anterior chamber and inflate the capsular bag. A micro-knife was then used to extend each wound the same width internally as the previously made groove. In patients one and four (three eyes), a threepiece IOL with a 6.0 mm optic was placed within the capsular bag under direct visualization. In patients two and three (four eyes), a one piece 5 x 6 mm implant was used. After rotating the haptics horizontally in each case, the visco-

Fig. 2A.

Fig. 2B.

(Gregg) Initial scleral incision in 4.5 mm technique.

(Gregg) Completed incision and flap in 6.0 mm technique.

(Gregg) Completed incision and flap in 4.5 mm technique.

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elastic was mechanically withdrawn and a miotic instilled. In the eyes with a 6 mm incision, a triangularshaped flap was constructed of half scleral thickness and dissected into clear cornea (Figure IB). This was done by directing a single radial incision to the corneal border from either end of the wound. A rectangular-shaped flap was made in the eyes with a 4.5 mm groove by adding radial incisions to each edge (Figure 2B). In all patients a 3.0 X 1.5 mm trabeculectomy was performed, followed by a peripheral iridectomy of the iris. The wound apices were then reapproximated with 10-0 polypropylene (Prolene®) sutures as shown. In each case this incomplete wound closure resulted in a mild shallowing of the anterior chamber, but in no case was the chamber flat. After the conjunctiva was closed with a single 8-0 chromic suture, a patch and shield were placed over the closed eyelids and the patients moved to the recovery room. RESULTS The results for each patient are presented in Table 2. From a mean preoperative visual acuity of 20/60, the final postoperative corrected acuity improved to 20/20 in most cases (range 20/20 to 20/40). The preoperative lOP decreased from a mean 27.29 to 15.29 with an average change of 12.00 mm (range 5 to 22). Glaucoma medications were discontinued in all patients after surgery. Patient four had a pressure spike to 35 mm Hg on postoperative day one, but this was lowered to 15 mm Hg by applying gentle pressure to the paracentesis wound with a 25-gauge needle. There were no other complications in any patient. The follow-up ranged from 9 to 23 months during which time there were no observed filtering bleb failures. Table 2. Results in patients treated by combined phacoemul. sification and trabeculectomy. Preoperative

Postoperative

Patient

Eye

VA

lOP (mm Hg)

LB

R

20/70

23

20/40

14

23

L

20/60

R

20/60 20/60

20 30

20/25 20/20

15 15.5

18 20

26 26 24

20/20 20/20 20/20 20/20

14.5 14 14 20

18

IG

L PH

R L

MR 364

L

20/60 20/60 20/80

42

VA

FollOP (mm low-up Hg) (months)

10 9

21

DISCUSSION Several therapeutic options are available for a patient with cataract and glaucoma. If the lOP is reasonably controlled, one may perform cataract surgery alone or perhaps plan to do a subsequent glaucoma operation if needed. If the glaucoma is uncontrolled to the point of threatening vision, a filter alone may be considered, with cataract surgery deferred until later. Another option is to perform both surgeries simultaneously. Performed alone, cataract surgery would be a simpler procedure with fewer complications. Even in patients with open-angle glaucoma, it has been shown that a posterior chamber lens can be safely implanted without compromising the IOP. 6- 9 However, pressure spikes in the immediate postoperative period are known to occur and can be damaging to an already compromised optic nerve. 10,11 Furthermore, most extracapsular techniques result in moderate conjunctival scarring, rendering a subsequent filter less successful. Performing an initial glaucoma procedure affords good lOP control, but for complete visual restoration a second operation must be performed. Combining the two operations seems to have the following advantages: (1) early visual restoration, (2) better long-term lOP control, and (3) protection against a pressure spike. Critics have argued that combining the operations may result in higher complications and less lOP control. Jay12 studied this question and reported that it did not seem to introduce new complications. Although this was a small series of patients, larger studies have also concluded that the triple procedure can be undertaken without incurring greater complications. 13 - 15 Other reports have demonstrated the efficacy of combining the cataract extraction and filter procedure in restoring vision and lowering IOP.16,17 Murchison and Shields 18 studied three groups of patients having cataract surgery with IOL implantation only, filtering surgery only, and combined cataract, IOL, and glaucoma surgery. Their findings indicated a similar final lOP for all three groups. Recently, Lyle and Jin 19 described their experience in performing phaco-trabeculectomy in 104 eyes with a 3 mm incision and foldable lens. This was compared to 112 eyes that had a more 'conventional 6 mm technique. In both groups final vision exceeded 20/40 in 87% and lOP reduced to 21 mm Hg or less in more than 90%. Based on our results, combining glaucoma surgery with cataract removal by the methods shown is a viable option. In all cases, vision was improved and lOP was reduced to an acceptable level with-

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out medication. When performing the triple procedure through the abbreviated flaps described, both the short-term and long-term lOP control can be combined with the early restoration of vision expected with small incision techniques. REFERENCES 1. Shields MB. Combined cataract extraction and guarded sclerectomy: reevaluation in the extracapsular era. Ophthalmology 1986; 93:366-370 2. Spaeth GL, Sivalingam E. The partial-punch: a new combined cataract-glaucoma operation. Ophthalmic Surg 1976; 7(1):53-57 3. Shields MB. Combined cataract extraction and glaucoma surgery. Ophthalmology 1982; 89:231-237 4. Longstaff S, Wormald RPL, Mazover A, Hitchings RA. Glaucoma triple procedures: efficacy of intraocular pressure control and visual outcome. Ophthalmic Surg 1990; 21:786-793 5. Starita RJ, Berstein LP. Extracapsular cataract extra~­ tion in primary open-angle glaucoma: surgical options. Clinical Signs in Ophthalmology 1989; 11:2-15 6. Handa J, Henry JC, Krupin T, Keates E. Extracapsular cataract extraction with posterior chamber lens implantation in patients with glaucoma. Arch Ophthalmol 1987; 105:765-769 7. McGuigan LJB, Gottsch J, Stark WJ, et at. Extracapsular cataract extraction and posterior chamber lens implantation in eyes with preexisting glaucoma. Arch Ophthalmol1986; 104:1301-1308 8. McMahan LB, Monica ML, Zimmerman TJ. Posterior chamber pseudophakes in glaucoma patients. Ophthalmic Surg 1986; 17:146-150

9. Monica ML, Zimmerman TJ, McMahan LB. Implantation of posterior chamber lenses in glaucoma patients. Ann Ophthalmol1985; 17:9-10 10. Galin MA, Lin LL-K, Obstbaum SA. Cataract extraction and intraocular pressure. Trans Ophthalmol Soc UK 1978; 98:124-127 11. Rich WJ, Radtke ND, Cohan BE. Early ocular hypertension after cataract extraction. Br J Ophthalmol 1974; 58:725-731 12. Jay JL. Extracapsular lens extraction and posterior chamber intraocular lens insertion combined with trabeculectomy. Br J Ophthalmol1985; 69:487-490 13. Jerndal T, Lundstrom M. Trabeculectomy combined with cataract extraction. Am J Ophthalmol1976; 81: 227-231 14. Johns GE, Layden WE. Combined trabeculectomy and cataract extraction. Am J Ophthalmol1979; 88:973981 15. Edwards RS. Trabeculectomy combined with cataract extraction: a follow-up study. Br J Ophthalmol 1980; 64:720-724 16. Ohanesian RV, Kim EW. A prospective study of combined extracapsular cataract extraction, posterior chamber lens implantation, and trabeculectomy. Am Intra-Ocular Implant Soc J 1985; 11:142-145 17. Skorpik C, Paroussis P, Gnad HD, Menapace R. Trabeculectomy and intraocular lens implantation: a combined procedure. J Cataract Refract Surg 1987; 13: 39-42 18. Murchison JF Jr, Shields MB. An evaluation of three surgical approaches for coexisting cataract and glaucoma. Ophthalmic Surg 1989; 20:393-398 19. Lyle WA, Jin JC. Comparison of a 3- and 6-mm incision in combined phacoemulsification and trabeculectomy. Am J Ophthalmol 1991; Ill :189-196

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