Evaluation of a new single-piece 4% water content hydrophobic acrylic intraocular lens in the rabbit model.

PURPOSE: To evaluate uveal and capsular biocompatibility of a 1-piece intraocular lens (IOL) manufactured from a new hydrophobic acrylic material that incorporates a barrier step at the optic-haptic junctions. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: The study IOL (Eternity-Uni W-60) was implanted in the right eyes of 5 New Zealand rabbits and the control IOL (Acrysof SN60WF) in the left eyes. Slitlamp examination was performed 1 through 4 weeks postoperatively. After death, the globes were enucleated and fixed in formalin. Capsular bag opacification scoring (Miyake-Apple view) was then performed followed by complete histopathology. RESULTS: At the 4-week examination, the mean posterior capsule opacification (PCO) score was 1.5 ± 1.0 (SD) in the study group and 2.2 ± 1.09 in the control group (P=.02). Anterior capsule opacification (ACO) was not present in the study eyes and was mild in the control eyes. On gross examination, the mean central PCO score was 0.9 ± 0.65 in the study group and 1.7 ± 1.20 in the control group (P=.07); the mean peripheral PCO score was 1.3 ± 0.67 and 2.4 ± 1.14 (P=.01) and the mean Soemmerring ring score was 3.8 ± 0.44 and 4.2 ± 1.09, respectively (P=.47). Histopathology confirmed that both IOLs were equally tolerated by the rabbit eyes. CONCLUSIONS: In this rabbit study, the new hydrophobic acrylic material was biocompatible. The barrier step incorporated to the optic-haptic junctions has the potential to enhance PCO prevention.

Assessment of a single-piece hydrophilic acrylic IOL for piggyback sulcus fixation in pseudophakic cadaver eyes.

PURPOSE: To evaluate a single-piece hydrophilic acrylic intraocular lens (IOL) designed for sulcus fixation in a piggyback configuration in postmortem pseudophakic human eyes. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Pseudophakic human cadaver eyes were imaged by high-frequency ultrasound (Artemis) to assess the overall position of the primary IOL and the sulcus diameter. The piggyback IOL (Sulcoflex) was then injected into the ciliary sulcus of these eyes. After fixation in formalin, they were reevaluated by high-frequency ultrasound for assessment of IOL fixation, fit, centration, tilt, and clearance from the primary IOL and intraocular structures and analyzed after sectioning. RESULTS: Data could be obtained from 11 eyes, all in which the primary IOL was located in the capsular bag. Different foldable IOLs and different degrees of Soemmerring ring formation were represented. The piggyback IOL could be injected and positioned in the ciliary sulcus and had overall appropriate centration and minimum or no tilt. Clearance between the 2 IOLs ranged from 232 to 779 µm, mostly depending on the thickness of the primary IOL. Direct assessment of the sulcus-fixated haptics showed no disturbances to the ciliary processes. CONCLUSIONS: The new IOL has large optic and overall diameters, smooth and undulating haptics, and a convex-concave optic profile. Results show that these characteristics minimize the possibility of interaction with the primary IOL and uveal tissues, decreasing the likelihood of optical aberrations and pigmentary dispersion.

Toxicity comparison of intraocular azithromycin with and without a bioadhesive delivery system in rabbit eyes.

PURPOSE: To determine whether the addition of a bioadhesive drug-delivery system to topical azithromycin induces intraocular inflammation and damage when introduced intraocularly by different approaches and in varying doses. SETTING: John A. Moran Eye Center, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Commercial topical azithromycin 1.0% was duplicated, including the benzalkonium chloride, but without inclusion of the Durasite bioadhesive drug-delivery system. Injections of 50 µL, 25 µL, and 10 µL of the antibiotic solutions were administered in a masked fashion to 2 rabbits; 1 eye (study eye) in each rabbit was randomized to receive azithromycin with the delivery system and the fellow eye (control eye) to receive azithromycin without the delivery system. Two rabbits had topical drops of each solution placed after a 2.8 mm incision was created. Masked slitlamp examinations, pachymetry, and intraocular pressure (IOP) were determined 1 day and 2 days postoperatively. The animals were humanely killed, and the endothelial density and histopathology were examined. RESULTS: The IOP (P<.001), pachymetry (P<.001), and signs of inflammation (P=.38 to .003) were consistently higher in the study eye, especially at the 50 µL dose, than in the control eye. This was confirmed by histopathology. CONCLUSION: If the drug-delivery system gains access to the anterior chamber, it may cause substantial corneal edema and inflammation, even at low doses and after topical administration.

Prevention of capsular bag opacification with a new hydrophilic acrylic disk-shaped intraocular lens.

PURPOSE: To evaluate capsular bag opacification with a new disk-shaped single-piece hydrophilic acrylic intraocular lens (IOL) suspended between 2 haptic rings connected by a pillar of the haptic material and with a commercially available single-piece hydrophobic acrylic IOL in rabbits. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: The study IOL was implanted in the right eyes of 5 New Zealand rabbits and the control IOL in the left eyes. Slitlamp examination was performed at weeks 1 through 5. After the rabbits were humanely killed, the globes were enucleated and examined by ultrasound. Capsular bag opacification scoring from the posterior aspect (Miyake-Apple view) was then performed, followed by histopathology. RESULTS: Trace honeycomb posterior capsule opacification (PCO) was noted in some study eyes. All control eyes developed moderate to marked PCO, which was more pronounced at the level of the optic-haptic junction. The mean PCO score was 0.4 ± 0.22 (SD) in the study group and 3.4 ± 0.54 in the control group (P=.000179, paired t test). Minimal proliferative cortical material was confined to the space between the anterior and posterior rings of the study IOL haptics. Anterior capsule opacification was absent in study eyes and mild in control eyes. There was no contact between the anterior capsule and the anterior surface of study IOLs. CONCLUSION: The peripheral rings of the study IOL, by expanding the capsular bag and preventing IOL surface contact with the anterior capsule, appear to prevent opacification of the capsular bag. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Digital dermoscopic monitoring of atypical nevi in patients at risk for melanoma.

BACKGROUND: Atypical nevi are a common risk factor for melanoma. OBJECTIVES: The objective was to determine the utility of monitoring dermoscopic photographs of atypical nevi in a high-risk population. METHODS: Over a 4.5-year period, digital dermoscopic photographs were taken of clinically atypical nevi at initial and follow-up visits, such that side-by-side comparisons could be made. RESULTS: A total of 5,945 lesions were monitored in 297 patients over 3 to 52 months (median, 22 months), and 324 lesions were biopsied. Photographic (dermoscopic) changes were noted in 96 of 5,945 (1.6%) lesions, which included 64 dysplastic nevi (67%), 25 common nevi (26%), and 1 melanoma (1.0%). Of 6 melanomas biopsied during the follow-up period, only 1 was detected by dermoscopic photographic change at follow-up. CONCLUSIONS: Most clinically atypical melanocytic nevi are stable over time, and lesions exhibiting dermoscopic changes are most likely to be dysplastic nevi. Although dermoscopy is a useful tool for clinical examination, the sensitivity of dermoscopic monitoring is limited by melanomas that may arise in normal skin or in clinically benign nevi that were not initially photographed.