Tadahiko Kozawa

Capsular stabilization device to preserve lens capsule integrity during phacoemulsification with a weak zonule

&NA; We describe a new capsular stabilization device for suspending a lens with weak zonular support. It is flexible, 10.0 mm in length, and fashioned from 5‐0 nylon. The contact portion is bent at 1.25 mm with an end bifurcating to form a T‐shape to minimize stress on the capsular equator. After a continuous curvilinear capsulorhexis is created, the capsular stabilization devices to hook the capsulotomy margin are inserted. The T‐shaped end is passed around the anterior capsular flap to fit the curvature of the equator. Phacoemulsification and aspiration using this device was performed in 12 eyes of 9 patients, and the usefulness and complications were analyzed. The capsular stabilization devices suspended the capsule and facilitated safe phacoemulsification in all eyes. Posterior capsule rupture occurred in 2 eyes. None of the cases had notable postoperative complications. This device ensures a stable capsule‐iris complex and reduces surgical risks.

Periostin, discovered by nano-flow liquid chromatography and mass spectrometry, is a novel marker of diabetic retinopathy

Diabetes can lead to serious microvascular complications including proliferative diabetic retinopathy (PDR), the leading cause of blindness in adults. Recent studies using gene array technology have attempted to apply a hypothesis-generating approach to elucidate the pathogenesis of PDR, but these studies rely on mRNA differences, which may or may not be related to significant biological processes. To better understand the basic mechanisms of PDR and to identify potential new biomarkers, we performed shotgun liquid chromatography (LC)/tandem mass spectrometry (MS/MS) analysis on pooled protein extracts from neovascular membranes obtained from PDR specimens and compared the results with those from non-vascular epiretinal membrane (ERM) specimens. We detected 226 distinct proteins in neovascular membranes and 154 in ERM. Among these proteins, 102 were specific to neovascular membranes and 30 were specific to ERM. We identified a candidate marker, periostin, as well as several known PDR markers such as pigment epithelium-derived factor (PEDF). We then performed RT-PCR using these markers. The expression of periostin was significantly up-regulated in proliferative membrane specimens. Periostin induces cell attachment and spreading and plays a role in cell adhesion. Proteomic analysis by LC/MS/MS, which permits accurate quantitative comparison, was useful in identifying new candidates such as periostin potentially involved in the pathogenesis of PDR.

Repositioning and scleral fixation of subluxated lenses using a T-shaped capsule stabilization hook

&NA; We describe a T‐shaped capsule stabilization hook (modified capsule expander [M‐CE]) used for repositioning and scleral fixation of the lens capsule of subluxated lenses. The 5‐0 polypropylene device is flexible and attached to a curved needle. The contact portion is bent at 1.25 mm, and the end bifurcates in a T configuration to form a 3.75 mm footpad from which the capsular bag can be suspended. Modified capsule expanders were implanted in 4 eyes of 4 patients with subluxated cataractous lenses and provided excellent support and centration of the intraocular lens (IOL)–capsular bag complex. The IOLs remained well centered and stable. The corrected distance visual acuity improved to at least 20/20 in all patients after surgery. Thus, M‐CEs were effective in fixating the lens capsule to the sclera in patients with significant zonular weakness. Financial Disclosure: Saori Yaguchi, Y. Asano, T. Kozawa, T. Miyawaki, K. Negishi, and K. Tsubota have no financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.

Accuracy of Intraocular Power Calculation Formulas

PURPOSE We examined the accuracy of intraocular lens power calculation formulas, with special emphasis on the prediction of refraction in different axial lengths. MATERIAL AND METHODS 786 cases were subdivided into four groups based on the axial length (short axial length < 22.0 mm, normal axial length = 22-24.4 mm, mid-range axial length = 24.5-26.9 mm and long axial length > 27 mm). Seven different formulas (Holladay, SRK, SRK II, SRK/T, S-SRK, M-SRK, L-SRK) were tested for their accuracy in predicting post-operative refraction. RESULT The best results were obtained using the S-SRK formula in the short axial length group (n = 114), The SRK and Holladay formulas in the normal axial length group (n = 278). The Holladay and SRK/T formulas in the mid-range axial length group (n = 135), and the SRK/T and L-SRK in the long axial length group (n = 259). CONCLUSION Our results emphasize the importance of using an intraocular lens formula specific for each range of axial length when calculating the predicted refraction.

Experimental study of small intraocular lenses using an eye model

ABSTRACT Contrast and glare tests were performed on small intraocular lenses (IOLs) using a new eye model, which was based on and about the same size as the Gullstrand eye model. Lenses with a small optic diameter were inserted and retinal images were observed under the operating microscope. Contrast and glare disability tests were done using the MCT‐8000 contrast tester and the Miller‐Nadler glare tester. No effect on contrast sensitivity attributable to glare was observed, but under severe glare light conditions a faint reflection around the circumference of the optic was found. Questionnaires from patients implanted with small optic IOLs confirmed that this phenomenon was similar to their symptoms.

Objective Evaluation of Zonular Weakness: Measurement of Lens Movement atthe Start of Capsulorhexis Using Extracted Porcine Eyes

Objective: To evaluate the degree of zonular weakness based on lens movement at the start of capsulorhexis using extracted porcine eyes. Methods: Zonular dehiscence of 18°, 36°, and 54° was created and alternated with healthy areas into five zones to create a model simulation of weakness of the zonule of Zinn corresponding to dehiscence of 90°, 180°, and 270°. During continuous curvilinear capsulorhexis (CCC), an image displaying the anterior capsule grasped by a cystotome and another displaying the initial tear were captured, and the two images were superimposed to measure the movement distance of the cortical opacities created using a hook. Porcine eyes with no dehiscence were used as the control group. Results: Compared with a distance of 0.44 ± 0.13 mm in the control group, the cortical opacity movement distances in the weakness group with dehiscence corresponding to 90°, 180°, and 270° were 0.68 ± 0.27, 1.01 ± 0.22, and 1.32 ± 0.35 mm, respectively. Significant differences were observed between the control, 90°, 180°, and 270° dehiscence groups (P<0.001). Conclusion: This study revealed numerical data for the degree of weakness of the zonule of Zinn in porcine eyes. Clinical application of this method may be useful for establishing surgical procedures and prognoses for cataract surgery in patients with weakness of the zonule of Zinn.

Categorization and Surgical Techniques of Weak Zonule Based on Findings at Capsulorhexis during Cataract Surgery

Purpose: We categorize weak zonule during capsulorhexis. Design: Retrospective interventional case series. Methods: The study examined 5447 consecutive eyes of 3527 cases that underwent phacoemulsification (PEA) and intraocular lens (IOL) implantation between March 2006 and March 2014 at Showa University Fujigaoka Hospital, Kanagawa, Japan. Weak zonule was categorized based on findings at capsulorhexis and difficulty in performing continuous curvilinear capsulorhexis (CCC). The categorization definitions were as follows: (1) Group N (normal) with no or slight lens movement at the start of the CCC and no difficulty in performing CCC, (2) Group W (weak) with moderate lens movement frequently accompanied by fold formation during CCC and some difficulty in performing CCC, (3) Group VW (very weak) because of severe lens movement and difficulties with the initial puncture, CCC can be performed with the aid of a highly retentive and cohesive ophthalmic viscoelastic device (OVD; Healon 5®), and (4) Group EW (extremely weak) with zonular deficiency in addition to the Group VW criteria and accounted for the cases of severe phacodonesis, lens subluxation, lens luxation into the anterior chamber, and dropped nucleus into the vitreous cavity that could be categorized preoperatively. We examined capsule stabilization device use during PEA, surgical lens removal, and IOL fixation in each group. Results: We defined 5098 eyes as Group N, 251 eyes as Group W, 55 eyes as Group VW, and 43 eyes as Group EW. As the zonule became weak, the use of the capsule stabilization device increased in PEA and intracapsular cataract extraction, and scleral suture fixation of IOL increased. Pars plana vitrectomy for lens removal was performed in 5 eyes (11.63%) categorized as Group EW. Conclusions: The categorization of weak zonule at CCC may be useful for selecting an appropriate capsule stabilization device and procedure during cataract surgery.

Modified capsule expander implantation to reposition and fixate the capsular bag in eyes with subluxated cataractous lenses and phacodonesis: intermediate-term results.

Purpose To report the intermediate‐term results of capsule stabilization for scleral fixation with implantation of the Yaguchi hook, a modified capsule expander stabilization hook. Setting Department of Ophthalmology, School of Medicine, University of Showa, Fujigaoka Rehabilitation Hospital, Yokohama, Japan. Design Retrospective case series. Methods Patients with zonular dialysis and phacodonesis were followed postoperatively for at least 2 years. All eyes had phacoemulsification and aspiration using an ordinary capsule expander and in‐the‐bag implantation of an intraocular lens (IOL). Capsule expanders were removed after the residual cortex was removed, and the capsular bag was fixated to the scleral wall via the ciliary sulcus using the modified capsule expander stabilization hook. Preoperative findings, intraoperative complications, and postoperative courses were examined. Results The mean age of the 11 patients (11 eyes) was 72.2 years ± 10.5 (SD); 5 patients were men. The mean postoperative follow‐up was 48.6 ± 13.6 months. The zonular dialysis range was 90 to 180 degrees in 1 eye, 180 degrees in 4 eyes, and 180 to 270 degrees in 1 eye. In 5 eyes, severe phacodonesis was observed without obvious zonular dialysis. In all eyes, the capsular bag and IOL were well centered without severe intraoperative or postoperative complications. Conclusion The modified capsule expander stabilization hook provided good centration and stabilization of the capsule–IOL complex in eyes with severely weak zonular fibers. Financial Disclosure Dr. Yaguchi, who is the inventor of the modified capsule expander, has received financial support from Handaya, Tokyo, Japan. No other author has a financial or proprietary interest in any material or method mentioned.

The impact of different anti-vascular endothelial growth factor treatment regimens on reducing burden for caregivers and patients with wet age-related macular degeneration in a single-center real-world Japanese setting

Objective To describe the burden associated with different anti-vascular endothelial growth factor (VEGF) treatment strategies for wet age-related macular degeneration (wAMD) in a real-word setting in Japan. Methods Single-center, cross-sectional survey of caregivers of patients with wAMD performed in a hospital in Mito-City, a rural area in Japan. Caregiver burden was evaluated using the Burden Index of Caregivers (BIC-11), and depressive symptoms were assessed by the Center for Epidemiologic Studies Depression scale. Retrospective medical chart review was conducted to monitor resource use and visual acuity outcomes in patients. The productivity loss of caregivers accompanying patients on hospital visits was estimated using the human capital method. Results Seventy-one patient-caregiver pairs were included. Most caregivers were female (74.6%), spouse/partner (54.9%), employed (46.5%), and the primary caregiver (85.9%). Patients received anti-VEGF treatment as follows: treat-and-extend (T&E; n = 42), switch (from as-needed [PRN] to T&E; n = 18), PRN (n = 10), and other (n = 1). Caregiver-related burden (total BIC-11 scores) were 4.29 (T&E) 4.60 (PRN), and 5.33 (switch) (p = NS). The mean number of hospital visits was lower with T&E than PRN (7.88 vs. 14.0 [p = 0.00674] in year 1 and 5.68 vs. 9.0 in year 2). For patients who switched from PRN to T&E, the mean number of hospital visits decreased from 13.21 to 7.43 (p<0.0001) in the first year after switch. The productivity loss associated with accompanying patients to the hospital was lower for caregivers of patients receiving T&E than PRN (mean differences: 74,456.04 JPY [p = 0.00284] in year 1 and 40843.14 JPY in year 2), and was also reduced for caregivers of patients who switched from PRN to T&E. Conclusion wAMD treatment with anti-VEGF agents via T&E reduced hospital visits compared with PRN, where associated monitoring visits are necessary to provide good patient outcomes. T&E was associated with a reduction trend in caregiver burden, including time and costs.

Objective classification of zonular weakness based on lens movement at the start of capsulorhexis

Purpose To quantify zonular weakness based on lens movement at the start of continuous curvilinear capsulorhexis (CCC) and establish a classification system for it. Setting Kozawa Eye Hospital and Diabetes Center, Mito, Japan. Design Retrospective interventional case series. Methods We examined 402 consecutive eyes of 316 patients who underwent CCC, phacoemulsification and aspiration (PEA), and intraocular lens (IOL) implantation. The movement of the lens capsule was measured using images from video recordings of the CCC procedure. Zonular weakness was classified based on the shifted distance: Grade I, less than 0.20 mm; Grade II, 0.20–0.39 mm; and Grade III, greater than 0.40 mm. For each of these grades, we examined the use of the capsule stabilization device during PEA, the surgical procedure for lens removal, and IOL fixation. Results We classified 276 eyes (68.6%) as Grade I, 102 eyes (25.4%) as Grade II, and 24 eyes (6.0%) as Grade III. As the grade increased, the use of the capsule stabilization device in PEA and scleral suture fixation of IOL increased. Conclusions Zonular weakness was quantified by measuring the movement of the lens capsule. An objective classification of zonular weakness based on lens movement may be useful for selecting the appropriate device and procedure during cataract surgery.