Nobuyuki Ishikawa

Cell adhesion on explanted intraocular lenses: Part 2: Experimental study of a surface-modified IOL in rabbits

PURPOSE: To develop a hydrophobic acrylic IOL with a hydrophilic, anti‐cell adhesive surface characteristic. SETTING: Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan. DESIGN: Experimental study. METHODS: Hydrophobic acrylic IOLs were coated with hydrophilic 2‐methacryloyloxyethyl phosphorylcholine (MPC) polymer and implanted in rabbit eyes following lens extraction. Cell adhesion on the IOL surface was histologically compared with that on an uncoated IOL under light microscopy. Specimens were also observed under scanning electron microscopy to examine the effects of MPC coating on cell morphology. RESULTS: Hydrophilic MPC coating reduced cell adhesion on acrylic IOLs at 1 month postoperatively. CONCLUSION: Coating an acrylic IOL with a hydrophilic polymer inhibited cell adhesion on the IOL surface. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Cell adhesion on explanted intraocular lenses: Part 1: Analysis of explanted IOLs

PURPOSE: To determine whether cell adhesion on an intraocular lens (IOL) in Japanese patients is affected by the optic material. SETTING: Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan. DESIGN: Experimental study. METHODS: Intraocular lenses of various materials explanted from Japanese patients were histologically examined under light microscopy. Specimens included 271 poly(methyl methacrylate) (PMMA) IOLs, 117 hydrophobic soft acrylic IOLs, and 48 silicone IOLs. The mean cell adhesion on the central area of the anterior surface of each IOL material (referred to as cell number) was evaluated. RESULTS: The cell number in the PMMA group was significantly higher than that in the silicone group in the periods of 1 to 5, 6 to 11, and more than 24 months. Although the cell number in the silicone group was less than one‐third and one‐twentieth the cell number in the hydrophobic soft acrylic group in the periods 1 to 5 months and 6 to 11 months, respectively, the difference was not statistically significant. CONCLUSION: In Japanese patients, the cell adhesion on silicone IOLs was less than that on PMMA IOLs. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Errors in the prediction of postoperative refraction following intraocular lens implantation in eyes with pseudoexfoliation syndrome

tion. 3–7 However, any tendency toward refraction errors remains unclear. In this study, we evaluated the deviations in refraction 1 day and 1 month after phacoemulsification with IOL implantation performed without complications compared with the predicted refraction in patients with pseudoexfoliation.

Expression pattern of sonic hedgehog and effect of topical mitomycin C on its expression in human ocular surface neoplasms

PurposeTo examine if the cells of human ocular surface neoplasms express sonic hedgehog (Shh) and the effects of topical mitomycin C on its expression.MethodsConjunctival tissues obtained from two normal subjects, two patients with squamous cell carcinoma of the ocular surface (conjunctiva), and one patient with ocular epithelial dysplasia were used in this study. Histological sections were processed for light microscopic immunohistochemical analysis for Shh.ResultsFaint immunoreactivity for Shh was detected in basal epithelial cells of limbus, bulbar, and palpebral conjunctival epithelial cells. On the other hand, squamous cell carcinoma cells markedly expressed Shh with positive staining for Patched 1(Ptc), the cell surface receptor of Shh. Similar marked expression of Shh was detected in the patient with ocular epithelial dysplasia, and this Shh expression was almost eliminated following topical mitomycin C treatment. A cell culture experiment was conducted to examine the effect of mitomycin C on Shh expression in a cultured squamous cell carcinoma cell line.ConclusionsConjunctival epithelium constitutively expresses a low level of Shh, and its expression increases during malignant conversion of epithelial cells. Reduction of Shh expression might be involved in the therapeutic efficacy of topical mitomycin C for ocular surface epithelial neoplasms.

Histology of Posterior Capsular Opacification

Lens epithelial cells (LECs) undergo tissue repair reaction following cataract-intraocular lens (IOL) surgery. However, the reaction in turn produces opacification of the lens capsule that potentially impairs vision. Histology and immunohistochemistry are employed for characterization of the tissues of capsular opacification. LECs transform into regenerated lens fiber structures and myofibroblasts. The former behavior develops Soemmering’s ring in the peripheral capsular bag and Elschnig’s pearls on the inner surface of the posterior capsule. Histology shows lens-like cellular arrangement in these structures. The latter response is called epithelial-mesenchymal transition (EMT) and generates fibrous tissue accumulation on the capsule. EMT-derived cells no longer exhibit an epithelial feature, but accumulate fibrous extracellular matrix around themselves. Contraction of EMT myofibroblasts shrinks the postoperative lens capsule around an IOL.

Histopathological Analyses of the Differences in Foreign Body Cell Reactions against Intraocular Lenses According to the Period of Implantation

We examine if cell adhesion to the surface of an intraocular lens varies with the period of implantation. Samples of extracted intraocular lenses (IOLs) that had been implanted during 1987-2000 (n=72, early group) and those during 2001–2014 (n=182, late group) were included. IOLs were stained with hematoxylin and eosin and grouped according to the presence or absence of cellular deposits on the central area of the IOL anterior surface. Silicone IOLs were excluded because the silicone material does not adhere to cells. The early group included four poly( ethyl methacrylate) (PEMA) IOLs, 45 poly (methyl methacrylate) (PMMA) IOLs, and 23 acryl IOLs, and the late group included four PEMA IOLs, 19 PMMA IOLs, 152 acrylic IOLs, and seven hydrogel IOLs. Twenty-six of 72 samples (36%) in the early group and 43 of 182 IOLs (23%) in the late group were associated with cellular deposits in the central area of the IOL surface. The difference was statistically significant using the chi-square test. The number of IOLs with cell adhesions was less in the late group when compared with the early group.