[Influence of Different Ablation Frequencies on the Clinical Results of Photorefractive Keratectomy Using the Same Excimer Laser Platform: A Contralateral Eye Study]. / Einfluss unterschiedlicher Ablationsfrequenzen auf die klinischen Ergebnisse bei photorefraktiver Keratektomie unter Verwendung derselben Excimer-Laser-Plattform: Ein kontralateraler Vergleich.

Background The objective of this study was to evaluate postoperative clinical outcomes of photorefractive keratectomy (PRK) using different ablation frequencies. Patients and Methods In this prospective, contralateral eye study, 56 eyes of 28 patients with myopia or myopic astigmatism were included. PRK was performed using the MEL90 excimer laser system (Carl Zeiss Meditec, Germany). One eye of each patient was treated with a repetition rate of 250 Hz, while the other one was treated with a repetition rate of 500 Hz. The treatment pattern in the 250 Hz and 500 Hz group only differed in terms of ablation frequency; there was no difference in laser pulse energy, spot size or ablation profile. Postoperative follow-ups were at 3 and 7 days and 1, 3 and 6 months. The following parameters were assessed: Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), higher-order aberrations (HOAs), corneal re-epithelisation time and corneal haze. Results Ablation depth was proportional to laser pulse counts at both frequencies. At 6 months, 100.0% of the eyes in the 250 Hz group and 96.4% in the 500 Hz group had a UDVA of 0.00 logMAR or better; 100% of the eyes in both groups were within ± 1.00D of the attempted correction. All eyes had a postoperative CDVA of 0.00 logMAR or better. There was no difference between the groups in postoperative HOAs, corneal re-epithelisation time or corneal haze. Conclusions Photorefractive keratectomy with a repetition rate of 250 Hz and 500 Hz showed comparable efficacy, safety and predictability in the correction of myopia. There were no significant complications due to the high repetition rate, such as postsurgical corneal haze.

[Postoperative Results after Implantation of a Toric, Aspheric Intraocular Lens]. / Postoperative Ergebnisse nach Implantation einer torischen, asphärischen Intraokularlinse.

PURPOSE: The purpose of this study was to evaluate the functional results and quality of vision after implantation of an aspheric, aberration-neutral, monofocal toric intraocular lens (IOL). PATIENTS AND METHODS: 18 eyes of 13 patients were enrolled in this prospective clinical study. The T-flex aspheric, aberration-free toric IOL (Rayner Intraocular Lenses Limited, U. K.) was implanted after femtosecond or standard phacoemulsification. Follow-up examinations were performed two to four months after surgery; these included subjective refraction, ETDRS uncorrected (UDVA) and corrected distance visual acuity (CDVA), wavefront analysis, measurements of stray light (C-Quant), and a questionnaire. RESULTS: Median UDVA was 0.06 logMAR (range: 0.30 to - 0.18 logMAR) postoperatively. Median CDVA increased from 0.20 logMAR (range: 0.64 to 0.00 logMAR) preoperatively to - 0.07 logMAR (range: 0.16 to - 0.26 logMAR) postoperatively. The median difference between achieved versus intended spherical equivalent was - 0.08 D (range: - 1.25 to + 0.65 D). Median subjective cylinder improved from - 2.00 D (range: - 6.50 to - 0.25 D) preoperatively to - 0.50 D (range: - 1.25 to 0.00 D) postoperatively. The median spherical aberrations (6 mm pupil size) were - 0.38 µm (range: - 0.69 to - 0.10 µm) postoperatively. Measurements of stray light (C-Quant) revealed a median value of 1.28 log(s) (range: 0.92 to 1.61 log[s]). CONCLUSION: The T-flex aspheric toric IOL provided beneficial and predictable functional results after surgery. The implantation of the T-flex is an effective method to correct a large range of corneal astigmatism.

[Functional results after implantation of an aspheric, aberration-neutral intraocular lens]. / Funktionelle Ergebnisse nach Implantation einer asphärischen, aberrationsneutralen Intraokularlinse.

PURPOSE: The aim of this study was to perform a clinical evaluation of the functional results and quality of vision after implantation of an aspheric, aberration-neutral, monofocal intraocular lens (IOL). PATIENTS AND METHODS: 47 eyes of 34 patients (median age: 68 years) with cataract were enrolled in this prospective clinical study that had Ethics Committee approval. The C-flex or Superflex aspheric IOL (Rayner, UK) was implanted after phacoemulsification. Follow-up examinations were performed two to four months after surgery including subjective refraction, ETDRS uncorrected (UDVA) and corrected distance visual acuity (CDVA), wavefront analysis, analysis of stray light (C-Quant), contrast sensitivity under different lighting conditions (F. A. C. T.) and a questionnaire. RESULTS: Two to four months after surgery, median UDVA was 0.08 logMAR (range: 0.64 to - 0.18 logMAR, n = 41). Median CDVA increased from 0.30 logMAR (range: 1.00 to - 0.02 logMAR) preoperatively to - 0.08 logMAR (range: 0.16 to - 0.22 logMAR) postoperatively (n = 47). Median difference between achieved vs. intended (Holladay 1-formula) spherical equivalent was + 0.06 D (range: - 1.06 to + 0.87 D). Median total HOA RMS (6 mm pupil size) was 0.66 µm (range: 0.41 to 1.19 µm). The median spherical aberrations were - 0.36 µm (range: - 0.70 to - 0.17 µm). Analysis of stray light (C-Quant) revealed a median value of 1.21 log(s) (range: 0.79 to 1.57 log[s]). CONCLUSION: The C-flex and Superflex aspheric IOLs provide good and predictable functional results. Patients are not negatively influenced by stray light and show slightly negative spherical aberrations.

[Exchange of aniridia IOLs for customized iris IOL implants]. / Austausch von Aniridie-IOL gegen individuelle Iris-IOL-Implantate.

BACKGROUND: Three groups of iris prostheses can be distinguished for the surgical treatment of iris defects: (1) segmental iris implants, (2) combined iris diaphragm intraocular lenses (IOL) and (3) pure iris implants. Most iris reconstructions are accompanied by aphakia correction with secondary IOL implantation. Although the primary goal is to create a pupil and to improve glare perception, contrast sensitivity and visual acuity, the esthetic result is also a relevant component. OBJECTIVE: Functional and esthetic results after replacement of an aniridia IOL implant with a custom-made artificial iris with IOL. MATERIAL AND METHODS: In this retrospective study with seven eyes from seven patients, an iris diaphragm IOL (Morcher GmbH, Stuttgart, Germany) was exchanged for medical reasons (subluxation) against a custom-made artificial iris made of silicone (ArtificialIris, HumanOptics, Erlangen, Germany) in combination with a sutured IOL. The follow-up period was at least 3 months. Best corrected distance visual acuity (BCVA), endothelial cell count (ECC), complications, glare perception as well as esthetic outcome and patient satisfaction were evaluated. RESULTS: The BCVA and ECC showed no statistically significant change between the preoperative and postoperative values (p > 0.05). There was a decentration of the iris IOL implant of 0.27 ± 0.19 mm three months postoperatively. On a visual analogue scale (VAS) from 1 to 10 (1 = not satisfied at all, 10 = extremely satisfied), satisfaction with the overall result was rated 8.6 ± 2.5. Subjective glare perception improved to 5.6 ± 3.5 and subjective esthetic impairment improved to 2.4 ± 2.0 on the VAS (1 = none, 10 = extremely strong). Postoperative complications included transient intraocular hypotonia in two eyes, intraocular pressure increase in two eyes, retinal detachment and transient vitreous hemorrhage in one eye each. Of the seven patients six would repeat the procedure. CONCLUSION: Compared to a rigid aniridia IOL implant, replacement with a custom-made artificial iris in combination with an IOL provides not only a good functional result but simultaneously also an esthetically pleasing result.

[Keratectasia after refractive surgery]. / Keratektasie nach refraktiver Chirurgie.

BACKGROUND: Refractive surgery has become more and more popular in the past years. One of the most severe complications is iatrogenic keratectasia. The purpose of this article is to review the current knowledge about iatrogenic keratectasia. METHOD. A literature research (Medline) using the key words keratectasia, complication after refractive surgery and cross-linking was carried out. Apart from this, our own data from partially unpublished studies have been used. RESULTS: Since the first publication of keratectasia in 1998 more and more cases of keratectasia have been published. The main risk factor is a preoperative irregular topography. But also thin corneas, deep ablations, thin residual stromal beds and young patients age at the time of the laser surgery are further risk factors. DISCUSSION: Although preoperative examinations before refractive surgery are becoming more and more accurate and the inclusion criteria for laser ablation have become stricter, iatrogenic keratectasia still occurs. Therefore longer follow-up visits should be performed over a longer period to diagnose keratectasia in an early stage and to provide therapy.

[Epi-LASIK with a 1000 hertz excimer laser]. / EpiLASIK mit einem 1000 Hertz Excimer-Laser.

PURPOSE: The aim of this study was to evaluate the safety, stability and efficacy of Epi-LASIK with a 1000 hertz excimer laser system. METHODS: 40 eyes of 23 patients underwent an Epi-LASIK procedure using the Gebauer EpiLift and the WaveLight Concept System 1000. Preoperatively as well as 1 month, and 3 months postoperatively, a complete ophthalmic examination, including objective and subjective refraction (UCVA, BCVA) and topography, was performed. RESULTS: The mean preoperative spherical equivalent (SE) was -4.07 D (SD ± 1.89 D). 1 month after surgery, the spherical equivalent was + 0.01 D (SD ± 0.33 D), and 3 months after surgery -0.06 D (SD ± 0.28 D). 3 months after the Epi-LASIK procedure, 90 % of the patients were within ± 0.5 D of the intended correction, and 97.5 % were within ± 1.0 D of the intended correction. The astigmatism was reduced from -0.77 D (SD ± 0.68 D) to -0.24 D (SD ± 0.29 D) 3 months after surgery. 34 of the 40 eyes had a clear cornea 3 months after surgery, and 6 of the 40 eyes presented with haze grade 0.5. CONCLUSIONS: In our pilot series of 40 eyes, the use of the 1000 hertz excimer laser did not reveal any specific clinical side effects potentially associated with the use of a high repetition rate. These first results with Epi-LASIK and the WaveLight Concept System 1000 are very promising.

[Intraoperative OCT in retinal detachment with macular involvement]. / Intraoperative OCT bei Netzhautablösung mit Makulabeteiligung.

BACKGROUND: Intraoperative optical coherence tomography (iOCT) has recently been introduced for the visualization of retinal structures within the operating microscope. OBJECTIVE: The aim of this study was to analyze the behavior of the retina and morphological features during surgery for retinal detachment with macular involvement. METHODS: A retrospective analysis of 41 consecutive eyes with macula-off retinal detachment, which were treated with pars plana vitrectomy (PPV) using iOCT. A qualitative analysis of morphological features of the retina at defined moments during surgery was carried out. RESULTS: The visualization of macular detachment with iOCT was successful in 63% of cases and in the other cases the height of retinal detachment surpassed the maximum depth of the scan by iOCT. With perfluorodecalin 53.7% of eyes showed subretinal fluid and 22% of eyes showed a wave-like configuration of the outer retinal layers. In 61% of the eyes persisting subretinal fluid could be detected under the final tamponade. The amount of subretinal fluid could not be detected intraoperatively with the naked eye. In one case a macular hole could be newly identified intraoperatively and in three cases macular detachment could not be found at the start of surgery, although a detachment had been expected. CONCLUSION: The use of iOCT rarely leads to changes or extension of the intervention; however, it provides real-time information on intraretinal and subretinal fluid, which is sometimes in contrast to the clinical assessment. The relevance of persistent subretinal fluid and folds of the outer retinal layers after surgery remains unclear. It can be speculated whether this could serve as a prognostic factor for the postoperative outcome.

[Orbital firearm injuries]. / Orbitale Schussverletzungen.

BACKGROUND: Injuries caused by firearms are fortunately rare in the field of ophthalmology. The treatment of an affected patient is a special challenge both ophthalmologically and emotionally. METHODS: We report on seven consecutive cases of patients with an orbital gunshot injury who presented in a university hospital over a period of 11 years. The course of events leading to the injury with the weapon involved, the type of projectile, the injury pattern, cranial imaging, treatment and course were evaluated. RESULTS: A total of seven cases of injuries caused by firearms could be documented and evaluated in the period 2007-2018. All seven patients were male. The average age was 44 ± 27.5 years. Of the injuries five were caused by a suicide attempt and two by an accident. Firearms were used except for one injury caused by a crossbow. There was a retained projectile in four of the cases, the bullet went through the body in two cases and one of the cases presented with a ricochet shot. The final visual acuity was unilateral amaurosis in 1 case and bilateral amaurosis in another case, 1/35 (measured at 1 m) in 1 case, while it varied between 0.2 and 0.7 in the other 4 cases. No patient died as a direct consequence of the firearm injury. CONCLUSION: Injuries caused by firearms are relatively rare in Germany and mostly have a suicidal background. The pattern of the injury of the ocular structures is very variable. A reconstruction attempt is principally recommended. In the care of patients interdisciplinary cooperation between ophthalmologists and neurosurgeons, orofacial surgeons, ear nose and throat (ENT) surgeons and psychiatrists is necessary.

[Six-month clinical results with the light adjustable lens]. / Klinische 6-Monats-Ergebnisse einer Licht-adjustierbaren Linse.

PURPOSE: The aim of this study was to evaluate the six-month clinical results of the light adjustable lens (LAL). MATERIAL AND METHODS: In 20 eyes of 12 patients with cataract a cataract surgery with implantation of a light adjustable lens has been performed. 2 ¹/2 weeks after surgery all intraocular lens adjustments were carried out. Preoperatively, immediately before the adjustment procedures and 1 month, 3 and 6 months after the adjustment procedure a complete ophthalmic examination was performed. RESULTS: All cataract surgeries have been carried out without any complications. 2 ¹/2 weeks after surgery the mean spherical equivalent was + 0.39 D (standard deviation [SD] ± 0.79 D). 6 months after the adjustment procedure the spherical equivalent was -0.07 D (SD ± 0.25 D). 6 months after the adjustment procedure all patients were within ± 0.5 D of intended refraction. Two weeks after surgery the mean cylinder was -0.82 D (SD ± 0.67 D) and was reduced after the adjustments to -0.14 D (SD ± 0.30 D). DISCUSSION: The light adjustable lens is a new IOL with the ability to correct up to two dioptres of sphere and cylinder after implantation. Our clinical results are promising. Especially the astigmatic correction is very promising, but further clinical investigations with larger patient numbers and longer follow-up are necessary.

Comparison of different excimer laser ablation frequencies (50, 200, and 500 Hz).

PURPOSE: The aim of this study was to compare the influence of different excimer laser (193 nm) ablation frequencies (50, 200, and 500 Hz) on porcine cornea. METHODS: For this study, fresh porcine cadaver eyes were obtained from the butcher. PRK and LASIK were performed using a WaveLight Concept System 500 excimer laser. Various repetition rates (50, 200, and 500 Hz) and intended corrections (between -3 and -9 D) were used. Corneal endothelium was investigated pre- and post-operatively with the endothelial cell microscope EM 1000 Tomey. Post-operatively, the corneas were embedded for light microscopic (HE, Picrosirius Red) and electron microscopic evaluation. RESULTS: The mean pre-operative cell count was 2,953 (SD 149) and the mean post-operative cell count was 2,974 (SD 156). There was no difference between the pre- and post-operative cell count and the different ablation frequencies. The distribution of collagen fibers and keratocytes was comparable in all different ablation frequencies. Also, the ultrastructural evaluation of keratocytes and fibers, assessed with transmission electron microscopy, was equal in all three different ablation frequencies. CONCLUSIONS: The endothelial cell density and structural and ultra structural evaluation of the different ablation frequencies (50, 200, 500 Hz) showed no specific side-effects that could be associated with higher repetition rates. The quality of the ablation was comparable in all three different laser ablation frequencies. The 500-Hz excimer laser can provide the same ablation quality as slower platforms, but can also offer the advantage of requiring less treatment time than other laser platforms with lower repetition rates.

[Wavefront-guided and wavefront-optimised LASEK--comparison of clinical results]. / Wellenfrontgestützte und wellenfrontoptimierte LASEK--Vergleich der klinischen Ergebnisse.

PURPOSE: The aim of this study was to compare refractive outcomes and wavefront results in eyes undergoing wavefront-optimised and wavefront-guided LASEK. METHODS: In this contralateral eye study wavefront-guided LASEK and wavefront-optimised LASEK have been carried out on 30 eyes each. Preoperatively, 1 month, 3 months and 6 months after surgery a full ophthalmological examination was carried out. Preoperatively and 6 months postoperatively additional wavefront measurement have been carried out on all patients. RESULTS: The mean preoperative refraction in the wavefront-guided group was -4.41 D (SD 1.38 D) and in the wavefront-optimised group -4.62 D (SD 1.86 D). The postoperative refraction was very good in both groups (wavefront-guided -0.06 D, SD 0.18 D; wavefront-optimised -0.03 D, SD 0.21 D). In both groups RMS of higher orders were increased slightly (wavefront-guided from 0.26 to 0.31 microm, wavefront-optimised from 0.27 to 0.32 microm) and also spherical aberrations increased slightly (wavefront-guided from 0.18 to 0.23 microm, wavefront-optimised from 0.16 to 0.21 microm). CONCLUSIONS: The refractive results with the Concept System 500 in patients with preoperatively low amounts of higher order aberrations after wavefront-guided and wavefront-optimised LASEK are comparable. As good wavefront measurements need a lot of experience and take a lot of time, there is no advantage of wavefront-guided ablation in patients with low preoperative aberrations.

[Cut quality of a new femtosecond laser system]. / Schnittqualität eines neuen Femtosekundenlasers.

OBJECTIVE: The aim of this study was to evaluate the cut quality and the cellular damage when using a new 200 kHz femtosecond laser. METHODS: 20 porcine eyes and 3 human eyes, not suitable for transplantation, were used for this study. The WaveLight UltraFlap femtosecond laser was used for flap creation. The surface of the cornea, the structure and ultrastructure of the corneal cells and stroma were evaluated thoroughly using light microscopy (HE-, PAS- and Picrosirius red staining), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). RESULTS: In all eyes, the flap could be lifted very easily and the flap appeared very smooth. Structural and ultrastructural evaluation with light and transmission electron microscopy on epithelium and endothelium showed no side effects of the laser application. The area around the flap cut was minimally affected and the keratocytes and collagen fibres showed minimal alteration due to laser treatment. Scanning electron microscopy revealed in all cases smooth surfaces and precise sidecuts. CONCLUSIONS: Precise corneal flaps can easily be created with this new femtosecond laser. At the same time, no structural and thermal side effects on corneal epithelium, stroma and endothelium appeared. Hence with this new femtosecond laser corneal flaps could be created easily without noteworthy side effects.

[Opacification of hydrophilic intraocular lens after multiple injections of bevacizumab]. / Eintrübung einer hydrophilen Intraokularlinse nach multiplen Bevacizumab-Injektionen.

In the literature various causes of opacification of hydrophilic lenses have been described. Pronounced opacity is a complication that must be taken seriously because it can lead to explantation or exchange of the intraocular lens (IOL). The calcification of hydrophilic IOLs is often made responsible for an explantation. Despite the rapidly increasing number of intravitreal injections, they have so far not been associated with opacification of lenses. This article reports on a female patient where opacification of the hydrophilic lens was obviously associated with multiple intravitreal injections over several years. It involved a secondary calcification with calcium phosphate deposition directly under the surface of the IOL. Possible pathomechanisms are discussed. Due to the increasing number of intravitreal injections the association with IOL opacity should be further evaluated in the future. Generally, with hydrophilic lens materials it must be taken into consideration that these can become opaque following diverse interventions.

[Optical quality of three trifocal intraocular lens models : An optical bench comparison]. / Optische Qualität dreier trifokaler Intraokularlinsenmodelle : Vergleich an der optischen Bank.

BACKGROUND: Knowledge of the optical quality of different trifocal intraocular lenses (IOL) is important in customized patient care. OBJECTIVE: Different trifocal IOL were compared regarding their optical quality. MATERIALS AND METHODS: We analyzed the FineVision (PhysIOL, Liège, Belgium), the AT LISA tri 839MP (Zeiss, Oberkochen, Germany), and the AcrySofIQ PanOptix (Alcon, Fort Worth, TX, USA) with a power of +21D for the distance using the OptiSpheric IOL PRO optical bench (Trioptics, Wedel, Germany). The additions for the near and intermediate distances were as follows: +3.5D/+1.75D (FineVision), +3.33D/+1.66D (AT LISA tri), and + 3,25D/+ 2,17D (PanOptix). We evaluated the modulation transfer function (MTF) at a spatial frequency of 50lp/mm and the Strehl ratio using 3­ (photopic) and 4.5-mm (mesopic) apertures. RESULTS: The MTF at 50 lp/mm (FineVision/AT Lisa tri/PanOptix) at the far focus was 0.373/0.399/0.400 (3-mm aperture) and 0.512/0.311/0.243 (4.5-mm aperture). At the intermediate focus, the MTF was 0.162/0.147/0.153 (3-mm aperture) and 0.092/0.125/0.137 (4.5-mm aperture). The MTF at the near focus was 0.229/0.192/0.404 (3-mm aperture) and 0.217/0.212/0.169 (4.5-mm aperture). The Strehl ratio was 0.335/0.298/0.370 (3-mm aperture) and 0.243/0.180/0.270 (4.5-mm aperture) at the far focus. At intermediate distances, the Strehl ratio was 0.189/0.185/0.162 (3-mm aperture) and 0.099/0.097/0.114 (4.5-mm aperture). The Strehl ratio was 0.305/0.283/0.464 (3-mm aperture) and 0.177/0.181/0.155 (4.5-mm aperture) at the near focus. CONCLUSION: Evaluation of the three trifocal IOL models at the optical bench could show distinct peaks at the far, intermediate, and near focus. The results were comparable in terms of optical performance.

[Opacification of a hydrophilic acrylic intraocular lens after DMEK : A material analysis]. / Eintrübung einer hydrophilen Acryl-Intraokularlinse nach DMEK : Eine Materialanalyse.

OBJECTIVE: Calcification of a hydrophilic intraocular lens (IOL) is a rare complication. We report on the analysis of an opacified IOL, which was explanted 2 years after Descemet membrane endothelial keratoplasty (DMEK), using light and scanning electron microscopy, X­ray spectroscopy and investigations on the optical bench. METHODS: In October 2012 a patient with pseudophakic keratopathy and Fuchs endothelial dystrophy underwent DMEK with double rebubbling. Due to primary graft failure the patient underwent penetrating keratoplasty in January 2013. The initial postoperative visual acuity was 0.2. Increasing opacification of the IOL lowered visual acuity down to hand movement, so that in November 2014 the patient underwent IOL replacement. The explanted IOL was first natively examined with an Olympus BX50 light microscope. In addition, image quality was determined on the optical bench. Subsequently, the explanted IOL was divided into two and one half was stained with Alizarin red and von Kossa and examined by light microscopy and the other half was analyzed by scanning electron microscopy. The composition of the deposits was examined by X­ray spectroscopy. RESULTS: The macroscopic view showed opacification of the IOL only in the central area of the lens where contact between the IOL and the gas bubble had taken place. Light and scanning electron microscopy revealed numerous fine granular, crystal-like deposits under the anterior IOL surface, which were linearly arranged parallel to the surface. Using energy dispersive X­ray spectroscopy the deposits were shown to be composed of calcium phosphate. No deposits were detected on the posterior surface. CONCLUSION: The cause of the opacification of hydrophilic IOL is not clearly understood; however, the injection of gas/air into the anterior chamber during DMEK appears to increase the risk of IOL opacification by changing the lens surface or by alterations to the blood-aqueous humor barrier. Granular deposits under the anterior IOL surface can cause such a strong decrease in visual acuity that IOL exchange becomes neccessary.