Comparison of the biomechanical behavior of foldable intraocular lenses

PURPOSE: To compare a standardized battery of biomechanical laboratory tests to assess the performance of popular foldable intraocular lenses (IOLs). SETTING: Biomedical testing facilities, Alcon Research, Ltd., Fort Worth, Texas, USA. METHODS: Using industry-standard biomechanical testing techniques, 1- and 3-piece foldable IOLs (Alcon AcrySof MA60BM, MA30BA, SA30AL, SA60AT; Allergan Sensar AR40, PhacoFlex II SI-40NB; Bausch & Lomb Soflex LI61U; Pharmacia & Upjohn CeeOn 920) and a 1-piece all-poly(methyl methacrylate) (PMMA) IOL (Alcon MZ30BD) were tested under identical conditions with regard to (1) tensile/elastic properties by comparing haptic pull strength and haptic elongation and (2) compression properties by comparing haptic compression forces, haptic compression force decay over time, and axial displacement. All tests were performed with the IOLs submersed in a controlled-temperature water bath (mean 35 degrees C +/- 2 degrees C [SD]). RESULTS: For all IOLs, the ultimate elongation and pull strength of the haptics before failure was highest with the Alcon SA30AL and SA60AT. Similarly, the force required to compress haptics to a prescribed 10.0 mm diameter was least with the SA30AL and the SA60AT lenses. These 1-piece lenses also showed the least decay of residual compression force as a function of time. Optic displacement along the optical axis with haptic compression to 10.0 mm was least with the Alcon 1-piece IOLs and the all-PMMA control IOL. CONCLUSION: AcrySof 1-piece SA30AL and SA60AT IOLs demonstrated superior biomechanical characteristics over other foldable IOL designs.     

Analysis of postoperative glare and intraocular lens design

PURPOSE: To assess the potential for reflected glare images from commonly used intraocular lens (IOL) materials and designs. SETTING: Mayo Clinic, Rochester, Minnesota, USA. METHODS: The interaction of reflected light rays from 3 commonly used IOLs (Bausch & Lomb LI61U and P359UV; Alcon AcrySof(R) MA60BM) with different optic designs (equi-biconvex: 10.0 and 15.0 mm anterior radius of curvature; unequal biconvex: 32.0 mm anterior radius of curvature) and optic materials (silicone, poly[methyl methacrylate], and acrylic) were examined in an eye model using the Zemax optical design program. The potential of each IOL model to produce subjective glare was determined from the size of the defocused reflected glare image at the retina. RESULTS: The unequal biconvex design concentrated reflected light on a retinal area that was 60-fold smaller than that of the equi-biconvex design. Increasing the refractive index of the IOL material from 1.43 (silicone) to 1.55 (acrylic) increased the amount of reflected light 5-fold. Compared to an equi-biconvex design composed of a lower refractive index material, the unequal biconvex design with a higher refractive index material increased the relative intensity of reflected light at the retina 300-fold, and for eyes with low corneal power the intensity increased 3500-fold. Similarly, for external glare apparent to an outside observer, the intensity of reflected light increased 400-fold and for low corneal power it increased 6000-fold. CONCLUSION: An unequal biconvex IOL design (32.0 mm anterior radius of curvature) composed of a higher refractive index material increased the potential for postoperative glare and external reflections.     

Adhesion of soluble fibronectin,vitronectin, and collagen type IV to intraocular lens materials

PURPOSE: To evaluate soluble fibronectin, vitronectin, and collagen type IV adhesion to poly(methyl methacrylate) (PMMA), fluorine-surface-modified PMMA, silicone, hydrophobic and hydrophilic acrylate, and hydrogel intraocular lenses (IOLs) and determine whether hydrophobic and hydrophilic acrylate materials have different fibronectin-adhesion properties. SETTING: Department of Medical Biochemistry, University of Oulu, Oulu, Finland. METHODS: One hundred fifty IOLs were incubated for 1 week at 37 degrees C with radioactive-iodine-labeled soluble fibronectin, vitronectin, or collagen type IV. Fifty IOLs were analyzed for each protein, 5 from each of 10 different IOL models (PMMA, Alcon MC60BM; fluorine-surface-modified PMMA, Chiron Fluorilens Centra-55F; silicone, Allergan Medical Optics SI-40NB and Pharmacia and Upjohn CeeOn 911A; hydrophobic soft acrylate, Alcon AcrySof MA60BM and SA30AL and AMO Sensar; hydrophilic soft acrylate, Ioltech Stabibag and Bausch and Lomb BL27; and hydrogel, Bausch and Lomb Hydroview. The amount of adherent protein was measured with a gamma counter at 1 and 7 days and expressed as counts per minute. RESULTS: At 1 week, significantly more fibronectin was bound to the hydrophobic acrylate IOLs than to the 2-hydroxyethyl methacrylate (HEMA) containing hydrophilic acrylate IOLs (P <.05 to.0001). Significantly more vitronectin was bound to the 2 silicone IOLs than to any other IOL (P <.01 to.0001) at 7 days. Collagen type IV adhered best to the hydrophilic acrylate IOLs, which were significantly different (P <.01 to.0001) than the other IOLs at 1 and 7 days. CONCLUSIONS: Each IOL material had a different affinity to each protein. Significant binding to 1 protein does not indicate that the IOL will bind significantly to all proteins; instead, each protein should be studied separately. Fibronectin bound significantly better to hydrophobic acrylate IOLs than to hydrophilic acrylate IOLs, suggesting that the HEMA-containing IOLs should be classified with the hydrogel IOL group.     

Visual complaints associated with the AcrySof acrylic intraocular lens(1)

PURPOSE: To describe the visual complaints of a series of patients implanted with the AcrySof(R) (Alcon Surgical) acrylic intraocular lens (IOL) that resolved with IOL exchange. SETTING: Jules Stein Eye Institute, Los Angeles, California, and John A. Moran Eye Center, Salt Lake City, Utah, USA. METHODS: This was a retrospective review of patients who had AcrySof IOL exchange from January 1997 to December 1998. RESULTS: Eight patients (9 eyes) with bothersome visual symptoms following AcrySof IOL implantation were identified. Problems included glare, halos around point light sources, and peripheral arcs of light, often worse at night. In each case, the IOL was well-centered in the capsular bag and there was no significant posterior capsule opacification. Six patients (7 eyes) had the MA30BA model with a 5.5 mm optic, and 2 patients (2 eyes) had the MA60BM model with a 6.0 mm optic. No extralenticular reasons for the patients' complaints could be identified. Exchanging the AcrySof IOLs with silicone or poly(methyl methacrylate) IOLs alleviated most symptoms. In 5 of 8 patients, dysphotopsias resolved completely. CONCLUSIONS: A small number of patients implanted with AcrySof IOLs have specific complaints of glare, halos, and peripheral arcs of light. Optical considerations that may help explain these symptoms include the high refractive index of the IOL material and the truncated design of the optic. Patients who are highly observant and those with large pupils may be particularly symptomatic. Intraocular lens exchange may be necessary in some cases.     

Scanning electron microscopic and histologic evaluation of the AcrySof SA30AL acrylic intraocular lens. Manufacturing quality and morphology in the capsular bag

PURPOSE: To evaluate the properties of the AcrySof(R) SA30AL (Alcon Laboratories, Inc.) single-piece foldable posterior chamber intraocular lens (IOL). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Two nonimplanted clinical-quality AcrySof IOLs were examined by gross, light, and scanning electron microscopy (SEM). In addition, 2 eyes implanted with this IOL obtained post-mortem, the first such eyes accessioned in our laboratory and the first described to date, were examined using the Miyake-Apple posterior photographic technique and by histologic sections. RESULTS: Scanning electron microscopy of the SA30AL IOL showed excellent surface finish. The edge of the optic was square (truncated) and had a matte (velvet or ground-glass) appearance, a feature that may minimize edge glare and other visual phenomena. A well-fabricated square or truncated optic edge was demonstrated. Miyake-Apple analysis revealed that the SA30AL IOL showed appropriate fit and configuration within the capsular bag. Histologic correlation of the IOL's square edge and its relation to the capsular bag and adjacent Soemmering's ring were noted. CONCLUSIONS: The AcrySof SA30AL IOL is a well-fabricated lens that situates well in the capsular bag. The truncated optic and its relationship to adjacent structures show a morphological profile that has been shown to be highly efficacious in reducing the rate of posterior capsule opacification.     

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

PURPOSE: To compare differences in subjective glare and spherical aberration between five foldable intraocular lenses (IOLs) made of different materials and to different designs. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.     

Nd:YAG capsulotomy rates after use of the AcrySof acrylic three piece and one piece intraocular lenses

BACKGROUND/AIM: Acrylic lens size and shape may influence the rate of posterior capsule opacification (PCO) and need for Nd:YAG capsulotomy. The aim of this study is to compare the Nd:YAG capsulotomy rate of the three piece acrylic/PMMA AcrySof MA series lens with the one piece acrylic AcrySof SA series lens. METHODS: 434 eyes of 329 patients who had cataract extraction and implantation of one of four types of intraocular lenses (IOLs) were evaluated for rate of Nd:YAG capsulotomy. 176 eyes received the acrylic AcrySof MA30AC IOL, 71 eyes the acrylic AcrySof MA60AC IOL, 45 eyes the acrylic AcrySof SA30AL IOL, and 142 eyes the acrylic AcrySof SA60AT IOL. RESULTS: The rates of Nd:YAG capsulotomy with the three piece IOL (MA30AC/MA60AC) and the one piece IOL (SA30AL/SA60AT) were 1.2% and 2.1% at 6 months, 2.8% and 5.9% at 12 months, and 3.6% and 7.5% at 24 months, respectively. The incidence of Nd:YAG capsulotomy was higher in patients who received the one piece IOL (p=0.01, log rank test). There was no difference in Nd:YAG capsulotomy rates when comparing lens optic size, age, sex, history of pars plana vitrectomy, and diabetes mellitus. CONCLUSIONS: This study shows a greater incidence of Nd:YAG capsulotomy in patients who receive one piece acrylic AcrySof lenses when compared to those who receive three piece acrylic AcrySof lenses.     

Lens epithelial cell outgrowth on 3 types of intraocular lenses.

PURPOSE: To compare the outgrowth of lens epithelial cells (LECs) on 3 types of intraocular lenses (IOLs) to determine the influence of lens material and lens design (optic edge) on this phenomenon. SETTING: Department of Ophthalmology, University of Vienna, Medical School, Vienna, Austria. METHOD: Ninety eyes scheduled for cataract surgery were included in a prospective comparative study. A standardized surgical procedure was performed by 1 experienced surgeon. Patients received 1 of 3 types of posterior chamber IOLs of similar design with a 6.0 mm optic and poly(methyl methacrylate) haptic: AcrySof (Alcon), HydroView (Bausch & Lomb), or Sensar (Allergan). Each IOL type was implanted in 30 eyes. Postoperative biomicroscopic examinations were performed 1, 3, 7, 30, 90, and 180 days and 1 year after surgery. Lens epithelial cells in each quadrant of the anterior lens surface were subjectively graded. The product with the highest density and the number of quadrants with this density were used to measure LEC outgrowth. RESULTS: Statistically significant differences (P <.05) were seen between the hydrophilic IOL and the 2 hydrophobic lenses from day 30 until the final examination. The HydroView lens had a higher number of LECs on its anterior surface than the AcrySof or Sensar IOL. There were no statistically significant differences between the 2 acrylic IOLs at any measurement. CONCLUSION: The findings suggest that lens surface properties have a greater influence on LEC outgrowth than lens design (ie, sharp optic edge).     

Posterior capsule opacification and Nd:YAG capsulotomy rates after implantation of silicone,hydrogel and soft acrylic intraocular lenses: a two-year follow-up study

PURPOSE: To compare the posterior capsule opacification (PCO) and neodymium:YAG (Nd:YAG) laser posterior capsulotomy rates associated with three different posterior chamber foldable intraocular lenses (IOL). METHODS: We retrospectively evaluated the rates of PCO and Nd:YAG laser capsulotomy in 1150 eyes two years after standard phacoemulsification with a no-stitch 3.5mm clear corneal incision (CCI) and in-the-bag implantation of one of three types of IOL: 190 eyes received a one-piece round-edged hydrogel IOL (Hydroview H60M, Bausch & Lomb); 475 eyes a three-piece round-edged silicone IOL (AMO PhacoFlex SI-40NB, Allergan); 485 eyes a three-piece square-edged soft acrylic lens (AcrySof MA60MA, Alcon). RESULTS: The PCO and Nd:YAG laser capsulotomy rates were respectively 43.15% and 20.5% in the Hydroview H60M group, 27.57% and 9.68% in the AMO PhacoFlex SI-40NB group, 10.5% and 2.47% in the AcrySof MA60MA group. CONCLUSIONS: PCO and Nd:YAG laser capsulotomy rates were significantly higher in the Hydroview H60M group and significantly lower with the AcrySof MA60MA lenses, which combine a bioactive constitutive material with the square-edged optic design.     

Sharp-edged intraocular lens design as a cause of permanent glare

PURPOSE: To evaluate patients who had implantation of an acrylic intraocular lens (IOL) and reported edge glare that did not lessen with time. SETTING: Hawthorn Eye Clinic, Kew, Victoria, Australia. METHOD: This retrospective study comprised patients who had uneventful phacoemulsification and then reported glare that did not abate after 12 months. RESULTS: Five patients (7 of 322 eyes; 2.2%) who received an AcrySof MA30BA IOL with a 5.5 mm optic and 1 patient (1 of 221 eyes; 0.5%) who received an AcrySof MA60BM IOL with a 6.0 mm optic reported permanent edge glare. Extensive retinal and neurological evaluations in 2 patients showed no deficits in 1 and an abnormal photopic red electroretinogram in the other. Pilocarpine 1% was used in 3 patients and gave no relief of symptoms. Two patients (3 eyes) had IOL explantation with complete resolution of glare symptoms. There was no statistical significance between the 2 types of IOLs. CONCLUSION: Sharp-edged IOL designs can cause permanent intractable glare.     

Quantitative Measurements of the Decentration Distance of Four Kinds of Intraocular Lens

Goodpostoperativevisioncanimprovethelifequalitiesofcataractpatientsgreatly[1]andtheintraocularlens(IOL)decentrationcanaffectvi鄄sualacuityandinduceglare.Todate,itisdiffi鄄culttomeasurethedecentrationdistance(DD)quantitatively.Thedecentrationconditionisusu鄄allyexaminedbynakedeyes.WeappliedthePhotoshopsoftwaretoanalyzethepositionsof4kindsofIOLsquantitatively.Theresultsarere鄄portedasfollows.PatientsandMethods1.Patients.After6monthsofcataractandIOLsurgery,thephotosofpseudophakiceyeswereta…     

Optical quality measurements of hydrophobic acrylic intraocular lenses

PURPOSE: To compare the optical quality of several models of hydrophobic acrylic intraocular lenses (IOLs). METHODS: Modulation transfer function (MTF) measurements were performed using a model eye system on four models of hydrophobic acrylic IOLs. Models tested were the AcrySof SA60AT, MA60AC, and MA60BM (Alcon, Ft Worth, Tex), as well as the model VA-60BB (Hoya, Tokyo, Japan). For benchmarking, the Alcon model MZ60BD polymethylmethacrylate (PMMA) lens was also measured. Three lenses of each model were tested at frequencies of 50 and 100 line pairs (lp)/mm (corresponding to 20/40 and 20/20, respectively). RESULTS: With a 3-mm aperture, the Alcon AcrySof models had mean MTF values ranging from 58.5% to 60.3% at 100 lp/mm and 78.0% to 79.7% at 50 lp/mm. The Hoya model VA-60BB provided statistically significantly lower (P<.05) MTF values than the Alcon AcrySof models at both frequencies (47.3 +/- 1.2% at 100 lp/mm and 71.8 +/- 1.9% at 50 lp/mm). With a 5-mm aperture, the Alcon AcrySof models had MTF values ranging from 32.9% to 34.3% at 100 lp/mm and 45.2% to 46.7% at 50 lp/mm. Under these larger aperture conditions, the Hoya model VA-60BB also had statistically significantly lower MTF values (20.9 +/- 0.8% at 100 lp/mm and 27.2 +/- 1.1% at 50 lp/mm). Under both apertures and frequencies, the Alcon PMMA lens had statistically significantly higher MTF values than the Hoya lens and statistically significant lower MTF values than all AcrySof models. CONCLUSIONS: Using both 3- and 5-mm aperture settings as well as frequencies corresponding to 20/20 and 20/40 vision, statistically significantly higher MTF values were obtained for AcrySof lenses, which were greater than the PMMA lens, which were greater than the Hoya model VA-60BB. The differences in MTF values between lens models are more exaggerated with a 5-mm aperture and may highlight differences in lens manufacturing processes.     

6.5 mm optic AcrySof implantation through a 3.0 mm incision

An Alcon AcrySof MA50BM intraocular lens (IOL) with an optic diameter of 6.5 mm can be implanted without further enlarging a 3.0 mm phacoemulsification incision. The IOL is placed in a Monarch II B cartridge (Alcon) designed for use with the 5.5 mm optic AcrySof SA30AL, and the tip of the cartridge is inserted in the incision but not the anterior chamber. With the cartridge tip pressing against the eye, holding up the inner edge of the corneal incision and pressing down on the outer edge of it, the plunger is advanced to insert the IOL. When the entire optic has been inserted in the eye, the cartridge is withdrawn and the trailing loop is tucked in the capsular bag. We have used this procedure to perform uneventful IOL implantation in 228 consecutive eyes, after which the incisions were 3.0 to 3.1 mm in width.     

The effect of lens design on dysphotopsia in different acrylic IOLs

PURPOSE: To compare the incidence and severity of all grades of dysphotopsia in three types of acrylic intraocular lenses: the Acrysof MA30 BA and MA60 BM IOLs (Alcon) and the Akreos Fit one-piece IOL (Bausch and Lomb). METHODS: In all 111 patients were prospectively recruited who had undergone uncomplicated cataract surgery in the previous 12 months. Patients were assessed using a combination of a questionnaire and standardised provocation test, and were scored on a grading scale of 0-6 (0 indicating no glare and 6 indicating the most severe symptoms). RESULTS: The overall incidence of dysphotopsia was 77.7%. Patients with absent or mild symptoms (scoring 2 or less on the grading scale) were greater in the group implanted with the Akreos IOLs (49/65 eyes, 75%) as opposed to (44/92 eyes, 48%) of the eyes implanted with Acrysof lenses. Patients with more marked symptoms of glare as judged by scores of 5-6 were uncommon, but more prevalent in the Acrysof lenses (12/92 eyes, 13%) compared to the Akreos lenses (3/65 eyes, 4.6%) respectively. Statistically the Mann-Whitney test showed that there was significantly less dysphotopsia with the Akreos lens when compared to the Acrysof MA30 (P=0.005) and MA60 lenses (P=0.002). CONCLUSION: This study demonstrates that dysphotopsia symptoms are commonly seen in certain brands of Acrylic IOLs. However, differences in design (not only related to the edge) significantly reduce the incidence of moderate and severe grades of dysphotopic symptoms.     

Comparison of higher order aberrations with spherical and aspheric IOLs compared to normal phakic eyes

PURPOSE: To compare higher order aberrations (HOA) in AcrySof SN60AT and Acrysof IQ SN60WF intraocular lenses (IOLs) and natural crystalline lenses in an age-matched population. METHODS: Sixty-nine eyes of 55 patients were examined. Group I included AcrySof spheric lenses, group II AcrySof aspheric lenses, and group III included patients with the natural crystalline lens. The HOA data were obtained with a LADARWave aberrometer (Alcon Inc.). Analysis was based on the RMS of coma, spherical aberrations (SA), and HOA. Statistical comparisons were performed with Kruskal Wallis variance analysis. RESULTS: In the case of coma, there were statistically significant differences between spheric and aspheric AcrySof (p<0.005) and between spheric AcrySof and natural crystalline lenses (p<0.005). The differences between aspheric AcrySof and natural crystalline lens group were not significant (p>0.05). SA were significantly different between spheric and aspheric AcrySof group, and spheric AcrySof and natural crystalline lens group (p<0.005), as well as between aspheric AcrySof and natural crystalline lens group (p<0.05). In case of HOAno significant differences were observed between aspheric AcrySof and natural crystalline lens group (p>0.05), but differences between groups AcrySof spheric and aspheric, and spheric AcrySof and natural crystalline lens, showed high significance (p<0.005). CONCLUSIONS: The AcrySof Natural IQ aspheric model SN60WF IOL did not change the optical quality of vision compared to a healthy population of 60-80 years of age. The AcrySof Natural model SN60AT spherical IOL resulted in higher HOAs relative to both the natural crystalline lens population and eyes after aspheric AcrySof IQ model SN60WF IOL implantation.     

Calcification of Hydroview H60M intraocular lenses: aqueous humor analysis and comparisons with other intraocular lens materials

PURPOSE: To compare the level of calcification on Hydroview H60M hydrophilic acrylic intraocular lenses (IOLs) (Bausch & Lomb) and other IOL materials. SETTING: Omori Medical Center, Department of Ophthalmology, Toho University, Tokyo, Japan. METHODS: The levels of calcification on Hydroview H60M hydrophilic acrylic IOLs, AcrySof SA60AT hydrophobic acrylic IOLs (Alcon Surgical, Inc.), Sensar AR40e hydrophobic acrylic IOLs (Advanced Medical Optics), ClariFlex (Advanced Medical Optics) silicone IOLs, and the MeniFlex ENV13 (Menicon) poly(methyl methacrylate) IOLs were compared in a calcium phosphate solution containing albumin. In a concentration-change experiment, the calcium and phosphate concentration levels were changed and the results observed by scanning electron microscopy. RESULTS: The Hydroview H60M IOL had the largest amount of deposits. Small amounts of deposits were found on the other IOLs in the following decreasing order: AcrySof SA60AT, Sensar AR40e, ClariFlex, and MeniFlex ENV13. The amount of deposits on the Hydroview H60M IOLs was statistically significantly greater than the amount on the other IOLs (P<.01). CONCLUSIONS: The hydrophilic acrylic IOLs (Hydroview H60M) had significantly higher amounts of calcified deposits than IOLs of other materials, indicating that hydrophilic acrylic IOLs easily accumulate calcified deposits in the body when the concentrations of calcium, phosphate, and albumin in the aqueous humor fluctuate as a result of a blood-aqueous barrier breakdown.     

Uveal and capsular biocompatibility of hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses.

PURPOSE: To evaluate the long-term response of 6 types of 3-piece intraocular lenses (IOLs) by assessing the cellular reaction on the anterior IOL surface, the behavior of posterior and anterior capsule fibrosis, and flare. SETTING: Department of Ophthalmology, Medical School, University of Vienna, Vienna, Austria. METHODS: One hundred eighty eyes were prospectively randomized to receive 1 of 6 IOLs: hydrophilic acrylic Hydroview (Bausch & Lomb) or MemoryLens (ORC); hydrophobic acrylic AcrySof MA60BM (Alcon) or AMO Sensar AR40 (Allergan); hydrophobic silicone CeeOn 920 or CeeOn 911A (Pharmacia). The patients had standardized cataract surgery, postoperative medication, and follow-up. One year after surgery, 155 eyes were assessed. The cellular reaction was evaluated by specular microscopy of the anterior IOL surface. Anterior and posterior capsule opacification (PCO) was assessed semiquantitatively by biomicroscopy. Flare was measured with a Kowa FC-1000 laser flare-cell meter. RESULTS: Regarding uveal biocompatibility, the hydrophobic acrylic IOLs showed the highest incidence of late foreign-body cell reaction (AcrySof, 30%; AR40, 17%) followed by the hydrophilic acrylic (MemoryLens, 8%; Hydroview, 4%) and silicone (CeeOn 920, 4%; CeeOn 911A, 0%) (P =.0044). In all cases, the cellular reaction was low grade and clinically insignificant. Regarding capsular biocompatibility, some eyes developed lens epithelial cell (LEC) outgrowth on the anterior IOL surface. The highest incidence was in the hydrophilic acrylic group (Hydroview, 85%; MemoryLens, 27%) followed by the hydrophobic acrylic (AcrySof, 4%; AR40, 3%). No silicone IOL had LECs on the anterior surface. The difference among IOL groups was significant (P =.0001). Anterior capsule opacification was more predominant in the hydrophobic IOL groups. Posterior capsule opacification of the central 3.0 mm area was lowest in the groups with a sharp-edged optic (CeeOn 911A, AcrySof) followed by the round-edged silicone (CeeOn 920), hydrophobic acrylic (AR40), and hydrophilic acrylic IOLs (P =.0001). There was a significant difference in flare between the AR40 lens and the Hydroview, MemoryLens, CeeOn 911A, and CeeOn 920 (P <.004). There was no statistically significant difference in the postoperative cell count at 1 year. The power calculation showed that the sample size was sufficient. CONCLUSIONS: The differences in cellular reaction, although clinically mild in normal eyes, indicate that there were more giant cells with hydrophobic acrylic IOLs and an increased tendency toward LEC outgrowth with hydrophilic lenses. The incidence of PCO was lowest in the hydrophobic IOL groups, especially in groups with a sharp-edged optic. Second-generation silicone IOLs with a sharp edge had good uveal and capsular biocompatibility 1 year after surgery.     

Spontaneous disinsertion of a multipiece foldable acrylic intraocular lens haptic 3 and 12 months after implantation

We report 2 cases of spontaneous postoperative haptic disinsertion with the Alcon AcrySof MA60BM posterior chamber intraocular lens (PC IOL). A 14-year-old girl with a history of acute retinal necrosis and pars plana vitrectomy with lensectomy for retinal detachment repair had secondary implantation of a PC IOL in the ciliary sulcus. Three months later, the superior haptic disinserted from the optic and dislocated into the anterior chamber. In the second case, a 22-year-old man had lens aspiration and PC IOL implantation in the capsular bag. One year after surgery, the PC IOL had a similar problem, with the disinserted superior haptic remaining in the capsular bag while the optic and inferior haptic dislocated into the anterior chamber. In both patients, the PC IOLs were exchanged for rigid single-piece PC IOLs. The patients have had no further problems.     

Effect of a yellow intraocular lens on scotopic vision, glare disability, and blue color perception

PURPOSE: To compare the photopic and scotopic contrast sensitivity with and without glare as well as blue color perception between eyes with an AcrySof SN60AT Natural intraocular lens (IOL) (Alcon Laboratories Inc.) and eyes with a conventional AcrySof SA60AT IOL. SETTING: Ankara University School of Medicine, Department of Ophthalmology, Ankara, Turkey. METHODS: Right eyes of 38 patients with an AcrySof Natural IOL and right eyes of 38 age-matched patients with a conventional AcrySof SA60AT IOL were included in a study. Contrast sensitivity was measured with the Functional Acuity Contrast Test under photopic conditions. Scotopic contrast sensitivity in the presence or absence of glare was measured using the Mesotest II (Oculus GmbH). Blue-green color vision was evaluated with the Moreland equation of the HMC Anomaloskop MR (Oculus GmbH). RESULTS: The mean age of patients was 66.6 years +/- 8.2 (SD) in the Natural IOL group and 66.4 +/- 8.0 years in the conventional IOL group. There was no statistically significant difference in photopic contrast sensitivity, scotopic contrast sensitivity with and without glare, or disability glare between the 2 groups (P>.05). Photopic and scotopic contrast sensitivity with and without glare significantly decreased with age in both groups (P<.01). There was no statistically significant difference in anomaloscope scores between the 2 groups (P>.05). The Moreland middle match point showed a significant shift toward blue with age in both groups (P<.01). CONCLUSIONS: The AcrySof SN60AT Natural IOL provided contrast sensitivity under photopic and scotopic conditions (with and without glare) and blue color perception comparable that obtained with the AcrySof SA60AT IOL. Scotopic vision and blue color discrimination decreased with age with both IOLs.