Advances in Understanding the Mechanism of Ophthalmic Viscosurgical Device Retention in the Anterior Chamber or on the Corneal Surface during Ocular Surgery.

Retention durability, especially in the eye, is one of the most important properties of ophthalmic viscosurgical devices (OVDs) during ocular surgery. However, the information on the physical properties of OVDs is insufficient to explain their retention durability. The purpose of this study is to clarify the mechanism of OVD retention to improve understanding of the behavior of OVDs during ocular surgery. To elucidate the mechanism of OVD retention, we have developed a new test method for measuring repulsive force. As a result, the maximum repulsive force of OVDs was positively and well correlated with the retention durability of investigated OVDs. Consequently, we demonstrated that the repulsive force could be used as an index of retention durability on the ocular surface and in the eye. We directly compared the intraocular retention durability of three OVDs (Shellgan, Viscoat, and Opegan-Hi) in ex vivo porcine eyes. Opegan-Hi was immediately removed from the anterior chamber, but Shellgan and Viscoat remained largely in the anterior chamber as determined by fluorescence imaging. These results showed that the intraocular retention behavior of OVDs was similar to their ocular surface behavior in our previous report, suggesting that retention durability is dependent on the OVD itself. The retention durability of Shellgan seemed to be higher than that of Viscoat, and the maximum repulsive force of Shellgan was 1.35-fold higher than that of Viscoat. Therefore, the repulsive force might be a useful index for assessing the difference in the retention durability between OVDs such as Shellgan and Viscoat.

Intrascleral fixation of intraocular lens haptics: histological advantages in a comparison with scleral suture fixation in rabbits.

PURPOSE: To disclose histological advantages of intrascleral fixation of intraocular lens haptics, in comparison with scleral suture fixation, in a study with rabbits. METHODS: Ten white rabbits, 10 weeks of age, were used in this experimental histopathological study. After unilateral lensectomy and anterior vitrectomy, an intraocular lens haptic was inserted into one eye of each rabbit. Intrascleral fixation was performed in five rabbits, whereas scleral suture fixation was performed in the others. At postoperative 1 week, the globe was enucleated in two rabbits in each group; at postoperative 8 weeks, the globe was enucleated in the remaining three rabbits in each group. Sections of the sclera around haptics and sutures were evaluated with haematoxylin and eosin and immunohistochemical staining methods. We assessed severity of inflammation on histopathological photos, taken near the haptic or suture in the sclera, by counting white blood cells. The Mann-Whitney U test was performed to analyse differences in the severity of inflammation between the groups. RESULTS: Samples in the intrascleral fixation group demonstrated reduced irregularity of collagen fibres; reduced infiltration of fibroblasts, giant cells, lymphocytes, neovascular cells, neutrophils and eosinophils and weaker staining for fibronectin (indicating tissue repair) and heat shock protein 70 (indicating cell damage). In addition, reduced white blood cell infiltration was observed in the intrascleral fixation samples at 8 weeks in both shallow sclera (p = 0.001) and deep sclera (p = 0.002). CONCLUSIONS: Histological analysis showed that intrascleral fixation caused fewer inflammatory changes than scleral suture fixation, with reduced fibroblast migration and production of cytotoxic factors.

Relationship between anterior capsule opening and direction of intraocular lens decentration.

PURPOSE: To compare intraocular lens (IOL) decentration between patients in whom the continuous curvilinear capsulorhexis (CCC) completely covers the IOL optic and those in whom it incompletely covers the IOL optic and determine how an incompletely covered CCC affects the IOL position. SETTING: Tertiary hospital in Japan. DESIGN: Single-center retrospective study. METHODS: 57 eyes of 57 patients (mean age 70.8 ± 6.2 years) that underwent phacoemulsification and IOL (SN60WF) implantation in the bag between April 2010 and April 2015 were included in this study. The patients were classified based on whether the CCC completely (CC group) or incompletely (NCC group) covered the IOL optic using an anterior eye segment analysis system (EAS-1000). The IOL decentration of the groups was analyzed using EAS-1000 at 1 week, 1 month, 3 months, and 6 months postoperatively and compared. The relationship between the NCC location and the IOL direction at 3 months postoperatively was analyzed. RESULTS: The NCC group (25 eyes) had a significantly higher amount of IOL decentration than the CC group (32 eyes) at 1 week, 1 month, 3 months, and 6 months postoperatively ( P < .05). There was a correlation between the direction of IOL decentration and the NCC location, and IOL decentration in the NCC group occurred in the opposite direction to the NCC area. CONCLUSIONS: An anterior capsule opening that completely covers the IOL optic is important to control IOL decentration.

Inhibition of anterior capsule opacification and contraction by the elevated anterior rim of the intraocular lens optic.

PURPOSE: To verify the anterior capsule opacification (ACO) and contraction (ACC) of the ZCB00V intraocular lens (IOL), made of the same material as the AR40e with a high ACC rate. STUDY DESIGN: Retrospective cohort study. METHODS: We evaluated 35 patients at 1 week, 1, 3 and 6 months post phacoemulsification with either a ZCB00V (n = 35) or FY-60AD (n = 34) IOL implantation. The ACC rate was calculated using retroillumination images of the anterior segment, and the ACO was measured using anterior segment photographs and image analysis software. The contact grade between the IOL and anterior capsule was estimated from the Pentacam® images. RESULTS: The postoperative ACC rates (mean ± standard deviation) at 3 months were 1.03%±2.54% for the ZCB00V and, and 7.12%±9.47% for the FY-60AD. The ZCB00V-implanted eyes showed a significantly lower postoperative ACC at 1 week, 3 months, and 6 months (P < 0.01). On the other hand, the FY-60AD-implanted eyes had more pronounced ACO, and a significantly larger area of opacification (62.24%±21.32% vs. 16.90%±8.34%; P = 0.0005). Pentacam® analysis revealed a space between the anterior capsule and IOL surface in the ZCB00V-implanted eyes, whereas the anterior capsule firmly adhered to the IOL surface in the FY-60AD-implanted eyes. CONCLUSION: The ACC and ACO were significantly lower in eyes with ZCB00V IOLs compared to those with the FY-60AD. The anterior segment image analysis revealed that the elevated anterior rim of the ZCB00V IOL prevented adhesion between the anterior capsule and IOL optic surface, suggesting an open capsule effect.

[Clinical Functionality of Dispersive OVDs: Improvement of One of the Properties of 3% Hyaluronic Acid and 4% Chondroitin Sulfate Combination].

Ophthalmic viscosurgical devices (OVDs) are mainly divided into two general categories: cohesive and dispersive. Dispersive OVDs such as the 3% hyaluronic acid and 4% chondroitin sulfate (HA/CS) combination have excellent adhesion to ocular tissues and protect the corneal endothelium to a greater extent than cohesive OVDs. Herein, we summarize our recent findings regarding one of the properties of the HA/CS combination related to clinical performance. (i) The room temperature stability of OVDs and needle clogging by OVDs remain clinical issues. We demonstrated that adding d-sorbitol to the HA/CS combination preserved its viscosity, which was equivalent after 2 year-storage at room temperature to the viscosity of HA/CS combination stored under refrigeration for 2 years without d-sorbitol. Besides, the HA/CS combination with d-sorbitol could be used repeatedly without cleaning or replacing the needle, suggesting that the addition of d-sorbitol prevents drying and solidification of the OVD on the needle. (ii) Although it can be inferred from numerous studies that the tissue adhesion of OVDs influences their retention by the eye, little is known about the physical properties of OVDs that contribute to intraocular retention. To address this issue, we compared two types of adhesive forces, detachment force and repulsive force, for each OVD. Compared with other dispersive OVDs, the HA/CS combination showed higher values for both adhesive forces. These results suggest that adhesive forces may be used as an index of dispersive OVD retention in the eye.

A Case of Pigment Dispersion Syndrome after Placement of Sulcus Intraocular Lens with 7-mm Optic Diameter after Posterior Capsule Rupture.

A 48-year-old woman diagnosed with primary angle closure suspect (PACS) in the right eye underwent cataract surgery, and a 7-mm optic diameter intraocular lens (IOL) was placed in the ciliary sulcus after intraoperative posterior capsule rupture. The patient developed uveitis and blurred vision the next day. The IOL was fixed between the iris and the anterior capsule. Irregularly shaped pupils due to posterior synechia and pigmentation on the IOL surface were observed. In the Scheimpflug image, the IOL on the anterior capsule was observed and the anterior chamber depth was 2.92 mm. A diagnosis of pigment dispersion syndrome and elevated intraocular pressure due to sulcus IOL placement was made. The patient underwent intrascleral IOL fixation surgery using an already inserted IOL to reposition the IOL under the anterior capsule. After 1 week, the blurred vision, anterior chamber inflammation, and IOL surface pigmentation were resolved. The right eye IOP was 15 mm Hg and the pupil became a regular circle. Scheimpflug images showed the IOL located behind the anterior capsule and an anterior chamber depth of 3.88 mm. Because the patient had a slightly shorter axial length of 22.89 mm and PACS, pigment dispersion may have occurred due to friction between the iris and the shape of the optic edge with a large optic diameter. In cases of posterior capsule rupture with short axial length and PACS, the use of a 7-mm optic diameter IOL in the sulcus should be avoided, or intrascleral IOL fixation should be selected as the surgical technique.

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.

Quantitative Assessment of Ophthalmic Viscosurgical Devices on Visibility, Spreadability, and Durability as Corneal Wetting Agents for the Wet Shell Technique.

PURPOSE: To evaluate ophthalmic viscosurgical devices (OVDs) as corneal wetting agents for the wet shell technique, a common procedure in Japan to maintain the wettability of corneal surfaces. METHODS: We surveyed Japanese ophthalmologists to determine the current state of the wet shell technique. After developing three ex vivo testing methods, we evaluated the corneal wetting properties of OVDs including 3% hyaluronic acid (HA) solution and OVD products, Opegan, Opelead, Viscoat, Shellgan, Discovisc, and Opegan-Hi. RESULTS: Overall, 214 ophthalmologists (70%) had performed the wet shell technique, and 91% of ophthalmologists who performed vitreous surgery had performed this technique. Using a questionnaire, we evaluated the performance of OVD as corneal wetting agents as follows: (i) visibility, smoothness of OVD surface; (ii) spreadability, coverage of the cornea; and (iii) retention durability, residual ratio of OVD on the corneal surface. The smoothness and spreadability of Opegan, Opelead, and 3% HA were superior to other OVDs. Adding an appropriate amount of balanced salt solution to the other OVDs improved smoothness and spreadability similar to that of Opelead or 3% HA. Shellgan and Viscoat, combination OVDs consisting of 3% HA and 4% chondroitin sulfate, showed high retention durability, resulting in remaining longer on the cornea compared with other OVDs. CONCLUSIONS: Physical properties of OVDs tested in this study may provide useful information for ophthalmologists to select a suitable OVD when performing the wet shell technique.

Addition Of D-Sorbitol Improves The Usability Of Ophthalmic Viscosurgical Devices.

PURPOSE: To evaluate the effects of D-sorbitol addition on changes in the extrusion force of ophthalmic viscosurgical devices (OVDs). METHODS: OVD formulations; the mixtures of 3% hyaluronic acid (HA) and 4% chondroitin sulfate (CS) containing 0%, 0.5%, or 1.0% D-sorbitol were prepared. Each prefilled syringe of OVD was stored at room temperature for 0, 15, 30, 60, or 120 mins after a small amount of viscoelastic agent was discharged from the needle. The extrusion force values (kgf) of these OVDs when reused after storage were measured with a texture analyzer. Moreover, 10 healthy adults (5 men and 5 women) used a pinch sensor to measure the extrusion force values for the HA/CS combination without D-sorbitol which was stored in the above manner, and used a 4-step scale to score the usability of OVD. RESULTS: For the HA/CS combination without D-sorbitol, the extrusion force value was increased from its initial value (storage duration, 0 min) as storage duration increased. However, for the HA/CS combination containing 0.5% or 1.0% D-sorbitol, this value remained almost unchanged over time. Likewise, the pinch sensor-determined extrusion force values of HA/CS combination without D-sorbitol increased, depending on storage duration. CONCLUSION: The addition of D-sorbitol to viscoelastic agent may suppress the needle clogging that occurs with OVD storage, and may improve the usability of OVDs during surgery.

Effects of decentration and tilt on the optical performance of 6 aspheric intraocular lens designs in a model eye.

PURPOSE: To compare the effect of decentration and tilt on the optical performance of 6 aspheric intraocular lens (IOL) designs in a model eye. SETTING: Department of Ophthalmology, Graduate School of Medicine, Dokkyo Medical University, Tochigi, Japan. DESIGN: Experimental study. METHODS: In theoretical simulations, the amount of spherical aberration in the IOL was varied to produce residual ocular spherical aberration (range -0.15 to 0.30 µm) at a 6.0 mm entrance pupil. Wavefront aberration analyses were performed with the ZEMAX optical design program (version August 20, 2014) to obtain the ocular root-mean-square values of astigmatism, coma, trefoil, and higher-order aberrations (HOAs) when the IOL was centered on the insertion position and misaligned at a 4.0 mm entrance pupil. The retinal visual images were calculated using the same conditions. Six 20.0 diopter (D) aspheric IOLs and one 20.0 D spherical IOL were used for the experimental studies. Each IOL was inserted in the model eye. The actual alignments were measured using a Scheimpflug camera (EAS-1000). The wavefront aberrations and visual images were gauged using a wavefront analyzer (KR-1W) at several IOL alignments. RESULTS: Intraocular lens decentration and tilt increased wavefront aberrations and degraded optical performance. Astigmatism, coma, and HOAs generated by misaligned IOLs were related to the amount of spherical aberration correction of the IOLs. The extent of spherical aberration remained unchanged by the amount of misalignment. Experimental model eye results showed trends similar to theoretical results. CONCLUSIONS: The spherical aberration correction amount in the aspheric IOL design was critical for the astigmatism, coma, and HOAs generated by the IOL misalignment. Additional spherical aberration corrections led to a more sensitive optical performance degradation resulting from IOL misalignment.

Open-capsule intraocular lens to prevent posterior capsule opacification.

PURPOSE: To develop a single-piece open-capsule intraocular lens (IOL) that can be inserted through a small incision and that prevents posterior capsule opacification (PCO) by expanding the capsule and circulating aqueous humor into the capsular bag. SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. DESIGN: Experimental study. METHOD: Using the same hydrophobic acrylic material as the NY-60 IOL, a prototype open-capsule IOL was constructed. The IOL has a single optic and 2 haptics, with a 2.8 mm high spacer and holes through which aqueous humor circulates into the capsular bag by separating the anterior capsule from the posterior capsule and expanding the capsule. The open-capsule IOL or NY-60 (as a control group) was inserted in rabbit eyes. Posterior capsule opacification development was evaluated by measuring the thickness of the cell layer at the center of the posterior capsule on histopathologic specimens and statistically comparing the thickness between the open-capsule IOL group and control group. RESULTS: The open-capsule IOL could be inserted through a 3.2 mm corneal incision using a D cartridge. The mean thickness of the cell layer at the center of the posterior capsule was 4.78 µm ± 2.61 (SD) in the open-capsule IOL group and 101.14 ± 25.19 µm in the control group and was significantly smaller in the open-capsule IOL group. CONCLUSION: The prototype single-piece IOL could be implanted through a small incision and prevented PCO by expanding the lens capsule and circulating aqueous humor into the capsular bag.

Comparison of anterior capsule contraction between 5 foldable intraocular lens models.

PURPOSE: To compare anterior capsule contraction in cataract patients having implantation of 1 of 5 foldable intraocular lens (IOL) models and evaluate lens epithelial cell (LEC) adhesion to each model. SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. METHODS: This study comprised 115 patients (126 eyes) without systemic or ocular complications who had phacoemulsification with IOL implantation. The eyes were randomly assigned to receive 1 of the following IOLs: acrylic MA60BM (Alcon), SA60AT (Alcon), AR40e (Advanced Medical Optics), or YA-60BBR (Hoya) or a silicone AQ310NV (Canon). Two weeks and 1, 3, and 6 months postoperatively, the anterior capsule opening area was measured using an anterior segment analysis system (EAS-1000, Nidek) and the percentage of anterior capsule contraction was compared for each postoperative period and IOL. Cell adhesion to each IOL type was evaluated using LECs from albino rabbits. RESULTS: The mean age of the patients was 73.6 years +/- 5.6 (SD). Eyes with the AQ310NV and AR40e IOLs had statistically significantly greater anterior capsule contraction. The rabbit study showed statistically significantly less LEC adhesion on these 2 IOL models. CONCLUSIONS: Anterior capsule contraction was significantly greater with the AQ310NV and AR40e IOLs than with the other IOLs. Results indicate that cell adhesion to the IOL is an important factor in preventing anterior capsule contraction.

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.

An in vitro model of posterior capsular opacity: SPARC and TGF-beta2 minimize epithelial-to-mesenchymal transition in lens epithelium.

PURPOSE: This report presents a novel model for studies of extracellular matrix (ECM) in posterior capsular opacification (PCO) in vitro. Lens epithelial cells (LEC) were cultured with an intraocular lens (IOL) on a surface of type IV collagen in an evaluation of the importance of the ECM-cell interaction in formation of PCO. Abnormal migration, proliferation, and expression of proteins associated with the epithelial-to-mesenchymal transition (EMT) that characterizes PCO were observed in the presence and absence of the matricellular protein SPARC (secreted protein, acidic and rich in cysteine), which regulates matrix-cell interactions. METHODS: The model for PCO in vitro consisted of an IOL placed on a membrane coated with collagen IV, a major constituent of the lens capsule. LECs from the lenses of wild-type (WT) and SPARC-null (SP-null) mice were cultured in the presence or absence of 10 ng/mL TGF-beta2 and 20 mug/mL recombinant human SPARC (rhSP) for up to 6 days. The migration of LECs was quantified. Labeling with BrdU and the measurement of DNA synthesis were assays for cell proliferation. Expression of the EMT markers, collagen type I, fibronectin, and alpha-smooth muscle actin were assessed using immunocytochemistry or Western immunoblots. RESULTS: LEC migration, proliferation, and the synthesis of EMT markers were enhanced in SP-null compared with WT LECs. TGF-beta2 inhibited the migration and proliferation of both WT and SP-null LECs in the presence of rhSP. TGF-beta2 increased the production of collagen type I, fibronectin, and alpha-SMA. The responses of SP-null LECs were rescued by the addition of recombinant human (rh)SP. CONCLUSIONS: A simple IOL culture system was useful for the evaluation of the effects of SPARC and TGF-beta2 on PCO in vitro. The action of TGF-beta2 on LEC migration and proliferation is influenced by SPARC, a regulator of matrix-cell interactions. The results indicate a functional intersection between pathways activated by TGF-beta2 and SPARC in the formation of PCO.

Active oxygen processing for acrylic intraocular lenses to prevent posterior capsule opacification.

PURPOSE: To evaluate active oxygen processing on the surface of acrylic intraocular lenses (IOLs) to prevent secondary posterior capsule opacification (PCO). SETTING: Department of Ophthalmology, Dokkyo Medical University School of Medicine, Mibu City, Tochigi, Japan. METHODS: Acrylic IOLs were prepared, and ultraviolet (UV)/ozone (UV/O3) or argon plasma was irradiated to the surface of the IOLs. Elemental analysis (electron spectroscopy for chemical analysis [ESCA]) of the IOL surfaces was performed to confirm surface modification. Changes produced by UV/O3 or argon plasma treatment were examined for fibronectin and lens epithelial cell (LEC) adhesion. To evaluate the PCO prevention by treated IOLs, 8-week-old albino rabbits were used. The rabbit eyes randomly had phacoemulcification and implantation of 3 different IOLs: the UV/O3-treated IOLs, argon plasma-treated IOLs, and the control IOLs. After 2 weeks, the rabbits were killed and their globes were dissected and fixed using formaldehyde 10%. The PCO was observed using light microscopy (DX51, ORIMPUS) after hematoxylin and eosin staining. RESULTS: Comparison of IOL surface composition by ESCA showed an increase in nitrogen content and hydroxyl substitute and carboxyl substitute groups on surfaces of treated IOLs. The fibronectin adhesion and the LEC adhesion on the UV/O3-treated and argon plasma-treated samples were increased. In the untreated group, there was statistically significant inhibition of PCO formation in the UV/O3-treated and argon plasma-treated groups. CONCLUSION: Active oxygen processing and argon plasma irradiation on the surface of IOLs was effective in preventing secondary PCO after cataract surgery.

[Effects of calcium on lens epithelial cells in rabbits].

PURPOSE: The action of lens epithelial cells (LECs) is important for cataract and posterior subcapsular cataract after cataract surgery. In this study, we analyzed the effects of calcium on the characteristics of LECs. METHODS: The LECs were collected using albino rabbits and incubated in minimum essential medium [MEM, Introgen Corp. (12% fetal bovine serum: FBS)] (37 degrees C, 5 % CO2) for a week to induce their proliferation. Cell culture dishes (35 mm) were prepared and 7 mm cylindrical pipes were placed in them. After that, around 10,000 cultured LECs were placed in the pipes and incubated. After 2 hours incubation, the pipes were removed and various doses of MEM (0, 2, 10 and 20 mM) replaced the calcium. Proliferation and shapes of LECs were observed using a confocal microscope and immunohistological analysis [alpha-smooth muscle actin (alpha-SMA) and bromodeoxyuridine (BrdU)]. The LECs were incubated with collagen gel and different calcium doses (0, 2, 10 and 20 mM) of MEM to calculate the contraction rate. RESULTS: It was observed that the LECs changed to fibroblast-like cells at high doses of calcium using a confocal microscope. Histological studies showed that the BrdU positive cells were increased by using 10 and 20 mM calcium MEM, but the positive cells were decreased by using 0 and 2 mM calcium MEM. Increase of alpha-SMA stained cells was recognized when using 0, 10 and 20 mM calcium MEM. The contraction rate of collagen gel was increased by using the 10 and 20 mM calcium MEM. CONCLUSION: The changes of calcium concentration might be an important factor for the development of cataract, posterior subcapsular opacification, and contraction of the lens capsule after cataract surgery.

[Protective effect on the corneal endothelium and remaining effect at the anterior chamber for three different kinds of viscoelastic devices].

PURPOSE: The present study was performed to evaluate the corneal endothelium protection and anterior chamber stagnation abilities of three different types of viscoelastic substances (Healon, Viscoat, HealonV). METHODS: Viscoelastic substances were selected at random for 120 eyes with cataracts, and the postoperative reduction rates of the corneal endothelium cells were compared. The residual viscoelastic substances after filling of the anterior chamber of pig eyes and aspiration with a handpiece were measured by an anterior eye segment image analysis system. The same procedures were performed in rabbit eyes and the residual levels of viscoelastic substances on the corneal endothelium were photographed histologically. RESULTS: The reduction rate of endothelium corneal cells tended to decrease with Viscoat three months after surgery. The results obtained with the anterior eye segment image analysis system showed that the residual level in the anterior chamber was higher with Healon. Histological analyses demonstrated residual Viscoat at the center of the corneal endothelium after perfusion. CONCLUSION: HealonV was superior in terms of spatial retention and Viscoat had corneal endothelium protection potential.

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.

Decreased visual acuity resulting from glistening and sub-surface nano-glistening formation in intraocular lenses: A retrospective analysis of 5 cases.

BACKGROUND: To report on five patients with decreased visual acuity due to glistening and severe sub-surface nano-glistening (SSNG) formation within their intraocular lenses (IOLs). DESIGN: Case reports and analysis of extracted IOLs. PARTICIPANTS AND SAMPLES: We report improved visual acuity when IOLs with severe glistening and SSNG were exchanged for clear IOLs in five patients. METHODS: Case reports. MAIN OUTCOME MEASURES: The main outcome measure was visual acuity. The secondary outcome measure was light transmission. Explanted IOLs were subjected to investigation. Pre- and postoperative slit lamp images of the anterior eye and microscopic images of the extracted IOLs were taken and compared. Light transmission of the IOL was measured using a double beam type spectrophotometer. An integrated value of the percentage light transmittance in the visible light spectrum was calculated. RESULTS: We report on five patients whose visual acuity improved when IOLs were exchanged because of severe glistening and SSNG. All of the affected IOLs were MA60BM (Alcon, Forth Wroth Texas, USA) and the original implantation had occurred over a range of 6-15 years prior to the IOL exchange. Light transmission was decreased in all affected lenses compared to a similar control IOL. CONCLUSIONS: Although only a few reports of cases in which glistening and SSNG have progressed to the level of decreased visual function have been published, the likelihood is that this phenomena will increase as the severity and incidence of these inclusions have been shown to increase with time. Appropriate evaluations of visual function in such patients are needed and consideration should be given to IOL exchange in symptomatic patients.

Analysis of cytoskeletal proteins in posterior capsule opacification after implantation of acrylic and hydrogel intraocular lenses.

PURPOSE: To analyze selected lens cytoskeletal proteins in posterior capsule opacification (PCO) 2 weeks after intraocular lens (IOL) implantation in rabbits. SETTING: Department of Ophthalmology, Dokkyo University School of Medicine, Tochigi, Japan. METHOD: Eight 10-week-old albino rabbits were prepared and anesthetized for phacoemulsification and aspiration of the crystalline lens and implantation of an acrylic or a hydrogel IOL. Two weeks postoperatively, the rabbits were killed and the IOLs removed for immunohistochemistry. Deparaffinized tissue sections were processed with antibodies against alpha-smooth muscle actin (alpha-SMA) and beta-crystallin to observe the types of PCO with the 2 IOL types. The proteins in the PCO tissue and the normal lens were homogenized, centrifuged, and analyzed using SDS-polyacrylamide gel electrophoresis (SDS-PAGE) densitometric analysis and Western immunoblotting for actin and vimentin. RESULTS: Immunohistochemistry demonstrated a fibroblastic cell type expressing alpha-SMA and partial regeneration of epithelial cells, resulting in a lenticular structure that stained irregularly for beta-crystallin. The immunoreactivity of fibroblast-like cells to beta-crystallin appeared weaker than that of the regenerated lenticular structure. SDS-PAGE showed variability in the content of cytoskeletal proteins in the insoluble fractions of the PCO. Degradation of the cytoskeletal components was greater with the acrylic IOL than with the hydrogel IOL. CONCLUSION: Cytoskeletal proteins expressed during the formation of PCO and IOL implantation may have potential as therapeutic target proteins to improve the biocompatibility of IOLs.