Degenerative effects of cobalt-chloride treatment on neurons and microglia in a porcine retina organ culture model.

In order to understand the pathological processes of retinal diseases, experimental models are necessary. Cobalt, as part of the vitamin B12 complex, is important for neuronal integrity. However, it is known that high quantities of cobalt induce cytotoxic mechanisms via hypoxia mimicry. Therefore, we tested the degenerative effect of cobalt chloride (CoCl2) on neurons and microglia in a porcine retina organ culture model. Organotypic cultures of porcine retinas were cultured and treated with different concentrations of CoCl2 (0, 100, 300 and 500 µM) for 48 h. After four and eight days, CoCl2 induced a strong degeneration of the porcine retina, starting at 300 µM. A loss of retinal ganglion cells (RGCs, Brn-3a), amacrine cells (calretinin) and bipolar cells (PKCα) was observed. Additionally, a high expression of hypoxia induced factor-1a (HIF-1a) and heat shock protein 70 (HSP70) was noted at both points in time. Also, the Caspase 3 protein was activated and P21 expression was induced. However, only at day four, the Bax/Bcl-2 ratio was increased. The effect of CoCl2 was not restricted to neurons. CoCl2 concentrations reduced the microglia amount (Iba1) and activity (Iba1 + Fcγ-Receptor) at both points in time. These damaging effects on microglia were surprising, since CoCl2 causes hypoxia and a pro-inflammatory environment. However, high concentrations of CoCl2 also seem to be toxic to these cells. Similar degenerative mechanisms as in comparison to retinal ischemia animal models were observed. In summary, an effective and reproducible hypoxia-mimicking organotypic model for retinal degeneration was established, which is easy to handle and ready for drug studies.

[New Developments in Cataract Surgery]. / Interessantes aus der Kataraktchirurgie.

Recent technological innovations in cataract surgery have made the procedure even more precise and safe and the odds of having a highly satisfied patient even higher. These innovations include visualisation systems - such as intraoperative aberrometry - which are particularly helpful when it comes to implanting toric IOLs, where even a slight rotation or misalignment can significantly reduce the postoperative visual quality. Another way to ensure the exact positioning of a toric IOL is to create a mark by making an intrastromal incision using the femtosecond laser. The latter technology has increased the precision of capsulotomy and other steps of the operation and has been successfully employed in patients with a challenging clinical profile, including paediatric and hypermature cataracts. The femtosecond laser, however, induces an increase in intraocular prostaglandins, which can lead to miosis. Applying topical NSAIDs before starting surgery has proved to be effective in coping with the consequences of the increase in prostaglandins. Good vision without using glasses for near, intermediate and far distances remains a goal for many patients. IOLs with extended depths of focus (EDOF) technology can provide this comfort - to some but not all patients. An intraocular sensor, Eyemate, that is implanted during cataract surgery, enables the glaucoma patient to check his or her IOP at any time and improves the management of glaucoma and its main risk factor, elevated IOP. Several methods - drugs or nutritive agents - are said to prevent cataractogenesis. These studies have probably to be taken with the proverbial grain of salt.

[Marginal protection of retinal cells by bisperoxovanadium : Appropriate therapy in the model of retinal ischemia?] / Marginale Protektion retinaler Zellen durch Bisperoxovanadium : Geeignete Therapie im Modell der retinalen Ischämie?

BACKGROUND: Ischemic processes usually lead to the destruction of retinal cells and therefore play a key role in a multitude of eye diseases. OBJECTIVE: The aim of this study was to investigate whether bisperoxovanadium has a potential neuroprotective effect in an ischemia/reperfusion animal model. MATERIAL AND METHODS: Initially, ischemia was induced in one eye of an ischemia/reperfusion model and 3 days later, a 14-day medication-based treatment was initiated. Bisperoxovanadium was administered intraperitoneally every 3 days. Subsequently, the number of ganglion cells, the rate of apoptosis, amacrine cells, macroglia, microglia, and their activation state, as well as photoreceptors were determined by histological and immunohistochemical analyses. RESULTS: In comparison to the control group, a significant retinal ganglion cell loss, a significant reduction of the inner layers as well as a decrease in photoreceptor and amacrine cell numbers could be determined in the ischemic eyes. In addition, there was an increase in the number of microglia in these animals. The rats treated with bisperoxovanadium did not exhibit a significant neuroprotective effect regarding the number of ganglion cells, the rate of apoptosis, macroglia, amacrine cells, or photoreceptors; however, a low structural degeneration of photoreceptors could be observed as an effect of the treatment. Additionally, fewer microglia and activated microglia were observed after bisperoxovanadium treatment. CONCLUSION: Bisperoxovanadium seems to have only a marginal neuroprotective effect on ischemic retinae. It needs to be examined whether earlier therapy onset, higher dose or different route of administration would significantly improve the results or whether this therapeutic approach is unsuitable.

[Early onset of fingolimod-associated macular edema]. / Frühzeitiges Auftreten eines Fingolimod-assoziierten Makulaödems.

BACKGROUND: Fingolimod, a disease-modifying sphingosine 1­phosphate receptor modulator, which was approved in Germany in 2011, decreases the relapse rate and reduces neuroinflammation in patients with relapsing-remitting multiple sclerosis. Macular edema is a well-known ocular side effect of fingolimod therapy. Specific intervals for ophthalmologic check-ups after starting fingolimod and definite treatment schedules for fingolimod-associated macular edema are, however, still lacking. CASE REPORT: We present a case of early fingolimod-associated macular edema in a 45-year-old female patient with relapsing-remitting multiple sclerosis. The patient complained about visual impairment 1 month after the start of fingolimod and visited an eye specialist. Funduscopic examination and imaging diagnostics revealed macular edema in both eyes. The treatment with fingolimod was immediately stopped. For therapy of macular edema topical application of nepafenac and oral acetazolamide were given. During the 6 months of treatment the macular edema completely disappeared and visual function recovered completely. DISCUSSION: At the time of diagnosis, it is fundamentally important to discuss the continuation of fingolimod administration with the attending neurologist and if necessary to discontinue the drug. Regular ophthalmologic check-ups at 4­week intervals over a period of 3 months are meaningful after beginning fingolimod treatment. As before, it is still a key aspect to determine predictive opthalmologic and neurological factors before beginning treatment to evaluate which patients are at risk of fingolimod-associated macular edema.

[Toric phakic intraocular lenses]. / Torische phake Intraokularlinsen.

After more than 3 years of follow-up, the satisfactory results achieved with the toric iris-fixated phakic intraocular lens (IOL) mean we can regard implantation of this lens as a procedure with the potential to provide safe, predictable, effective and stable correction of astigmatic errors, providing patients are carefully selected and receive adequate preparation for surgery. The iris-fixated toric phakic IOL (Verisyse, Advanced Medical Optics; Artisan, Ophtec) is a PMMA lens with a total diameter of 8.5 mm and an optic diameter of 5 mm. It has a spherical anterior and a toric posterior surface. Its refractive power ranges from -2 dpt to -21 dpt for myopia and from +2 dpt to +12.5 dpt for the correction of hyperopia. Cylindrical correction is available from 2 dpt to 7.5 dpt. The Visian toric implantable Collamer lens (Staar) differs in that it is foldable and can be inserted through a very small incision of about 2.8 mm. It is placed in front of the natural lens in the ciliary sulcus. The aim of implanting these phakic IOLs is to correct the entire refractive error, meaning both the spherical and the astigmatic error, in a single step. Different lens models are available, and the selection depends on the direction of the cylinder axis and the anatomical situation, among other things.

[Presbyopia treatment using a femtosecond laser]. / Presbyopietherapie mit Femtosekundenlaser.

Presbyopia is by far the most common refractive error worldwide, with no permanent therapeutic option available. All efforts to restore accommodation by the use of surgery have not led to a generally accepted therapy. However, there is evidence from an animal model that the use of a femtosecond (fs) laser might influence the modulus of elasticity in the lens. Fs-laser impulses can create intralenticular disruption in animal eyes as well as human cadaver lenses and improve elasticity. The concept of treating presbyopia with fs-laser requires a new, complex theory combining the optical and the mechanical aspects of accommodation in the eye. Diagnostic tools for measuring optical change in power and geometrical modification as the eye views from far to near are needed to obtain objective clinical data. A non-invasive treatment of presbyopia to restore accommodation might be possible in the future.

[Unusual masquerade of an ocular carcinoma metastasis]. / Untypische Masquerade einer okulären Karzinommetastase.

BACKGROUND: Idiopathic and therapy resistant uveitis especially of unclear origin, is a diagnostic challenge for ophthalmologists. Metastases to the anterior chamber or vitreous body can occasionally mimic the clinical picture of uveitis, a variant on the usual lymphomatous masquerade syndrome. The underlying pathological pathways leading to the metastatic spread of tumor cells within the fluid compartments of the eye remain unclear. CASE REPORT: We present an unusual case of vitreous metastases to the right eye of a patient in whom an underlying primary malignancy was unknown. After recurrent episodes of cortisone-refractive panuveitis with pseudohypopyon, a diagnostic vitreous biopsy was performed. Cytopathological examination of the vitreous sample revealed carcinoma cells with an immune profile suggestive of lung cancer metastasis. Subsequent staging investigations revealed a primary lung adenocarcinoma as well as cerebral, adrenal and osseous metastases. THERAPY: Due to the extent of dissemination of this non-small cell lung cancer (NSCLC), only palliative treatment including external beam irradiation and systemic chemotherapy was possible to reduce pain and to maintain vision as well as an attempt at systemic control of the disease.

Clinical benefit, complication patterns and cost effectiveness of laser in situ keratomileusis (LASIK) in moderate myopia: results of independent meta analyses on clinical outcome and postoperative complication profiles.

PURPOSE: Laser in situ keratomileusis (LASIK) means a patient investment of 2426 Euro per eye, which usually cannot be funded by European health care insurers. In the context of recent resource allocation discussions, however, the cost effectiveness of LASIK could become an important indication of allocation decisions. Therefore an evidence based estimation of its incremental cost effectiveness was intended. METHODS: Three independent meta analyses were implemented to estimate the refractive gain (dpt) due to conventional LASIK procedures as well as the predictability of the latter (%) (fraction of eyes achieving a postoperative refraction with maximum deviation of +/- 0.5 dpt from the target refraction). Study reports of 1995 - 2004 (English or German language) were screened for appropriate key words. Meta effects in refractive gain and predictability were estimated by means and standard deviations of reported effect measures. Cost data were estimated by German DRG rates and individual clinical pathway calculations; cost effectiveness was then computed in terms of the incremental cost effectiveness ratio (ICER) for both clinical benefit endpoints. A sensitivity analysis comprised cost variations of +/- 10 % and utility variations alongside the meta effects' 95% confidence intervals. RESULTS: Total direct costs from the patients' perspective were estimated at 2426 Euro per eye, associated with a refractive meta benefit of 5.93 dpt (95% meta confidence interval 5.32 - 6.54 dpt) and a meta predictability of 67% (43% - 91%). In terms of incremental costs, the unilateral LASIK implied a patient investion of 409 Euro (sensitivity range 351 - 473 Euro) per gained refractive unit or 36 Euro (27 - 56 Euro) per gained percentage point in predictability. When LASIK associated complication patterns were considered, the total direct costs amounted up to 3075 Euro, resulting in incremental costs of 519 Euro / dpt (sensitivity range 445 - 600 Euro / dpt) or 46 Euro / % (34 - 72 Euro / %). Most frequently reported LASIK complications were "central islands / over- / undercorrection / regression" (meta incidence estimate 24%) and "haze" (15%), which were identified by means of an independent meta analysis. CONCLUSION: Bearing incremental costs of 519 Euro per gained refractive unit in mind, the conventional LASIK procedures showed an encouraging cost effectiveness range; the latter estimate may serve as a rationale for future allocation discussions in ophthalmology.

Epidemiological and health economical evaluation of intraoperative antibiosis as a protective agent against endophthalmitis after cataract surgery.

OBJECTIVE: To evaluate risk factors for endophthalmitis after cataract surgery and to retest recent findings on the protective effect of intraoperative antibiosis and the promoting effect of the clear corneal as compared to sclerocorneal incision. In addition, the economics of intraocular intraoperative antibiosis as a prophylaxis in cataract surgery are asketched. DESIGN: Survey study. PARTICIPANTS: Five hundred thirty-eight ophthalmosurgical centres in Germany. MAIN OUTCOME MEASURE: epidemiological evaluation: responder specific endophthalmitis incidence in year 2000; economical evaluation: direct cost analysis based on incidence data and local cost estimates (health service's perspective). RESULTS: A total of 310 (58%) questionnaires were computed resulting in an overall count of 404,356 cataract surgeries and 291 self-reported endophthalmitis cases (crude rate 0.072%). The risk of postoperative endophthalmitis for sclerocorneal versus clear corneal incisions was not significantly reduced (relative risk 0.97, 99% confidence interval 0.69-1.38). The hypothesis of a protective effect of intraocular antibiosis could be confirmed by a significantly decreased risk ratio of 0.69 (99% confidence interval 0.48-0.99) indicating a significant benefit from intraoperative intraocular antibiosis. A similar tendency was observed for an intraoperative periocular antibiosis with a significantly reduced risk ratio of 0.68 (99% confidence interval 0.49-0.96). These risk estimates had been adjusted for the size of the surgical centre: a significantly reduced risk ratio of 0.70 (99% confidence interval 0.49-0.98) for postoperative endophthalmitis was observed for local centres. Cost evaluation for the prophylactic use of intraocular intraoperative antibiosis in cataract surgery revealed an economically relevant decrease in direct endophthalmitis associated costs. CONCLUSIONS: Whereas this 2000 appraisal of a recent survey in 1996 could not reproduce the benefit of sclerocorneal incision, the protective effect of intraoperative intraocular antibiotic prophylaxis could be confirmed. However, the results of this survey have to be interpreted with care, since it is not based on individual case information, but rather on aggregate questionnaire data.

Clinical outcome and subjective quality of life after photodynamic therapy in patients with age-related macular degeneration.

PURPOSE: Whereas the efficacy of photodynamic therapy (PDT) in preventing the progression of age-related macular degeneration (ARMD) is established, its effect on quality of life is under discussion. METHODS: All patients who underwent PDT during 2000 and 2001 at the University Eye Hospital of Mainz were interviewed using a standardized 82-item questionnaire on quality of life and patient satisfaction in ophthalmologic patients. Information was assessed in terms of 82 questions; global scores ranging from 1.0 (optimum self-estimated quality of life) to 4.0 (worst) were derived. Cataract patients' scores were used to characterize the ARMD patients' subjective outcome; the latter were then related to clinical outcome parameters via logistic regressions. RESULTS: A total of 84 patients (50% female, median age 77 years) were interviewed, who underwent a median of three PDT interventions. During the period of PDT treatment, their median decrease in visual acuity was 3 lines from 0.125 to 0.063. Patients who reported a subjective increase in visual function during this period showed a median private flexibility score of 1.86; patients with the subjective impression of visual function decrease, a median score of 2.71; the median scores for mobility were 2.00 versus 3.00, for flexibility in reading 1.91 versus 3.64, for psychological stress 1.56 versus 2.25, and for communicational flexibility 1.72 versus 2.25. The difference in reading flexibility was statistically significant (p=0.001) after correction for clinical cofactors. CONCLUSIONS: The established clinical benefit of PDT treatment concerning its efficacy in ARMD progression prevention coincides with an at least slight subjective benefit in quality of life and patient satisfaction. However, the latter is associated with the patients' subjective impression of visual acuity progression rather than with clinically validated outcome after PDT treatment.

Scanning laser polarimetry and retinal thickness analysis before and after laser in situ keratomileusis.

PURPOSE: To evaluate changes in retinal nerve fiber layer (RNFL) thickness after laser in situ keratomileusis (LASIK) using a scanning laser polarimeter with fixed corneal compensation (GDx) and the retinal thickness analyzer (RTA). METHODS: Thirty-eight eyes of 19 healthy subjects (10 female and 9 male; mean age 37.0-/+8.8 years) underwent GDx and RTA measurements before and after LASIK. All subjects revealed mild to high myopia (mean spherical refraction: -4.0-/+2.75 D). Measurements using GDx were followed by RTA measurements after pupil dilation. All measurements were performed the day before LASIK and 1 week postoperatively. RESULTS: GDx revealed a decrease in nerve fiber layer thickness measurements after LASIK, but did not reach statistical significance (p>0.05). Using RTA, mean RNFL thickness (MRNFL) and RNFL cross sectional area decreased significantly after LASIK (p=0.03 and p=0.02, respectively). CONCLUSIONS: Scanning laser polarimetry revealed a slight decrease in RNFL thickness measurements after LASIK. MRNFL and RNFL cross section were significantly lower after LASIK using RTA. The changes might be artifacts in a small group of myopic subjects.

[Rotational stability in intraocular lenses with C-loop haptics versus Z haptics in cataract surgery. A prospective randomised comparison]. / Rotationsstabilität monofokaler Intraokularlinsen mit C-Haptik versus Z-Haptik nach Kataraktchirurgie. Prospektiver randomisierter Vergleich.

The aim of the study was to compare the rotational stability of intraocular lenses (IOLs) with C-loop haptics and those with Z haptics. A total of 50 patients with cataracts were prospectively randomised in equal numbers using a design equivalent to IOL MS 612 S (C-loop haptic) and MS 6120 (Z haptic, both HumanOptics, Erlangen). Complete ophthalmological examinations were performed including assessment of the IOL rotation after 1 day, 1 month and 3 months postoperatively. The significances between the groups were evaluated using the Wilcoxon test. The Fisher exact test was used for the primary finding of the study (rotation of at least 10 degrees ). The IOL group with the C-loop haptics showed a median lens rotation of 0 degrees on the first day and 2 degrees clockwise after 1 month and 3 months. In the Z haptic group, there was no median rotation in the IOL group. Moreover, the range of IOL rotation of the C-loop haptics was broader (3 months postoperatively: maximum in the C-loop haptics: 21 degrees with 15.5 degrees in the Z haptics). There was no significant difference at any time. At 3 months postoperatively, 32% of the C-loop haptic IOL and 16% of the Z haptic IOL rotated at least 10 degrees (P=0.32). In 59% of the IOL with C-loop haptics, the direction of the rotation was clockwise. This was 40% for the IOL with Z haptics (P=0.33). At 3 months postoperatively, both IOLs demonstrated good rotational stability with a low mean deviation from the target axis. IOLs with Z haptics showed a tendency to greater rotational stability than C-loop haptics but without any significant difference. There was no significant difference in visual rehabilitation.

[Laser in situ keratomileusis (LASIK) and scanning laser ophthalmoscopy]. / Laser-in-situ-Keratomileusis (LASIK) und Scanning-Laser-Ophthalmoskopie Originalien.

BACKGROUND: To determine the influence of Laser in situ keratomileusis (LASIK) on the measurements of retinal thickness and optic nerve head topography using the Retinal Thickness Analyzer (RTA). METHODS: RTA measurements were performed before and after LASIK. Forty-eight eyes of 25 healthy subjects were included. Mean age was 40.0+/-10.6 years. Mean preoperative refractive error (spherical equivalent) was -3.3+/-3.6 dpt, and 0.2+/-0.9dpt postoperatively. Correlation between ablation depth and duration and change of retinal thickness postoperatively was performed. All patients received a pachymetry preoperatively. RESULTS: Postoperatively, mean retinal nerve fiber layer thickness (MRNFL) and cross sectional area (RNFL cross section area) significantly decreased after LASIK (MRNFL preop: 0.18 mm, postop: 0.11 mm, P =0.026, RNFL cross section preop: 1.17 mm(2), postop: 0.71 mm(2), P =0.015). Ablation depth revealed a significant correlation with changes in retinal thickness measurements postoperatively (Delta MRNFL: Ablation depth, P =0.001, r=-0.5). Duration of the ablation was not significantly correlated to the MRNFL measurements postoperatively (P =0.27, r=-0.08). No correlation was found between the central corneal thickness and the change in retinal thickness after LASIK (P =0.51). CONCLUSION: Due to changes in corneal architecture after LASIK, measurements using RTA reveal a decrease in MRNFL and RNFL cross section area. These changes are likely artifacts. Further studies with a longer follow-up are desirable.

[Microbial keratitis following laser in situ keratomileusis. Prevention, differential diagnosis, and therapy]. / Mikrobielle Keratitis nach Laser-in-situ-Keratomileusis. Prävention, Differenzialdiagnose und Therapie.

Laser in situ keratomileusis (LASIK) is an effective option and currently one of the most commonly applied surgical techniques in the correction of refractive errors such as myopia, hyperopia, and astigmatism. In contrast to photorefractive keratectomy, it maintains the integrity of Bowman's membrane and the epithelium leading to faster visual rehabilitation as well as less pain and discomfort. Nevertheless, following LASIK the stroma is exposed to infectious organisms. Sight-threatening complications after LASIK are reported to be as rare as 1 in 1000 procedures. However, any infectious keratitis remains potentially devastating. Reports about infectious keratitis following LASIK have increasingly surfaced in recent years. We present a review of the literature on microbial keratitis and present our own cases and recommendations for possible prophylaxis and therapy.

Contrast sensitivity and glare disability by halogen light after monofocal and multifocal lens implantation.

BACKGROUND: Standard examination of contrast sensitivity under conditions of glare disability is performed with incandescent light. A new halogen glare test that simulates glare as seen with oncoming vehicle headlights was used to measure glare disability in patients implanted with multifocal and monofocal intraocular lenses (IOLs). METHODS: 28 patients with an average age of 69 years (SD 12 years) were implanted with a monofocal IOL (SI-40NB, Allergan) and 28 patients with an average of 66 years (12 years) were implanted with a refractive multifocal IOL (Array-SA-40N, Allergan). All patients were followed for 5 months postoperatively. Contrast sensitivity at four spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) with and without a glare source were measured using the halogen glare test (CSV-1000 HGT). Statistical analysis was performed using the two sample Wilcoxon test. The local significance level was set at 0.05. RESULTS: When tested at the lowest spatial frequency (3 cpd) without halogen glare, contrast sensitivity was lower in the multifocal group than in the monofocal group (p=0.0292). With additional glare, there was no difference between both groups. At all other spatial frequencies (6, 12, and 18 cpd), when tested without halogen glare (6 cpd, p=0.5250; 12 cpd, p=0.8483; 18 cpd, p=0.9496) and with moderate (3 cpd, p=0.7993; 6 cpd, p=0.4639; 12 cpd, p=0.7456; 18 cpd, p=1.0) and high halogen glare (3 cpd, p=0. 1513; 6 cpd, p=0.2016; 12 cpd, p=0.3069; 18 cpd, p=0.9933), there was no statistically significant difference between groups. Patients in both groups of age 70 or older had reduced contrast sensitivity without halogen glare and with moderate and strong glare. When monofocal and multifocal patients older than 70 years of age were analysed separately, there was no statistically significant difference in contrast sensitivity with and without glare. Astigmatism >1 dioptre had no significant influence on contrast sensitivity and glare disability when monofocal and multifocal eyes were compared. CONCLUSION: Reduced contrast sensitivity was found in the multifocal group only at the lowest spatial frequency without halogen glare. The monofocal and multifocal groups had no statistically significant differences in contrast sensitivity with moderate and strong glare. These results suggest no difference in glare disability induced by halogen light similar to oncoming vehicle headlights for patients implanted with monofocal and multifocal IOLs.

Solvent for removing silicone oil from intraocular lenses: experimental study comparing various biomaterials.

PURPOSE: To evaluate the effectiveness of a perfluorocarbon-perfluorohexyloctane (PFHO)-in removing silicone oil from different intraocular lenses (IOLs) and determine whether any removal technique enhances the removal of silicone oil. METHODS: Six IOL materials were analyzed: standard poly(methyl methacrylate) (PMMA), heparin-surface-modified (HSM) PMMA, AcrySof, 2 polyHEMAs with different water contents, and a second-generation SLM-2 silicone. One or 2 microL of a highly viscous silicone oil (5700 cs) was applied to the center of each IOL optic. Perfluorohexyloctane (2 mL) was then used to remove the silicone oil by 1 of 3 techniques: immersion of the IOL in PFHO; irrigation of the silicone oil with a small, blunt cannula; mechanical wiping with a PFHO-saturated Merocel swab (used only when irrigation failed). Next, each IOL was examined by light and scanning electron microscopy. The expanse of silicone oil residue remaining on the IOLs was objectively quantified using an integrated computerized analysis system combined with energy-dispersive spectrometry. RESULTS: After application of 1 microL silicone oil, immersion in PFHO did not remove silicone oil from any IOL material. Irrigation with PFHO removed the silicone oil from the HSM PMMA and polyHEMA IOLs, but oil remained on the other lens materials. Mechanical wiping was necessary to remove the oil from the PMMA, AcrySof, and silicone IOLs. Attempts to remove 2 microL of silicone oil produced similar results. Although mechanical wiping of the AcrySof IOL removed all silicone oil, a slight residue remained on the PMMA and silicone IOLs. The PFHO irrigation removed significantly more silicone oil from the HSM PMMA than the unmodified PMMA IOL (P =.001). More silicone oil was removed from polyHEMA IOLs than from the AcrySof or silicone IOLs (P =.05). CONCLUSION: Although PFHO can remove silicone oil, it is of limited usefulness. The effectiveness of PFHO depends on the removal technique, IOL material, and amount of silicone oil present. Based on these results, we recommend PFHO irrigation followed by mechanical wiping with a PFHO-saturated swab.

Osmolality of various viscoelastic substances: comparative study.

PURPOSE: To determine the osmolality of various viscoelastic substances. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, and Institute for Medical Device Testing, Memmingen, Germany. METHODS: The analysis was carried out according to the European Pharmacopoeia by means of a calibrated osmometer using the freezing-point depression method. Each syringe was analyzed as a duplicate analysis. RESULTS: Mean osmolalities (mOsmol/kg) of the sodium hyaluronate viscoelastic substances were Allervisc 299; Allervisc Plus 307; Amvisc Plus 335; AMO Vitrax 284; Biolon 279; Dispasan 311; Dispasan Plus 314; Healon 295; Healon GV 312; Healon5 322; HYA-Ophtal 376; Microvisc 313; Microvisc Plus 341; Provisc 307; Rayvisc 312; Viscoat 340; Visko 296; Visko Plus 319. Mean osmolarities of the hydroxypropyl methylcellulose viscoeslatic substances were Adatocel 278; HPMC Ophtal L 358; HPMC Ophtal H 360; La Gel 317; OcuCoat 309; Visco Shield 376. CONCLUSIONS: There were significant differences in osmolality among viscoelastic substances, which may explain the differences in corneal thickness after cataract surgery. A viscoelastic substance with an osmolality of 305 mOsmol/kg or slightly higher is preferable, especially in patients with a compromised corneal endothelium.

Implantation of the modified endocapsular bending ring in pediatric cataract surgery using a viscoadaptive viscoelastic agent.

Cataract surgery and intraocular lens (IOL) implantation in pediatric eyes remain controversial. Using a viscoadaptive viscoelastic agent, we implanted a modified capsular bending ring (CBR) as well as an acrylic IOL with a sharp-optic-edge design in the capsular bag. All operated eyes demonstrated a low postoperative inflammatory reaction and a clinically well-centered IOL. The band-shaped, sharp-edged CBR facilitates the creation of a sharp, discontinuous bend in the equatorial capsule, which prevents anterior and posterior capsule opacification. Combining the viscoadaptive viscoelastic agent and the CBR enhances the safety of primary and secondary posterior chamber IOL implantation in pediatric cataract surgery, reduces capsule opacification, and may facilitate IOL exchange.

Implantation of a toric poly(methyl methacrylate) intraocular lens to correct high astigmatism.

A 57-year-old man experienced a decrease in visual function because of cataract formation. Corneal astigmatism was 13.4 diopters (D) because he had had a penetrating keratoplasty 27 years before. Cataract surgery was planned, and biometric data for toric intraocular lens (IOL) implantation were collected for the manufacture of a custom IOL. After phacoemulsification, a toric poly(methyl methacrylate) (PMMA) IOL of +19.0 D spherical and +12.0 D cylindrical power was implanted via a sclerocorneal tunnel incision. Three months postoperatively, corneal astigmatism was 14.3 D and best corrected visual acuity (BCVA), 20/25. Postoperative refraction (+1.5 -3.0 x 90) and BCVA remained stable for 7 months. No significant IOL rotation was observed. Implantation of a toric PMMA IOL corrected high corneal astigmatism. Toric IOL technology with high cylindrical power allows enhancement of IOL surgery.