[Marginal protection of retinal cells by bisperoxovanadium : Appropriate therapy in the model of retinal ischemia?]

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.

Lidocaine-Assisted Xylocaine Jelly Anesthesia versus one Quadrant Sub-Tenon Infiltration for Self-Sealing Sclerocorneal Incision Routine Phacoemulsification

Purpose

To compare the effect of Xylocaine jelly and intracameral lidocaine with one quadrant instant sub-Tenon infiltration for self-sealing sclerocorneal phacoemulsification.

METHODS

One hundred patients were enrolled into a prospective randomized study, receiving either a combination of topical 2% Xylocaine jelly and 0.5 ml of intracameral 1% lidocaine or sub-Tenon infiltration with 2 ml of 2% Xylocaine on the operating table. All patients underwent a standard divide and conquer phacoemulsification procedure through a superior sclerocorneal frown incision followed by implantation of a polymethylmethacrylate intraocular lens. Intraoperative pain was indicated by the patient by squeezing the bedside nurse's hand, who allocated it to particular stages of surgery on a chart. After surgery, patients assessed the pain experienced using a 10-unit visual analogue scale.

Results

Pain was indicated on 31 occasions during the operation in the sub-Tenon group (mainly the injection itself) and 67 times in the topical group. The median overall subjective pain score was 3 in the jelly group and 0 in the sub-Tenon. Five eyes (10%) had to be converted to sub-Tenon during the surgery because of intolerable pain.

CONCLUSIONS

Whereas lidocaine supported Xylocaine jelly anesthesia provided acceptable analgesia for 90% of patients operated, sub-Tenon anesthesia proved to deliver better intraoperative comfort in all patients receiving sclerocorneal incision cataract surgery.

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.

[New Developments in Cataract Surgery]

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.

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 + Fc_γ-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.

[Unusual masquerade of an ocular carcinoma metastasis]

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.

Komplikationen nach Laser-in-Situ-Keratomileusis (LASIK): Ergebnisse einer Metaanalyse zu Inzidenzen und Folgekosten

PURPOSE

Laser in situ Keratomileusis (LASIK) is considered to be safe and effective for the treatment of moderate myopia. Nevertheless, the treatment can result in complications, associated with additional costs for treatment of the latter and an associated reduction of the primary treatment's overall cost efficiency.

METHODS

To both identify clinically relevant LASIK-associated complications and to estimate their expectable incidence and treatment cost-profile, a quantitative meta-analysis of trial publications between 1995 - 2004 was implemented. Inclusion criteria were a minimum sample size of 25 eyes, a reported preoperative patient refraction between - 1 und - 14 dioptres and the documentation of an at least 6 months recall period. For each reported complication its "meta incidence" (point estimate and 95 % confidence interval) was estimated. Furthermore, for each complication a clinical pathway for its treatment was modelled assuming a worst case scenario; the treatment costs for this pathway were simulated. The resulting costs for the treatment of one complication were then averaged by the expectable incidence of the respective complication; the maximum "expectable" costs for the respective complication's treatment were then summed up to correct the overall LASIK direct costs.

RESULTS

A total of 30 trial reports was included into the meta-analysis; in total, 21 clinically relevant complications were identified (31 % intraoperative complications, among which 19 % were microkeratome-associated, versus 69 % postoperative complications, among which 87 % were classified as long-term postoperative). The most frequent complication was "light sensations" with a meta incidence of 46 % (95 % confidence interval 42 - 50 %), the most cost intensive complications were those requiring clinical re-treatment (overall meta incidence 24 % and expectable cost increase of 449 euro per primary LASIK procedure). In summary the total direct costs of 2426 euro per eye for the initial LASIK procedure may be increased by a total of maximum 648.30 euro, according to a maximum "expectable" cost increase of 27 % per primary LASIK due to complications.

CONCLUSION

At least the worst case scenario introduced into this investigation demonstrated an economically relevant order for the expectable LASIK complications and the associated additional costs for complication treatment.

[Cataract surgery in childhood uveitis]

The development of cataract is the most frequent vision-threatening complication of uveitis in children. In such cases cataract surgery is associated with a particular risk of intra- and postoperative complications and requires an intensive perioperative immunosuppression, an essentially atraumatic operation in a quiscient eye, and aggressive amblyopia treatment. When these factors are taken into consideration, a timely cataract operation can result in a sustained visual rehabilitation even for children with uveitis.

[Incremental cost effectiveness of multifocal cataract surgery]

PURPOSE

Supplementation of cataract patients with multifocal intraocular lenses involves an additional financial investment when compared to the corresponding monofocal supplementation, which usually is not funded by German health care insurers. In the context of recent resource allocation discussions, however, the cost effectiveness of multifocal cataract surgery could become an important rationale. Therefore an evidence-based estimation of its cost effectiveness was carried out.

METHODS

Three independent meta-analyses were implemented to estimate the gain in uncorrected near visual acuity and best corrected visual acuity (vision lines) as well as the predictability (fraction of patients without need for reading aids) of multifocal supplementation. Study reports published between 1995 and 2004 (English or German language) were screened for appropriate key words. Meta effects in visual gain and predictability were estimated by means and standard deviations of the reported effect measures. Cost data were estimated by German DRG rates and individual lens costs; the cost effectiveness of multifocal cataract surgery was then computed in terms of its marginal cost effectiveness ratio (MCER) for each clinical benefit endpoint; the incremental costs of multifocal versus monofocal cataract surgery were further estimated by means of their respective incremental cost effectiveness ratio (ICER). An independent meta-analysis estimated the complication profiles to be expected after monofocal and multifocal cataract surgery in order to evaluate expectable complication-associated additional costs of both procedures; the marginal and incremental cost effectiveness estimates were adjusted accordingly. A sensitivity analysis comprised cost variations of +/- 10 % and utility variations alongside the meta effect estimate's 95 % confidence intervals.

RESULTS

Total direct costs from the health care insurer's perspective were estimated 3363 euro, associated with a visual meta benefit in best corrected visual acuity and near visual acuity of 5.1 lines (95 % confidence interval 3.8 - 6.4 lines) and 6.1 lines (4.7 - 7.5 lines), respectively, and a meta predictability estimate of 81 % (72 - 89 %). The mean MCER for best corrected visual acuity results became 659 euro per gained visual acuity line (sensitivity range 473 - 973 euro). For near visual acuity, a mean MCER of 555 euro (sensitivity range 404 - 787 euro) per gained visual line was found. In terms of incremental costs, multifocal cataract surgery implied an additional mean investment of 63 euro (sensitivity range 0 - 234 euro) per additionally gained near visual acuity line, and 5 euro (0 - 18 euro) per additionally gained percentage point in predictability, when compared to monofocal cataract surgery as the standard treatment. The meta-analysis on complication profiles revealed posterior capsule opacification (meta incidence 20 %) and vitreous loss (meta incidence 2 %) as the complications to be expected most frequently. The cost adjustment for expectable complication patterns after multifocal cataract surgery implied total direct costs of 3491 euro, resulting in marginal costs of 576 euro per line (sensitivity range 419 - 817 euro per line) gained in near visual acuity and 684 euro per line (491 - 1011 euro per line) gained in best corrected visual acuity.

CONCLUSION

Bearing incremental costs of 63 euro per additionally gained vision line (near visual acuity) in mind, multifocal cataract surgery comprises a cost effective alternative to the monofocal standard treatment.

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.

Ausgleich des kornealen Astigmatismus mit torischer Intraokularlinse: Ergebnisse der Multicenterstudie

This clinical trial was conducted to evaluate visual acuity, refraction and rotation after implantation of the foldable toric intraocular lens (IOL) MicroSil Toric.

PATIENTS AND METHODS

68 eyes of 48 patients from four different surgical departments were examined over a follow-up of three months after cataract surgery.

RESULTS

An individually produced IOL with cylindrical correction between 2.0 and 12.0 D was implanted in all eyes. Postoperatively, 68 % of the eyes achieved an uncorrected visual acuity (VA) of 0.5 or better, 12 % achieved 1.0 or better. A corrected VA of 0.5 or better was achieved by 85 %, 31 % achieved a corrected VA of 1.0 or better. Corrected VA improved by 3 (+/- 2) lines. The uncorrected VA improved by 6.0 lines in the mean. The increases in uncorrected and corrected VA were statistically significant (p < 0.001). The efficacy index amounted to 1.1 in the median and 1.3 (+/- 1.5) in the mean. Residual refraction (spherical equivalent) was 0.89 D (+/- 0.7 D) in the mean and was reduced by 5.14 D (+/- 4.78 D) in the mean. The total astigmatic error was reduced both in a statistically as well as in a clinically significant manner from 4.6 D (+/- 2.3 D) to 1.12 D (+/- 0.9 D) in the mean. 75 % of eyes needed a postoperative cylindrical correction of less than 1.5 D, 95 % less than 2.25 D. Corneal astigmatism was not changed significantly (p = 0,435). The surgically induced astigmatism (Naeser) amounted to 0.7 D in the median. In 85 % of the cases IOL rotation was less than 5 degrees. 15 % of the IOLs rotated more than 5 degrees, one IOL more than 10 degrees (max. 28 degrees). Patients ranked their surgical outcome on a scale from 1 (very good) to 6 (poor) which resulted in a mean score of 1.9 (+/- 1.0; min. 1.0; max. 5.0). No clinically relevant correlations of clinical parameters and satisfaction were detected.

CONCLUSION

Implantation of the foldable, toric IOL with Z-haptics decreased the refractive error and improved postoperative visual outcome. This IOL was suitable for low as well as for high astigmatism. IOL rotation was low during the follow-up of three months resulting in sufficient correction of the pre-existing astigmatism.

Rotationsstabilität monofokaler Intraokularlinsen mit C-Haptik versus Z-Haptik nach Kataraktchirurgie

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.

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.

[Mitomycin C in refractive corneal surface surgery with the excimer laser: first experience and review of the literature]

Haze formation with loss of corneal transparency and surface irregularities and myopic regression are the major complications after corneal refractive surface surgery. The use of mitomycin C (MMC) with its antibiotic and antineoplastic properties is intended to inhibit wound healing mechanisms leading to subepithelial fibrosis. We report the use of MMC to achieve visual rehabilitation in the re-treatment of 3 eyes of 2 patients following refractive corneal surgery. According to the literature, the local use of MMC 0.02 % for 2 minutes is safe and enables one to treat and prevent stromal haze and myopic regression and allows a reduction of the postoperative topical pharmacotherapy. Results are still limited due to small case numbers and short follow-up periods.

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.

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.

Mikrobielle Keratitis nach Laser-in-situ-Keratomileusis

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.

[Laser in situ keratomileusis (LASIK) and scanning laser ophthalmoscopy]

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.

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.

Visusverlauf, Lebensqualit�t und subjektive Zufriedenheit von AMD-Patienten nach Abschluss einer PDT-Behandlung

BACKGROUND

The efficacy of PDT to prevent the progression of AMD has been established. This study now assesses the patients' quality of life and self-reported satisfaction after PDT.

MATERIAL AND METHODS

All patients who underwent PDT during 2000 and 2001 at the University Eye Hospital of Mainz were interviewed using an AMD-specific modification of a standardized 82-item questionnaire on quality of life and satisfaction in ophthalmological patients. Different aspects of those parameters were derived as scores, which were then related to clinical outcome parameters.

RESULTS

During the period of PDT treatment, the median decrease in visual acuity was three stages in the patients examined. Patients who reported a subjective increase in visual function during this period showed for example a median "private flexibility" score of 1.86, and patients with the subjective impression of a decrease in visual function a median score of 2.71.

CONCLUSION

The established clinical efficacy of PDT treatment to prevent AMD progression coincides with an encouraging patient satisfaction after the treatment.

Disease-specific assessment of quality of life after decompression surgery for Graves' ophthalmopathy

PURPOSE

Graves' ophthalmopathy (GO) is an organ-specific autoimmune disease. Hydrophily of accumulated acidic mucopolysaccharides into bulbar adipose tissue leads to swelling of the eye muscles. Orbital surgical decompression is performed in severe cases of compressive optic neuropathy and severe corneal exposure or failure of steroid therapy. The study was designed to evaluate decompression surgery with respect to the clinical benefit and the patient's satisfaction by means of a disease-specific questionnaire.

METHODS

The 90-item study questionnaire was distributed to 105 patients with GO who underwent orbital decompression surgery at the authors' institution.

RESULTS

A total of 88% of patients stated that decompression had helped them, 80% of the interviewees would undergo decompression again, 78% were content with their eye symptoms, and 71% were satisfied with the cosmetic result of decompression. Furthermore, analysis showed a clinically relevant increase in quality of life after surgery. The correlation between the clinical endpoint proptosis at last examination and the quality of life score proved to be significant (p=0.05).

CONCLUSIONS

The large majority of interviewees were satisfied with the result of the orbital decompression. These results confirmed that disfiguring proptosis is an important indication for decompression surgery.

Phake Intraokularlinsen

Phakic intraocular lenses (PIOLs), which are located closer to the eye's nodal points than the anterior corneal surface, can provide superior optical quality for higher corrections because of retention of normal prolate corneal asphericity and larger effective optical zones. Improvements in the material and design of phakic intraocular lenses and their insertion devices combined with advances in the understanding of the anatomical and physiological interactions of the PIOLs with intraocular structures, have increased safety and efficacy. Safety of these implants over the long term remains a concern, but in several situations PIOLs are the refractive correction of choice. The purpose of this review is to compare the different types of PIOLs regarding outcome and complications. Improvements in imaging technologies should improve the accuracy of ICL sizing and allow more precise prediction of effective lens position with more accurate power calculation. It is important to inform patients that phakic lens surgery only corrects the refractive aspect, and that the refractive error itself as well as the changes by surgery still has the potential for serious complications.

Lebensqualit�t und Patientenzufriedenheit nach Kataraktchirurgie

BACKGROUND

Assessment of patient satisfaction and quality of life becomes increasingly important for the overall evaluation of therapy regimes. However, it is not certain whether standard quality of life questionnaires suffice to assess immediate changes in patient conditions such as induced by cataract surgery.

METHODS

The increase in visual acuity was observed in 152 cataract patients as an objective efficacy parameter. In addition, subjective patient satisfaction and quality of life was obtained from these patients by means of a cataract-specific questionnaire 1 day before and 4 weeks after surgery. The questionnaire concentrates on the patients' overall flexibility and mobility, their estimation of medical and nursing care, changes in ophthalmological conditions and on complications after surgery.

RESULTS

With an internal consistency of 82% the instrument can be regarded as moderately reliable but self-reported quality of life before surgery was found to be remarkably biased. None of the above quality of life determinants showed a clinically relevant correlation with the objective increase in visual acuity (absolute correlations <20%). Significant impact factors for overall quality of life satisfaction were the patients' overall flexibility ( p=0.049) and their estimation of medical and nursing care ( p=0.027).

CONCLUSIONS

Standard quality of life determinants provide independent subjective information in addition to the increase in visual acuity as an objective measure of clinical outcome. Overall assessment of patient satisfaction cannot be regarded as sufficient for the subjective evaluation of cataract surgery, since its estimation primarily depends on the patients' appreciation of medical and nursing care. An appropriately extensive means of quality of life assessment seems necessary and post-surgical data seems sufficient for the estimation of subjective therapy outcome measures in cataract patients.

[Complications of foldable intraocular lenses requiring explantation. Results of the 2000 and 2001 survey in Germany]

PURPOSE

A survey was sent to all members of the German Society of Ophthalmic Surgeons to evaluate complications that required explantation of foldable intraocular lenses (IOLs).

METHODS

Data on preoperative visual acuity, foldable IOL design and material, and the reason for explantation were obtained and analysed. We received 185 surveys for 2000 and 2001.

RESULTS

In 2000 and 2001, the most common reasons for IOL explantation were: incorrect lens power (31%) and dislocation (19%) in three-piece acrylic IOLs, incorrect power (31%) and decentration (17%) in monofocal silicone IOLs, and opacification (46%) in hydrophilic IOLs. The most common reasons for the exchange of monofocal IOLs were lens opacification in 2000 and incorrect IOL power in 2001.

CONCLUSION

Besides the most frequent complications of decentration and incorrect power observed in rigid IOLs,new complications associated with foldable IOLs occurred (e.g., optic opacification and calcification). Accurate calculation of IOL power and further improvements in material and design are still necessary to minimize the rate of explantations.

[Is a cataract avoidable? Current status with special emphasis on the pathophysiology of oxidative lens damage, nutritional factors, and the ARED study]

The benefit of long-term nutrient intake to reduce the risk of age-related ocular disease such as cataract or macular degeneration is subject to controversy. Conclusions about the benefits and risks of antioxidant supplements can be expected after reviewing the current literature concerning oxidative-induced lens damage and nutritional effects. Identification of influenceable risk factors for senile cataracts could achieve immense economical relevance. In contrast to former longitudinal epidemiological studies, the AREDS report failed to verify protective properties of highly concentrated vitamin supplements on cataract formation. Although there are enough epidemiological indications for reducing the risk of cataracts by the intake of antioxidants, a general recommendation for the use of supplements is untimely or even wrong until stringent evidence of efficacy is provided. The usefulness of cataract prevention is discussed.

[Dynamic aberrometry during accommodation of phakic eyes and eyes with potentially accommodative intraocular lenses]

Since the introduction of potentially accommodative intraocular lenses (IOLs), it was hard to perform an objective evaluation of the accommodative amplitude in pseudophakic eyes. Laser interferometric measurements were performed to evaluate anterior chamber depth changes, which provides information on the functionality of potentially accommodative IOLs. By means of wavefront analysis, the dynamic behaviour of potentially accommodative IOLs can be determined. All measurements in this study were performed using a Hartmann-Shack aberrometer at a frequency of 7 Hz. Six to 8 weeks after implantation of potentially accommodative IOLs (CrystaLens AT-45, C&C Vision, 1CU, Humanoptics), 43 eyes were investigated using this dynamic wavefront analysis. Patients focussed at a distance target for 10 s, followed by focussing at a near target for 10 s and then again at a distance target for a further 10 s. During these 30 s, a total of 200 single measurements were performed. The same measurements were also conducted in healthy eyes of young persons as well as in eyes after implantation of standard IOLs for comparative purposes. The dynamic course of changes in low-order aberrations (defocus, astigmatism) as well as high-order (e.g., fourth-order spherical aberration) were analysed. Dynamic wavefront analysis allowed objective and observer-independent measurement of changes in accommodation in phakic and pseudophakic eyes. Dynamic aberrometry is capable of objectively quantifying the effect of any surgical option for the treatment of presbyopia. We recommend use of this technology in addition to the common psychophysical examinations to attain objective information on the efficacy of the treatment modality used.

Changes in the tear proteins of diabetic patients

BACKGROUND

Previous studies have shown a significant increase in tear protein peaks in the tears of diabetic patients suffering from dry eye. The aim of this study was to analyze the tear protein patterns from patients with diabetes mellitus who do not suffer from ocular surface diseases (DIA).

METHODS

A total of 515 patients were examined in this study (255 healthy subjects (controls) and 260 patients suffering from diabetes mellitus). Tear proteins were separated by sodium-dodecyl-sulfate polyacrylamide gel electrophoresis. After digital image analysis densitometric data files were created and subsequently used for multivariate statistical procedures.

RESULTS

A significant increase in the number of peaks was detected in diabetic patients compared to controls (P < 0.0003). The analysis of discriminance revealed a highly significant discrimination between diabetic patients and controls (Wilks lambda: 0.27; P < 0.000001). Furthermore, a significant difference in the protein pattern of diabetic patients could be detected between those suffering from dry eye or not (P < 0.002). The changes in protein patterns of diabetic patients increased with the duration of the diabetic disease. In diabetic patients with a disease duration longer than 10 years the changes were significantly more expressed than in patients with a shorter diabetic history (P < 0.003) and in healthy subjects (P < 0.0001).

CONCLUSIONS

The tear protein patterns of diabetic patients are very different in the number and intensity of spots from those of healthy subjects. Furthermore, it could be demonstrated that the differences found in the tear patterns of diabetic patients are not equal to those found in previous studies in patients suffering from dry-eye disease. The alterations in the diabetic tears were correlated with the duration of the diabetic disease. With longer disease, history changes in the tear protein patterns increased. With the course of the disease some protein peaks appeared that are not present in healthy persons. Our study shows that the analysis of electrophoretic tear protein patterns is a new non-invasive approach in the early diagnosis and analysis of the pathogenesis of diabetes induced ocular surface disease.

[Striae in the flap after laser in situ keratomileusis. Etiology, diagnosis and treatment]

OBJECTIVE

Laser in situ keratomileusis (LASIK) has become the leading refractive option to correct myopia, hyperopia and astigmatism. In addition to the relative rapid visual recovery and the lack of postoperative pain, new flap-related complications are being added. The formation of striae can lead to a significant loss of corrected visual acuity if the central pupil zone is affected. Awareness of possible complications is important not only for the surgeon, but also for the ophthalmologist in practice for a rapid diagnosis and prompt management.

CLINICAL COURSE AND THERAPY

Striae have a variety of appearances and are caused by misalignment/displacement of the corneal flap after replacement or are results of a slippage effect of the flap over the stromal bed after LASIK. Symptomatic striae ideally are treated on the first or second day after surgery by refloating the flap, irrigation with balanced salt solution or hypotonic saline solution, stroking and stretching the surface with moist and dry sponges. In more severe cases scraping away the epithelium and antitorque or interrupted sutures can be performed to treat persistent striae.

CONCLUSION

Symptomatic deep striae should be diagnosed early and managed promptly within the first days. Any later intervention decreases the chance of successful elimination and visual outcome. Hints to prevent the development of striae formation are provided.

[Complications with foldable intraocular lenses with subsequent explantation in 1998 and 1999. Results of a questionnaire evaluation]

PURPOSE

A questionnaire was sent to all members of the German Society of Ophthalmic Surgeons to evaluate complications of foldable intraocular lenses (IOLs) that required explanation.

METHODS

Information on preoperative visual acuity, foldable IOL design and material as well as the reason for IOL explantation was obtained and analysed. We received 167 completed questionnaires for 1998 and 1999.

RESULTS

In 1998 and 1999 the most common reasons for IOL explantation were as follows: incorrect lens power for 56% of the 3-piece hydrophobic acrylic IOLs, 16% because of glare or other photic phenomena, 40% of the 1-piece hydrophilic acrylic IOLs were explanted because of incorrect lens power and 30% for IOL damage. For the 3-piece monofocal silicone IOLs, 41% were explanted because of incorrect IOL power and 32% because of IOL decentration. For the 1-piece Hydrogel IOL, 76% were explanted because of opacification of the optic and 14% because of incorrect lens power. Most multifocal IOLs were explanted because of photic phenomena.

CONCLUSION

In addition to the most common complications such as decentration and incorrect IOL power observed in rigid IOLs, new complications associated with foldable IOLs occurred such as optic opacification, glare and photic phenomena. Some complications seemed to appear in particular IOL types (opacification: SC-60BOUV, MDR), while others were observed in all types of foldable lenses. Accurate calculation of the IOL power and further improvement of the IOL material and design seem to be necessary to minimise the rate of explantations.

Correlation of blood-glucose control with oxidative metabolites in plasma and vitreous body of diabetic patients

PURPOSE

In diabetes hyperglycemia and other mechanisms lead to the production of oxidative metabolites that can enhance the production of growth factors, leading to increased proliferative activity. Strict blood-glucose control reduces the progression of retinopathy better than standard control. This study investigated patients with diabetic retinopathy for evidence of oxidative metabolites in plasma and the vitreous body, correlating these values with blood-glucose control.

METHODS

The study comprised 136 patients suffering from proliferative diabetic retinopathy. They were grouped according to their mean glycosylated hemoglobin value for the last 9-12 months. Patients with values < or = 10% (mean 8.7%; n=64) were considered strict glucose control patients, those with values > 10% (mean 12.8%; n=72) were considered standard glucose control patients. Lipid peroxides were determined in blood plasma and the vitreous body by two methods (thiobarbituric acid reactive substances and malondialdehyde-like substances). If present, retinal traction with fibrovascular proliferations (>2 disk areas) was quantified and served as an indicator of proliferative activity.

RESULTS

Patients with strict blood-glucose control had significantly (p < 0.01) lower lipid peroxide values in plasma and the vitreous body than standard glucose control patients. These latter had significantly (p<0.01) higher rate of fibrovascular proliferation (50%) than strict glucose control patients (9. 7%).

DISCUSSION

Strict blood-glucose control leads to reduced oxidative tissue damage both systemically and locally in the eye, and reduced proliferative activity. Oxidative metabolites can stimulate proliferation by increasing the amounts of different growth factors an cytokines such as vascular endothelial growth factor. Thus, it can be speculated that in hyperglycemia the relative increase of oxidative metabolites contributes both to damage of retinal vessels and to more pronounced proliferative activity in diabetic retinopathy.