Kensaku Miyake

Effect of Intraocular Lens Fixation on the Blood-Aqueous Barrier

We used slit-lamp fluorophotometry to evaluate the influence of various intraocular lens fixation sites on the blood-aqueous barrier in 106 eyes. After an average follow-up period of 1.1 years, eyes with anterior chamber lenses with closed or rectangular loops had a significantly higher concentration of fluorescein than did eyes with other types of implants (P less than .1 to P less than .001). In eyes with posterior chamber lenses, those with ciliary sulcus fixation had a significantly higher concentration of fluorescein than did those with intracapsular fixation (P less than .02). Compared with aphakic eyes without implants, eyes with any implant other than posterior chamber lenses with intracapsular fixation had significantly higher fluorescein concentrations (P less than .02 to P less than .001). These results indicated that the flexibility and the intraocular location of the lens loops are significant factors in securing the integrity of the blood-aqueous barrier of pseudophakic eyes. Posterior chamber lenses with intracapsular fixation caused the least trauma to the blood-aqueous barrier.

New classification of capsular block syndrome

Purpose: To propose a new classification of capsular block syndrome (CBS) to improve understanding of the etiology and provide effective treatment. Setting: Shohzankai Medical Foundation, Miyake Eye Hospital, Nagoya, and Japanese Red Cross Society, Wakayama Medical Center, Wakayama, Japan. Methods: Three groups of eyes with CBS were reviewed: eyes originally reported and diagnosed as having CBS; eyes experiencing CBS after hydrodissection and luxation of the lens nucleus; and eyes with CBS accompanying liquefied aftercataract or capsulorhexis‐related lacteocrumenasia. Results: In all 3 groups, the CBS occurred in eyes with a ‐continuous curvilinear capsulorhexis (CCC). It was characterized by accumulation of a liquefied substance within a closed chamber inside the capsular bag, formed because the lens nucleus or the posterior chamber intraocular lens (IOL) optic occluded the anterior capsular opening created by the CCC. Depending on the time of onset, CBS can be classified as intraoperative (CBS seen at the time of lens luxation following hydrodissection), early postoperative (original CBS), and late postoperative (CBS with liquefied aftercataract or lacteocrumenasia). The etiology of the accumulated substance and the method of treatment are different in each type. Conclusion: Capsular block syndrome is a complication of cataract/10L surgery that can occur during and after surgery. Correctly identifying the type of CBS is crucial to understanding the nature and effective treatment of this disorder.

Correlation between intraocular lens hydrophilicity and anterior capsule opacification and aqueous flare

Purpose: To study the correlation between a basic parameter of intraocular lens biocompatibility, hydrophilicity, and two clinical parameters, postoperative inflammation and anterior capsule opacification. Setting: Miyake Eye Hospital, Nagoya, Japan. Methods: Three combinations of IOLs that were identical in shape but had distinct contact angles of water were used in this prospective double‐masked study: (1) experimental comparison of collagen type IV and poly(methyl methacrylate) (PMMA) IOLs in rabbit eyes; (2) clinical comparison of heparin‐surface‐modified and PMMA IOLs; (3) clinical comparison of three foldable IOLs, silicone, acrylic, and memory. One of the two IOLs being compared in each situation was randomly assigned to both eyes of each animal or patient. At 1 and 3 months postoperatively, the degree of anterior capsule opacification and the amount of flare in the anterior chamber were determined. Results: In all three comparative situations, greater postoperative inflammation and more rapid anterior capsule opacification was seen in the eyes with hydrophobic IOLs. Conclusion: There was a correlation between the hydrophilicity of an IOL and the severity of postoperative inflammation and the speed of anterior capsule opacification.

Intravitreal injection of bevacizumab for macular edema secondary to branch retinal vein occlusion:results after 12 months and multiple regression analysis.

Purpose: To evaluate the 12-month follow-up results of intravitreal bevacizumab therapy for macular edema secondary to branch retinal vein occlusion and to identify the pretreatment factors that were associated with an improvement of the final visual outcome. Methods: Fifty eyes of 50 patients with macular edema secondary to branch retinal vein occlusion received an injection of 1.25 mg/0.05 mL bevacizumab. Additional injections were done when recurrence of macular edema occurred or the treatment was not effective. The best-corrected visual acuity and foveal thickness were measured. Stepwise multiple regression analyses were also performed. Results: The mean logarithm of the minimum angle of resolution visual acuity improved significantly from 0.53 to 0.26, and the mean foveal thickness decreased significantly from 523 to 305 &mgr;m during the 12-month follow-up period. The mean number of injections was 2.0 (range, 1–4). Stepwise multiple regression analyses showed that younger patients had both better visual acuity at 12 months and greater improvement of visual acuity during 12 months. In addition, better pretreatment visual acuity was associated with better visual acuity at 12 months but with less improvement of the visual acuity. Conclusion: Intravitreal bevacizumab therapy can be a long-term effective treatment for macular edema secondary to branch retinal vein occlusion.

Corneal Endothelial Changes in Pseudoexfoliation Syndrome

Using specular microscopy and computer-assisted morphometry, we studied 27 eyes with pseudoexfoliation syndrome, 17 apparently normal fellow eyes, and 15 eyes of matched normal subjects with no ocular disease other than senile cataract. Endothelium of the eyes with pseudoexfoliation syndrome showed significantly lower cell density than did the endothelium from control eyes. Endothelium of both eyes of patients with unilateral pseudoexfoliation syndrome showed significant morphologic changes in cell size (polymegethism) and shape variability (pleomorphism); these changes were essentially the same in overtly affected and apparently normal fellow eyes. The results suggested that the corneal endothelial changes are consistent and might serve as an early sign of the disorder.

Liquefied aftercataract: a complication of continuous curvilinear capsulorhexis and intraocular lens implantation in the lens capsule.

PURPOSE To describe a new type of aftercataract that contains a liquefied, milky white substance between the lens optic and the posterior lens capsule. METHOD We reviewed the medical records of 41 patients identified as having this type of aftercataract. RESULTS All 41 eyes (41 patients) underwent uneventful phacoemulsification after continuous curvilinear capsulorhexis and implantation of a posterior chamber intraocular lens made from polymethylmethacrylate. Two months to 6 years after surgery (average+/-SD, 3.8+/-1.7 years), fibrosis was noted evenly along the entire circumference and between the anterior surface of the intraocular lens optic and the edge of the capsular opening created by continuous curvilinear capsulorhexis. This led to formation of a closed chamber between the intraocular lens and the posterior lens capsule, which then accumulated a liquefied, milky white substance. Twenty-three of the 41 eyes showed liquefied aftercataract in conjunction with other types of aftercataract: in 12 eyes with fibrosis, in 11 eyes with Elschnig pearls, and in one eye with a Soemmering ring. None of the eyes had any signs of inflammation; six of the 41 eyes had reduced visual acuity caused exclusively by the liquefied aftercataract. Before cataract surgery, 14 eyes were diagnosed with diabetic retinopathy, four with glaucoma, and two with uveitis. CONCLUSION We report a new type of aftercataract characterized by a liquefied, milky white substance that accumulates between the lens optic and the posterior lens capsule when the anterior capsular opening, originally created by continuous curvilinear capsulorhexis, becomes occluded with the lens optic.

Reducing angiographic cystoid macular edema and blood–aqueous barrier disruption after small-incision phacoemulsification and foldable intraocular lens implantation: Multicenter prospective randomized comparison of topical diclofenac 0.1% and betamethasone 0.1%

PURPOSE: To compare the effectiveness of a topical nonsteroidal drug (diclofenac 0.1%) and a topical steroidal drug (betamethasone 0.1%) in preventing cystoid macular edema (CME) and blood–aqueous barrier (BAB) disruption after small‐incision cataract surgery and foldable intraocular lens (IOL) implantation. SETTINGS: Shohzankai Medical Foundation Miyake Eye Hospital, Tokyo, Japan. METHODS: This multicenter interventional double‐masked randomized study comprised 142 patients having phacoemulsification and foldable IOL implantation. Seventy‐one patients were randomized to receive diclofenac eyedrops and 71, betamethasone eyedrops for 8 weeks postoperatively. The incidence and severity of CME were evaluated by fluorescein angiography. Blood–aqueous barrier disruption was determined by laser flare–cell photometry. RESULTS: Of the patients, 63 were men and 79 were women. Five weeks after surgery, the incidence of fluorescein angiographic CME was lower in the diclofenac group (18.8%) than in the betamethasone group (58.0%) (P<.001). At 1 and 2 weeks, the amount of anterior chamber flare was statistically significantly less in the diclofenac group than in the betamethasone group (P<.05). At 8 weeks, intraocular pressure was statistically significantly higher in the betamethasone group (P = .0003). CONCLUSIONS: Diclofenac was more effective than betamethasone in preventing angiographic CME and BAB disruption after small‐incision cataract surgery. Thus, nonsteroidal antiinflammatory agents should be considered for routine treatment of eyes having cataract surgery.

Long-Term Corneal Endothelial Changes After Intraocular Lens Implantation

We studied the morphologic characteristics of the corneal endothelium in a series of patients who had undergone phacoemulsification with intraocular lens implantation performed by one surgeon. Specular microscopy and computer-assisted morphometry were performed preoperatively and three years after surgery. Nineteen eyes that received posterior chamber lenses with intracapsular fixation had a mean endothelial cell loss of 18.1%, without any significant change in cell size (polymegethism) or shape variability (pleomorphism). Implantation of anterior chamber lenses with the posterior capsule left intact (18 eyes) caused a similar degree of cell loss (23.5%) but caused marked polymegethism and pleomorphism of the cells. Endothelial cell loss (28.5%) and morphologic changes were greatest in five eyes that received anterior chamber lenses because of a rupture of the posterior capsule.

Pupillary fibrin membrane. A frequent early complication after posterior chamber lens implantation in Japan.

The incidence of pupillary fibrin membrane formation, a relatively frequent complication of cataract surgery in Japan even for experienced surgeons, was noted in 2038 consecutive cases of senile cataract removal and primary posterior chamber intraocular lens (PC IOL) implantation. The overall incidence was 4.4%. Comparisons among cases showed the incidence to be significantly higher among: (1) patients who received dry- versus wet-sterilized lenses (P less than 0.001), (2) eyes with premature, subcapsular, or nuclear cataracts than among those with mature cataracts (P less than 0.05), (3) patients with systemic hypertension (P less than 0.01), (4) eyes not treated postsurgically with topical antiprostaglandins (P less than 0.001), and (5) patients who had undergone previous PC IOL implantation in the fellow eye (P less than 0.001). These findings suggest that the formation of the fibrin membrane is a kind of immunologic reaction. Accordingly, use of antiprostaglandin agents and complete removal of lens material and epithelial cells are recommended, especially for patients undergoing second-eye operations or those with a predisposition to breakdown of the blood-aqueous barrier.

ESCRS Binkhorst Lecture 2002: Pseudophakic preservative maculopathy

&NA; Many antiglaucoma eyedrops are reported to cause cystoid macular edema (CME) in aphakia and pseudophakia. We review 4 clinical and laboratory studies that compare the incidence of CME in early postoperative pseudophakia in eyes that received preserved latanoprost and timolol, nonpreserved timolol, and the preserved and nonpreserved vehicle for these drugs and looked at the morphological damage to cells and the changes in the indicators of cytokine and prostaglandin (PG) synthesis caused by latanoprost and timolol and the preservative benzalkonium chloride. Based on the findings of these studies, which indicate that the preservative causes increased synthesis of PGs and other substances and intensified postoperative inflammation, the term pseudophakic preservative maculopathy is proposed for CME caused by antiglaucoma eyedrops.