Types Of Foldable Intraocular Lenses Research Articles

Glare disability and spherical aberration with five foldable intraocular lenses: a prospective randomized study

To compare differences in subjective glare and spherical aberration between five foldable intraocular lenses (IOLs) made of different materials and to different designs. This prospective study comprised 175 cataract patients who underwent phacoemulsification and were randomized to receive one of five types of foldable IOL (AcrySof MA30BA, Alcon; Sensar AR40, AMO; AcrySof SA30AL, Alcon; Sensar AR40e, AMO, and Tecnis Z9000, Pharmacia & Upjohn). All patients received a questionnaire investigating the incidence of subjective photic phenomena. Two months postoperatively, we collected data regarding subjective glare and evaluated pupil size, visual acuity and wavefront aberration of the cornea and eye. With regard to difficulty in performing ordinary activities under different light conditions and light and dark adaptation, the difference between the groups was not significant (p > 0.05, chi-squared test). With respect to difficulty in driving at night, the MA30BA group had a significant higher incidence of photic phenomena than the SA30AL, AR40e and Z9000 groups (p < 0.05, chi-squared test). Wavefront measurements revealed a significant difference between the Z9000, AR40e and SA30AL groups, which showed the lowest values, and the MA30BA group, which showed the highest value (p < 0.05, anova with Tamhane posthoc test). New generation IOLs such as the Pharmacia Z9000, AMO AR40e and AcrySof SA30AL have a lower incidence of glare and spherical aberrations; however, their impact on future IOL design should be conditioned by further data, especially regarding posterior capsule opacification.

Bacterial adhesion to rigid and foldable posterior chamber intraocular lenses: in vitro study

Purpose To determine the in vitro bacterial adherence to intraocular lenses (IOLs) routinely used at 1 center. Setting University Hospital of Vienna, Vienna, Austria. Methods Four types of rigid IOLs (hydrophobic poly[methyl methacrylate] [PMMA] and hydrophilic heparin-surface-modified PMMA) and 5 types of foldable intraocular lenses (hydrophobic silicone, hydrophobic acrylic, and hydrophilic acrylic) were used in the experiment. Under standardized conditions, the IOLs were contaminated with 2 strains of Staphylococcus epidermidis. A sonication method and impression method were used for quantification. The mean bacterial density per lens type (colony forming units/mm 2) was compared. Results With both germs and both quantification methods, more bacteria was found on hydrophobic lenses than on IOLs with hydrophilic surfaces ( P = .001). The Alcon AcrySof® and Askin UV80F® IOLs had the greatest and the Corneal Acrygel® and Bausch & Lomb Hydroview® IOLs the least affinity to these microorganisms. Conclusion The data suggest that hydrophilic IOLs can help reduce the rate of postoperative endophthalmitis as a result of their surface properties.

Glistenings in foldable intraocular lenses

Purpose: To evaluate the formation of glistenings in foldable intraocular lenses (IOLs) of various materials after cataract surgery. Setting: University Eye Clinic of Trieste, Trieste, Italy. Methods: In this prospective study, 273 patients were randomized to have implantation of 1 of 7 types of foldable IOLs in the capsular bag after phacoemulsification. The IOLs were the CeeOn® Edge 911A (Pharmacia & Upjohn Co.), ACR6D® (Corneal), AcrySof® (Alcon), SI-40NB (AMO), Hydroview® H60M (Storz), Sensar® (AMO), and Stabibag® (Ioltech). The presence of glistenings in the IOL optic was assessed by slitlamp evaluation 7, 30, 90, 180, 360, and 720 days after surgery. The glistenings were graded at each control. Results: Glistenings were observed in all IOL groups. The percentage of patients with glistenings ranged from 40.0% to 67.5%, with the percentage increasing up to 90 days after surgery and then becoming stable in most groups. The AcrySof group had a continuous increase over time. The mean grade of glistenings increased up to 180 days after surgery and then became stable in most groups. The AcrySof and 911A groups had a continuous increase over time. Conclusions: Glistening formation was observed in 7 different foldable IOLs. The AcrySof group had a higher percentage and a greater density of glistenings.

Inflammation after implantation of hydrophilic acrylic, hydrophobic acrylic, or silicone intraocular lenses in eyes with cataract and uveitis: Comparison to a control group

Purpose: To compare the course of inflammation after small-incision cataract surgery with implantation of 1 of 3 types of foldable intraocular lenses (IOLs) in eyes with uveitis. Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: Seventy-four eyes with uveitis and cataract and 68 control eyes with cataract were prospectively selected to receive a foldable hydrophilic acrylic (Hydroview®, Bausch & Lomb), hydrophobic acrylic (AcrySof®, Alcon), or silicone (CeeOn® 911, Pharmacia) IOL. All surgery was performed by the same surgeon using a standardized protocol: clear corneal incision, capsulorhexis, phacoemulsification, and in-the-bag IOL implantation. Preoperative and postoperative inflammation was evaluated by measuring aqueous flare preoperatively and 1, 3, 7, 28, 90, and 180 days after surgery using the Kowa FC-1000® laser flare-cell meter. All uveitic eyes were in remission for at least 3 months before surgery. Results: In the uveitic eyes, there was no statistically significant difference in the postoperative course of flare and cell among the 3 IOL groups. Six months after surgery in uveitic eyes, flare values reached preoperative levels and the cell count was lower than preoperatively in all 3 IOL groups. Relative flare values were higher in the eyes with uveitis and a CeeOn 911 IOL; however, the difference between this group and the 2 acrylic IOL groups was not significant. Conclusions: There were no significant differences in inflammation after implantation of foldable IOLs in uveitic eyes. Although absolute flare values and cell counts in eyes with uveitis were higher than in control eyes, primarily because of a damaged blood-aqueous barrier (BAB), BAB recovery was similar between the 2 groups. The changes in the BAB indicate that foldable IOL implantation is safe in uveitic eyes.

Cellular reaction on the anterior surface of 4 types of intraocular lenses

Purpose To assess the cellular reaction on the anterior surface of 4 types of foldable intraocular lenses (IOLs). Setting Department of Ophthalmology, University Hospital of Vienna, Vienna, Austria. Methods One hundred eyes scheduled for cataract surgery were prospectively randomized into 4 groups of 25 eyes each using random number tables. Group 1 received a Hydroview™ IOL (Bausch & Lomb), Group 2 an AcrySof® IOL (Alcon), Group 3 a MemoryLens® IOL (ORC), and Group 4 a CeeOn® 920 IOL (Pharmacia). Patients were examined 1, 3, 7, 30, 90, and 180 days postoperatively. Postoperative biomicroscopic examinations were done with a slitlamp, and a specular microscope was used to document the presence of cell deposits and identify areas with the highest density of cells. Results The local tissue response revealed 2 patterns: a nonspecific foreign-body reaction to the IOL (small round, fibroblast-like, epithelioid, and giant cells) and a lens epithelial cell (LEC) reaction. The highest incidence of LECs was in the Hydroview group, in which LECs were present on 81.8% of lenses 180 days postoperatively. During the first postoperative days, small round and fibroblast-like cells were found on all IOLs. From 7 days on, the incidence and density of these cells were less severe in the Hydroview and CeeOn 920 groups. After several weeks, epithelioid cells and foreign-body giant cells were seen on some IOLs. These cells appeared more often on AcrySof, MemoryLens, and CeeOn IOLs. Conclusion This study found IOL-related differences in cellular reaction after cataract surgery. The incidence of a nonspecific foreign-body reaction to 4 IOLs is consistent with the results of previous studies. The incidence of LECs was highest in the Hydroview group and lowest in the AcrySof group. The CeeOn 920 group had the lowest incidence of all types of cells.

Course of postoperative inflammation after implantation of 4 types of foldable intraocular lenses

Purpose To compare the course of postoperative inflammation after small incision cataract surgery with implantation of 4 types of foldable intraocular lenses (IOLs). Setting Department of Ophthalmology, University Hospital of Vienna, Austria. Methods One hundred twenty eyes were prospectively randomized to receive a foldable silicone (Pharmacia 920), hydrogel (Bausch & Lomb Hydroview™), methyl methacrylate/hydroxyethyl methacrylate (Mentor MemoryLens®), or acrylic (Alcon AcrySof®) IOL. All surgery was performed by the same experienced surgeon using a standardized surgical protocol: clear corneal incision, capsulorhexis, phacoemulsification, and in-the-bag implantation of the IOL. All patients received standardized postoperative medication and follow-up. Postoperative inflammation was evaluated by measuring aqueous flare preoperatively and 1, 3, 7, 14, 28, 90, and 180 days after surgery using the Kowa 1000 laser flare–cell meter. Results Except on the first day after surgery, when the AcrySof group had higher flare values than the other groups ( P = .0265), no significant differences were found up to 6 months. Re-establishment of the blood−aqueous barrier was similar in eyes with the AcrySof, Hydroview, and MemoryLens IOLs; the course of postoperative inflammation was different in eyes with the silicone IOL. Conclusion Comparison of postoperative flare values after implantation of 4 foldable IOLs showed no clinically relevant differences in the course of postoperative inflammation.

Change in capsulorhexis size with four foldable loop-haptic lenses over 6 months

Purpose: To compare the change in continuous curvilinear capsulorhexis (CCC) size after implantation of four types of three-piece foldable intraocular lenses (IOLs) and determine whether initial CCC size and IOL characteristics play a role in the change.Methods: This study comprised 133 eyes that had phacoemulsification and in-thebag implantation of one of four types of foldable IOLs: Alcon AcrySof™ MA30BA (n = 36); lovision™ 127 (n = 29); Mentor ORC MemoryLens™ (n = 39); Allergan PhacoFlex II™ (n = 29). Photographs of the CCCs were taken with a digital retinograph 1 day and 6 months after surgery. Using image-analysis software, the CCC surface was measured and changes between 1 week and 6 months were evaluated. Characteristics of the IOLs including overall diameter, optic thickness, and haptic centrifugal force were measured with micrometric tools.Results: The median change in CCC surface size at 6 months was +5.5% in the lovision group, indicating a slight enlargement. This finding was significantly different from that in the other three IOL groups (P < .0001), which had a tendency toward CCC contraction. Median change in CCC size was −2.3% in the MemoryLens group, −2.8% in the AcrySof group, and −6% in the PhacoFlex group. The MemoryLens was the most predictive IOL, with the smallest standard deviation; it was the only group in which no patient developed CCC contraction of more than 10%. Although the lovision and PhacoFex IOLs have common physical characteristics except for optic thickness (lovision 30% thicker), the CCCs in the lovision group were significantly more stable (P < .0001). Results indicate that the high centrifugal haptic force associated with acrylate/methacrylate polymer optics of the AcrySof and MemoryLens IOLs may prevent CCC contraction of greater than 10% in 97.4% of cases.Conclusion: Although there were statistically significant differences, patients in all four three-piece foldable IOL groups had good CCC stability. However, the more stable and predictable CCCs were in the IOL groups that had the strongest centrifugal haptic force and an acrylate/methacrylate polymer optic (AcrySof and MemoryLens).