Tadashi Senoo

Analysis of surface whitening of extracted hydrophobic acrylic intraocular lenses

PURPOSE: To identify the cause of light scattering on the surface (ie, whitening) of extracted AcrySof intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. METHODS: Dislocated IOLs extracted from 3 patients were stored and the IOL surfaces examined under light microscopy. The effect of whitening on visual function was evaluated by measuring light transmission with a spectrophotometer. To determine the cause of opacification, the IOLs were examined for calcium phosphate deposits using an electron probe X‐ray microanalyzer. The IOL surface, including the presence of organic deposits and evidence of hydrolysis, was also examined by Fourier‐transform infrared spectrophotometry. The IOLs were then dried, immersed again in physiological saline, and serially examined for changes in opacification. RESULTS: The optic surfaces of all IOLs had opacification due to whitening. Light transmission in the visible range of 360 to 800 nm was 4% less than that of unused IOLs. The X‐ray microanalysis showed no calcium phosphate deposits. Fourier‐transform infrared spectrophotometry of the IOL optic material showed no evidence of hydrolysis. Opacification disappeared after the IOLs were dried and then reappeared over time when the IOL was immersed again in physiologic saline. CONCLUSIONS: The findings strongly suggest that whitening of the hydrophobic acrylic IOL was due to trace water molecules that infiltrate the optic. Within the 3‐dimensional network of the polymeric lens material, the molecules are too small to form observable voids but can form water aggregates of sufficient size to scatter visible light, causing opacification (ie, whitening).

Decreased visual function due to high-level light scattering in a hydrophobic acrylic intraocular lens

PurposeTo investigate the effects of light scattering from the surface of hydrophobic acrylic intraocular lenses (IOLs) on visual function.MethodsA 67-year-old man was implanted with an IOL (MA60BM) in January 1998, but became aware of decreased visual function in May 2008. Observation with a slit lamp revealed light scattering throughout the entire optic of the IOL, which was extracted and replaced. Postoperative visual function improved at 1 month. The cause of light scattering was investigated with a focus on water permeating the IOL material. To confirm the effect of light scattering on visual function, light transmission of the extracted IOL was measured in physiological saline at 33°C, and the simulated retinal image was evaluated in a model eye.ResultsObservation of the extracted IOL showed light scattering from the optic surface layer, the main cause of which was phase-separated water within the IOL material. Light transmission in the extracted IOL was 16.3% lower than that in an unused IOL in the visible range. Moreover, the simulated retinal image was hazy compared to that of the unused IOL.ConclusionSevere surface light scattering from an IOL optic may decrease visual function.

Clinical evaluation of the transparency of hydrophobic acrylic intraocular lens optics

PURPOSE: To clinically evaluate postoperative changes in the transparency of hydrophobic acrylic intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. DESIGN: Case‐control study. METHODS: Eyes having phacoemulsification were randomly assigned to have implantation of 1 of 3 hydrophobic acrylic IOL models. The IOLs were photographed at 0 degree and 90 degrees 1 week, 6 months, and 1 year after implantation using a Nidek EAS‐1000 anterior chamber analyzer in slit mode. The images were used to determine the intensity of light scattering in the surface and middle regions of the IOL optic. RESULTS: The study comprised 65 eyes of 57 patients with a mean age of 72.5 years. The rate of increase in light‐scattering intensity was similar in the middle and surface regions of the Tecnis ZA9003 aspheric IOL. The increase in light‐scattering intensity in both regions of the AF‐1 VA‐60BB spherical IOL was greater than that in the aspheric IOL at all the measurement points. The intensity of light scattering was highest and tended to increase over time in both regions of the AcrySof SA60AT spherical IOL; the rate of increase in intensity was higher in the surface region than in the middle region, and the difference was significantly greater at 6 months and 1 year than at 1 week. CONCLUSION: Our results suggest that AcrySof SA60AT and AF‐1 VA‐60BB IOLs are likely to develop glistenings over time and that the former may develop whitening. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Prevalence of typical migraine aura without headache in Japanese ophthalmology clinics

The aim of this study was to investigate the prevalence and characteristics of typical aura without headache (TAWH) in Japan. We distributed a self-report questionnaire comprising seven items. Of 1914 cases, the number of patients who provided valid answers was 1063. They included 1063 out-patients with 81 of these patients positive in the ID migraine screener Japanese version. TAWH was diagnosed in 35 patients (3.2%), aged 23–87 years, and included 12 males and 23 females. The age of patients with TAWH showed a biphasic distribution (20–39 years and 60–69 years), similar to the age distribution of all patients. Migraine with aura was diagnosed in 67 patients (6.3%) and showed a monophasic age distribution (40–49 years). These data suggest that TAWH is not a rare headache type in clinics especially in a setting of general ophthalmology clinics, and some patients of migraine with aura may transform to TAWH with ageing.

Evaluation of the Incidence of Endophthalmitis after Intravitreal Injection of Anti-Vascular Endothelial Growth Factor

Aims: To report the incidence of infectious and noninfectious endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor (VEGF) from a multicenter clinical trial in Japan. Methods: A retrospective multicenter review of the data of patients who received intravitreal anti-VEGF injections between January 2007 and March 2011 was undertaken. Cases with the clinical diagnosis of endophthalmitis resulting from intravitreal injection were identified and reviewed. Results: A total of 5,236 intravitreal anti-VEGF injections (1,209 intravitreal injections of bevacizumab, 3,827 injections of ranibizumab, and 200 injections of pegaptanib sodium) had been administered. Five patients (0.095%), all of whom had received bevacizumab, were diagnosed as having endophthalmitis after the intravitreal injection. All patients visited the institutes for re-examination within 1–2 days after the injection. Among the 5 patients, 2 (0.038%) were culture positive for Streptococcus oralis and Enterococcus faecalis, respectively. The remaining 3 eyes (0.057%) developed presumed noninfectious endophthalmitis. Conclusion: Although endophthalmitis is a rare complication associated with intravitreal injection, in this series intravitreal anti-VEGF injection caused infectious or noninfectious endophthalmitis at a relatively high frequency. Further investigations are needed to consider an appropriate injection protocol for minimizing the incidence rates of endophthalmitis, and to assess the optimal treatment protocol for intravitreal injection-related endophthalmitis although it was difficult to differentiate these two entities.

Preventing secondary cataract and anterior capsule contraction by modification of intraocular lenses

Advances in intraocular lens (IOL) design have led to the use of lenses with improved performance including tinting, asphericity, multifocality and accommodation. To maximize the visual performance of these IOLs, postoperative complications such as secondary cataracts and anterior capsule contraction must be prevented. Various types of secondary cataracts may occur, each associated with complex biological reactions. Different design configurations, including square-edge IOLs, have been used to prevent secondary cataracts and anterior capsule contraction, but these have not been successful in sufficiently eliminating these complications. We have found that surface modification of IOL surfaces chemically improves surface quality and is also useful in preventing secondary cataracts and anterior capsule contraction. The UV/ozone treatment that we used as a surface modification method is a simple and highly effective method with no safety issues regarding materials following treatment. The combination of square-edge design and surface modification may be able to completely eliminate these postoperative complications.

Observation of whitening by cryo-focused ion beam scanning electron microscopy.

Our results indicate that ECCE conversion can achieve good results. Converting to ECCE because of a dense nucleus or the inability to achieve a continuous curvilinear capsulorhexis seems reasonable, given that in these situations one may be able to perform an ECCE similar to the way it would have been performed had it been planned. However, if vitreous loss is present, the ECCE may result in vitreous traction. It is now generally accepted that anything that could result in vitreous traction during complicated cataract surgery should be avoided. Procedures such as cellulose sponge vitrectomy and wound sweeping with a spatula are no longer considered acceptable because of the inherent traction they produce. Delivery of the nucleus during ECCE can be achieved by “pulling”manually or by “pushing” externally or internally (using balanced salt solution or an ophthalmic viscosurgical device). In the presence of vitreous loss, all these techniques may result in vitreoretinal traction (unless fragments anterior to the posterior capsule are manually removedafter a thoroughanteriorvitrectomy). Many trainees now receive little ECCE training, making the chance of a successful conversion less likely. If ECCE is unsuccessful, subsequent vitreoretinal surgery may be hampered by an enlarged wound and a cornea that may take longer to recover than if ECCE had not been attempted. In light of the above, we currently recommend that conversion to ECCE at our unit be considered only by surgeonswho are trained in ECCE surgery and vitreous loss is neither present nor likely. We hope that future studies will elucidate the role of ECCE conversion and allow surgeons to make more informed decisions.

The Effects of Drug Delivery Via Hydrophilic Acrylic (Hydrogel) Intraocular Lens Systems on the Epithelial Cells in Culture

BACKGROUND AND OBJECTIVE Secondary posterior subcapsular opacification is still among the most important complications after phacoemulsification. MATERIALS AND METHODS This study was designed to assess the inhibitory effects of drugs delivered via hydrophilic acrylic (hydrogel) intraocular lens (IOL) systems in vitro. Lens epithelial cells were collected from albino rabbits. The following seven groups of hydrogel IOLs were prepared: untreated IOLs and IOLs infiltrated with diclofenac sodium, tranilast, mitomycin C, colchicines, 5-fluorouracil, and ethylenediaminetetraacetic acid. The IOLs were fixed to a Cell Culture Insert; they were then bathed and incubated in minimum essential medium containing cultured lens epithelial cells. Subsequently, a comparative analysis of the cells adhering to the collagen membrane and the lens surfaces was conducted. RESULTS Adhesion of lens epithelial cells to the lens surfaces and the collagen membrane was observed in the control group. However, only slight cellular adhesion was found on the surfaces of the IOLs and on the collagen membrane in the treated IOL groups. CONCLUSION Use of hydrogel IOLs infiltrated with drugs was associated with inhibition of posterior subcapsular opacification in vitro.

Efficacy of ophthalmic nonsteroidal antiinflammatory drugs in suppressing anterior capsule contraction and secondary posterior capsule opacification

PURPOSE: To evaluate the efficacy of ophthalmic nonsteroidal and steroidal antiinflammatory drugs in preventing anterior capsule contraction and secondary posterior capsule opacification (PCO) using an experimental cataract model. SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. METHODS: Eight‐week‐old albino rabbits weighing about 2 kg each had phacoemulsification and intraocular lens implantation. After surgery, the rabbits were divided into 3 treatment groups: diclofenac sodium ophthalmic solution, bromfenac sodium ophthalmic solution, and betamethasone ophthalmic solution. In each group, the ophthalmic solution was applied to the left eye of each rabbit twice daily; the right eye served as an untreated control. To evaluate anterior capsule contraction, the percentage of incised anterior capsule opening area was calculated on diaphanoscopic images obtained with an EAS‐1000 anterior segment analyzer. For evaluation of PCO, a tissue section was stained with hematoxylin–eosin and observed under a light microscope. The PCO was quantified on the basis of the thickness of the lens epithelial cell layer on the central subcapsular area and compared among groups. RESULTS: Fifteen albino rabbits were used in the study. Treatment with diclofenac sodium and bromfenac sodium ophthalmic solution prevented progression of anterior capsule contraction and PCO. Treatment with bromfenac ophthalmic solution did not prevent either complication. CONCLUSION: Postoperative treatment with ophthalmic nonsteroidal antiinflammatory drug solutions prevented anterior capsule contraction and PCO in rabbit eyes.

Influence of intraocular lens implantation on anterior capsule contraction and posterior capsule opacification

Purpose To evaluate whether and how intraocular lens (IOL) implantation influences the development of anterior capsule contraction and posterior capsule opacification (PCO). Setting Department of Ophthalmology, Dokkyo Medical University, Mibu, Tochigi, Japan. Design Experimental study. Methods Phacoemulsification was performed in 8‐week‐old white rabbits. A hydrophobic acrylate IOL (12.5 mm) (YA‐60BBR) was implanted in 1 eye and no IOL was implanted in the fellow eye. Slitlamp microscopy and anterior segment analysis were performed to evaluate anterior capsule contraction after the surgery. Four weeks postoperatively, sections of the eyes were made, and the thickness of the proliferated lens epithelial cell (LEC) layer at the posterior capsule was measured to assess the PCO. In addition, LECs from white rabbits were cultured in medium containing 50% aqueous humor or in medium containing 50% saline to determine the influence of the aqueous humor on LECs and to compare the degree of LEC proliferation. Results Starting 2 weeks after surgery, anterior capsule contraction progressed more significantly in the IOL group than in the group without IOLs. Four weeks postoperatively, LEC thickness at the posterior capsule was significantly less in the group without IOLs than in the IOL group. In the culture study, LEC proliferation was more inhibited in the aqueous humor group than in the saline group. Conclusions Progression of anterior capsule contraction and PCO is less likely in aphakic eyes than in IOL‐implanted eyes. The mechanism of prevention may involve aqueous humor–induced inhibition of LEC proliferation. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.