- Email: [email protected]
Timolol gel versus acetazolamide in the prophylaxis of ocular hypertension after phacoemulsification
Timolol gel versus acetazolamide in the prophylaxis of ocular hypertension after phacoemulsification Anastasios John Kanellopoulos, MD, Henry D. Perry, MD, Eric D. Donnenfeld, MD
ABSTRACT Purpose: To compare postoperative intraocular pressure (lOP) after administration of acetazolamide and timolol following phacoemulsification and intraocular lens implantation. Setting: Ophthalmic Consultants of Long Island, Rockville Centre, New York, USA. Methods: Sixty patients were included in a prospective, randomized, masked trial. The patients received either two doses of oral, sustained-release acetazolamide (Diamox® Sequels®) or a single dose of topical timolol 0.5% gel (Timoptic XE®) . Intraocular pressure was measured by Goldmann applanation tonometry preoperatively and 1 day postoperatively. Results: Mean preoperative lOP was 16.4 mm Hg . One day postoperatively, it was 19.5 mm Hg in the oral acetazolamide group and 15.9 mm Hg in the timolol gel group. One patient in the acetazolamide group developed significant adverse reactions . Conclusion: Prophylactic use of topical timolol 0.5% gel for viscoelastic-induced ocular hypertension after cataract extraction appears to offer better lOP control than oral acetazolamide and has potentially fewer adverse systemic effects. J Cataract Refract Surg 1997; 23:1070-1074
U
se of viscoelastic substances has become an integral part of anterior segment surgery. Viscoelastics have facilitated the development of several surgical techniques, allowing better tissue manipulation, maintenance of intraocular spaces, and protection of intraocular tissues during surgery. The advantages these substances provide have made them an important component of anterior segment surgery.
Reprint requests to Anastasios j. lVlnellapoulas, MD, Department of Ophthalmology, State University ofNew York, Health Science Center at Brooklyn, 450 Clarkson Avenue, Box 58, Brooklyn, New York 11203, USA. 1070
Nevertheless, the tendency to cause ocular hypertension postoperatively remains a concern. No single mechanism has been proven responsible for the postoperative ocular hypertensive effect of viscoelastic substances. The most widely accepted hypothesis is obstruction of the outflow channels by the large molecular size of viscoelastic substances. 1•2 Meticulous care is therefore taken intraoperatively to remove the substances from the anterior chamber. The attempt to remove as much viscoelastic as possible prevents the postoperative ocular hypertensive effect. Prophylactic treatment with ocular antihypertensive medical therapy has also been used to prevent acute
J CATARACT REFRACT SURG-VOL 23, SEPTEMBER 1997
TIMOLOL GEL VERSUS ACETAZOLAMIDE FOR rop PROPHYLAXIS
pressure rises in the immediate postoperative period. Postoperative pressure increases may be treated with topical beta-blockers, intracameral or topical miotics, topical or oral carbonic anhydrase inhibitors, or topical apraclonidine hydrochloride. In our anterior segment surgery routine, eyes remain patched for 1 day after cataract surgery. We have traditionally used oral acetazolamide after cataract surgery while the patch is in place. We decided to study timolol 0.5% gel because of its reported prolonged ocular contact and effective action. We did not include a control group, which would receive no prophylaxis, because we have encountered occasional patients with extreme intraocular pressure (lOP) spikes the day after phacoemulsification surgery with the use of viscoelastics when no prophylactic agent was administered. We report a prospective, randomized, masked trial comparing our traditional two doses of oral 500 mg sustained-release acetazolamide in the immediate period following cataract surgery with a single dose of topical timolol 0.5% gel-forming solution administered after the completion of surgery.
Methods All patients with a history of asthma and restrictive or obstructive pulmonary disease were excluded, as were those with a known history of glaucoma or ocular hypertension and those with the intraoperative complication of vitreous loss. Sixty consecutive patients having cataract extraction and intraocular lens implantation were randomly assigned to two groups. Patients in the first group received one dose of timolol 0.5% gelforming solution (Timoptic XE®) immediately after the completion of the surgery and before the patch was placed on the eye. Patients in the second group received two doses of oral, sustained-release acetazolamide 500 mg (Diamox® Sequels®) after the completion of the surgery and again that evening following discharge from the operating facility. In all patients, cataract extraction was performed by all three authors using sutureless phacoemulsification through a 5.5 mm scleral tunnel incision followed by implantation of a poly(methyl methacrylate), 5.5 mm optic diameter intraocular lens (IOL). The viscoelastic used in all cases was sodium hyaluronate (Healon®). At
the completion of 10L implantation, all patients received 1: 100 acetylcholine chloride (Miochol®) intracamerally, followed by meticulus standardized irrigation/ aspiration for 45 seconds to remove the administered viscolastic agent. All patients received a corticosteroidantibiotic ointment (Maxitrol®) and the eye was patched. As noted, the patients assigned to the first group also received a drop of timolol gel. Intraocular pressure was measured in all patients 1 day preoperatively and the first day postoperatively. The lOPs were measured by a trained technician who was unaware of patients' group assignment. The technician used Goldmann applanation tonometry with a slitlamp.
Results The sex, preoperative lOP, prophylaxis used, and postoperative lOP for the 60 patients are shown in Table 1. Preoperatively, the mean lOP of the 34 women and 26 men was 16.4 mm Hg (range 9.0 to 26.0 mm Hg). One day postoperatively, it was 19.5 mm Hg in the acetazolamide group (range 11.0 to 32.0 mm Hg) and 15.9 mm Hg in the timolol gel group (range 4.0 to 24.0 mm Hg). Postoperative lOP in the two groups is compared in Figure 1. One patient in the acetazolamide group developed severe gastrointestinal distress. The difference of the two means, evaluated with a Student's t- test, was statistically significant (P < .001).
Discussion The large molecular size of visco elastics decreases conventional aqueous outflow from the trabecular meshwork. Concomitant administration of hyaluronidase with viscoelastic solution has been shown to increase outflow facility and prevent lOP increase. I ,3 Hyaluronidase is present naturally in aqueous humor, but the quantity is apparently insufficient to metabolize the large volume of hyaluronic acid injected into the anterior chamber during surgical procedures. The large molecules of visco elastics probably exit the eye via outflow channels without being metabolized. 4,5 The clearance rate of viscoelastic substances from the anterior chamber appears to be related to the viscosity of the agent, which is directly related to the molecular weight and concentration. The viscosity of the most commonly used viscoelastic agents ranges
J CATARACT REFRACT SURG-VOL 23, SEPTEMBER 1997
1071
TIMOLOL GEL VERSUS ACETAZOLAMIDE FOR lOP PROPHYLAXIS
Table 1. Sex, preoperative and postoperative lOP, and treatment used in the two groups. Preop lOP
Preop lOP Patient Sex
2 3 4
F F F M
5
F
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
F M F M M M
25 26
F F
F F
M F F F M
F F M F
F F
27 28 29
F M
30
M
F
(mm Hg) x2 15 19 16 18 14 20 16 14 19 17 18 16 17 12 10 19 15 16 16 14 20 16 9 17 10 17 15 16 24 12
Postop lOP Glaucoma
Prophylaxis Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Acetazolamide Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel
12 16 16 23 22 18 30 18 19 21 26 12 10 11 18 18 15 14 26 12 16 16 32 19 12 14 16 18 19 13
No No No No No No No No No No Yes
No No No No No Yes
No No No No Yes Yes
No No No No No No No
from 2 million to 4000 centistokes. The viscoelastic used in our study, Healon, has a molecular weight of 2.5 to 3.8 million and a viscosity of200,000 centistokes. When the concentration of the viscoelastic is held constant, the lower the viscosity of the substance, the higher and more prolonged the lOP rise. 6,7 Viscoelastic substances affect lOP at a different rate. 8,9 Although this study compared viscoelasticinduced ocular hypertension after two prophylactic treatments, the actual lOP increase was significantly related to the degree of surgical trauma and the individual variation in trabecular meshwork anatomy. These are important factors that influence postoperative lOP levels. Pre-existing poor outflow facility, tight wound closure, and extensive inflammation may also contrib1072
Patient Sex 31 32 33 34 35
36 37 38 39
40
M M M F M F M F F M
41 42 43 44 45
M M M M
46 47
M
48 49
M M
50 51
M
M F
M
52
F
53 54 55
F M
56 57
F F
58 59 60
F
F
F
F
(mm Hg) x 2 18 15 15 18 16 18 20 18 14 16 16 18 15 14 18 20 14 16 18 18 13 16 18 20 16 18 14 26 16 16
Prophylaxis Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel Acetazolamide Acetazolamide Acetazolamide Timolol gel Acetazolamide
Postop lOP Glaucoma 14 16 23 4 26 20 23 20 19 18 10 15 26 12 15 26 24 12 20 16 18 18 16 22 17 24 13 18 10 17
No No No No No No No No No No No No No No No Yes
No No No No No No No No No No No No Yes
No
ute to a more senous lOP Increase after anterior segment surgery. Despite the meticulous attention given to the removal of the viscoelastic agent at the end of cataract surgery, this variable may also affect the results in an unknown fashion. Our data suggest that the use of timolol gel was more effective than oral acetazolamide in prophylaxis for postoperative viscoelastic-induced ocular hypertension. Of particular concern were the six patients whose postoperative lOP values were greater than 25.0 mm Hg. All these patients were in the oral acetazolamide group (Figure 2). This could be explained by poor compliance of some of the patients to the second dose of acetazolamide or to insufficient viscoelastic-induced hypertension prophylaxis by the
] CATARACT REFRACT SURG--VOL 23, SEPTEMBER 1997
TIMOLOL GEL VERSUS ACETAZOLAMIDE FOR lOP PROPHYLAXIS 35 0
30 0
0
25
•
0
0
0
0
0
f
20 0
0
0
• • •-
15
•
0
0
10
5
o
0
0
•
•••
0
0
•
0
•
•
•
0
0
0
0
0
••
••
0
• o
5
10
20
15
25
30
35
Patienttl
• Timolol Gel
o Acetazolamide
Figure 1. (Kanellopoulos) Postoperative lOP (mm Hg) in the two study groups.
acetazolamide regimen. One patient in this group developed a significant adverse reaction to the oral acetazolamide, whereas no adverse reactions were noted in the timolol gel group. Timolol gel administration by the surgeon can also diminish problems with patient compliance to prescribed medication. However, timolol gel is contraindicated in patients with restrictive or obstructive pulmonary disease and some patients with cardiac disease because systemic absorption of this medication could result in significant adverse reactions. 10 Carbonic anhydrase inhibitors also have a long list of potential adverse reactions, such as fatal aplastic anemia, nephrolithiasis, and sulfa-allergy cross-reactivity.ll Therefore, neither medicine seems to be ideal for all patients. As noted previously, patients with vitreous loss were excluded from this study. No significant intraoperative complications were seen in the patients studied. This study did not address prophylaxis in patients with pre-existing glaucoma or a known history of ocular hypertension. These patients usually have decreased baseline outflow facility and would therefore have a higher risk of developing viscoelastic-induced
ocular hypertension following phacoemulsification surgery. Our results suggest that the use of timolol gel 0.5% in the prevention of viscoelastic-induced ocular hypertension following cataract extraction offers better postoperative lOP control than oral acetazolamide. In addition, topical timolol 0.5% gel may have fewer adverse systemic effects than oral acetazolamide.
References 1. Berson FG, Patterson MM, Epstein DL. Obstruction of
aqueous outflow by sodium hyaluronate in enucleated human eyes. Am J Ophthalmol1983; 95:668-672 2. Passo MS, Ernest JT, Goldstick TK. Hyaluronate increases intraocular pressure when used in cataract extraction. Br J Ophthalmol 1985; 69:572-575 3. Hein SR, Keates RH, Weber PA. Elimination of sodium hyaluronate-induced decrease of outflow facility with hyaluronidase. Ophthalmic Surg 1986; 17:731-734 4. Balazs EA. Sodium hyaluronate in viscosurgety. In: Miller D, Stegmann R, eds, Healon (Sodium Hyaluronate); a Guide to Its Use in Ophthalmic Surgery. New York, NY, John Wiley and Sons, 1983; 5-28
J CATARACf REFRACf SURG-VOL 23. SEPTEMBER 1997
1073
TlMOLOL GEL VERSUS ACETAZOLAMIDE FOR lOP PROPHYLAXIS
5. Morgan RK, Skuta GL. Viscoelastic-related glaucomas. Semin Ophthalmol 1994; 9:229-234 6. Schubert HD, Denlinger JL, Balazs EA. Exogenous Nahyaluronate in the anterior chamber of the owl monkey and its effect on intraocular pressure. Exp Eye Res 1984; 39:137-152 7. Liesegang TJ. Viscoelastic substances in ophthalmology. Surv Ophthalmol 1990; 34:268-293 8. Burke S, Sugar J, Farber MD. Comparison of the effects of two viscoelastic agents, Healon and Visco at, on postoperative intraocular pressure after penetrating keratoplasty. Ophthalmic Surg 1990; 21:821-826 9. Lane SS, Naylor DW, Kullerstrand LJ, et al. Prospective comparison of the effects of Occucoat, Viscoat, and Healon on intraocular pressure and endothelial cell loss. J Cataract Refract Surg 1991; 17:21-26 10. Nelson WL, Fraunfelder FT, Sills JM, et al. Adverse
1074
respiratory and cardiovascular events attributed to timolol ophthalmic solution. Am J Ophthalmol 1986; 102:606611 11. Fraunfelder FT, Meyer SM, Bagby GC Jr, Dreis MW. Hematologic reactions to carbonic anhydrase inhibitors. Am J Ophthalmol 1985; 100:79-81
From the Department ofOphthalmology, State University ofNew York, Health Science Center at Brooklyn (Kanellopoulos), the Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School Boston (Kanellopoulos), and the Department of Ophthalmology, North Shore University Hospital Manhasset, New York, and New York University Medical Center, New York (Kanellopoulos, Perry, Donnenfeld), USA. Supported in part by the Liom Club International Oakbrook, Illinois, USA.
J CATARACT REFRACT SURG-VOL 23, SEPTEMBER 1997
ABSTRACT Purpose: To compare postoperative intraocular pressure (lOP) after administration of acetazolamide and timolol following phacoemulsification and intraocular lens implantation. Setting: Ophthalmic Consultants of Long Island, Rockville Centre, New York, USA. Methods: Sixty patients were included in a prospective, randomized, masked trial. The patients received either two doses of oral, sustained-release acetazolamide (Diamox® Sequels®) or a single dose of topical timolol 0.5% gel (Timoptic XE®) . Intraocular pressure was measured by Goldmann applanation tonometry preoperatively and 1 day postoperatively. Results: Mean preoperative lOP was 16.4 mm Hg . One day postoperatively, it was 19.5 mm Hg in the oral acetazolamide group and 15.9 mm Hg in the timolol gel group. One patient in the acetazolamide group developed significant adverse reactions . Conclusion: Prophylactic use of topical timolol 0.5% gel for viscoelastic-induced ocular hypertension after cataract extraction appears to offer better lOP control than oral acetazolamide and has potentially fewer adverse systemic effects. J Cataract Refract Surg 1997; 23:1070-1074
U
se of viscoelastic substances has become an integral part of anterior segment surgery. Viscoelastics have facilitated the development of several surgical techniques, allowing better tissue manipulation, maintenance of intraocular spaces, and protection of intraocular tissues during surgery. The advantages these substances provide have made them an important component of anterior segment surgery.
Reprint requests to Anastasios j. lVlnellapoulas, MD, Department of Ophthalmology, State University ofNew York, Health Science Center at Brooklyn, 450 Clarkson Avenue, Box 58, Brooklyn, New York 11203, USA. 1070
Nevertheless, the tendency to cause ocular hypertension postoperatively remains a concern. No single mechanism has been proven responsible for the postoperative ocular hypertensive effect of viscoelastic substances. The most widely accepted hypothesis is obstruction of the outflow channels by the large molecular size of viscoelastic substances. 1•2 Meticulous care is therefore taken intraoperatively to remove the substances from the anterior chamber. The attempt to remove as much viscoelastic as possible prevents the postoperative ocular hypertensive effect. Prophylactic treatment with ocular antihypertensive medical therapy has also been used to prevent acute
J CATARACT REFRACT SURG-VOL 23, SEPTEMBER 1997
TIMOLOL GEL VERSUS ACETAZOLAMIDE FOR rop PROPHYLAXIS
pressure rises in the immediate postoperative period. Postoperative pressure increases may be treated with topical beta-blockers, intracameral or topical miotics, topical or oral carbonic anhydrase inhibitors, or topical apraclonidine hydrochloride. In our anterior segment surgery routine, eyes remain patched for 1 day after cataract surgery. We have traditionally used oral acetazolamide after cataract surgery while the patch is in place. We decided to study timolol 0.5% gel because of its reported prolonged ocular contact and effective action. We did not include a control group, which would receive no prophylaxis, because we have encountered occasional patients with extreme intraocular pressure (lOP) spikes the day after phacoemulsification surgery with the use of viscoelastics when no prophylactic agent was administered. We report a prospective, randomized, masked trial comparing our traditional two doses of oral 500 mg sustained-release acetazolamide in the immediate period following cataract surgery with a single dose of topical timolol 0.5% gel-forming solution administered after the completion of surgery.
Methods All patients with a history of asthma and restrictive or obstructive pulmonary disease were excluded, as were those with a known history of glaucoma or ocular hypertension and those with the intraoperative complication of vitreous loss. Sixty consecutive patients having cataract extraction and intraocular lens implantation were randomly assigned to two groups. Patients in the first group received one dose of timolol 0.5% gelforming solution (Timoptic XE®) immediately after the completion of the surgery and before the patch was placed on the eye. Patients in the second group received two doses of oral, sustained-release acetazolamide 500 mg (Diamox® Sequels®) after the completion of the surgery and again that evening following discharge from the operating facility. In all patients, cataract extraction was performed by all three authors using sutureless phacoemulsification through a 5.5 mm scleral tunnel incision followed by implantation of a poly(methyl methacrylate), 5.5 mm optic diameter intraocular lens (IOL). The viscoelastic used in all cases was sodium hyaluronate (Healon®). At
the completion of 10L implantation, all patients received 1: 100 acetylcholine chloride (Miochol®) intracamerally, followed by meticulus standardized irrigation/ aspiration for 45 seconds to remove the administered viscolastic agent. All patients received a corticosteroidantibiotic ointment (Maxitrol®) and the eye was patched. As noted, the patients assigned to the first group also received a drop of timolol gel. Intraocular pressure was measured in all patients 1 day preoperatively and the first day postoperatively. The lOPs were measured by a trained technician who was unaware of patients' group assignment. The technician used Goldmann applanation tonometry with a slitlamp.
Results The sex, preoperative lOP, prophylaxis used, and postoperative lOP for the 60 patients are shown in Table 1. Preoperatively, the mean lOP of the 34 women and 26 men was 16.4 mm Hg (range 9.0 to 26.0 mm Hg). One day postoperatively, it was 19.5 mm Hg in the acetazolamide group (range 11.0 to 32.0 mm Hg) and 15.9 mm Hg in the timolol gel group (range 4.0 to 24.0 mm Hg). Postoperative lOP in the two groups is compared in Figure 1. One patient in the acetazolamide group developed severe gastrointestinal distress. The difference of the two means, evaluated with a Student's t- test, was statistically significant (P < .001).
Discussion The large molecular size of visco elastics decreases conventional aqueous outflow from the trabecular meshwork. Concomitant administration of hyaluronidase with viscoelastic solution has been shown to increase outflow facility and prevent lOP increase. I ,3 Hyaluronidase is present naturally in aqueous humor, but the quantity is apparently insufficient to metabolize the large volume of hyaluronic acid injected into the anterior chamber during surgical procedures. The large molecules of visco elastics probably exit the eye via outflow channels without being metabolized. 4,5 The clearance rate of viscoelastic substances from the anterior chamber appears to be related to the viscosity of the agent, which is directly related to the molecular weight and concentration. The viscosity of the most commonly used viscoelastic agents ranges
J CATARACT REFRACT SURG-VOL 23, SEPTEMBER 1997
1071
TIMOLOL GEL VERSUS ACETAZOLAMIDE FOR lOP PROPHYLAXIS
Table 1. Sex, preoperative and postoperative lOP, and treatment used in the two groups. Preop lOP
Preop lOP Patient Sex
2 3 4
F F F M
5
F
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
F M F M M M
25 26
F F
F F
M F F F M
F F M F
F F
27 28 29
F M
30
M
F
(mm Hg) x2 15 19 16 18 14 20 16 14 19 17 18 16 17 12 10 19 15 16 16 14 20 16 9 17 10 17 15 16 24 12
Postop lOP Glaucoma
Prophylaxis Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Acetazolamide Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel
12 16 16 23 22 18 30 18 19 21 26 12 10 11 18 18 15 14 26 12 16 16 32 19 12 14 16 18 19 13
No No No No No No No No No No Yes
No No No No No Yes
No No No No Yes Yes
No No No No No No No
from 2 million to 4000 centistokes. The viscoelastic used in our study, Healon, has a molecular weight of 2.5 to 3.8 million and a viscosity of200,000 centistokes. When the concentration of the viscoelastic is held constant, the lower the viscosity of the substance, the higher and more prolonged the lOP rise. 6,7 Viscoelastic substances affect lOP at a different rate. 8,9 Although this study compared viscoelasticinduced ocular hypertension after two prophylactic treatments, the actual lOP increase was significantly related to the degree of surgical trauma and the individual variation in trabecular meshwork anatomy. These are important factors that influence postoperative lOP levels. Pre-existing poor outflow facility, tight wound closure, and extensive inflammation may also contrib1072
Patient Sex 31 32 33 34 35
36 37 38 39
40
M M M F M F M F F M
41 42 43 44 45
M M M M
46 47
M
48 49
M M
50 51
M
M F
M
52
F
53 54 55
F M
56 57
F F
58 59 60
F
F
F
F
(mm Hg) x 2 18 15 15 18 16 18 20 18 14 16 16 18 15 14 18 20 14 16 18 18 13 16 18 20 16 18 14 26 16 16
Prophylaxis Timolol gel Acetazolamide Acetazolamide Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel Acetazolamide Timolol gel Timolol gel Acetazolamide Timolol gel Acetazolamide Acetazolamide Acetazolamide Timolol gel Acetazolamide
Postop lOP Glaucoma 14 16 23 4 26 20 23 20 19 18 10 15 26 12 15 26 24 12 20 16 18 18 16 22 17 24 13 18 10 17
No No No No No No No No No No No No No No No Yes
No No No No No No No No No No No No Yes
No
ute to a more senous lOP Increase after anterior segment surgery. Despite the meticulous attention given to the removal of the viscoelastic agent at the end of cataract surgery, this variable may also affect the results in an unknown fashion. Our data suggest that the use of timolol gel was more effective than oral acetazolamide in prophylaxis for postoperative viscoelastic-induced ocular hypertension. Of particular concern were the six patients whose postoperative lOP values were greater than 25.0 mm Hg. All these patients were in the oral acetazolamide group (Figure 2). This could be explained by poor compliance of some of the patients to the second dose of acetazolamide or to insufficient viscoelastic-induced hypertension prophylaxis by the
] CATARACT REFRACT SURG--VOL 23, SEPTEMBER 1997
TIMOLOL GEL VERSUS ACETAZOLAMIDE FOR lOP PROPHYLAXIS 35 0
30 0
0
25
•
0
0
0
0
0
f
20 0
0
0
• • •-
15
•
0
0
10
5
o
0
0
•
•••
0
0
•
0
•
•
•
0
0
0
0
0
••
••
0
• o
5
10
20
15
25
30
35
Patienttl
• Timolol Gel
o Acetazolamide
Figure 1. (Kanellopoulos) Postoperative lOP (mm Hg) in the two study groups.
acetazolamide regimen. One patient in this group developed a significant adverse reaction to the oral acetazolamide, whereas no adverse reactions were noted in the timolol gel group. Timolol gel administration by the surgeon can also diminish problems with patient compliance to prescribed medication. However, timolol gel is contraindicated in patients with restrictive or obstructive pulmonary disease and some patients with cardiac disease because systemic absorption of this medication could result in significant adverse reactions. 10 Carbonic anhydrase inhibitors also have a long list of potential adverse reactions, such as fatal aplastic anemia, nephrolithiasis, and sulfa-allergy cross-reactivity.ll Therefore, neither medicine seems to be ideal for all patients. As noted previously, patients with vitreous loss were excluded from this study. No significant intraoperative complications were seen in the patients studied. This study did not address prophylaxis in patients with pre-existing glaucoma or a known history of ocular hypertension. These patients usually have decreased baseline outflow facility and would therefore have a higher risk of developing viscoelastic-induced
ocular hypertension following phacoemulsification surgery. Our results suggest that the use of timolol gel 0.5% in the prevention of viscoelastic-induced ocular hypertension following cataract extraction offers better postoperative lOP control than oral acetazolamide. In addition, topical timolol 0.5% gel may have fewer adverse systemic effects than oral acetazolamide.
References 1. Berson FG, Patterson MM, Epstein DL. Obstruction of
aqueous outflow by sodium hyaluronate in enucleated human eyes. Am J Ophthalmol1983; 95:668-672 2. Passo MS, Ernest JT, Goldstick TK. Hyaluronate increases intraocular pressure when used in cataract extraction. Br J Ophthalmol 1985; 69:572-575 3. Hein SR, Keates RH, Weber PA. Elimination of sodium hyaluronate-induced decrease of outflow facility with hyaluronidase. Ophthalmic Surg 1986; 17:731-734 4. Balazs EA. Sodium hyaluronate in viscosurgety. In: Miller D, Stegmann R, eds, Healon (Sodium Hyaluronate); a Guide to Its Use in Ophthalmic Surgery. New York, NY, John Wiley and Sons, 1983; 5-28
J CATARACf REFRACf SURG-VOL 23. SEPTEMBER 1997
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TlMOLOL GEL VERSUS ACETAZOLAMIDE FOR lOP PROPHYLAXIS
5. Morgan RK, Skuta GL. Viscoelastic-related glaucomas. Semin Ophthalmol 1994; 9:229-234 6. Schubert HD, Denlinger JL, Balazs EA. Exogenous Nahyaluronate in the anterior chamber of the owl monkey and its effect on intraocular pressure. Exp Eye Res 1984; 39:137-152 7. Liesegang TJ. Viscoelastic substances in ophthalmology. Surv Ophthalmol 1990; 34:268-293 8. Burke S, Sugar J, Farber MD. Comparison of the effects of two viscoelastic agents, Healon and Visco at, on postoperative intraocular pressure after penetrating keratoplasty. Ophthalmic Surg 1990; 21:821-826 9. Lane SS, Naylor DW, Kullerstrand LJ, et al. Prospective comparison of the effects of Occucoat, Viscoat, and Healon on intraocular pressure and endothelial cell loss. J Cataract Refract Surg 1991; 17:21-26 10. Nelson WL, Fraunfelder FT, Sills JM, et al. Adverse
1074
respiratory and cardiovascular events attributed to timolol ophthalmic solution. Am J Ophthalmol 1986; 102:606611 11. Fraunfelder FT, Meyer SM, Bagby GC Jr, Dreis MW. Hematologic reactions to carbonic anhydrase inhibitors. Am J Ophthalmol 1985; 100:79-81
From the Department ofOphthalmology, State University ofNew York, Health Science Center at Brooklyn (Kanellopoulos), the Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School Boston (Kanellopoulos), and the Department of Ophthalmology, North Shore University Hospital Manhasset, New York, and New York University Medical Center, New York (Kanellopoulos, Perry, Donnenfeld), USA. Supported in part by the Liom Club International Oakbrook, Illinois, USA.
J CATARACT REFRACT SURG-VOL 23, SEPTEMBER 1997