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PubMed1995

Analysis of 100 explanted one-piece and three-piece silicone intraocular lenses.

PURPOSE: The authors analyzed incidence and types of complications seen after implantation of silicone posterior chamber intraocular lenses (PC IOLs). These data were compared with those obtained in previous studies with standard polymethylmethacrylate IOLs. METHODS: Data from the laboratory database were collected on 100 explanted silicone IOLs submitted to the Center for Intraocular Lens Research from 1986 to 1994. RESULTS: Of the 100 IOLs, 63 were three-piece designs with polypropylene loops and 37 were one-piece plate lenses. The two most important reasons for explantation were IOL decentration (42.0%) and inflammation (27.7%). There was no significant difference for the reasons of explantations between one- and three piece IOLs (P > 0.1). Intraocular lenses that had been removed due to inflammatory reactions had a significantly longer implant duration (19.2 +/- 18.9 months) than lenses that were explanted because of decentration (9.19 +/- 12.1 months) (P = 0.018). CONCLUSIONS: The results presented here showed that there is no substantial difference between these IOLs and polymethylmethacrylate lenses in terms of reasons for explantation. The authors' data suggest that clinical outcome is not as dependent on the type of lens selected as it is on the quality of surgery. The key to good results is the use of "capsular surgery," namely techniques that ensure secure in-the-bag IOL fixation.

Cataract Extraction↗
PubMed1998

Laser in situ keratomileusis for moderate and high myopia and myopic astigmatism.

OBJECTIVE: This study evaluated the predictability, stability, and safety of laser in situ keratomileusis (LASIK) in myopia and myopic astigmatism. DESIGN: The study design was a prospective, unmasked, nonrandomized clinical trial. PARTICIPANTS: Participating were 25 patients with myopia (37 eyes) with astigmatism of less than 1.00 diopter (D), divided into 3 subgroups (-5.00 to -9.90 D, 8 eyes; -10.00 to -14.90 D, 10 eyes; -15.00 to -29.00 D, 19 eyes), and 37 patients with myopia (56 eyes) with corneal astigmatism of 1.00 to 4.50 D, divided into 3 subgroups (-5.00 to -9.90 D, 12 eyes; -10.00 to -14.90 D, 24 eyes; -15.00 to -29.00 D, 20 eyes). INTERVENTION: LASIK was performed using the Automatic Corneal Shaper and the Keracor 116 excimer laser. MAIN OUTCOME MEASURES: Visual acuity, manifest refraction, central corneal islands, ablation decentration, and patient satisfaction were measured. RESULTS: At 12 months, predictability, regression between 1 and 12 months, uncorrected visual acuity (UCVA), loss of two or more lines of corrected visual acuity, and patient satisfaction of the spherical (toric) groups are reported. Subgroups -5.00 to -9.90 D: 100% (75%) +1.00 D; regression less than or equal to 1.00 D in 100% (91.7%); UCVA greater than or equal to 20/40 in 87.5% (70%); none lost two or more lines; 100% (84%) highly satisfied. Subgroups -10.00 to -14.90 D: 60% (78.3%) +/-1.00 D; regression less than or equal to 1.00 D in 100% (87%); UCVA greater than or equal to 20/40 in 77.8% (86.4%); 10% (4.3%) lost two lines; 90% (91%) highly satisfied. Subgroups -15.00 to -29.00 D: 38.9% (21.4%) +/-1.00 D; regression less than or equal to 1.00 D in 72.2% (64.3%); UCVA greater than or equal to 20/40 in 33.3% (40%); 5.6% (7.1%) lost two lines; 78% (50%) highly satisfied. Differences of predictability and change of manifest refraction between subgroups of -5.00 to -9.90 D and -15.00 to -29.00 D were statistically significant. Central islands (decentrations) were observed in 17% (5.6%) of eyes of the spherical and in 16% (4.1%) of the toric group. Overall, the corneal interface was visible in 8.2%. CONCLUSIONS: The LASIK method used in this study showed stability of manifest refraction and adequate uncorrected central visual acuity in a large percentage of patients with myopia up to -15.00 D. Corneal stability was not as uniform. Central corneal islands were observed in a sizable minority of patients despite pretreatment. For myopia greater than 15.00 D, accuracy and patient satisfaction were sufficiently poor to advise against using the authors' treatment technique in these groups. Visually significant microkeratome and laser-related problems were noted in a smaller percentage of patients. Patients with astigmatism correction were less pleased with results than were patients who received spherical corrections.

Adolescent↗
PubMed1999

Retreatment after laser in situ keratomileusis.

OBJECTIVE: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) retreatment for correcting residual myopia. DESIGN: Retrospective noncomparative case series. PARTICIPANTS AND INTERVENTION: Fifty-nine consecutive eyes (43 patients) underwent LASIK retreatment at 3 or 6 months after the primary LASIK procedure. Lifting the corneal flap and reablating the stromal bed with a VISX 20/20 excimer laser was the procedure used for LASIK enhancement. MAIN OUTCOME MEASURES: The following parameters were studied before and after retreatment: visual acuity, refraction, videokeratography, applanation tonometry, and corneal thickness. Complications after LASIK enhancement also were evaluated. Follow-up was 12 months. RESULTS: Before retreatment, only 3.38% of eyes (2 of 59) had an uncorrected visual acuity of 0.5 (20/40) or better, and after retreatment, this percentage increased to 60% (30 of 50) at 6 months and 61.8% (34 of 55) at 12 months. After reoperation, mean best-corrected visual acuity improved by half a line over the values before retreatment. The preretreatment refraction of -2.92 +/- 1.22 diopters (D) (mean +/- standard deviation) decreased significantly to -0.44 +/- 0.80 D at 6 months and to -0.61 +/- 0.82 D at 12 months (P < 0.001). In 82% of eyes (41 of 50) at 6 months and 81.8% (45 of 55) at 12 months, the spherical equivalent was within 1.00 D of emmetropia. There was a significant regression of effect (0.38 D) between 3 and 12 months (P < 0.01). Postretreatment refraction was related to the original refraction before the primary LASIK, the preretreatment refraction, and the ablation diameter used. Although no vision-threatening complications were found, epithelial ingrowth and flap melting were more common after than before LASIK retreatment, with 31% of eyes at 12 months with epithelial ingrowth and 10.9% with flap melting. However, LASIK enhancement improved decentration and night-vision problems. CONCLUSIONS: LASIK retreatment was an effective and predictable procedure for correcting residual myopia. Epithelial ingrowth and flap melting were more frequent after than before LASIK retreatment, whereas decentration and night-vision symptoms improved.

Adult↗
PubMed2001

Dynamic contributions to superior shoulder stability.

It has been suggested that superior decentralization of the humeral head is a mechanical factor in the etiology of degenerative rotator cuff tears. This superior decentralization may be caused by muscular imbalance. The objective of this study was to investigate the contribution of individual shoulder muscles to superior stability of the glenohumeral joint. In 10 fresh frozen cadaver shoulders the tendons of the rotator cuff, teres major, latissimus, pectoralis major, deltoid and biceps were prepared. The shoulders were tested in a shoulder-loading device in 0 degrees, 30degrees, 60 degrees and 90 degrees of glenohumeral abduction. A constant superior force of 20 N was applied to the humerus. Tensile loads were applied sequentially to the tendons in proportion to their cross-sectional areas and translations of the humeral head relative to the glenoid were recorded with a 3Space Fastrak system. Depression of the humeral head was most effectively achieved by the latissimus (5.6 +/- 2.2 mm) and the teres major (5.1 +/- 2.0 mm). Further studies should elucidate their possible in vivo role in the frontal plane force couple to counter balance the deltoid. The infraspinatus (4.6 +/- 2.0 mm) and subscapularis (4.7 +/- 1.9 mm) showed similar effects while the supraspinatus (2.0 +/- 1.4 mm) was less effective in depression. Therefore, the infraspinatus and subscapularis should be surgically repaired whenever possible. The supraspinatus may be of less importance for superior stability than previously assumed.

Biomechanical Phenomena↗
PubMed1992

Case mix management education in a Canadian hospital.

The Sunnybrook Health Science Centre's matrix organization model includes a traditional departmental structure, a strategic program-based structure and a case management-based structure--the Clinical Unit structure. The Clinical Unit structure allows the centre to give responsibility for the management of case mix and volume to decentralized Clinical Unit teams, each of which manages its own budget. To train physicians and nurses in their respective roles of Medical Unit directors and Nursing Unit directors, Sunnybrook designed unique short courses on financial management and budgeting, and case-costing and case mix management. This paper discusses how these courses were organized, details their contents and explains how they fit into Sunnybrook's program of decentralized management.

Cost Allocation↗
PubMed2000

Two year results: sharp versus rounded optic edges on silicone lenses.

To evaluate the role of optic edge design of 2 silicone intraocular lenses (IOLs) in 2 year clinical results. Department of Ophthalmology, University of Vienna, Medical School, Allgemeines Krankenhaus, Austria. In this comparative clinical study, 50 eyes had phacoemulsification and implantation of a high-refractive 3-piece silicone IOL with sharp optic edges (CeeOn model 911F) (n = 25) or a 3-piece silicone lens with rounded optic edges (CeeOn model 920) (n = 25). Biomicroscopic findings, including those of specular microscopic examination of the anterior lens surface, were documented and the results analyzed. After 2 years, a significant between-group difference in posterior capsule opacification (PCO) but not in anterior capsule alterations was observed. Behind all CeeOn 911F sharp-edge IOLs, the capsule remained clear; in 2 of 23 capsules behind the CeeOn 920 rounded-edge, a neodymium: YAG laser capsulotomy had to be performed for dense central fibrotic PCO. Seven of 21 of the remaining eyes had first-degree central fibrotic PCO, 14 of 23 had peripheral mixed fibrotic and slender Elschnig pearl PCO, and 8 of 23 had second-degree peripheral PCO. Specular microscopic findings did not differ between the 2 groups. No severe IOL decentration occurred in any eye; 25% in the sharp-edge group and 40% in the rounded-edge group had minimal decentration. The silicone IOL with the sharp optic edge design was associated with significantly reduced PCO 2 years postoperatively.

Aged↗
PubMed2001

Capsulorhexis phimosis in retinitis pigmentosa despite capsular tension ring implantation.

A 56-year-old man with retinitis pigmentosa presented with dense nuclear sclerosis and scattered zonular loss with laxity confirmed by ultrasound biomicroscopy. He had extracapsular cataract extraction with a 6.0 mm continuous curvilinear capsulorhexis and implantation of a capsular tension ring (CTR) and a single-piece poly(methyl methacrylate) (PMMA) intraocular lens (IOL) in the capsular bag in his left eye. Severe anterior capsule fibrosis and contracture of the capsulorhexis opening with nasal decentration of the IOL were noted 4 months after surgery. A neodymium:YAG (Nd:YAG) laser anterior capsulotomy was performed to prevent further zonular stress and IOL decentration. The centripetal forces of capsular fibrosis after cataract surgery may exceed the centrifugal resistance of the standard CTR and PMMA IOL in patients with retinitis pigmentosa. Such patients must be carefully monitored postoperatively. An Nd:YAG laser anterior capsulotomy is a safe and effective option to manage anterior capsule fibrosis.

Capsulorhexis↗
PubMed2003

Clinical results of laser in situ keratomileusis with superior and nasal hinges.

PURPOSE: To compare the differences in the clinical results of LASIK with a nasal corneal flap and with a superior corneal flap. SETTING: Department of Ophthalmology, Kangnam St. Mary's Hospital, Seoul, Korea. METHODS: This randomized prospective study comprised 30 patients whose age and degrees of myopia were similar. In 1 group (25 eyes), a superior hinge was made and in the other group (25 eyes), a nasal hinge was made. Uncorrected visual acuity (UCVA), spherical equivalent (SE), astigmatism, and corneal topographical change before surgery and 1 week and 2 and 6 months after surgery were compared. The tear breakup time (BUT) and the Schirmer test before surgery and 2 months postoperatively were also compared. RESULTS: At 6 months, there were no significant between-group differences in UCVA, SE, astigmatism, and corneal ablation decentration (P >.05). At 2 months, the results of BUT and the Schirmer tests were 6.80 seconds and 9.54 mm, respectively, in the nasal hinge group (P >.05) and 5.08 seconds and 6.05 mm, respectively, in the superior hinge group (P <.05). CONCLUSIONS: There were no between-group differences in UCVA, SE, astigmatism, and corneal ablation decentration at 6 months, but the BUT and Schirmer test results were aggravated after LASIK in the superior hinge group.

Adult↗
PubMed2003

Ablation centration in myopic laser in situ keratomileusis. comparing the Visx S3 ActiveTrak and the Visx S2.

PURPOSE: To compare ablation centration and outcome measurements in myopic laser in situ keratomileusis (LASIK) using the eye-tracking Visx S3 ActiveTrak and the nontracking Visx S2 excimer lasers. SETTING: University-based refractive surgery practice. METHODS: In a retrospective study, 71 consecutively treated myopic eyes that had LASIK with the Visx Star S3 ActiveTrak were compared to 71 control-matched eyes treated with the Visx Star S2 without pupil tracking. Primary outcome variables including ablation centration, uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, complications, and induced cylinder analyzed by vector analysis were evaluated 3 months postoperatively. RESULTS: The myopia ranged from -1.50 to -11.25 diopters (D) and the cylinder, from +0.25 to +2.75 D. Ninety-four of 142 eyes (66%) were available for analysis at 3 months; 50 eyes could be used to analyze ablation centration. At 3 months, the mean decentration of the ablation zone from the entrance pupil was 0.22 mm +/- 0.20 (SD) in tracked eyes (n = 25) and 0.21 +/- 0.26 mm in nontracked eyes (n = 25) (P =.88). Three eyes (12%) in the tracked group were decentered 0.5 to 1.0 mm, and 1 eye (4%) in the nontracked group was decentered more than 1.0 mm. All other eyes were decentered less than 0.5 mm. There was an association in the tracked group between greater decentrations and higher levels of myopia (r = 0.67), but this association did not exist in the nontracked group (r = -0.03). CONCLUSION: Comparable ablation centration as well as visual and refractive outcomes can be achieved with and without active eye tracking during myopic and astigmatic myopic LASIK.

Adult↗
PubMed1993

Comparison of shape recovery ratios of single-piece poly(methyl methacrylate) intraocular lens haptics.

We studied shape recovery ratios of several single- and three-piece intraocular lens (IOL) haptics after conducting compression tests for various lengths of time. Results of the comparison of poly(methyl methacrylate) (PMMA) IOL haptics configured of a single piece and of three pieces showed a superior shape recovery ratio for single-piece haptics. Comparisons of the shape recovery ratios among single-piece PMMA haptics and conventional three-piece haptics made of polyvinylidene fluoride (PVDF), PMMA, and polypropylene (PP) revealed that the shape recovery ratio of single-piece PMMA haptics was higher than the ratios of the conventional three-piece PMMA and PP haptics. The ratios of two of three of the single-piece PMMA haptics, however, were lower than the ratios of three-piece PVDF haptics. The form and manufacturing procedures of haptics likely have a significant impact on the shape recovery ratio of haptics, even those made of the same material. Since decentration after IOL surgery could be caused by the condition of the patient's lenticular capsule and Zinn's zonule, it is difficult to conclude that the shape recovery ratio is the only factor in IOL stability. Nevertheless, this study indicates that IOL haptics that cause less decentration and have better mechanical properties should be developed.

Lenses, Intraocular↗
PubMed1993

Topographical analysis of the centration of excimer laser photorefractive keratectomy.

A major advantage of myopic photorefractive keratectomy (PRK) is the precision with which the excimer laser ablates corneal tissue. But like other refractive surgery procedures, PRK must solve the problem of accurately centering the treatment zone. We present our technique for PRK centration with postoperative corneal topographic data on 110 patients from Phase IIB and III of the clinical trials. The distance between the center of the post-PRK flat zone and the corneal vertex was determined by topography in millimeters and meridian degrees. On average, treatment zones were decentered down and right 0.52 mm at 196.74 degrees; 92.73% were centered within 1.00 mm, while 57.27% were within 0.50 mm. The centration data were correlated to postoperative visual acuity as well as treatment zone diameter. Mean uncorrected visual acuity was 20/20 for decentrations up to 1.00 mm but fell to 20/30 for deviations greater than 1.00 mm. Best corrected acuity was also preserved below 1.00 mm but compromised above this level. No difference in decentration was found between 4.5 mm and 5.0 mm ablation zones. Our findings indicate that PRK centration is accurate within 1.0 mm in over 92% of cases and that visual acuity is relatively preserved despite deviations from perfect centration. Further technical improvements will enhance the accuracy of PRK.

Adult↗
PubMed1996

Centration and fixation of silicone intraocular lenses: clinicopathological findings in human autopsy eyes.

PURPOSE: To analyze centration and fixation of three-piece and one-piece silicone intraocular lenses (IOLs) in human autopsy eyes. SETTING: Center for Intraocular Lens Research, Medical University of South Carolina, Charleston. METHODS: Thirty eyes among those submitted to the center between 1986 and 1994 were evaluated. The globes were sectioned at the equatorial plane and photographed from a posterior view. Gross examination was performed to determine IOL type, fixation, centration, and additional pathology. The results were compared with those of a control group of autopsy eyes implanted with one-piece and three-piece poly(methyl methacrylate) (PMMA) IOLs. The control group matched the silicone group in patient age, fixation site, and duration of implantation. RESULTS: Twenty-three eyes (79.3%) had three-piece silicone IOLs and 7 eyes (20.7%), one-piece plate IOLs. Average patient age in the three-piece group was 77.3 years +/- 6.7 (SD) and in the one-piece group, 74.3 +/- 3.8 years. The 30 IOLs were symmetrically fixated in the bag. Average decentration of the three-piece and one-piece IOLs did not differ significantly, 0.37 +/- 0.31 mm and 0.26 +/- 0.13 mm, respectively (P = .37). There was also no significant difference in decentration between the silicone groups and the PMMA groups (P = .93). CONCLUSION: Centration and fixation of silicone IOLs were equivalent to those of standard PMMA IOLs.

Aged↗
PubMed1996

Four year follow-up of the MemoryLens.

PURPOSE: To determine whether the long-term results of implantation of thermoelastic MemoryLens intraocular lenses (IOLs) are comparable to those of conventional poly(methyl methacrylate) (PMMA) IOLs. SETTING: St. Elisabeth Hospital, Dillingen, Germany. METHODS: This retrospective study compared visual acuity, astigmatism, lens decentration, biocompatibility, and posterior capsule opacification in 36 eyes with a MemoryLens with those in 36 eyes with a conventional PMMA IOL over 4 years. The MemoryLenses were implanted in 1991 after cataract extraction by phacoemulsification. RESULTS: Four years postoperatively, best corrected visual acuity was 20/20 to 20/25 in 63.9% of the MemoryLens group and 55.6% of the PMMA group. Mean astigmatism was 0.84 diopters (D) in the MemoryLens group and 1.20 D in the PMMA group. No cellular precipitates, as evaluated by biomicroscopy, or lens decentration greater than 0.5 mm were found in either group. Posterior capsule opacification, which developed in 22.2% in the MemoryLens group and 38.9% in the PMMA group, was treated with a neodymium: YAG laser capsulotomy. CONCLUSION: The MemoryLens allows small incision cataract surgery and long-term results that compare favorably with those of PMMA IOLs.

Aged↗
PubMed1996

Corneal optical irregularity after excimer laser photorefractive keratectomy. The Summit Photorefractive Keratectomy Topography Study Group.

PURPOSE: To assess the influence of corneal surface microirregularities on objective and subjective visual performance after photorefractive keratectomy (PRK). SETTING: Multicenter clinical trial. METHODS: The alpha version of the Potential Corneal Acuity (PCA) computer program, currently under development, was used to qualitatively and quantitatively analyze the corneal surface of 176 eyes of 176 patients 1 year after PRK. Color maps of corneal surface irregularities were reviewed and quantitative values (PCA) predicting best spectacle-corrected visual acuity (BSCVA) as limited by the cornea were evaluated for associations with qualitative topography patterns, optical zone decentration, and clinical outcomes of BSCVA, uncorrected visual acuity (UCVA), subjective patient satisfaction, and a subjective glare/halo index. RESULTS: Qualitatively, corneas after PRK were generally characterized by a ring of optical irregularity at the juncture of the ablation zone and untreated cornea. Standard corneal topography maps graded as irregular after PRK had a significantly higher PCA value than those graded as regular. There was a trend toward higher PCA values with greater optical zone decentration that was not statistically significant. Actual BSCVA was identical to that which the PCA value predicted in 32% of patients and was within one Snellen line in 71%, within two lines in 89%, and within three lines in 94%. The correlation between the PCA and the glare/halo index and with subjective patient satisfaction was statistically significant. The relationship between PCA and UCVA was not significant. CONCLUSIONS: A ring of optical microirregularity of the corneal surface can appear at the juncture of the treated and untreated cornea after PRK, indicating that the optical zone edge might affect objective and subjective postoperative visual outcomes. Further understanding of corneal surface topography and refinement of the PCA program should help explain visual outcome after PRK.

Adult↗
PubMed1997

Topographical analysis of ablation centration after excimer laser photorefractive keratectomy and laser in situ keratomileusis for high myopia.

PURPOSE: To evaluate the ablation centration after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for high myopia and to assess the association between decentration and best corrected visual acuity (BCVA), glare, monocular diplopia, and halo phenomenon. SETTING: Mater Private Hospital, Dublin, Ireland. METHODS: Corneal topography was used to analyze centration in two groups of patients with myopia of more than 6.0 diopters: 18 had PRK and 18, LASIK. A standardized questionnaire assessed the preoperative and postoperative prevalence of glare, monocular diplopia, and halo phenomenon. RESULTS: "Significant" ablation decentration (0.5 mm) in the LASIK group (1.33 mm) was almost twice that in the PRK group (0.75 mm). Glare increased from 27% preoperatively to 42% in the PRK group; monocular diplopia increased in the LASIK group. Halo phenomenon decreased after both procedures. CONCLUSION: Laser in situ keratomileusis represents a step forward in the surgical correction of high myopia, but the accuracy of the corneal ablation location must be improved. Suction ring fixation of the globe or real time tracking systems may help improve centration.

Adult↗
PubMed1997

Centration of intraocular lenses with circular haptics.

PURPOSE: To evaluate two intraocular lens (IOL) models with a circular haptic configuration designed to better distribute forces within the capsular bag over 360 degrees. SETTING: University and Maria Middelares hospitals, Antwerp, Belgium. METHODS: Two IOLs with circular haptics were evaluated for 6 months after implantation: a one-piece, all-poly(methyl methacrylate) (PMMA), Corneal IS M 5.5 lens with a 5.5 mm biconvex optic, overall diameter of 9.8 mm, and two semicircular open haptics (n = 103); a plano-convex, all-PMMA, modified Anis lens with a 5.5 mm plano-convex optic, total diameter of 10.0 or 11.0 mm (depending on diopter), and closed-loop haptics (n = 335). All lenses were inserted through a 5.5 mm scleral incision after phacoemulsification and placed in the capsular bag through a 4.5 mm curvilinear capsulorhexis. The IOLs centered without being rotated. RESULTS: Six months after implantation, the IOL optics were well centered, even in eyes with an eccentric capsulorhexis (19%). In two eyes with partial zonulysis and in seven with posterior capsule rupture, decentration of less than 0.5 mm was observed. Both lenses provided uniform capsular support without causing stress lines in the posterior capsule. There were no cases of capsule contraction syndrome. Posterior capsule fibrosis reducing visual acuity occurred in 4% of eyes in both series. CONCLUSION: The Corneal IS M 5.5 and the Anis lens with circular haptics prevented late optic decentration and, therefore, would be useful in cases of eccentric capsulorhexis, partial zonulysis, anterior radial tears, and posterior capsule rupture. These IOLs may also prevent capsular contraction.

Adult↗
PubMed1998

Anterior capsule contraction with foldable silicone intraocular lenses.

PURPOSE: To examine the causes signs, and symptoms of anterior capsule contraction syndrome and the response to neodymium YAG (Nd:YAG) anterior capsulotomy. SETTING: Madigan Army Medical Center, Tacoma, Washington, USA. METHODS: This retrospective review comprised 70 cases of phacoemulsification with foldable plate-haptic silicone intraocular lens (IOL) implantation. Patients who developed anterior capsule contraction postoperatively, defined as the anterior capsule being visible through an undilated pupil, had a radial anterior capsulotomy with an Nd:YAG laser. Variables analyzed were visual acuity, subjective complaints, associated inflammation, and IOL decentration. RESULTS: Ten eyes of 9 patients (14%) developed anterior capsule contraction and had Nd:YAG laser radial anterior capsulotomy. Three of 9 patients reported decreased visual acuity and glare. Two other patients had chronic anterior chamber inflammation unresponsive to steroids after surgery that resolved after Nd:YAG anterior capsulotomy. Intraocular lens decentration was observed in 3 patients before the Nd:YAG capsulotomy. Posterior lens dislocation occurred in 1 patient after capsulotomy and required surgical lens exchange. CONCLUSION: One-piece foldable silicone IOLs may not provide enough peripheral capsule expansion.

Foreign-Body Migration↗
PubMed1998

Evaluation of a 3-piece silicone intraocular lens with poly(methyl methacrylate) haptics.

PURPOSE: To evaluate the safety and performance of a foldable silicone intraocular lens (IOL) in small incision phacoemulsification surgery. SETTING: Vaasa Central Hospital, Vaasa, Finland. METHODS: Phacoemulsification with primary implantation of a posterior chamber IOL was performed in 50 patients. All eyes were implanted with a CeeOn IOL (model 920, Pharmacia & Upjohn) with a silicone optic and poly(methyl methacrylate) haptics. The ease of folding, implanting, and unfolding the IOL in the bag were recorded. Visual acuity, postoperative complications, optic decentration, and optic tilt were measured at 5 postoperative visits. The IOLs were evaluated for haze and discoloration and the IOL surface, for inflammatory or pigment deposits. Follow-up was 12 months. RESULTS: In 44 of 50 cases, folding the IOL was easy, and in 46 of 50, unfolding the IOL was controlled. The mean follow-up was 11.45 months +/- 0.52 (SD). No postoperative complications occurred, and 96% of patients achieved a best corrected visual acuity (BCVA) of 0.5 or better and 56%, a BCVA of 1.0 or better. The IOL decentration was less than 0.25 mm in 89% of cases, and there was no optic tilt. The neodymium:YAG laser capsulotomy rate was 11%. CONCLUSION: Good visual outcome and excellent centration were achieved with the CeeOn model 920 IOL. It is therefore suitable for small incision cataract surgery. Because of the IOL's smooth, polished surface, the choice of instruments for folding and implantation is important.

Aged↗