Iris Posterior Synechiae After Descemet Membrane Endothelial Keratoplasty in Asian Eyes: Prevention and Management of Posterior Synechiae.

OBJECTIVES: To evaluate the efficacy of a mydriatic agent for posterior synechiae after phacoemulsification and intraocular lens (IOL) implantation followed by Descemet membrane endothelial keratoplasty (staged DMEK). METHODS: In this prospective study, the outcomes of DMEK with or without mydriasis (0.5% tropicamide and 0.5% phenylephrine hydrochloride [Mydrin-P; Santen, Osaka, Japan]) after the DMEK procedure were analyzed. Patients underwent IOL implantation approximately 4 weeks before DMEK. Six months after DMEK, the iris posterior synechiae severity score was evaluated based on the extent of posterior synechiae affecting the eight areas (45° each) of the pupillary rim (posterior synechiae score; grades 0-8). Best spectacle-corrected visual acuity, central corneal thickness, endothelial cell density, axial length, and the amount of air at the end of the surgery were also evaluated. RESULTS: Fifteen eyes of 15 patients (mydriatic: n=8, control: n=7) were eligible for inclusion. Iris posterior synechiae were detected in all seven eyes (100.0%) in the control group, whereas they were noted in two eyes in the mydriatic group (25%). The mean iris posterior synechiae score was 0.69±1.20 in the mydriatic group and was significantly lower than that in the control group (4.57±0.90; P<0.001). There was no significant difference in other clinical factors. Although the incidence and scores of posterior synechiae in the control group were higher, the incidence was significantly reduced with the use of a mydriatic agent (in the mydriatic group). CONCLUSIONS: Use of a mydriatic agent is an effective measure to prevent postoperative synechiae after DMEK.

Vitamin U, a novel free radical scavenger, prevents lens injury in rats administered with valproic acid.

Valproic acid (2-propyl-pentanoic acid, VPA) is the most widely prescribed antiepileptic drug due to its ability to treat a broad spectrum of seizure types. VPA exhibits various side effects such as organ toxicity, teratogenicity, and visual disturbances. S-Methylmethioninesulfonium is a derivative of the amino acid methionine and it is widely referred to as vitamin U (Vit U). This study was aimed to investigate the effects of Vit U on lens damage parameters of rats exposed to VPA. Female Sprague Dawley rats were divided into four groups. Group I comprised control animals. Group II included control rats supplemented with Vit U (50 mg/kg/day) for 15 days. Group III was given only VPA (500 mg/kg/day) for 15 days. Group IV was given VPA + Vit U (in same dose and time). Vit U was given to rats by gavage and VPA was given intraperitoneally. On the 16th day of experiment, all the animals which were fasted overnight were killed. Lens was taken from animals, homogenized in 0.9% saline to make up to 10% (w/v) homogenate. The homogenates were used for protein, glutathione, lipid peroxidation levels, and antioxidant enzymes activities. Lens lipid peroxidation levels and aldose reductase and sorbitol dehydrogenase activities were increased in VPA group. On the other hand, glutathione levels, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and paraoxonase activities were decreased in VPA groups. Treatment with Vit U reversed these effects. This study showed that Vit U exerted antioxidant properties and may prevent lens damage caused by VPA.

Finite element analysis of neodymium: yttrium-aluminum-garnet incisions for the prevention of anterior capsule contraction syndrome.

BACKGROUND: Anterior capsular contraction syndrome is a potential complication of continuous curvilinear capsulorhexis (CCC). Three neodymium: yttrium-aluminum-garnet (Nd:YAG) laser relaxing incisions decrease anterior capsular contraction but the mechanism is unknown. The present study analyzed the biomechanical mechanism of three Nd:YAG laser relaxing incisions made to reduce anterior capsular contraction. METHODS: A three-dimensional control model and a three-dimensional Nd:YAG model of the anterior capsule with an opening diameter of 6 mm were created. Three incisions of 1 mm in length were made centrifugally at intervals of 120° around the opening circle. The stress alterations of the anterior capsule after CCC with and without Nd:YAG relaxation were numerically simulated and compared. RESULTS: In the control model, the stress was axially uniform in the inner area and relatively high near the inner rim of the opening. Meanwhile, in the Nd:YAG model, the stress level was very low in the inner opening areas, especially near the three incisions. The relaxing incisions in the Nd:YAG model significantly released the relatively high stress on the anterior capsule. Additionally, there was a high stress gradient near the relaxing incisions. CONCLUSION: Biomechanical effects of stress release may be the preventive mechanism of Nd:YAG incision against anterior capsular contraction syndrome.

Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind.

OBJECTIVES: The deterministic character of radiation-induced cataract is being called into question, raising the possibility of a risk in patients, especially children, exposed to ionizing radiation in case of repeated head CT-scans. This study aims to estimate the eye lens doses of a pediatric population exposed to repeated head CTs and to assess the feasibility of an epidemiological study. METHODS: Children treated for a cholesteatoma, who had had at least one CT-scan of the middle ear before their tenth birthday, were included. Radiation exposure has been assessed from medical records and telephone interviews. RESULTS: Out of the 39 subjects contacted, 32 accepted to participate. A total of 76 CT-scans were retrieved from medical records. At the time of the interview (mean age: 16 years), the mean number of CT per child was 3. Cumulative mean effective and eye lens doses were 1.7mSv and 168mGy, respectively. CONCLUSION: A relatively high lens radiation dose was observed in children exposed to repeated CT-scans. Due to that exposure and despite the difficulties met when trying to reach patients' families, a large scale epidemiological study should be performed in order to assess the risk of radiation-induced cataracts associated with repeated head CT.

Anterior capsule relaxing incisions with neodymium:YAG laser for patients at high-risk for anterior capsule contraction.

PURPOSE: To examine the effect of anterior capsule relaxing incisions created with a neodymium:YAG (Nd:YAG) laser on prevention of anterior capsule contraction after cataract surgery in high-risk patients. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. DESIGN: Randomized masked clinical trials. METHODS: Patients at high risk for anterior capsule contraction had anterior capsule relaxing incisions in either eye 3 days postoperatively. The anterior capsule opening was measured using a Scheimpflug videophotography system (EAS-1000) immediately and 1, 3, and 6 months after capsulotomy, and the percentage reduction in area was calculated. The degree of intraocular lens (IOL) decentration and tilt, posterior capsule opacification (PCO), and other complications were also assessed. RESULTS: Of the 84 patients included, 30 had primary angle closure, 28 had pseudoexfoliation, and 26 had diabetic retinopathy. There was no significant difference in the mean opening area between fellow eyes at baseline. In patients with primary angle closure, the area was significantly greater and the percentage reduction in area was significantly less in the capsulotomy group than in the no-capsulotomy group (P≤.0428). In patients with pseudoexfoliation or diabetic retinopathy, the percentage reduction was significantly less in the capsulotomy group than in the no-capsulotomy group (P≤.0493), although there was no significant difference in area. No significant difference was found in IOL decentration or tilt, PCO, or incidence of other complications. CONCLUSION: Neodymium:YAG laser anterior capsule relaxing incisions in the early period after cataract surgery were effective in preventing anterior capsule contraction in high-risk patients and had no adverse effects. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Prevention of anterior capsule contraction by anterior capsule relaxing incisions with neodymium:yttrium-aluminum-garnet laser.

PURPOSE: To examine the effect of two or three neodymium:yttrium-aluminum-garnet (Nd:YAG) laser relaxing incisions made in the anterior capsular rim on prevention of anterior capsule contraction after cataract surgery. DESIGN: Randomized clinical trials. METHODS: One hundred patients scheduled for bilateral cataract surgery were randomized to one of two groups: two or three relaxing incisions in the left eye and no incisions in the right eye, and relaxing incisions in the right eye and no incisions in the left eye. The anterior capsule opening area was measured using Scheimpflug photography immediately after capsulotomy and at one, three, and six months after capsulotomy, and the percentage reduction was calculated. The degree of intraocular lens (IOL) decentration and tilt and of posterior capsule opacification (PCO) also were examined. RESULTS: There was no significant difference in the anterior capsule opening area between fellow eyes at baseline (P > or = .1770). In patients who underwent two incisions, no significant difference was found between fellow eyes in the opening area (P > or = .4098) or in the percentage of reduction (P > or = .8730) throughout follow-up. In patients who underwent three incisions, the opening area in eyes with capsulotomy was significantly greater than that in eyes without capsulotomy (P < or = .0154), and the percentage reduction was significantly smaller in eyes with capsulotomy than in eyes without capsulotomy (P < or = .0016). No significant differences were found in the IOL decentration and tilt, or in PCO. CONCLUSIONS: Three relaxing incisions made in the anterior capsule decrease the anterior capsule contraction, whereas two incisions do not.

Healon5 sandwich technique for phacoemulsification in vitrectomized eyes.

We have developed a safe approach to phacoemulsificaiton in post-vectromized eyes. The technique, called the Healon5 sandwich, uses the viscoadaptive properties of sodium hyaluronate 2.3% (Healon5) to prevent a posterior chamber dehiscence.

Uveal and capsular biocompatibility of a single-piece, sharp-edged hydrophilic acrylic intraocular lens with collagen (Collamer): 1-year results.

PURPOSE: To analyze uveal and capsular biocompatibility 1 year following implantation of a sharp-edged, hydrophilic, collagen-containing posterior chamber intraocular lens (IOL). SETTING: Department of Ophthalmology, University of Vienna Medical School, Vienna, Austria. METHOD: In a prospective study, a Collamer CC4204BF IOL was implanted in 30 eyes of patients with senile cataract. A standardized surgical technique and postoperative regimen were applied. To assess uveal biocompatibility, cellular inflammation on the anterior IOL surface was evaluated with a specular microscope. Capsular biocompatibility was registered semiquantitatively with a biomicroscope, based on an assessment of fibrosis on the anterior and posterior capsules. Tyndall values were measured with the Kowa FC-1000 laser flare-cell meter. Decentration of the lens was also registered. RESULTS: One year after implantation, the values of flare and cell count in the anterior chamber were lower than preoperatively. Round and spindle-shaped, epithelioid, and foreign-body giant cells were not found on the anterior surface of the IOL. The capsulorhexis rim was moderately fibrosed in 56.6% of cases. Fibrosis of the capsule over the optic was also moderate in 36.6%. The central portion of the posterior capsule was devoid of fibrosis in 43.3% and mildly fibrosed in 50%. Three lenses revealed outgrowth of lens epithelial cells to the anterior surface of the IOL. A neodymium:YAG capsulotomy had to be performed in 1 case. All lenses were well centered in the capsular bag 1 year after implantation. CONCLUSIONS: The absence of inflammatory cells on the anterior surface of the IOL indicates the high uveal biocompatibility of the lens. In terms of capsular biocompatibility, the results were satisfactory.

Prevention of lens damage associated with cigarette smoke exposure in rats by alpha-tocopherol (vitamin E) treatment.

PURPOSE: To evaluate the possible protective effect and mechanism of alpha-tocopherol (vitamin E) treatment on lens degeneration associated with in vivo exposure to cigarette smoke and to further clarify the role of iron in cigarette smoke-generated lens damage. METHODS: Twenty-eight male Wistar rats were randomly divided into four equal groups. Rats in groups 3 and 4 were exposed to cigarette smoke for 1 hour each day over 90 consecutive days, and rats in groups 1 and 2 were treated in similar fashion but only exposed to room air. Additionally, vitamin E was given to the rats in groups 2 and 4 via intramuscular route. At the end of the study, both eyes of all the animals were enucleated; one eye was prepared for histopathologic examination, and the fellow eye was used for the measurement of iron and calcium levels. RESULTS: Significantly higher iron and calcium levels were observed in the lenses of group 3 rats than in other groups. Similar comparisons performed between groups 1 and 2, groups 1 and 4, and groups 2 and 4 did not show any significant difference. Distinct histopathologic changes in the anterior lens epithelium, such as hyperplasia, hypertrophy, epithelial multilayering, and the presence of epithelial cells over posterior lens capsule, observed in group 3 rats were not present in other groups. CONCLUSIONS: Cataractogenesis after cigarette smoke exposure was associated with an accumulation of iron and calcium in the rat lens, and vitamin E supplementation protected such accumulations and cataractogenesis.

[Risk factors for the vis a tergo of the "open eye" in cataract extraction with local anesthesia]. / Risikofaktoren für die Vis a tergo am "offenen Auge" bei Katarakt-Extraktionen in Lokalanästhesie.

In a prospective study, 244 patients who were scheduled to undergo extracapsular cataract extraction with implantation of the intraocular lens (ECCE/IOL) under local anesthesia were examined to evaluate the risk factors for vis a tergo (VAT) at the "open eye". The intraoperative blood pressure was found to be the most important factor for the occurence of VAT. We think that a reversible suprachoroidal effusion syndrome is responsible for this effect. In order to minimize intraoperative complications, we recommend routine monitoring and treatment if the intraoperative blood pressure is too high during cataract surgery with local anesthesia.

[PUVA treatment and the problem of ocular damage (author's transl)]. / Die Photochemotherapie: Zur Frage ihrer Nebenwirkungen am Auge.

Recently, psoriasis has been shown to respond favorably to PUVA treatment, i.e., local or systemic therapy with a photosensitizer (e.g., 8-methoxypsoralen) and subsequent long UV irradiation. The possibility of this treatment damaging the eye is discussed in the light of various experimental results. As toxic changes only occur when photosensitizer and UVA act jointly, the eyes of PUVA-treated patients must be shielded from any ultraviolet exposure by UV-absorbing protective glasses with side shields. Such glasses should have no significant absorption in the visible range. The new Spectra Shield process enables lenses to be coated in such a way that virtually no UV or IR radiation is transmitted.