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Secondary implantation of open-loop, flexible, anterior chamber intraocular lenses
Secondary implantation of open-loop, flexible, anterior chamber intraocular lenses C.R. Ellerton, FRCOphth, S.M. Rattigan, FRCS!, F.M. Chapman, FRCOphth, D.K. Chitkara, FRCOphth, D.L. Smerdon, FRCSEd, FRCOphth
ABSTRACT Purpose: To assess the results of implantation of secondary, open-loop, flexible, anterior chamber intraocular lenses (IOLs) and compare the findings with those of other published studies. Setting: A combined ophthalmology and ear, nose, and throat hospital in Middlesbrough, Cleveland, England. Methods: This retrospective study comprised 81 patients who had secondary implantation of a flexible, open-loop, anterior chamber IOL by one surgeon. The incidence of postoperative complications was ascertained, and best corrected preoperative and postoperative visual acuities were compared. Results: Two serious complications occurred: one severe loss of vision that is still under investigation and one retinal detachment that was repaired with good residual visual function. Of all 81 patients, 92.5% were within one Snellen line of their preoperative best corrected visual acuity. These results compare favorably with those of other published studies. Conclusion: Using an open-loop, flexible, anterior chamber lens for secondary implantation is still an acceptable way to treat aphakia. The poor reputation of these lenses is undeserved. J Cataract Refract Surg 1996; 22:951-954
D
espite a more favorable press over the past 6 years, I the use of anterior chamber intraocular lenses (IOLs) for secondary implantation is still regarded with suspicion? The development of the sutured posterior chamber lens technique reflects the degree of this suspicion. 3 .4 Lim et al. I showed that the poor reputation of From North Riding Infirmary, Middlesbrough, Cleveland, England. Reprint requests to David L. Smerdon, FRCSEd, FRCOphth, North Riding Infirmary, Newport Road, Middlesbrough, Cleveland TSI 5JE, England.
closed-loop, flexible, anterior chamber IOLs is deserved. These lenses have an estimated explantation rate between 0.25 and 0.70%. Open-loop, flexible, anterior chamber lenses, however, have an explantation rate between 0.06 and 0.16%, about five times lower. I We have been using open-loop, flexible, anterior chamber lenses of the Multiflex type for secondary implantation for the past 7 years. Our clinical impression was that even when vitreous surgery was required during the procedure, the results were still acceptable. This study was designed to test that impression.
J CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996
951
SECONDARY IMPLANTATION OF OPEN-LOOP AC IOLs
Materials and Methods The aims of the study were as follows: 1. To determine the number of secondary, open-loop, flexible, anterior chamber lenses implanted by one surgeon over the past 7 years. 2. To determine the incidence of postoperative problems encountered such as explantation, endophthalmitis, loop malplacement, pseudophakic bullous keratopathy (PBK), cystoid macular edema (CME), retinal detachment, incomplete vitreous clearance, and induced glaucoma. 3. To establish the percentages of patients achieving a visual acuity of 6/9 or better and 6/12 or better and examine the postoperative refraction results. 4. To ascertain the preoperative and postoperative best corrected visual acuities of all patients and to compare the results with those of other published series. Patients were identified from the operating theater register and one surgeon's personal operating log. Case records were retrieved and examined. The following information was recorded: name, unit number, date of birth, side of operation, axial length, best corrected preoperative visual acuity, preoperative refraction, desired postoperative refraction, reason for aphakia, date of previous operation, whether there was vitreous in the anterior chamber preoperatively, anesthetic type, technique for any vitreous surgery, IOL type and power, best corrected postoperative visual acuity, postoperative refraction, and postoperative complications and how soon after surgery they occurred.
Results Over the study period (June 1, 1987, to May 31, 1994), 108 secondary lens implantations were performed under the direction of one surgeon (D.L.S.); 23 were done by other members of the surgical team and were thus excluded. Of the 85 left, 1 had a secondary posterior chamber IOL inserted, 2 were excluded for short follow-up, and 1 set of notes could not be found. This left 81 patients in the analysis. Patient age ranged from 22 to 92 years (mean 67 years). There were 47 right (58%) and 34 left (42%) eyes. The axial lengths varied from 19.26 to 28.07 mm (mean 23.67 mm). 952
Sixty patients (75%) had a best corrected visual acuity of 6/12 or better and 46 (57%), 6/9 or better. Only 12 (15%) had a preoperative refraction recorded. Another 40 were contact lens wearers (49%) whose best corrected visual acuity was recorded as the best contact lens acuity, leaving 29 cases (36%) with aphakic glasses and no preoperative refraction recorded in the notes. Desired postoperative refraction was from +3.00 to - 3.00 diopters (D); in 62 cases (77%) -1.00 D was aimed for. Eighty patients had had previous surgery: 67 intracapsular cataract extractions; 5 extracapsular cataract extractions; 4 repairs of penetrating wound with spontaneous lens absorption; 3 needlings; 1lensectomy. One patient had a dislocated lens without previous surgery. The interval between the first operation and the secondary lens implantation ranged from 1 to 47 years (mean 10.5 years). Fifty-six records (69%) documented vitreous in the anterior chamber. It was present in 30 eyes (37%) and not present in 26 (32%). In the other 25 cases (31 %), there was no mention of vitreous. Surgeries were performed using general anesthetic in 77 eyes (95%) and local anesthetic in 4 (5%). Twenty-three eyes (28%) required vitreous surgery; 13 (16%) had sponge-and-scissors, 6 (7%) had an automated vitrectomy, and in 4 (5%), single strands of vitreous under tension were cut with scissors. Seven records (9%) noted vitreous in the anterior chamber preoperatively but did not mention vitreous surgery during secondary lens implantation. All lenses inserted were open-loop, flexible, and anterior; they were the same style but supplied by different manufacturers as IOL contracts changed. The powers ranged from +8.00 to +29.00 D (mean + 19.60 D). No cases of explantation, endophthalmitis, or loop mal placement were encountered in this series. One case (1.2%) of PBK developed 30 months after secondary lens implantation. One case (1.2%) of severe documented CME was encountered; vision was severely reduced from the immediate postoperative period and has remained so. One case (1.2%) of retinal detachment occurred 14 days after surgery. After the retina was flattened, the final visual acuity was 6/18. There were six cases (7%) of incomplete vitreous clearance (vitreous could be seen in the anterior chamber at some time postoperatively). All had vitreous in the anterior cham-
J CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996
SECONDARY IMPLANTATION OF OPEN-LOOP AC IOLs
ber preoperatively. In two, no vitreous surgery was performed during the secondary lens implantation, one had a sponge-and-scissors and two, automated vitrectomies. The other had a strand cut and the tag was visible in the anterior chamber postoperatively but was not under tension. Four cases (5.0%) had wound leaks, one requiring resuturing, and there was one iris prolapse (1.2%). One 10L (1.2%) required repositioning when a foot was found through an iridectomy. Four cases (5.0%) required YAG laser treatment: two iridotomies for iris bombe and two for capsule remnants for visual reasons. One patient (1.2%) had diplopia with an exotropia. Of the 81 eyes, 60 (74%) achieved 6/9 or better and 69 (85%) achieved 6/12 or better with best corrected visual acuity. A postoperative refraction was recorded on 70 cases (86%). Four cases ended with a spherical equivalent more than 3.00 0 outside the aimed for postoperative sphere. Of the 11 cases (14%) with no postoperative refraction, 7 achieved 6/9 or better uncorrected visual acuity, 1 had a retinal detachment, 1 age-related maculopathy (ARM), and 1 myopic degeneration; in the last case, the reason for the lack of a refraction was unknown. Best corrected preoperative and postoperative visual acuities were compared using criteria established in previous series; 92.5% of patients were within one Snellen line of their best corrected preoperative acuity, leaving 7.5% who did not achieve this level. The worst reduction in visual acuity was in the eye with CME; one other eye with ARM had a seven line reduction in best corrected acuity.
Discussion Our population had one retinal detachment, an incidence of 1.2%. This is high compared with the rates for modern cataract surgery, which are between 0.1 and 0.4%,5 but is comparable to rates reported in other series (Table 1), which varied from 0 to 1.9%.6-9 We had a single case of CME with a very poor visual outcome. Our CME incidence of 1.2% compares favorably with that reported in other series (Table 1), which varied from 1.3 to 7.7%. Our incidence of PBK (1.2%) also compared favorably with that reported in other series (Table 1), which varied from 1.9 to 11.6%. One factor that affects these results is the latency between stimulus and effect of complications such as retinal detachment and corneal decompensation. Cystoid macular edema is perhaps a more realistic measure of immediate success, but this depends on how vigorously reduced vision is investigated. The one patient in our series for whom no cause of reduced vision was recorded could likely have been in this category. The success of the secondary lens implantation also depends on the state of the eye preoperatively. Preoperative endothelial cell analysis might help determine why PBK rates vary. In our practice, this would not affect the choice of operation. The question that remains is whether open-loop, flexible, anterior chamber lenses still have a place in routine secondary lens implantation or whether we should change to transsclerally sutured posterior chamber lenses. Our results and those of others suggest acceptable results from the use of anterior chamber lenses. We know what to expect in the way of complications. We
Table 1. Incidence of complications, percentages. Study Complication Explantation Endophthalmitis Loop malposition Pseudophakic bullous keratopathy Cystoid macular edema Retinal detachment NR
=
Current (n 81)
=
MREH6 (n
= 79)-
(n
LGf
= 52)-
Weene8 (n 43)
=
Biro9 (n 107)-
0 0 2.8 2.8 4.6 0
0 0 0 1.2
1.3 0 2.5 3.8
0 0 1.9
2.3 0 2.3 11.6
1.2 1.2
1.3 1.3
7.7 1.9
2.3 0
NR
=
information not recorded or not given
* Series of mixed anterior and posterior chamber secondary IOLs
J CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996
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SECONDARY IMPLANTATION OF OPEN-LOOP AC IOLs
should only change techniques if the alternative procedure is proven over the years to give better results with lower complications. Not enough information exists concerning the long-term follow-up of transsclerally sutured lenses. A recent study suggests an impressively low rate of CME2 but a high level of other complications, such as erosion of the sutures through the scleral flaps, induction of glaucoma, and suprachoroidal hemorrhage. 2 ,lO The level of complications encountered with these techniques is leading to a re-evaluation of the flexible, open-loop, anterior chamber lens. 11 In some cases, an anterior chamber lens cannot be used and a sutured posterior chamber lens would be a better choice. We conclude that at present, open-loop, flexible, anterior chamber lenses remain an acceptable way of treating aphakia.
References
5.
6.
7.
8.
9.
1. Lim ES, Apple ~C, Tsai Jc, et al. An analysis of flexible anterior chamber lenses with special reference to the normalized rate oflens explantation. Ophthalmology 1991; 98:243-246 2. Solomon K, Gussler JR, Gussler C, Van Meter WS. Incidence and management of complications of transsclerally sutured posterior chamber lenses. J Cataract Refract Surg 1993; 19:488-493 3. Hu BV, Shin OH, Gibbs KA, Hong YJ. Implantation of
954
4.
10.
11.
posterior chamber lens in the absence of capsular and zonular support. Arch Ophthalmol1988; 106:416-420 Stark WJ, Gottsch JO, Goodman OF, et al. Posterior chamber intraocular lens implantation in the absence of capsular support. Arch Ophthalmol 1989; 107: 10781083 Powe NR, Schein 00, Gieser SC, et al. Synthesis of the literature on visual acuity and complications following cataract extraction with intraocular lens implantation. Arch Ophthalmol 1994; 112:239-252; correction p 889 Leatherbarrow B, Trevett A, Tullo AB. Secondaty lens implantation: incidence, indications and complications. Eye 1988; 2:370-375 Hayward JM, Noble BA, George N. Secondaty intraocular lens implantation: eight year experience. Eye 1990; 4:548-556 Weene LE. Flexible open-loop anterior chamber intraocular lens implants. Ophthalmology 1993; 100:16361639 Biro Z. Results and complications of secondaty intraocular lens implantation. J Cataract Refract Surg 1993; 19: 64-67 Schein 00, Kenyon KR, Steinert RF, et al. A randomized trial of intraocular lens fixation techniques with penetrating keratoplasty. Ophthalmology 1993; 100:14371443 Arkin MS, Steinert RF. Sutured posterior chamber intraocular lenses. Int Ophthalmol Clin 1994; 34(3):67-85
] CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996
ABSTRACT Purpose: To assess the results of implantation of secondary, open-loop, flexible, anterior chamber intraocular lenses (IOLs) and compare the findings with those of other published studies. Setting: A combined ophthalmology and ear, nose, and throat hospital in Middlesbrough, Cleveland, England. Methods: This retrospective study comprised 81 patients who had secondary implantation of a flexible, open-loop, anterior chamber IOL by one surgeon. The incidence of postoperative complications was ascertained, and best corrected preoperative and postoperative visual acuities were compared. Results: Two serious complications occurred: one severe loss of vision that is still under investigation and one retinal detachment that was repaired with good residual visual function. Of all 81 patients, 92.5% were within one Snellen line of their preoperative best corrected visual acuity. These results compare favorably with those of other published studies. Conclusion: Using an open-loop, flexible, anterior chamber lens for secondary implantation is still an acceptable way to treat aphakia. The poor reputation of these lenses is undeserved. J Cataract Refract Surg 1996; 22:951-954
D
espite a more favorable press over the past 6 years, I the use of anterior chamber intraocular lenses (IOLs) for secondary implantation is still regarded with suspicion? The development of the sutured posterior chamber lens technique reflects the degree of this suspicion. 3 .4 Lim et al. I showed that the poor reputation of From North Riding Infirmary, Middlesbrough, Cleveland, England. Reprint requests to David L. Smerdon, FRCSEd, FRCOphth, North Riding Infirmary, Newport Road, Middlesbrough, Cleveland TSI 5JE, England.
closed-loop, flexible, anterior chamber IOLs is deserved. These lenses have an estimated explantation rate between 0.25 and 0.70%. Open-loop, flexible, anterior chamber lenses, however, have an explantation rate between 0.06 and 0.16%, about five times lower. I We have been using open-loop, flexible, anterior chamber lenses of the Multiflex type for secondary implantation for the past 7 years. Our clinical impression was that even when vitreous surgery was required during the procedure, the results were still acceptable. This study was designed to test that impression.
J CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996
951
SECONDARY IMPLANTATION OF OPEN-LOOP AC IOLs
Materials and Methods The aims of the study were as follows: 1. To determine the number of secondary, open-loop, flexible, anterior chamber lenses implanted by one surgeon over the past 7 years. 2. To determine the incidence of postoperative problems encountered such as explantation, endophthalmitis, loop malplacement, pseudophakic bullous keratopathy (PBK), cystoid macular edema (CME), retinal detachment, incomplete vitreous clearance, and induced glaucoma. 3. To establish the percentages of patients achieving a visual acuity of 6/9 or better and 6/12 or better and examine the postoperative refraction results. 4. To ascertain the preoperative and postoperative best corrected visual acuities of all patients and to compare the results with those of other published series. Patients were identified from the operating theater register and one surgeon's personal operating log. Case records were retrieved and examined. The following information was recorded: name, unit number, date of birth, side of operation, axial length, best corrected preoperative visual acuity, preoperative refraction, desired postoperative refraction, reason for aphakia, date of previous operation, whether there was vitreous in the anterior chamber preoperatively, anesthetic type, technique for any vitreous surgery, IOL type and power, best corrected postoperative visual acuity, postoperative refraction, and postoperative complications and how soon after surgery they occurred.
Results Over the study period (June 1, 1987, to May 31, 1994), 108 secondary lens implantations were performed under the direction of one surgeon (D.L.S.); 23 were done by other members of the surgical team and were thus excluded. Of the 85 left, 1 had a secondary posterior chamber IOL inserted, 2 were excluded for short follow-up, and 1 set of notes could not be found. This left 81 patients in the analysis. Patient age ranged from 22 to 92 years (mean 67 years). There were 47 right (58%) and 34 left (42%) eyes. The axial lengths varied from 19.26 to 28.07 mm (mean 23.67 mm). 952
Sixty patients (75%) had a best corrected visual acuity of 6/12 or better and 46 (57%), 6/9 or better. Only 12 (15%) had a preoperative refraction recorded. Another 40 were contact lens wearers (49%) whose best corrected visual acuity was recorded as the best contact lens acuity, leaving 29 cases (36%) with aphakic glasses and no preoperative refraction recorded in the notes. Desired postoperative refraction was from +3.00 to - 3.00 diopters (D); in 62 cases (77%) -1.00 D was aimed for. Eighty patients had had previous surgery: 67 intracapsular cataract extractions; 5 extracapsular cataract extractions; 4 repairs of penetrating wound with spontaneous lens absorption; 3 needlings; 1lensectomy. One patient had a dislocated lens without previous surgery. The interval between the first operation and the secondary lens implantation ranged from 1 to 47 years (mean 10.5 years). Fifty-six records (69%) documented vitreous in the anterior chamber. It was present in 30 eyes (37%) and not present in 26 (32%). In the other 25 cases (31 %), there was no mention of vitreous. Surgeries were performed using general anesthetic in 77 eyes (95%) and local anesthetic in 4 (5%). Twenty-three eyes (28%) required vitreous surgery; 13 (16%) had sponge-and-scissors, 6 (7%) had an automated vitrectomy, and in 4 (5%), single strands of vitreous under tension were cut with scissors. Seven records (9%) noted vitreous in the anterior chamber preoperatively but did not mention vitreous surgery during secondary lens implantation. All lenses inserted were open-loop, flexible, and anterior; they were the same style but supplied by different manufacturers as IOL contracts changed. The powers ranged from +8.00 to +29.00 D (mean + 19.60 D). No cases of explantation, endophthalmitis, or loop mal placement were encountered in this series. One case (1.2%) of PBK developed 30 months after secondary lens implantation. One case (1.2%) of severe documented CME was encountered; vision was severely reduced from the immediate postoperative period and has remained so. One case (1.2%) of retinal detachment occurred 14 days after surgery. After the retina was flattened, the final visual acuity was 6/18. There were six cases (7%) of incomplete vitreous clearance (vitreous could be seen in the anterior chamber at some time postoperatively). All had vitreous in the anterior cham-
J CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996
SECONDARY IMPLANTATION OF OPEN-LOOP AC IOLs
ber preoperatively. In two, no vitreous surgery was performed during the secondary lens implantation, one had a sponge-and-scissors and two, automated vitrectomies. The other had a strand cut and the tag was visible in the anterior chamber postoperatively but was not under tension. Four cases (5.0%) had wound leaks, one requiring resuturing, and there was one iris prolapse (1.2%). One 10L (1.2%) required repositioning when a foot was found through an iridectomy. Four cases (5.0%) required YAG laser treatment: two iridotomies for iris bombe and two for capsule remnants for visual reasons. One patient (1.2%) had diplopia with an exotropia. Of the 81 eyes, 60 (74%) achieved 6/9 or better and 69 (85%) achieved 6/12 or better with best corrected visual acuity. A postoperative refraction was recorded on 70 cases (86%). Four cases ended with a spherical equivalent more than 3.00 0 outside the aimed for postoperative sphere. Of the 11 cases (14%) with no postoperative refraction, 7 achieved 6/9 or better uncorrected visual acuity, 1 had a retinal detachment, 1 age-related maculopathy (ARM), and 1 myopic degeneration; in the last case, the reason for the lack of a refraction was unknown. Best corrected preoperative and postoperative visual acuities were compared using criteria established in previous series; 92.5% of patients were within one Snellen line of their best corrected preoperative acuity, leaving 7.5% who did not achieve this level. The worst reduction in visual acuity was in the eye with CME; one other eye with ARM had a seven line reduction in best corrected acuity.
Discussion Our population had one retinal detachment, an incidence of 1.2%. This is high compared with the rates for modern cataract surgery, which are between 0.1 and 0.4%,5 but is comparable to rates reported in other series (Table 1), which varied from 0 to 1.9%.6-9 We had a single case of CME with a very poor visual outcome. Our CME incidence of 1.2% compares favorably with that reported in other series (Table 1), which varied from 1.3 to 7.7%. Our incidence of PBK (1.2%) also compared favorably with that reported in other series (Table 1), which varied from 1.9 to 11.6%. One factor that affects these results is the latency between stimulus and effect of complications such as retinal detachment and corneal decompensation. Cystoid macular edema is perhaps a more realistic measure of immediate success, but this depends on how vigorously reduced vision is investigated. The one patient in our series for whom no cause of reduced vision was recorded could likely have been in this category. The success of the secondary lens implantation also depends on the state of the eye preoperatively. Preoperative endothelial cell analysis might help determine why PBK rates vary. In our practice, this would not affect the choice of operation. The question that remains is whether open-loop, flexible, anterior chamber lenses still have a place in routine secondary lens implantation or whether we should change to transsclerally sutured posterior chamber lenses. Our results and those of others suggest acceptable results from the use of anterior chamber lenses. We know what to expect in the way of complications. We
Table 1. Incidence of complications, percentages. Study Complication Explantation Endophthalmitis Loop malposition Pseudophakic bullous keratopathy Cystoid macular edema Retinal detachment NR
=
Current (n 81)
=
MREH6 (n
= 79)-
(n
LGf
= 52)-
Weene8 (n 43)
=
Biro9 (n 107)-
0 0 2.8 2.8 4.6 0
0 0 0 1.2
1.3 0 2.5 3.8
0 0 1.9
2.3 0 2.3 11.6
1.2 1.2
1.3 1.3
7.7 1.9
2.3 0
NR
=
information not recorded or not given
* Series of mixed anterior and posterior chamber secondary IOLs
J CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996
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SECONDARY IMPLANTATION OF OPEN-LOOP AC IOLs
should only change techniques if the alternative procedure is proven over the years to give better results with lower complications. Not enough information exists concerning the long-term follow-up of transsclerally sutured lenses. A recent study suggests an impressively low rate of CME2 but a high level of other complications, such as erosion of the sutures through the scleral flaps, induction of glaucoma, and suprachoroidal hemorrhage. 2 ,lO The level of complications encountered with these techniques is leading to a re-evaluation of the flexible, open-loop, anterior chamber lens. 11 In some cases, an anterior chamber lens cannot be used and a sutured posterior chamber lens would be a better choice. We conclude that at present, open-loop, flexible, anterior chamber lenses remain an acceptable way of treating aphakia.
References
5.
6.
7.
8.
9.
1. Lim ES, Apple ~C, Tsai Jc, et al. An analysis of flexible anterior chamber lenses with special reference to the normalized rate oflens explantation. Ophthalmology 1991; 98:243-246 2. Solomon K, Gussler JR, Gussler C, Van Meter WS. Incidence and management of complications of transsclerally sutured posterior chamber lenses. J Cataract Refract Surg 1993; 19:488-493 3. Hu BV, Shin OH, Gibbs KA, Hong YJ. Implantation of
954
4.
10.
11.
posterior chamber lens in the absence of capsular and zonular support. Arch Ophthalmol1988; 106:416-420 Stark WJ, Gottsch JO, Goodman OF, et al. Posterior chamber intraocular lens implantation in the absence of capsular support. Arch Ophthalmol 1989; 107: 10781083 Powe NR, Schein 00, Gieser SC, et al. Synthesis of the literature on visual acuity and complications following cataract extraction with intraocular lens implantation. Arch Ophthalmol 1994; 112:239-252; correction p 889 Leatherbarrow B, Trevett A, Tullo AB. Secondaty lens implantation: incidence, indications and complications. Eye 1988; 2:370-375 Hayward JM, Noble BA, George N. Secondaty intraocular lens implantation: eight year experience. Eye 1990; 4:548-556 Weene LE. Flexible open-loop anterior chamber intraocular lens implants. Ophthalmology 1993; 100:16361639 Biro Z. Results and complications of secondaty intraocular lens implantation. J Cataract Refract Surg 1993; 19: 64-67 Schein 00, Kenyon KR, Steinert RF, et al. A randomized trial of intraocular lens fixation techniques with penetrating keratoplasty. Ophthalmology 1993; 100:14371443 Arkin MS, Steinert RF. Sutured posterior chamber intraocular lenses. Int Ophthalmol Clin 1994; 34(3):67-85
] CATARACT REFRACT SURG-VOL 22, SEPTEMBER 1996