Evaluation of the cataractogenic effect of viscoanesthetic solutions on the rabbit crystalline lens.

PURPOSE: To evaluate the toxicity and cataractogenic effect of solutions combining sodium (Na) hyaluronate 1.0% and 1.5% with lidocaine 1.0% on the rabbit crystalline lens. The amount of pupil dilation provided by the addition of lidocaine to the Na hyaluronate solutions was also assessed. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Five solutions were injected into the anterior chamber of 18 pigmented rabbits in a randomized manner by the same surgeon, the intraocular component of VisThesia (Na hyaluronate 1.5%/lidocaine 1.0%), the intraocular component of VisThesia Light (Na hyaluronate 1.0%/lidocaine 1.0%), Ophthalin Plus (Na hyaluronate 1.5%), and a balanced salt solution; and both eyes of 2 other rabbits were injected with nonpreserved aqueous lidocaine 1.0%. The pupil diameter of each eye was measured before injection, immediately after, and 1 and 5 minutes after injection. After a follow-up of 3 months with slitlamp examinations, the rabbits were killed, and their eyes were enucleated. The crystalline lenses were evaluated from a posterior or Miyake-Apple view, and the eyes were fixated in 10% formalin for histopathologic analyses. RESULTS: Pupil diameter was significantly larger 1 and 5 minutes after injection in the VisThesia (P = .01 and P = .007) and VisThesia Light (P = .008 and P = .007) groups, whereas the differences were not significant in the Ophthalin Plus (P = .317 and P = .102) and balanced salt solution groups (P = .317 and P = .180). Fast and large pupillary dilation was observed in the aqueous lidocaine group, starting during the injection. No differences in the transparency of the natural lens and the red fundus reflex were noted during slitlamp examinations. Postmortem analyses from a posterior view also showed no differences in the transparency of the crystalline lens. The histopathologic appearance of the lens capsule, anterior and equatorial lens epithelial cells, and epithelial lens bow was comparable in the eyes, without signs of cell vacuolization or disruption. CONCLUSIONS: Intracameral injection of the solutions used in this study caused no localized opacity or overall change in the transparency of the crystalline lenses as observed during clinical and postmortem examinations as well as histopathologic analyses of the enucleated rabbit eyes. Viscoanesthesia may have application in phakic intraocular lens implantation.

Posterior capsule opacification in rabbit eyes implanted with 1-piece and 3-piece hydrophobic acrylic intraocular lenses.

PURPOSE: To evaluate the outcome of posterior capsule opacification (PCO) after implantation in rabbit eyes of currently available 3-piece and 1-piece hydrophobic acrylic intraocular lenses (IOLs) with square optic edges. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: The 3-piece designs evaluated were the AR40e (Advanced Medical Optics Inc.) and the MA60AC (Alcon, Inc.); the 1-piece designs were the SA60AT and the SA30AT (Alcon, Inc.). Nine lenses of each type were implanted in a randomized manner by the same surgeon in 18 Dutch Belted pigmented rabbits. After a follow-up of 3 weeks, the rabbits were killed and analyses of the enucleated eyes were performed from the posterior or Miyake-Apple view. The intensity of central PCO, peripheral PCO, and Soemmering's ring formation was scored from 0 to 4. The area of Soemmering's ring formation was also scored from 0 to 4 based on the number of quadrants involved. Other parameters analyzed were capsulorhexis coverage of the IOL anterior surface, IOL centration, fixation, and presence of striae. Results from the posterior view were complemented by histopathologic evaluation of the eyes. RESULTS: No statistically significant difference was found between the 4 groups of IOLs in the parameters analyzed from the posterior view. When cell ingrowth occurred with the 1-piece designs, causing peripheral and central PCO formation, it was more likely to start at the optic-haptic junctions, as observed during the clinical follow-up with slitlamp examination and confirmed by gross and histopathologic analyses of the enucleated eyes. CONCLUSIONS: The square, truncated optic edge is the most important IOL design feature for PCO prevention. The optic-haptic junctions of the 1-piece designs appear to be sites where the barrier effect of the truncated optic edge is less effective.

Late postoperative opacification of a hydrophilic acrylic (hydrogel) intraocular lens: a clinicopathological analysis of 106 explants.

PURPOSE: To report clinical, pathologic, histochemical, ultrastructural, and spectroscopic analyses of MemoryLens intraocular lenses (IOLs) explanted from patients who had visual disturbances caused by postoperative opacification of the lens optic. DESIGN: Noncomparative, large case series with clinicopathologic correlation. PARTICIPANTS: A total of 106 hydrophilic acrylic IOLs of the same design explanted from 106 different patients. All patients had decreased visual acuity at presentation approximately 2 years after cataract surgery, associated with a whitish fine granularity on the optical surfaces of the IOLs. METHODS: The explanted IOLs were submitted to the John A. Moran Eye Center and were examined under light microscopy, histochemically, and with scanning electron microscopy (SEM) equipped with an energy dispersive x-ray spectroscopy detector with light element capabilities (EDS). MAIN OUTCOME MEASURES: The IOLs were examined for distribution, structure, and composition of the deposits causing opacification of their optic components. RESULTS: The average interval between lens implantation and opacification was 25.8+/-11.9 months. The most frequently associated medical and ophthalmic conditions were diabetes and glaucoma. However, some patients did not have any preexisting medical or ophthalmic conditions. Most of the IOLs had been implanted in 1999 and 2000. Microscopic analyses revealed the presence of multiple fine, granular deposits of variable sizes on the anterior and posterior optic surfaces, especially on the anterior surface. The deposits stained positive for calcium. The EDS confirmed the presence of calcium and phosphate within the deposits. CONCLUSIONS: The results obtained suggest the surface deposits to be composed, at least in part, by calcium and phosphate. A special polishing technique used in the manufacture of most of these IOLs may have caused changes in the lens surface leading to deposit formation. Further studies should be undertaken to confirm this hypothesis.

Analysis of elements of interlenticular opacification.

PURPOSE: To report the histopathologic and ultrastructural features of three cases of interlenticular opacification (ILO) between piggyback intraocular lenses. DESIGN: Interventional case series with clinicopathologic correlation. METHODS: Three pairs of acrylic piggyback lenses were explanted due to decrease in visual acuity associated with ILO. Lenses were evaluated with gross and light microscopic examinations in all cases. The anterior lens in one case was examined with scanning electron microscopy and energy dispersive x-ray spectroscopy. RESULTS: The material opacifying the interlenticular space was composed mostly of retained/regenerative cortical material in all cases. From the peripheral interface towards the central interface, the opacifying material changed as the interlenticular space was progressively narrower. The material attached to the peripheral interface, where the interlenticular space was wider, was very thick. At the midperipheral interface, the thick cortical material was broken into multiple globules due to liquefactive degeneration. At the paracentral zone, compression of the globules formed a flat, compact layer of an amorphous material. At the central interface (contact zone), almost no material could be found between the piggyback lenses. CONCLUSIONS: Analyses of ILO cases where all the components of the opacifying material were in situ allowed us to confirm that the pathogenesis of this complication is similar to that of posterior capsule opacification; thus, careful removal of lens epithelial cells and cortical material is mandatory in piggyback implantation.

Pathological evaluation of postmortem human eyes implanted with a new single-piece hydrophobic acrylic lens.

PURPOSE: To report the pathological findings in 14 human cadaver eyes implanted with a single-piece AcrySof(Alcon Laboratories) posterior chamber intraocular lens (IOL). SETTING: David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Fourteen human autopsy eyes implanted with a single-piece AcrySof (SA30AL) IOL were evaluated. The eyes were sectioned at the equatorial plane, and the anterior segment containing the IOL in the capsular bag was evaluated from a posterior perspective (Miyake-Apple view) and from an anterior perspective (surgeon's view) after removal of cornea and iris. They were then processed through paraffin, sectioned, and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome and examined under light microscopy. RESULTS: All IOLs had symmetric in-the-bag fixation. Slight decentration was measured in 1 eye, which also had an anterior capsule tear. Grade 1 anterior capsule opacification was present in 9 eyes. No central posterior capsule opacification or posterior capsule folds were observed in any eye. Soemmering's ring formation was observed in 5 eyes. Zonular stretch caused by different degrees of capsular bag contraction was present in 4 eyes without decentration of the IOL. CONCLUSIONS: Analyses of pseudophakic cadaver eyes from the posterior (Miyake-Apple) view, complemented by microscopic analyses, proved useful in the evaluation of IOL-capsular bag interaction. These studies are more important in cases of newly introduced lens designs.

Analysis of the capsule edge after Fugo plasma blade capsulotomy, continuous curvilinear capsulorhexis, and can-opener capsulotomy.

PURPOSE: To compare the quality of the edges of anterior capsulotomies performed in porcine eyes using 3 different techniques. SETTING: David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA. METHODS: Four porcine eyes were submitted to the center in 10% neutral buffered formalin. The cornea of the eyes had been removed, and a continuous capsulotomy had been performed in each eye using the Fugo plasma blade. To provide morphologic correlation, 4 additional porcine eyes were used in the study. In 2, a manual continuous curvilinear capsulorhexis (CCC) was performed after the cornea or cornea/iris was removed and in the other 2, a can-opener capsulotomy (COC) was performed. The eyes were then placed in 10% neutral buffered formalin. Gross (macroscopic) and microscopic analysis of each eye was performed, and photographs were taken. One eye in each group was also prepared and analyzed under scanning electron microscopy (SEM). RESULTS: The capsulotomy margin in the Fugo blade group presented some regularly spaced tags directed centrally with smooth edges at the base. Such a configuration would not interfere with the dynamics of the capsulorhexis sphincter and would generally not lead to radial tears. The smooth and regular nature of the capsulotomy margin in the CCC group was confirmed by gross and microscopic examinations of the eyes. The capsulotomy margin in the COC group presented some sharp notches directed outward, irregularly spaced, and irregular in shape. These are known to have a tendency to extend and form radial tears. CONCLUSION: Although performance of an anterior capsulotomy with the Fugo blade was associated with some margin irregularities, the geometry of the centrally directed tags prevented them from becoming the site of radial tear formation. The base of the capsulotomy performed with the Fugo blade appeared to be almost as smooth and regular as in the CCC under SEM evaluation.

Capsulorhexis ovaling and capsular bag stretch after rigid and foldable intraocular lens implantation: experimental study in pediatric human eyes.

PURPOSE: To compare the amount of capsulorhexis ovaling and capsular bag stretch produced by various intraocular lenses (IOLs) implanted in pediatric human eyes obtained post-mortem. SETTING: David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Salt Lake City, Utah, USA. METHODS: In this nonrandomized comparative study, 16 pediatric human eyes obtained postmortem were divided into 2 groups: Eight eyes were obtained from children younger than 2 years (Group A), and 8 eyes were obtained from children older than 2 years (Group B). All eyes were prepared according to the Miyake-Apple posterior video technique. Six types of rigid and foldable posterior chamber IOLs manufactured from poly(methyl methacrylate) (single-piece), silicone (plate and loop haptics), and hydrophobic acrylic (single-piece and 3-piece AcrySof, Alcon Laboratories) biomaterials were implanted. The capsulorhexis opening and capsular bag diameters were measured before IOL implantation and after in-the-bag IOL fixation with the haptics (or the main axis) at the 3 to 9 o'clock meridian. The percentage of ovaling of the capsulorhexis opening was calculated by noting the difference in the opening's horizontal diameter before and after IOL implantation. The percentage of capsular bag stretch was also calculated by noting the difference in the horizontal capsular bag diameter before and after IOL implantation. RESULTS: All IOLs produced ovaling of the capsulorhexis opening and stretching of the capsular bag parallel to the IOL haptics. There were significant differences in capsulorhexis ovaling and capsular bag stretch (P<.001, analysis of variance) between the 6 IOL types in each group of eyes. The postimplantation difference was significant only between the single-piece hydrophobic acrylic IOL (AcrySof) and the other IOLs. The single-piece hydrophobic acrylic IOL was associated with significantly less capsulorhexis ovaling and capsular bag stretch in both groups (mean 12.06% +/- 0.59% [SD] and 7.6% +/- 1.47%, respectively). CONCLUSIONS: Modern rigid and foldable IOLs designed for the adult population implanted in the capsular bag of infants and children produced variable degrees of capsulorhexis ovaling and capsular bag stretch. The Miyake-Apple posterior video technique confirmed the well-maintained configuration of the capsular bag (with minimal ovaling) after implantation of a single-piece hydrophobic acrylic IOL because of its flexible haptic design.

Management of bipseudophakia with implantation of an iris claw lens.

We discuss a case of bipseudophakia with secondary dislocation of a posterior chamber intraocular lens (IOL) into the anterior chamber that was managed by explantation of the anterior and posterior chamber IOLs and implantation of an iris claw IOL.

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.

Viscoanesthesia. Part I: toxicity to corneal endothelial cells in a rabbit model.

PURPOSE: To evaluate the toxicity of a solution combining sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to the rabbit corneal endothelium. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Each rabbit cornea was excised, and the endothelium was exposed to 1 of the following solutions for 20 minutes: viscoanesthetic solution (0.5%, 1.0%, or 1.65% lidocaine in sodium hyaluronate 1.5%; 5 corneas each), sodium hyaluronate 1.5% (n = 5), balanced salt solution (BSS(R)) (n = 5), mitomycin-C 0.02% (n = 2), dextran 15% (n = 2), or distilled water (n = 2). The endothelium was then stained with trypan blue and alizarin red. Two corneas were stained immediately after excision. Cell morphology and damage to the corneal endothelium were analyzed by microscopic examination. RESULTS: The endothelium in the corneas of the viscoanesthetic groups was comparable to that in the sodium hyaluronate 1.5% and the BSS groups and to the corneas not exposed to any solution. In some areas of the 1.0% and the 1.65% viscoanesthesia groups, the corneal endothelial cells presented irregular intercellular borders. Staining with trypan blue, which indicates cellular damage, was observed in some linear areas corresponding to corneal folds in all groups. The folds were probably caused during manipulation for corneal excision and staining. The corneal endothelium was destroyed in the mitomycin group. In the dextran and distilled-water groups, morphological alterations probably resulting from osmotic changes were observed. CONCLUSIONS: The 3 concentrations of viscoanesthetic solutions appeared to be safe to rabbit corneal endothelium.

Viscoanesthesia. Part II: toxicity to intraocular structures after phacoemulsification in a rabbit model.

PURPOSE: To investigate the toxicity of a solution that combines sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to intraocular structures. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Phacoemulsification was performed in both eyes of 29 rabbits. They were divided into 3 groups; in each group (n = 7), 1 viscoanesthetic solution was used before capsulorhexis. After irrigation/aspiration, 0.2 mL of the solution was purposely left in the capsular bag. In 1 rabbit in each group, the solution was injected into the vitreous cavity through a posterior capsulorhexis. In 8 rabbits used as controls, balanced salt solution (BSS(R)) (n = 4) or sodium hyaluronate 1.5% (n = 4) was injected into the vitreous cavity. Enucleations were performed 15, 30, and 60 days postoperatively. Histological sections were cut and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson trichrome stains. RESULTS: Light microscopic evaluation of the eyes enucleated after 15, 30, and 60 days in the study and control groups showed similar findings in intraocular structures such as the ciliary body and retina. No evidence of an inflammatory reaction, cell necrosis, or cell degeneration was observed in the histological sections. CONCLUSIONS: The use of viscoanesthesia during phacoemulsification appeared to be safe, with no histologic abnormalities observed with the 3 lidocaine concentrations. The efficacy of the anesthetic effects of these solutions will be addressed in clinical trials.

Viscoanesthesia. Part III: removal time of OVD/viscoanesthetic solutions from the capsular bag of postmortem human eyes.

PURPOSE: To investigate and evaluate the removal time of various ophthalmic viscosurgical device (OVD)/viscoanesthetic solutions containing sodium hyaluronate 1.5% with different concentrations of lidocaine (0.5%, 1.0%, and 1.65%). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Six postmortem human eyes were prepared per the Miyake-Apple posterior video technique. Capsulorhexis, hydrodissection/delineation, and nuclear emulsification were performed, followed by thorough cleaning of the capsular bag using an irrigation/aspiration (I/A) tip. The time and ease of removal of 4 solutions from the capsular bag were evaluated. The solutions were Ophthalin Plus (sodium hyaluronate, 15 mg/mL) and sodium hyaluronate 15 mg/mL mixed with lidocaine 0.5%, lidocaine 1.0%, and lidocaine 1.65%. The solutions were dyed with fluorescein to enhance visualization. After the capsular bag was filled with 1 of the solutions, a posterior chamber intraocular lens was implanted. The solution was then aspirated using an automated I/A device set at 250 mm Hg of aspiration. The time required to remove most and then all the material was recorded. RESULTS: The mean time required for removal of most of the Ophthalin Plus, viscoanesthesia 0.5%, viscoanesthesia 1%, and viscoanesthesia 1.65% solutions was 8.7 seconds +/- 2.1 (SD), 7.7 +/- 1.1 seconds, 9.7 +/- 0.6 seconds, and 6.3 +/- 1.5 seconds, respectively (P =.1). The mean time to remove all the solutions was 21.3 +/- 3.2 seconds, 19.7 +/- 2.5 seconds, 18.3 +/- 3.2 seconds, and 15.7 +/- 2.1 seconds, respectively (P =.166). No subjective difference in viscosity or consistency was found among the solutions. CONCLUSIONS: The addition of lidocaine to the OVD solution did not significantly alter the viscosity or consistency of the solution or change its removal time from the capsular bag.

Loop memory of haptic materials in posterior chamber intraocular lenses.

PURPOSE: To compare the shape recovery ratios after compression of haptic materials used in the manufacture of intraocular lenses (IOLs). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: The loop memory of 40 silicone-optic posterior chamber IOLs was studied. All the IOLs had modified-C haptics made of poly(methyl methacrylate) (PMMA; n = 10), polyimide (n = 10), polyvinylidene fluoride (PVDF; n = 10), and polypropylene (PP; n = 10). After the overall diameter of each lens was measured (day 0), the lenses were inserted into plastic wells (9.5 mm in diameter) and immersed in water (37 degrees C) for 1 month. They were then placed on an open plate and allowed to reexpand for 2 months. Overall diameter measurements were performed within 5 minutes of the IOLs' removal from the wells and at subsequent time points (days 14, 28, 30, 60, 74, 88, and 95). RESULTS: The loop memory of each lens was expressed as the difference between the initial overall diameter measurement (pretest) and the measurement at each time point; the lower the value, the higher the memory. The overall difference among the 4 groups was statistically significant at each time point (P < or = .001). From days 30 to 95, silicone-PMMA, silicone-elastimide, and silicone-PVDF IOLs had similar loop memory mean values, which were significantly lower than the mean value of silicone-PP IOLs (P <.05). The latter design tended to be deformed after removal from the wells, with increased optic-haptic angulation. CONCLUSION: Studying the loop memory of haptic materials (PMMA, polyimide, PVDF, and PP) used in the manufacture of posterior chamber IOLs can help surgeons choose an appropriate IOL for each patient.

Permanent blue discoloration of a hydrogel intraocular lens by intraoperative trypan blue.

A 79-year-old white man had cataract surgery in the right eye with implantation of an Acqua intraocular lens (IOL) (Mediphacos). Trypan blue 0.1% was used during surgery to stain the anterior capsule and enhance the contrast during capsulorhexis. Seven days after surgery, the patient presented with "dark and double" vision (monocular diplopia). The IOL was decentered superiorly and appeared dark blue. The lens was explanted 2 months after surgery and sent for gross and microscopic analyses in a dry state and after hydration. The same analyses were performed on 2 unused lenses of the same design that had been immersed in diluted trypan blue solutions (0.01% and 0.001%). On the explanted lens, the dark blue staining was denser in the optic, especially in its periphery. The blue discoloration could not be removed after 24 hours of lens immersion in a balanced salt solution at 37 degrees C. Permanent staining of the unused lenses was also obtained after immersion in the trypan blue solutions.

Capsular bag opacification after experimental implantation of a new accommodating intraocular lens in rabbit eyes.

PURPOSE: To evaluate the development of capsular bag opacification in rabbit eyes after implantation of an intraocular lens (IOL) designed to minimize contact between the anterior capsule and the IOL and ensure expansion of the capsular bag. SETTING: David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Ten New Zealand white rabbits had a study IOL (new accommodating silicone IOL [Synchrony, Visiogen, Inc.]) implanted in 1 eye and a control IOL (1-piece plate silicone IOL with large fixation holes) implanted in the other eye. Intraocular lens position, anterior capsule opacification (ACO), and posterior capsule opacification (PCO) were qualitatively assessed using slitlamp retroillumination photographs of the dilated eyes. Anterior capsule opacification and PCO were graded on a 0 to 4 scale after the eyes were enucleated (Miyake-Apple posterior and anterior views after excision of the cornea and iris). The eyes were also evaluated histopathologically. RESULTS: The rate of ACO and PCO was significantly higher in the control group. Fibrosis and ACO were almost absent in the study group; the control group exhibited extensive capsulorhexis contraction, including capsulorhexis occlusion. Postoperative IOL dislocation into the anterior chamber and pupillary block syndrome were observed in some eyes in the study group. CONCLUSIONS: The special design features associated with the study IOL appeared to help prevent PCO. Complications in the study group were probably caused by the increased posterior vitreous pressure in rabbit eyes compared to human eyes and the relatively large size of the study IOL relative to the anterior segment of rabbit eyes.

Single-piece hydrophobic acrylic intraocular lens explanted within the capsular bag: case report with clinicopathological correlation.

A 74-year-old woman had uneventful phacoemulsification with implantation of a single-piece hydrophobic acrylic intraocular lens (IOL) (SA30AL) in her left eye. Two weeks after the surgery, the patient presented for ophthalmological consultation reporting pseudophakic dysphotopsia, which she had subjectively noted since surgery. Explantation/exchange of the IOL was performed 3 months after the surgery. The IOL was strongly attached to the capsule, which was fibrotic and contracted; explantation of the capsular bag complex in toto was done. To our knowledge, this is the first case of explantation of this IOL design with clinicopathological correlation.

Correlation between different measurements within the eye relative to phakic intraocular lens implantation.

PURPOSE: To obtain measurements of the white-to-white distance and the anterior chamber and ciliary sulcus diameters in phakic human eyes obtained post-mortem to find a correlation between these measurements. SETTING: David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Twenty-two phakic human eyes obtained from eye banks within 24 hours of death were evaluated. The following measurements were performed: white-to-white distance, anterior chamber diameter with a plastic sizer after a small limbal incision, and anterior chamber and ciliary sulcus diameters after fixation and sagittal section of the eyes. The first 10 eyes were studied at the 6 o'clock to 12 o'clock meridian and the last 12 eyes, at the 3 o'clock to 9 o'clock meridian. RESULTS: A positive correlation was found between the white-to-white measurements and the anterior chamber diameter in the 10 eyes studied at the 6 o'clock to 12 o'clock meridian but not in the 12 eyes studied at the 3 o'clock to 9 o'clock meridian. The latter is the meridian frequently used by surgeons to perform white-to-white measurements and thus choose the overall size of the phakic intraocular lens to be implanted. No correlation was found between the white-to-white measurements and the ciliary sulcus diameter in the 2 meridians. CONCLUSION: Experimental studies using cadaver eyes are helpful in evaluating sizing techniques for phakic IOL implantation as well as in better understanding the anatomical relationships between ocular structures.

Posterior capsule opacification in rabbit eyes implanted with hydrophilic acrylic intraocular lenses with enhanced square edge.

PURPOSE: To evaluate the development of posterior capsule opacification (PCO) after implantation of single-piece hydrophilic acrylic intraocular lenses (IOLs) with an enhanced square edge. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: The standard 570H Centerflex (Rayner Ltd.) design was compared to 2 new designs with enhanced square edges: the 570E and the 570C. Ten IOLs of each type were implanted in a randomized manner by the same surgeon in 15 pigmented rabbits. After a follow-up of 3 weeks, the rabbits were killed and the eyes were analyzed from the posterior view. The intensity of central PCO, peripheral PCO, and Soemmering's ring formation was graded from 0 to 4. The area of Soemmering's ring was graded from 0 to 4 based on the number of quadrants involved. Other parameters analyzed were capsulorhexis coverage of the IOL edge and IOL centration and fixation. Results from the posterior view were complemented by histopathological evaluation. RESULTS: Posterior capsule opacification was lowest in the 570C group, highest in the 570H group, and intermediate in the 570E group. There was a statistically significant difference between the 3 groups in peripheral PCO (P = .039). No significant difference was found between the groups in the other parameters analyzed. When cell ingrowth occurred with the 570H, it started at the optic-haptic junctions, as observed during the clinical follow-up and confirmed by gross and histopathological analyses. CONCLUSIONS: The square optic edge is the most important IOL design feature for PCO prevention. However, it should be present for 360 degrees around the IOL optic to provide an effective barrier effect.

Implantation of a single-piece, hydrophilic, acrylic, minus-power foldable posterior chamber intraocular lens in a rabbit model: clinicopathologic study of posterior capsule opacification.

PURPOSE: To compare the extent of posterior capsule opacification (PCO) after implantation of a standard-power biconvex Centerflex intraocular lens (IOL) and a newly introduced biconcave high-minus-power Centerflex design in rabbit eyes. SETTING: The Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, and the David J. Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA. METHODS: Twelve rabbits had phacoemulsification and implantation of 2 foldable single-piece hydrophilic acrylic Centerflex posterior chamber IOLs. The right eyes received a standard-power (+21.00 diopters [D]) biconvex-optic lens and the left eyes, a minus-power (-7.00 D) biconcave-optic IOL. Formation of PCO was evaluated 3 weeks after surgery using the Miyake-Apple posterior photography technique. Histological sections from each globe were prepared to analyze capsular bag status and assess postsurgical intracapsular lens epithelial cell (LEC) proliferation, especially ingrowth of LECs across the visual axis. The data were analyzed using the Kruskal-Wallis 1-way analysis of variance for nonparametric measurements and the Mann-Whitney rank sum test. RESULTS: There was no significant difference in Soemmering's ring formation between the 2 IOL models. The biconcave minus-power IOL showed significantly lower central and peripheral PCO scores than the biconvex standard-power lens (P<.05). Pathological evaluations revealed that the effective site of blockage of LECs was at the truncated optic edge of both lenses, even in the presence of retained and/or regenerative cortical material. CONCLUSIONS: This study confirms the efficacy of a truncated IOL optic in helping reduce the incidence of PCO. Both IOL designs have optic geometries that create clear-cut barrier effects. However, the biconcave minus-power IOL, which has a thicker, square, truncated optic edge with a ridge that encircles the periphery of the optic for 360 degrees, appears to have an enhanced barrier effect, especially at the optic-haptic junction. This further minimizes the ingrowth of migrating LECs toward the visual axis.

Bipseudophakia: clinicopathological correlation of a dropped lens.

PURPOSE: To examine postmortem human globes containing an anterior chamber and a posterior chamber intraocular lens (IOL). SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Charleston, South Carolina, USA. METHODS: The globes were sectioned at the equator, and the anterior and posterior segments were macroscopically examined. Gross photographs were taken using the Miyake-Apple posterior photographic technique. Histological sections were cut and stained with hematoxylin and eosin, periodic acid-Schiff, and Masson's trichrome. RESULTS: Histopathological findings included a large Soemmering's ring, a tear in the posterior capsule, 1 haptic of the anterior chamber IOL displaced into the iridectomy, thin and atrophic corneal epithelium, separation of Bowman's layer and stroma by fibrovascular tissue, and atrophy of the retinal ganglion cell layer and nerve fiber layer. CONCLUSION: In cases in which secondary IOL implantation is indicated, removing the dislocated IOL appears to be a reasonable choice.