23- vs 20-gauge pars plana vitrectomy in combination with bimanual microincisional cataract surgery (b-MICS) for the treatment of macular hole and cataract as a one-step procedure.

BACKGROUND/AIMS: 23-gauge pars plana vitrectomy (ppv) is a new method for vitreo-retinal surgery. It may reduce operation time, the risk of complications, and patient discomfort, especially in combination with simultaneous bimanual microincisional cataract surgery (b-MICS). METHODS: Seventy-five consecutive patients who underwent combined cataract surgery and ppv at our center between 1 January 2008 and 31 December 2010 were included. The first 36 patients were treated with 20-gauge ppv, the following 39 patients with 23-gauge ppv. Study end points 8 weeks after surgery were duration of the procedure, improvement of visual acuity, and occurrence of complications. RESULTS: Duration of surgery was reduced in 23- vs 20-gauge ppv (54.0 ± 11.6 vs 61.0 ± 19.0 min, P=0.08). Visual acuity improved significantly in both the groups (20-gauge: logMAR 0.750 ± 0.304 before and 0.369 ± 0.273 after surgery; 23-gauge: logMAR 0.663 ± 0.340 before and 0.339 ± 0.273 after surgery). There were no appreciable group differences in baseline or post-treatment visual acuity. CONCLUSIONS: 23-gauge ppv in combination with b-MICS is a suitable, safe, and effective method for the treatment of combined cataract and vitreo-retinal diseases. The procedure is somewhat shorter and patient discomfort during and after surgery is improved. In terms of efficacy and safety, 23-gauge ppv is equivalent with conventional 20-gauge ppv.

[Methods of anesthesia in eye surgery]. / Anästhesieverfahren in der Augenheilkunde.

There are several methods for local and general anesthesia in ophthalmological surgery that attempt to provide a stress and pain-free operating environment for both patient and surgeon. The decision-making depends on medical as well as on ophthalmological criteria and jointly falls to ophthalmologists and anesthesiologists. Topical and injective anesthesia (with or without conscious sedation) are generally methods of choice but general anesthesia can be preferable or mandatory in patients with particular internal diseases, children, emergencies and for extended surgical procedures. Pre-emptive analgesia before the operation is a meaningful complement in ophthalmological anesthesia.

Bilateral Exudative Retinal Detachment in HELLP Syndrome.

The HELLP syndrome is a pregnancy complication, life-threatening for mother and child, characterized by hypertension, elevated liver enzymes and low platelets. Blurred vision is the most common visual complaint. A rare case of bilateral exudative retinal detachment associated with the HELLP syndrome is described in a 30-year-old Caucasian woman at 33 weeks' gestation. The retinal detachment did reattach with good improvement in vision under steroid therapy. The case highlights the importance of early involvement of the ophthalmologist when pregnant women complain about visual disorders.

[An in-vivo evaluation of Brilliant Blue G in macular surgery]. / Anfärbung der inneren Grenzmembran der Netzhaut mit Brilliant Blau.

OBJECTIVE: The aim of this study was to evaluate the functional outcome of Brilliant Blue G (BBG) and the staining properties in macular surgery. METHODS: BBG was applied during vitrectomy for macular holes (n = 21) or epiretinal membranes (n = 18) in a prospective, non-comparative consecutive series of patients (Brilliant Peel®; Fluoron® GmbH, Neu-Ulm, Germany). Before and after surgery all patients underwent a complete clinical examination including measurement of best corrected visual acuity and intraocular pressure, perimetry, fundus photography and optical coherence tomography. RESULTS: Vitrectomy was performed in combination with a cataract operation in 14 patients. All macular holes were closed successfully. Visual acuity was in average 0.16 preoperatively in macular hole cases and increased up to 0.4 after 6 months. Visual acuity of patients with epiretinal membranes changed on average from 0.3 to 0.45 after 6 months. The retina thickness in patients with epiretinal membranes was initially 402.6 µm according to the OCT and 304.7 µm after 6 months postoperatively. No toxic effects attributable to the dye were noted during patient follow-up, especially all perimetry tests were normal. CONCLUSIONS: Brilliant blue provides a sufficient and selective staining of the ILM. No retinal toxicity or adverse effects related to the dye were observed in this study. The long-term safety of this dye will have to be evaluated in larger patient series and a longer follow-up.

[Training program for vitreoretinal surgery in Nairobi, Kenya from 2000 - 2006]. / Trainingsprogramm zur vitreoretinalen Chirurgie in Nairobi, Kenia, in den Jahren 2000 - 2006.

BACKGROUND: After the U. S. Embassy bombing in 1998 in Nairobi, Kenya, a relief operation was immediately initiated by the Department of Ophthalmology of the Ludwig Maximilians University (LMU) Munich, Germany. Surgical devices and material (such as a vitrectomy unit, silicon oil, perfluorodecalin, intraocular lenses, sutures) were supplied to operate on 42 ocular-injured victims of this bombing attack. Apart from these specific operations in Kenya, there is a big need for vitreoretinal surgery in East Africa, as in all other developing countries. Therefore, a vitreoretinal training program was started in 2000 in Nairobi, Kenya. We report about the first 7 years of collaboration between the Ludwig Maximilians University of Munich, Germany and the University of Nairobi in cooperation with the Kenyatta National Hospital, Kenya. MATERIAL AND METHODS: The training program was based on an annual project week in which the author (CLS) carried out vitreoretinal surgery himself and assisted and supervised surgery done by the local Kenyan colleagues at the Kenyatta National Hospital. Within the observation period of the present work (2000 - 2006) the following data were collected: number and kind of surgery, indications, surgeons, grading of eye pathology and the surgical procedure, time to prepare for surgery and duration of surgery. RESULTS: In total, 293 vitreoretinal surgeries were performed during the observation period. Surgeries carried out by the local Kenyan colleagues independently, without intervention of the author, increased from 29.4 % (2000) to 78.6 % (2006). Due to a constant development in the learning process during the project week more severe cases were treated and preparation time for surgery from the nursing side has shortened. CONCLUSIONS: By initiating a project week with high frequency surgery, supported by a highly experienced visiting surgeon, vitreoretinal surgery can be successfully set up in an ophthalmic clinic of a developing country. This approach has some advantages when compared to long-period projects, especially for the purposes of sustainability. However, to be successful it requires systematic planning which is described in this article.

[Relationship between lens power in refraction]. / Linsenbrechkraft bei unterschiedlicher Refraktion.

BACKGROUND: To achieve emmetropia, several components such as the cornea and lens power, and axial length have to be coordinated. Until now, not much is known about the influence of these factors on each other. METHODS: A total of 66 healthy subjects were enrolled in this study. Ocular dimensions including anterior chamber depth, lens thickness, vitreous chamber depth, and axial length were measured by A-scan ultrasonography. Corneal radius and corneal refractive power were determined by ophthalmometry. The equivalent lens power was calculated by a method based on the Gullstrand schematic eye. RESULTS: As expected, a good correlation was found to exist between refraction and axial length. Lens power was independent of refraction, but in emmetropic eyes a good correlation between lens power and axial length could be found. Higher axial length was related to lower values of lens power and vice versa. CONCLUSION: In emmetropic eyes, deviation of axial length seems to be compensated by lens power and if this mechanism does not function, ametropia results.

Vitreoretinal surgery: pre-emptive analgesia.

AIM: Vitrectomies are performed either under general anesthesia (GA), local anesthesia (LA), or a combination of both. Postoperative pain is expected to be less in patients with LA because of prolonged action of the local anaesthetic. Pre-emptive analgesia is based on the idea that analgesia initiated before a nociceptive event will be more effective than analgesia commenced afterwards. The authors compared postoperative analgesia in patients with GA combined with preoperative or postoperative LA. METHODS: 90 patients scheduled for vitrectomy without buckling were enrolled in the study. 60 patients underwent GA, 30 without LA, 15 with preoperative LA, and 15 with postoperative LA. 30 patients received LA alone. Subjective postoperative pain was determined using the visual analogue scale. RESULTS: Postoperative pain was less under LA alone compared to GA alone (p < 0.0001). Additional preoperative application of LA resulted in less pain than additional postoperative application (p <0.05). Additional postoperative peribulbar aneasthesia did not differ from GA alone. CONCLUSION: The authors conclude that LA alone or preoperatively in addition to GA provides the best comfort for the patient in vitreoretinal surgery.

[Brainstem anesthesia with respiratory arrest after retrobulbar block--a case report with a review of literature]. / Hirnstammanästhesie mit Atemstillstand nach Retrobulbäranästhesie--Kasuistik mit Literaturüberblick.

BACKGROUND: This case shows the time course and typical clinical features of brain stem anaesthesia. It is presumed that it follows accidental injection of local anaesthetic into the subarachnoidal space via the optic nerve sheaths. HISTORY AND SIGNS: We report the case of a 70-year-old man, who became unconscious shortly after retrobulbar anaesthesia. The first symptoms developed after an interval of several minutes following the injection of the local anaesthetic. After the appearance of cranial nerves deficits the patient complained of difficulty breathing and became unconscious and apnoeic. THERAPY AND OUTCOME: It was decided to intubate the patient. Heart rate and systolic blood pressure dropped, therefore, a central line was placed and intravenous fluids were given. The patient was brought to the intensive care unit where he was extubated uneventfully the same day. CONCLUSIONS: The quick clinical recovery of the patient without any sequelae and the unremarkable results of internal and neurological examines support the diagnosis of brain stem anaesthesia.

[All-trans-retinol (atR) inhibits expression of the metalloproteinase stromelysin in retinal pigment epithelium (RPE)]. / All-trans-Retinal (atR) hemmt die Expression der Metalloproteinase Stromelysin in retinalem Pigmentepithel (RPE).

BACKGROUND: The pathobiology in proliferative vitreoretinopathy (PVR) is complex. The mechanism of the release of retinal cells from their cellular bond is unknown. The metalloproteinase stromelysin cleaves proteins of the extracellular matrix (ECM). This may liberate retinal cells. The expression of stromelysin in human RPE cells has been demonstrated. Here, stromelysin gene expression under all-trans-Retinal (atR) was investigated. MATERIALS AND METHODS: Human RPE-cells were used from passage 2 to 5. The expression of the human stromelysin gene was determined by reverse transcriptase-polymerase chain reaction using specific oligonucleotides. RPE-cells were incubated with 162 nmol/l tetraphorbolester (TPA) alone or simultaneous with 1 mumol/l atR. RESULTS: TPA increased the expression of stromelysin in RPE cells. Incubation with TPA and atR lowered this increase. The decrease of expression was calculated semiquantitatively. CONCLUSIONS: The expression of stromelysin in RPE cells is lowered after incubation with 1 mumol/l atR. The dedifferentiation of RPE-cells may decrease intracellular atR levels. This could turn an inhibition of stromelysin gene expression to an increase. This may then release retinal cells from their cellular bond and therefore be one of the initial steps in the development of PVR.

[Inhibition of proliferation of retinal pigment epithelium in vitro: vitamin A pharmacodynamics I]. / Hemmungen der Proliferation retinalen Pigmentepithels in vitro. Vitamin A-Pharmakodynamik I.

BACKGROUND: In proliferative vitreoretinopathy and choroidal neovascularization, retinal pigment epithelial (RPE) cells proliferate among other cell types. Cell proliferation is controlled by many factors. One such factor is the "superfamily" of nuclear receptors. Ligands of these receptors are vitamin A and D, triiodothyronine and dexamethasone. All-trans-retinal (atR) inhibits human RPE-cell proliferation. AtR binds to the nuclear ligand-dependent transcription factors RAR (retinoic acid receptor) and RXR (retinoid X receptor). Pharmacodynamics of atR were investigated with respect to inhibition of RPE cell proliferation. MATERIALS AND METHODS: Primary human RPE cell lines were used up to passage 5. RPE cells were incubated with atR ranging from 1 pM up to 1 microM. AtR was added every other day for 7 days. Cell proliferation was determined by cell counting. RESULTS: AtR inhibited RPE cell proliferation in a biphasic manner. Two IC50 values were calculated, one in the picomolar range, 10 pM (5-24, 95% confidence interval) and one in the nanomolar range, 17 nM (8-37). Furthermore, inhibition of cell proliferation was examined using specific RAR agonists. Agonists of the RAR-b subgroup inhibited cell proliferation at the lowest concentrations. CONCLUSIONS: RPE cell proliferation in vitro is inhibited by agonists of RAR. Agonists of the RAR-b subgroup inhibit RPE cell proliferation at the lowest concentrations.

[Intra-vitreal rt-PA and gas introduction in submacular hemorrhage]. / Intravitreale rt-PA- und Gaseingabe bei submakulärer Blutung.

UNLABELLED: Efficacy and complications of intravitreally injected tissue plasminogen activator (rt-PA) and sulfahexafluoride gas (SF6) in submacular hemorrhage are demonstrated. PATIENTS AND METHODS: Fifty-three patients with submacular hemorrhage were treated (27 women, 26 men, mean age 79 +/- 1 years). Causes of hemorrhage were a choroidal neovascularization in 47 patients and macroaneurysm in 6 patients. After i.v. administration of 500 mg acetazolamide and disinfection of the conjunctiva, 50 micrograms rt-PA in 0.1 ml (BSS) and 0.5 ml SF6 were injected intravitreally. The patient was positioned prone for 24 h. RESULTS: In 23 patients with choroidal neovascularization visual acuity improved by 2 lines and more; in 12 patients vision remained unchanged. In 12 patients visual acuity deteriorated. In 5 of 6 patients with a macroaneurysm vision improved from less than 0.1 to 0.1-0.5. Postoperative complications were four cases of vitreous hemorrhage and one case of endophthalmitis. CONCLUSION: The intravitreal injection of rt-PA and SF6 is an alternative method for treatment of submacular hemorrhage.

[Expression of the nuclear glucocorticoid receptor in human pigment epithelium]. / Expression des nukleären Glukokortikoid-Rezeptors in humanem retinalen Pigmentepithel.

BACKGROUND: Proliferative vitreoretinopathy (PVR) may follow complicated retinal detachment. The normally quiescent retinal pigment epithelium (RPE) proliferates and dedifferentiates. These alterations of specialized cell characteristics are probably due to regulatory nuclear receptors. In this paper, human RPE cells were examined for expression of the nuclear glucocorticoid receptor (GR). Ligands for this receptor may influence the proliferation of RPE cells. MATERIALS AND METHODS: RPE cells were cultured from human donor eyes. The GR was demonstrated using reverse transcriptase-polymerase chain reaction. RESULTS: It was demonstrated for the first time that the GR is expressed by human RPE cells. CONCLUSIONS: Steroids play an important role in cell metabolism, especially in protein synthesis. This may be important for the proliferation of RPE cells and the release of enzymes that digest the basal lamina. Therapeutic interaction with the glucocorticoid-signal pathway may be useful for the inhibition of RPE cell proliferation.

[Metalloproteinase stromelysin. Expression in human retinal pigment epithelium (RPE)]. / Metalloproteinase Stromelysin. Expression in humanem retinalem Pigmentepithel (RPE).

BACKGROUND: Under normal circumstances the retinal pigment epithelium (RPE) does not undergo cell division. After retinal detachment or the development of choroidal neovascularization (CNV) it can be induced to reenter the cell cycle. The RPE cells proliferate and dedifferentiate. A prerequisite for proliferation of RPE cells is degradation of the extracellular matrix (ECM), which may be induced by metalloproteinases. We investigated the potential role of human RPE cells in the expression of the metalloproteinase stromelysin. MATERIALS AND METHODS: Human RPE cells were cultured from donor eyes. Stromelysin was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) from mRNA. RESULTS: Human RPE cells in culture express stromelysin. Its expression is enhanced by tetraphorbolacetate (TPA). CONCLUSIONS: Stromelysin generally degrades important constituents of the ECM. This may induce the detachment of RPE cells from the basement membrane and initiate RPE proliferation and dedifferentiation.

Hyalocytes inhibit retinal pigment epithelium cell proliferation in vitro.

Under pathological conditions such as retinal detachment or proliferative vitreoretinopathy, the normally quiescent retinal pigment epithelium (RPE) may proliferate. We investigated whether hyalocytes, endogenous to the vitreous, might play a role in modulating the proliferation of RPE cells in vitro. We cultured hyalocytes from bovine eyes and RPE cells from human eyes. RPE cell proliferation was determined by [3H]-thymidine incorporation following incubation with hyalocyte-conditioned media (HCM). HCM inhibited RPE cell proliferation with no effect on cell viability as based on trypan blue exclusion. This inhibition was partially antagonized by a specific neutralizing antibody against transforming growth factor-beta (anti-TGF beta antibody). Fractionation of HCM into low- and high-molecular-weight components showed inhibition of RPE cell proliferation in both fractions, suggesting that there may be multiple inhibitors. Whereas protease inhibition of HCM did not alter the inhibition of RPE cell proliferation, acid activation of HCM, which causes activation of latent TGF beta, enhanced its inhibitory effect. These data suggest that cultured hyalocytes secrete active and latent TGF beta and that this accounts for a portion of their inhibitory effect on RPE cell proliferation in vitro.

Vitreoretinal surgery in intermediate uveitis.

Between 1987 and 1992, vitrectomies were performed in 42 eyes with intermediate uveitis. Pre- and postoperative clinical and ophthalmological parameters were reviewed. Especially the pre- and postoperative time courses of visual acuity were analyzed. We looked for parameters influencing the final visual results. Furthermore, we revised pre- and postoperative recurrent exacerbations of the disease and the duration and dosage of postoperative corticosteroid therapy. The best final visual results were reached in eyes with the best preoperative visual acuities. Anatomic retinal findings and the preoperative duration of intermediate uveitis predominantly influenced the final visual results. Overall, 75% of our patients reached visual acuities of above 20/200. When asked to state their opinion about the final functional result, 80% of the patients were contented. We advocate vitrectomy in patients with intermediate uveitis after intensive follow-up and careful consideration. The anatomic integrity of the retina, a good preoperative visual acuity, and a short preoperative duration of intermediate uveitis are the most important factors influencing the final visual results.

Prognostic factors in vitreous surgery for proliferative diabetic retinopathy.

A total of 25 proliferative diabetic eyes of 24 patients scheduled for vitrectomy were examined. The overall preoperative visual acuity was below 0.1, corresponding to hand movement in most patients because of intravitreal hemorrhage. Hence, funduscopy was not possible. The following tests were performed in addition to standard clinical examination: Purkinje entoptic phenomenon, laser interferometry, perception of color flashes, and flicker-VEP using 1.8, 7.6, 15, and 30 Hz as stimulating frequencies. Only the flicker-VEP revealed results predicting reliably the functional visual outcome at 6 months after vitrectomy. Patients with a positive preoperative response to 15 or 30 Hz had a significantly (P < 0.05) better visual outcome at 6 months after vitrectomy (mean postoperative visual acuity 0.11; 95% confidence interval, 1/25-0.32) as compared with patients showing a positive preoperative VEP-response to only 1.8 and 7.6 Hz (mean postoperative visual acuity, hand movement; 95% confidence interval, light without projection--1/35). The flicker-VEP can give additional information about the integrity of the retina and the function of the optic nerve and can therefore help the surgeon to predict the functional result after vitrectomy.

The sensitivity of adrenergic varicosities to the 3H-noradrenaline-releasing effect of potassium.

After the loading of incubated, homogeneously innervated tissues with 3H-noradrenaline (monoamine oxidase and catechol-O-methyl transferase inhibited, calcium-containing solution) high K+ released the 3H-amine from adrenergic varicosities. In paired experiments the sensitivity of rat atria to high K+ exceeded that of vasa deferentia. In the rat vas deferens the releasing effect of high K+ was enhanced by drugs or procedures which induce a carrier-mediated outward transport of 3H-noradrenaline, i.e., by ouabain, by glucose deprivation and by hypoxia. In the presence of extracellular calcium desipramine failed to affect the releasing effect of high K+ (except in the absence of glucose or during hypoxia), but in the absence of calcium desipramine reduced it. Apparently, whenever the axoplasmic levels of 3H-noradrenaline are increased, high K+ is able to induce some carrier-mediated outward transport of the 3H-amine. It is suggested that "organ differences" with respect to the sensitivity to high K+ may well be due to hypoxia (plus some lack of glucose) of those varicosities that had been loaded with 3H-noradrenaline. The risk of storage of 3H-noradrenaline in hypoxic varicosities appears to be greater in incubated than in perfused organs, and in the former it is greater in sparsely than in densely innervated tissues.

The heterogeneity of the neuronal distribution of exogenous noradrenaline in the rat vas deferens.

After loading of the incubated rat vas deferens with 0.2 mumol/l 3H-noradrenaline (followed by 100 min of wash-out with amine-free solution), the efflux of endogenous and exogenous compounds was determined by HPLC with electrochemical detection and by column chromatography with scintillation counting. Two different types of heterogeneity of labelling were found. The first one is due to the preferential labelling of varicosities close to the surface of the tissue, the second one to the preferential labelling of vesicles close to the surface of loaded varicosities. As diffusion distances within the tissue and within varicosities are then longer for endogenous than for exogenous amine and metabolites, the composition of spontaneous efflux of exogenous compounds differed from that for endogenous compounds. Because of preferential neuronal and vesicular re-uptake of endogenous noradrenaline, the percentage contribution by noradrenaline to overall efflux was: endogenous less than exogenous. While 3H-DOPEG was the predominant exogenous metabolite, DOPEG and MOPEG equally contributed to the "endogenous" efflux. Desipramine abolished the consequences of the first heterogeneity of labelling, i.e., it increased the efflux more for endogenous than for exogenous noradrenaline; moreover it decreased the efflux of 3H-DOPEG, but increased that of 3H-MOPEG. The reserpine-like compound Ro 4-1284, on the other hand, abolished the consequences of the second type of heterogeneity; it reduced the specific activity of "total efflux" (i.e., of the sum of noradrenaline + DOPEG + MOPEG) to the specific activity of the tissue noradrenaline. The degree of heterogeneity of labelling was reduced after inhibition of monoamine oxidase and also when the tissues were loaded with 2 or 20 mumol/l 3H-noradrenaline. It is proposed that the various "compartments" and "pools" of noradrenaline described in the literature reflect the two heterogeneities described here.