Comparison of modern high-speed vitrectomy systems and the advantages of using dual-bladed probes.

PURPOSE: This study analyzes the efficiency of different vitrectomy systems and compares single with double-bladed cutters. METHODS: The systems EVA™ (DORC), Constellation® Vision System (ALCON), megaTRON S4HPS (Geuder) and Stellaris® PC (Bausch and Lomb) were used. We chose 20G and 23G probes, since not all systems had switched to a smaller G at the time the study was conducted in 2016. Cut rates were varied in increments of 1000 cuts/min from 500 cpm to the system's maximum and vacuum pressures were varied in increments of 100 mmHg, from 100 to 600 mmHg up to the individual system's maximum. In this study water, egg white, Pluronic®-F127 gel and isolated porcine vitreous were used as models of human vitreous. The vitrectomy efficiency was calculated from the aspirated mass (g) within 30 s. The aperture of the different vitrectomy probes was filmed with a high-speed camera. RESULTS: The area under the curve analysis showed differences in efficiency between vitrectomy systems. For water, a reverse relationship between the aspirated mass and cut rate was shown. By contrast, for most systems aspirated egg white and porcine vitreous showed a non-linear increase or decrease for 4000 cpm and above. For all vitreous surrogates, EVA™'s double-bladed probe aspirated significantly (p < 0.001) more vitreous than its mono-bladed probe. Video recordings showed less vitreous traction for double- in contrast to single-bladed probes. CONCLUSION: We can demonstrate differences in the efficiency of vitrectomy depending on the vitrectomy system used. Double-bladed probes were more efficient and probably safer than single-bladed probes.

First aid therapy for corrosive chemical eye burns: results of a 30-year longitudinal study with two different decontamination concepts.

PURPOSE: There is currently uncertainty about the most efficacious decontamination solution for corrosive chemical eye burns. This 30-year longitudinal study evaluated the relative efficacy of two different decontamination methods. Passive decontamination consists of rinsing with tap water, 0.9% normal saline, isotonic buffered phosphate solution, or Ringer's lactate. Active decontamination adds an amphoteric, polyvalent, and chelating component with Previn® (Diphoterine®) solution (Laboratoire Prevor, Valmondois, France). METHODS: A prospective evaluation of patients treated in two specialized eye clinics for eye burns was begun in 1988. Recorded data included exposure circumstances, type of corrosive, different types of first therapy, and clinical treatment and outcome. Patients were treated from clinic admission and up to 24 h after the corrosive chemical burn with rinsing for 15 min using two different protocols. From 1988 to 2005, sterile 0.9% normal saline or Ringer's lactate was used. Since 2006, sterile, hypertonic, amphoteric Previn® solution was used. Comparative statistical analysis was done with the Fisher contingency tables and Wilcoxon tests. RESULTS: There were a total of 1495 patients with 2194 chemically burned eyes. In 1988-2005, the annual incidence was 66.1/year; in 2006-2017, it was 65.5/year. Similar incidences were noted when initial rinsing was with tap water or isotonic buffered phosphate solutions. There was a significantly more severe outcome of corrosive chemical eye burns with any first aid rinsing solutions other than Previn® solution or tap water was used (p < 0.001). Previn® solution or tap water rinsing in the pre-hospital setting and secondary rinsing with Previn® solution in the hospital decreased lesion severity in comparison with all other rinsing solutions (p < 0.001). CONCLUSION: The frequency of corrosive chemical eye burns was comparatively high despite tightening of occupational health and safety regulations over the past 30 years. The severity of corrosive chemical eye burns has been dramatically decreased since the introduction of Previn® solution for initial and secondary rinsing. A new protocol for immediate Previn® solution use by the Cologne Fire Brigade and secondary Previn® solution rinsing in hospital has reduced the frequency of severe corrosive chemical eye burns to less than 60% as compared to the period of 1988-2005 when other rinsing solutions were utilized.

[Symptoms and therapy for steroid glaucoma]. / Klinik und Therapie des Steroidglaukoms.

In steroid responders, topical or systemic application of steroids leads to extracellular deposits in the trabecular meshwork which increase trabecular meshwork outflow resistance. 30-40 % of the normal population are steroid responders. About 5 % develop an intraocular pressure (IOP) rise of > 15 mmHg. These patients are termed "high responders". In patients with primary open angle glaucoma (POAG), the proportion of steroid responders sums up to 90 %. The extent of steroid response depends on the kind of steroid used and on the duration of its administration. Dexamethasone has the highest IOP increasing potency. Differential diagnoses are POAG, ocular hypertension, normal tension glaucoma, pseudoexfoliation glaucoma and secondary glaucoma due to different reasons. To make the diagnosis, a detailed anamnesis is crucial. A recompensated IOP after the end of steroid use proves the diagnosis. The treatment of steroid glaucoma includes topical antiglaucoma medications, glaucoma filtration surgery, trabeculotomy, and laser surgery. So far, only few comparative studies on different treatment options have been published on steroid glaucoma. In some cases of therapy-resistant IOP increases following intravitreal or subconjunctival steroid administration, operative removal of the steroids can be considered. A gene therapy treatment of steroid glaucoma is still a topic of research.

[Multicentric study regarding assessment of the driving ability of LASIK and orthokeratology patients compared with conventionally corrected persons]. / Multizentrische studie zur fahreignungsbegutachtung von LASIK- und orthokeratologie-patienten im vergleich zu konventionell korrigierten personen.

PURPOSE: Corneal optical zone induced by LASIK and orthokeratology (Ortho-K) treatment modifies the refraction of the incoming light bundle in its border area in situations of dawn and darkness. Considering the legal regulations of the driver's license and the recommendations of the German Society of Ophthalmology (DOG) and the American Academy of Ophthalmology (AAO), the vision for driving suitability of ortho-K patients is tested and compared with that of LASIK patients and a reference group (juvenile: < 30 years, adult: > 40 years) under different criterions. The examination of the visual acuity, contrast sensitivity under mesopic conditions and glare contrast sensitivity are main topics of the study. METHODS: This multicentre retrospective study includes 333 eyes of 167 subjects. 65 subjects were habitual wearers of reverse-geometry contact lenses, 60 subjects were treated by LASIK. 42 subjects use glasses, contact lenses or none of them. The follow-up time was 22.8 ± 11.9 months. The measurement of the visual acuity was based on DIN Standard 58220 part 3 and the ISO Standard 8596. The Mesotest II (Oculus Inc.) was used for testing contrast sensitivity under mesopic conditions and glare contrast sensitivity. Detecting the personal evaluation of vision and satisfaction, subjects were instructed to complete a questionnaire (NEI-RQL-42). RESULTS: Relating to the legal requirements in Germany, sufficient visual acuity was found in 76.7 % of the LASIK group, in 73.9 % of the Ortho-K users and in 85.7 % of the reference group (72.7 % in the adult group, 100 % in the juvenile group). Considering the DOG recommendations under inclusion of mesopic vision and glare sensitivity, 71.7 % of the LASIK subjects and 95.7 % of the Ortho-K subjects are suitable for driving a motor vehicle of the German classes A, A1, B, BE, M, S, L and T. With regard to the legal situation in the USA, 100 % of the Ortho-K users, 93.2 % of the LASIK group, 86.4 % of the adult reference group and 100 % of the juvenile reference group are fit to drive. The evaluation of the subjective questionnaire showed very high ratings in the Ortho-K (mean 85 of 100 points) and the LASIK (mean 86 of 100 points) group with no statistically significant differences. CONCLUSION: Considering the legal regulations, the volume of the subjects of Ortho-K and LASIK showed no significant difference of individuals considered fit to drive in comparison to a reference group. Neither LASIK nor Ortho-K patients have any restriction in the ability to drive a vehicle. The requirements of the DOG with regard to contrast sensitivity under mesopic conditions and glare contrast sensitivity for driving a vehicle are better fulfilled in the Ortho-K group compared to the group of LASIK patients. According to the DOG recommendations there are fewer subjects that are suitable for driving a motor vehicle as in the reference group. This fact must be discussed preoperatively.

[Influence of corneal biomechanical properties on myopic regression after laser in situ keratomileusis]. / Einfluss der kornealen Biomechanik auf die Myopieregression nach Laser-in-situ-Keratomileusis.

BACKGROUND: Laser in situ keratomileusis is a safe and accepted method for correcting myopia. The operational results in terms of accuracy as well as the subjective acceptance of patients for corrections to - 8 D are now considered to be promising (Seiler, Refraktive Chirurgie der Hornhaut, 2000); however, postoperative results show individual patient problems in long-term stability. It is believed that the preoperative condition of the cornea (e.g. thickness, biomechanical properties) could have an influence on postoperative problems such as myopic regression. METHOD: This study included a total of 46 eyes from 25 patients. At 3 months postoperatively, 15 patients (19 eyes) showed a SEQ of -0.50 D or more. Within this group, 11 patients (15 eyes) developed a regression (regression group) within the first 3 postoperative months. The remainder of the total group did not show any regression (stability group). The subjects of this study were on average 33 ± 8 years (stability group) and 31 ± 7 years old (regression group). The corneal thickness was tested and refractive error, visual acuity (BCVA/UCVA) and intraocular pressure was measured. In addition, the corneal hysteresis (CH) and corneal resistance factor (CRF) were determined. RESULTS: The mean preoperative spherical equivalent refraction was -3.14 D ± 1.41 D (SE) in the stability group and - 6.47 D ± 1.40 D (p = 0.001)in the regression group. Also, the postoperative spherical equivalents were statistically significant different (p < 0.05). In contrast, the mean preoperative corneal thickness showed no differences in both groups (p = 0.96) (stability group 563 ± 36 µm and regression group 563 ± 28 µm). CONCLUSIONS: The aim of the study to detect a possible causal relationship between myopia regression after LASIK and the biomechanical properties of the cornea and corneal thickness could not be clearly identified.

[Evaluation of the valence objective and subjective methods for measuring pseudophakic accommodation]. / Evaluierung der Wertigkeit objektiver und subjektiver Verfahren zur Messung von pseudophaker Akkommodation.

PURPOSE: The aim of this study was to compare the validity and plausibility of various subjective and objective measurement methods for evaluation of pseudophakic accommodation. SETTING: Eye Clinic Bellevue, Kiel, Germany. METHODS: A total of 21 patients were examined over an average period of 34 months (range 12-51 months) after implantation of a potentially accommodative, model 1CU intraocular lens (IOL, HumanOptics, Germany). The following subjective measurements were taken: near point measurement with the accommodometer (Clement Clarke, Harlow, UK), defocus curve and near visual acuity with far and near reading charts. The IOLMaster (Carl Zeiss Meditec, Germany), ACMaster (Carl Zeiss Meditec, Germany) and Shin-Nippon K 5001 AR (Shin-Nippon, Japan) were employed as objective measurement devices. With this devices information is obtained about the anterior chamber depth (ACD, preoperative and postoperative), the movement of the IOL and the refractive change of eyes during the accommodative process. RESULTS: Depending on the method utilized there were large variations of the examined IOL in relation to the extent of the measured accommodative effects in their entirety with the objective as well as the subjective measurement method. CONCLUSIONS: A differentiation of pseudophakic accommodation and pseudophakic pseudoaccommodation is not possible with the conventional measurement methods applied and examined in this study. Only the ACMaster is an objective method for measurement of the axial shift of an IOL. However, subjective measurement methods can only record the total of both accommodation portions but do not allow any scientifically-founded statement about the functional principle of a potentially accommodative IOL.

[Coincidence of adenocarcinoma and MALT lymphoma of the prostate--first report]. / Koinzidenz Adenokarzinom und MALT-Lymphom der Prostata--Eine Erstbeschreibung.

INTRODUCTION: First description of a prostate adenocarcinoma coinciding with the rare MALT lymphoma of the prostate. CASE REPORT: 68-year-old patient with a pT2c, pN0, M0, Gleason 3 + 3 prostate carcinoma (retropubic radical prostatectomy with pelvic lymphadenectomy) and systemic indolent MALT lymphoma of the prostate (bone marrow biopsy). Therapy and course are described and further explained by referring to case reports found in the literature. In this context, possible pathogenetic mechanisms, the prognosis for this special disease and possible therapeutic approaches are discussed. CONCLUSION: MALT lymphomas of the prostate are rare, and so far a coincidence with a prostate carcinoma is unprecedented. The prostate carcinoma is treated according to stage, while the MALT lymphoma is managed according to individual treatment strategies. The histopathological classification is more important for the prognosis. Treatment with antibiotics to eradicate possible copathogenic Helicobacter pylori is discussed as an innovative therapeutic approach. The pathogenesis of the MALT lymphoma of the prostate cannot yet be clarified definitively according to a literature review.

Secondary implantation of scleral-fixated intraocular lenses.

PURPOSE: To evaluate the results of a large series of secondary implantations using scleral-fixated posterior chamber intraocular lenses (IOLs). SETTING: Bellevue Eye Hospital, Kiel, Germany. METHODS: This retrospective review comprised 624 consecutive patients who had secondary implantation of a posterior chamber IOL with scleral fixation between 1988 and 1995. All patients had been aphakic for at least 1 year. An ab interno or ab externo suture technique through the ciliary sulcus was used. Visual outcome and complications 1 year after surgery were determined. RESULTS: Best corrected visual acuity improved or remained unchanged in 92.0% of eyes; 8.0% lost one or two lines. Intraocular lens decentration of more than 1.5 mm occurred in 1.9% of eyes. Suture erosion was observed in 17.9%, cystoid macular edema in 5.8%, retinal detachment in 1.4%, and vitreous hemorrhage in 1.0%. Severe uveitis occurred in 0.5%. CONCLUSION: Secondary IOL implantation with scleral fixation was a safe procedure. Although there was a small risk of significant complications, more than 90% of patients regained or improved their preoperative visual acuity.

Histopathological comparison of photorefractive keratectomy and laser in situ keratomileusis in rabbits.

BACKGROUND: After 193 nm excimer laser photorefractive keratectomy (PRK) for myopia, superficial opacities in the ablation zone and regression of refractive results can occur. Clinical studies have emphasized that corneal clarity and early refractive stability can be achieved with laser in situ keratomileusis (LASIK). We present clinical and histological results that compare PRK and LASIK for the treatment of myopia in rabbits. MATERIALS AND METHODS: We treated 12 New Zealand white rabbits with PRK and 12 with LASIK using a 193-nm excimer laser (Aesculap Meditec). In both techniques, the identical excimer software and ablation parameters of -10 D treatment depth were used. Six months after surgery, all eyes were removed and prepared for light, fluoresence and transmission electron microscopy. RESULTS: At the time of enucleation, nine eyes in the PRK group had a moderate to high degree of haze (grade 2 to 3), whereas after LASIK, all corneas showed an almost clear interface in the ablation zone. Correspondingly, all histological investigations after LASIK showed a regular stromal architecture, in contrast to the obvious anteri or stromal disorganization after PRK. CONCLUSION: The preserved integrity of the superficial corneal layers after LASIK ensures quick wound healing with minimal tissue proliferation, resulting in a transparent corneal interface. This technique appears especially suitable for correcting high myopia.

[Fine structure of conjunctival lymphatic vessel valves]. / Feinstruktur konjunktivaler Lymphgefässklappen.

BACKGROUND: Lymphatic valves are due to ensure a zentripetal flow of lymph. The majority of the authors regard these valves as bicuspid structures with joint insertion points of the downstream localized free valvular edges. Because of that valvular structure a retrograde flow of lymph is impossible. Observations of our own however demonstrated retrograde flow of fluid under physiological conditions. In the following paper the structure of conjunctival lymphatic valves should be investigated or rather those structures, which were regarded as valves hitherto. Are there segmental connections, which allow retrograde flow of lymph? Is a regulation of lymph flow possible without self-acting valves? MATERIALS AND METHODS: In the conjunctiva of bovine post-mortem eyes (n = 100) segmental connections of lymphatic vessels with a diameter of less than 1 mm were opened specifically under control of slit lamp microscope after having undertaken an interstitial double contrast lymphography (solution of Berliner Blue/air). Some of these preparations (n = 20) could be investigated further on with the scanning electron microscope. That procedure allowed to make the patterns of flow and vessels structures in the beginnings of the lymphatic system observed with the slit lamp microscope congruent with those structures shown by the scanning electron microscope. RESULTS: The following segmental connections could be demonstrated: 1. Lymphatic vessels, which flow like a pipe into the wall of another segment. 2. Laterally arranged oval connections with valve resembling an aperture. 3. Segments of lymphatic vessels arranged in a line, which flow into one another between two hump-shaped protrusions with bicuspid valvular structures. Also the existence of different connecting structures ("valves") in one segment ("gear segment") were observed. In bulbus-like segmental connections arranged one behind the other with two valvular leaflets it could be demonstrated by scanning electron microscopy, that the two leaflets were attached apart at the vessel wall. That divergence to the previous models of lymphatic valves means, that these valvular leaflets cannot work as self-acting valves and prevent retrograde flow. CONCLUSIONS: However according to the valveless model of Libau a directed regulation of flow is possible. Perhaps the valvular structures described above play an important part by the interaction between the endothelium of lymphatic vessels and the substances transported in the lymph. The variety of segmental connections, the network of vessels with different diameters, which seem to be connected by feed-back, demand a new way of looking at the initial lymph flow.

Cicatricial ectropion in ichthyosis: a novel approach to treatment.

Four kinds of ichthyosiform dermatoses have been described. Only lamellar ichthyosis or ichthyosis congenita is associated with the development of ectropion and subsequent eye symptoms. Conservative treatments have been tried but surgical correction of the ectropion was ultimately required for symptomatic relief. Autografts have been used successfully, provided an available donor site can be found. Grafts taken from the arm, eyelids, postauricular skin, and groin have been used with success. An uncircumcised youth with total body involvement from ichthyosis developed bilateral upper and lower ectropion. The penile foreskin was the only possible suitable donor site because it seemed unaffected by the disease. A circumcision was performed and the foreskin divided into four separate full-thickness skin graft triangles to treat the four-lid ectropion. There was successful resolution of the eye symptoms and a watertight closure. To our knowledge, this is a unique case in which penile foreskin has been used to correct cicatricial ectropion.

Retrobulbar (intraconal) anesthesia with a curved needle: technique and results.

We report the results of two prospective studies of retrobulbar anesthesia using curved 25 mm and 28 mm needles. These studies were prompted by our experience with the 25 mm needle in more than 13,000 cases of intraconal anesthesia in which one case of postoperative ischemic neuropathy was the only complication. The technique involves the transcutaneous introduction of the curved needle at the middle of the lower lid, following a curved track close to the inferior orbital wall, around the globe, parallel to the plane of the medial orbital wall (i.e., in a strictly sagittal plane lateral to the optical axis in primary gaze). No complications were noted in the prospective studies. Side effects were chemosis in 30% of cases, subconjunctival hemorrhage in 5%, and lid hemorrhage in 2%. Since these comparative studies, we have used the 28 mm needle without significant complications in more than 8,000 cases. This method of retrobulbar anesthesia is superior to peribulbar anesthesia, and because of its safety and reliability, is preferable.

[Saccular initial segments of the lymphatic vessel system]. / Zur Frage der kolbenförmigen Initialsegmente des Lymphgefässsystems.

It is commonly said that the lymphatic system begins "blindly" as saccular outpocketings. In order to examine these saccular outpocketings, 120 injections into the conjunctival lymphatics of 60 bovine postmortem eyes were carried out, measuring the level of injection pressure and simultaneously documenting the various filling stages photographically. 20 trials were selected for further analysis. We recorded low initial pressures when the tip of the needle was situated close to a larger lymphatic vessel and the coloured solution (1% aqueous Berliner Blue) as possibly applied intravascularly. Higher initial pressures were seen on positioning inside fine networks of vessels. Extremely high initial pressures without any visible filling of vessels but in the presence of simultaneously increasing depots of dye were probably caused by absent or insufficient connection between the tip of the needle and a vessel. During lymphography numerous coarser and finer, tube-like projections (saccular outpocketings) filled, from which further progression of the coloured solution could only be observed when higher injection pressures were applied. We were able to prove that such segments had connections to neighbouring vessels as well as forming plexus of their own. Based on our findings we have reason to doubt the existence of tube-like initial segments in the lymphatic system. Rather in the conjunctiva of the bovine eye this system has the structure of a fine network where tube-like segments can be demonstrated as temporary filling stages.

[Endocapsular cataract surgery and endocapsular artificial lens implantation]. / Endokapsuläre Kataraktchirurgie und endokapsuläre Kunstlinsenimplantation.

This paper describes a simple procedure for endocapsular cataract extraction followed by implantation of an artificial lens with endocapsular fixation. The special instruments required, as well as a new endocapsular artificial lens, are also described. The advantages of this safe and gentle procedure are pointed out and the author's experience in 4700 cases is communicated.