[Influence of Macular Hole Width on Visual Acuity, Endotamponade and Closure Rate]. / Einfluss der Lochbreite auf Visus, Endotamponade und Verschlussrate beim Makulaforamen.

Background: The influence of the width of a full-thickness macular hole on preoperative visual acuity and its role for the intraoperative approach and closure rate were analysed in a prospective study. Methods: For 47 patients with a full thickness macular hole, a precise analysis of the central retina was performed with SD-OCT. An SF6-gas-air mixture was used, with a lower concentration (15 %) for smaller holes ≤ 400 µm (group 1, n = 17) and a higher concentration (30 %) for larger holes > 400 µm (group 2, n = 30). Besides preoperative visual acuity, postoperative IOP fluctuations and closure rate were reviewed. Results: The mean hole width with SD-OCT was 419 ± 155 µm, with a significant negative correlation with preoperative visual acuity (r = - 0.56, p = 0.002). In the first group, mean early postoperative IOP was 23 mmHg and in the second group 33 mmHg (p < 0.001). Thus, for small macular holes, early postoperative IOP decompensation from gas expansion in the eye could be minimised. The closure rate was 90 %, with no significant difference between the two groups (p > 0.05). Conclusion: Determining the width of a macular hole with SD-OCT is an important indicator for the necessary endotamponade. Using a lower gas concentration (15 %) for smaller holes (≤ 400 µm) to prevent postoperative IOP fluctuations does not negatively influence closure rates.

[Relevant Parameters of Optic Nerve Analysis from Spectral Domain OCT for Glaucoma Diagnostics]. / Relevante Parameter der Papillenanalyse mittels Spectral-Domain-OCT zur Glaukomdiagnostik.

BACKGROUND: In early diagnosis and follow-up of patients with glaucoma anatomic-diagnostic examinations have become more important in addition to static perimetry. Patients with open angle glaucoma suffer a slow visual field loss due to the loss of ganglion cells, which these examinations could detect earlier than perimetry can. METHODS: Parameters of the optical coherence tomography (OCT) were analysed in 89 patients (175 eyes) with advanced open angle glaucoma. In a prospective study, the functional findings from static perimetry (HFA-II, 24-2-programme) and the anatomic parameters of optic nerve analysis with SD-OCT (Cirrus-OCT) were evaluated. RESULTS: The results showed a mean deviation (MD) in perimetry of - 8.31 ± 9.76 dB and in the analysis of the optic nerve head of 71.93 ± 15.86 µm retinal nerve fibre layer (RNFL) as well as 85.54 ± 28.2 µm RNFL for the inferior quadrant, 0.95 ± 0.46 mm(2) for the rim area and 0.69 ± 0.18 for the vertical CD ratio. There was a significant correlation (p < 0.05) between MD und RNFL (r = 0.603), as well as RNFL of the inferior quadrant (r = 0.620), rim area (r = 0.552) and average CD ratio (r = - 0.551). The best correlation for the optical nerve head analysis was found between MD and vertical CD ratio (r = - 0.568). CONCLUSIONS: There was a good correlation between functional and anatomic parameters in perimetry and OCT. In particular, the mean and inferior retinal nerve fibre layer thickness, the rim area, and the vertical CD ratio revealed to be significant parameters in glaucomatous eyes.

[Surgical treatment of chronic macular oedema with a combination therapy]. / Operative Behandlung des chronischen Makulaödems durch eine Kombinationstherapie.

BACKGROUND: The treatment of therapy-resistent chronic macular oedema remains a challenge. Therefore a combination therapy, consisting of medical, biological and mechanical components was assessed. METHODS: A surgical treatment was performed in 35 eyes (34 patients) with chronic and therapy-resistant macular oedema, resulting from diabetic maculopathy (n = 25), vitreoretinal traction (n = 7) or following a retinal venous occlusion (n = 3). An intravitreal injection of bevacizumab was given on the day before surgery, consisting of pars plana vitrectomy with ILM peeling with Brilliant Blue G (BBG), as well as an air tamponade combined with postoperative prone positioning. The visual function and the central retinal thickness were measured in follow-up. RESULTS: Functionally, the visual acuity could be stabilised to an average of 0.18 and macular oedema was reduced in most patients. Anatomically, a significant reduction in central macular thickness by 193 µm (29 %), from 598 µm to 405 µm (p < 0.001), and a regression in the intraretinal cystoid changes were observed. No significant complications occurred, whereas in 6 patients additional consecutive treatment was necessary. CONCLUSION: A stabilisation of the visual acuity and an improvement in the structural retinal situation could be achieved by an elaborate combination therapy, based on a pharmacological, a biological and a mechanical approach. Long-term follow-up and consecutive supplementary treatments are necessary to ensure the functional stability.

[Effect of ocular compression on anterior chamber dimensions in cataract surgery using topical anaesthesia]. / Einfluss der Okulopression auf die Vorderkammerdimensionen vor der Kataraktoperation in topischer Anästhesie.

PURPOSE: Ocular compression is part of the preparation before cataract surgery to reduce the incidence of a positive intraoperative pressure. The purpose of this clinical study was to assess the influence of ocular compression on the anterior chamber dimensions and biometric parameters before cataract surgery using topical anaesthesia. METHODS: In a prospective, comparative observational study the biometric parameters were assessed with slitlamp-adapted anterior segment OCT (SL-OCT, Heidelberg Engineering) and ultrasound biometry (A-Scan+, Sonomed) in 51 consecutive patients (51 eyes) with a mean axial eye length of 22.90 ± 1.05 mm before cataract surgery. The measurements were performed in all patients before and immediately after ocular compression (Oculopressor G-15392, Geuder). In 32 patients the measurements were repeated 10 minutes after ocular compression. RESULTS: The optical and acoustic values of the anterior chamber depth did not change significantly after ocular compression (p > 0.05). Digital gonioscopy with OCT revealed a mean increase of the anterior chamber angle of 2.37° (p < 0.001) from 45.75 ± 7.28° to 48.12 ± 7.28°, and the angle opening distance of 37 µm (p = 0.017) from 627 ± 184 µm to 664 ± 162 µm. Also the average acoustic axial vitreous distance decreased significantly from 15.22 ± 0.98 to 15.18 ± 0.96 mm (p = 0.034) with a posterior shift in the relative lens position (p = 0.018). CONCLUSIONS: In this clinical study, only slight anterior chamber and biometric changes were observed after ocular compression before cataract surgery using topical anaesthesia. There was a significant increase of the anterior chamber angle and angle opening distance with a concomitant decrease of the vitreous distance and shifting of the iris lens diaphragm.

[Application of mitomycin in primary covered sclerotomy]. / Die gedeckte Sklerotomie mit primärer Mitomycin-C-Applikation.

BACKGROUND: The covered sclerotomy is a minimally invasive, standardized fistulating glaucoma surgical procedure with reduced risk of complications. Early postoperative bleb fibrosis is a main success-limiting problem. In this clinical study IOP follow-up and the one year success rate after primary application of mitomycin C (MMC) is analyzed. PATIENTS AND METHODS: In 76 eyes with advanced glaucoma and without previous fistulating surgery, a covered sclerotomy combined with 3-minute-application of MMC0,02 % was performed. Over a period of 12 months, bleb and pressure were controlled regularly. The success rates were compared primarily with data from an earlier study without application of MMC. RESULTS: The mean age of the patients was 70 ± 11 years. 45 % had a pseudoexfoliation syndrome while 41 % were pseudophakic. The mean intraocular pressure (IOP) was 27 ± 8,5 mmHg preoperatively. After 12 months it was 16,2 ± 4,3 mmHg (p < 0.05) with a mean IOP reduction of 40 %. The absolute success rate (intraocular pressure < 21 mmHg without antiglaucoma therapy) was 58 % and the relative success rate (intraocular pressure < 21 mmHg under treatment) was 71 %. A revision or a needling was performed in 22 eyes (29 %). MMC-related complications were not observed. CONCLUSION: Through the additional MMC application on the base of the primary covered sclerotomy a significant pressure reduction could be achieved. 58 % of the patients didn't need any glaucoma medicine. The absolute success rate was higher than without additional inhibitions of the fibrosis.

[Use of resources in cataract surgery-More waste is (not) always possible]. / Ressourceneinsatz in der Kataraktchirurgie ­ Mehr Müll geht (n)immer.

BACKGROUND: Aspects of ecological sustainability are becoming more important in the healthcare system. The use of resources is particularly high in the operating theater. Cataract surgery is one of the most frequent procedures in ophthalmology and even in medicine overall. Its CO2 footprint is therefore quantitatively relevant. Approaches to conserve resources can be implemented at the levels of production and transport of materials and also in the form of reduction and management of waste. MATERIAL AND METHODS: In this paper the sources of the waste load, the management of waste separation, the implementation of single-use instruments and the influence of innovative technologies during cataract surgery are presented based on the current literature. RESULTS: Particularly the use of plastic materials for packaging and single-use instruments, also for reasons of hygiene, lead to an increased waste production. The simple separation of compound materials is difficult and only meaningful if the materials used in eye operations can be recycled; however, international comparisons show that cataract surgery can be performed with the same quality of results while conserving resources. Measures in organization and infrastructure are presented. CONCLUSION: In the future, innovative strategies should be developed and the use of resources in Germany should also be critically questioned in order to reduce the CO2 footprint of cataract surgery.

Interaction between ubiquitin-protein ligase SCFSKP2 and E2F-1 underlies the regulation of E2F-1 degradation.

The transcription factor E2F-1 is important in the control of cell proliferation. Its activity must be tightly regulated in a cell-cycle-dependent manner to enable programs of gene expression to be coupled closely with cell-cycle position. Here we show that, following its accumulation in the late G1 phase of the cell cycle, E2F-1 is rapidly degraded in S/G2 phase. This event is linked to a specific interaction of E2F-1 with the F-box-containing protein p45SKP2, which is the cell-cycle-regulated component of the ubiquitin-protein ligase SCFSKP2 that recognizes substrates for this ligase. Disruption of the interaction between E2F-1 and p45SKP2 results in a reduction in ubiquitination of E2F-1 and the stabilization and accumulation of transcriptionally active E2F-1 protein. These results indicate that an SCFSKP2-dependent ubiquitination pathway may be involved in the downregulation of E2F-1 activity in the S/G2 phase of the cell cycle, and suggest a link between SCFSKP2 and cell-cycle-dependent gene control.

p45SKP2 promotes p27Kip1 degradation and induces S phase in quiescent cells.

The F-box protein p45SKP2 is the substrate-targeting subunit of the ubiquitin-protein ligase SCFSKP2 and is frequently overexpressed in transformed cells. Here we report that expression of p45SKP2 in untransformed fibroblasts activates DNA synthesis in cells that would otherwise growth-arrest. Expression of p45SKP2 in quiescent fibroblasts promotes p27Kip1 degradation, allows the generation of cyclin-A-dependent kinase activity and induces S phase. Coexpression of a degradation-resistant p27Kip1 mutant suppresses p45SKP2-induced cyclin-A-kinase activation and S-phase entry. We propose that p45SKP2 is important in the progression from quiescence to S phase and that the ability of p45SKP2 to promote p27Kip1 degradation is a key aspect of its S-phase-inducing function. In transformed cells, p45SKP2 may contribute to deregulated initiation of DNA replication by interfering with p27Kip1 function.

[Clinical experience with brilliant blue G staining of the retinal surface]. / Klinische Erfahrungen zur Färbung der Netzhautoberfläche mit Brilliant blau G.

BACKGROUND: Staining of the retinal surface has improved the intraoperative removal of semitransparent membranes during macular surgery. The purpose of this study was to evaluate the clinical experiences with brilliant blue G (BBG) staining of the retinal surface. METHODS: BBG (Brilliant peel, Fluoron) was applied during vitrectomy and macular surgery in 43 patients. In 47 % there was a macular hole (MH), whereas 53 % had epiretinal membranes (ERM). Intraoperatively BBG was applied on the retinal surface under infusion or air conditions for 30 - 60 s. In MH the internal limiting membrane (ILM) and in ERM the membrane was removed. Postoperatively all patients were examined on average after 9 weeks. RESULTS: Although intraoperative BBG staining was less intensive compared to ICG staining, the staining was sufficient to safely remove the semitransparent membranes in all cases. In all patients with MH hole closure was achieved, and in 96 % with ERM the metamorphopsiae decreased. The mean decimal visual acuity increased from 0.25 ± 0.13 to 0.37 ± 0.20 (p < 0.05) and improved in 63 % of the patients. Clinically, there were no toxic side-effects from BBG staining. CONCLUSIONS: BBG allowed a complete and selective staining of the retinal surface. Thus, ILM and ERM could be removed safely during macular surgery. No clinical retinal toxicity was observed.

[Combined implantation of monofocal and multifocal intraocular lenses for presbyopia correction in cataract patients]. / Kombinierte Implantation einer Mono- und einer Multifokallinse zur Presbyopiekorrektur bei Kataraktpatienten.

BACKGROUND: The purpose of this study was to assess uncorrected far and near vision after implantation of a multifocal intraocular lens (IOL) in the second eye in patients with a unilateral monofocal IOL. PATIENTS AND METHODS: 13 cataract patients with a monofocal intraocular lens in one eye (SA60AT, Alcon) and postoperative emmetropia received a multifocal lens in the second eye (ReSTOR, Alcon). Two and six months postoperatively the clinical examination, far and near vision, near aniseikonia (AWAYA-New Aniseikonia Test), stereo vision (Lang I test) and the mesopic contrast sensitivity (F. A. C.T) were tested. In addition, the grade of satisfaction without glasses in general, and with far and near vision were noted on a visual analogue scale (0 - 10). Furthermore, independence from glasses and the presence of optical phenomena were assessed. RESULTS: The mean uncorrected far visual acuity 6 months postoperatively was 1.06 +/- 0.28 for the monofocal lens, 0.88 +/- 0.23 for the multifocal lens, and 1.16 +/- 0.24 binocularly. The uncorrected near visual acuity was Nieden 1 binocularly for all patients and ranged from Nieden 1 - 3 for the multifocal lens to Nieden 2 - 11 for the monofocal lens. 77% of the patients received the multifocal lens in their far dominant eye. The mean uncorrected near aniseikonia was < 1%. The mesopic contrast sensitivity showed no significant differences between the two IOL types and compared to binocular values. The satisfaction with the uncorrected visual acuity was in general 8.88 +/- 1.21, with the far visual acuity 9.42 +/- 1.24, and 7.33 +/- 1.72 with the near visual acuity. After 6 months 67% of the patients used glasses only for periods of prolonged reading. Halos and a low degree of glare were noted by 38.5% of patients 2 months postoperatively. At the 6 months visit 33.3% still had halos and only 8% glare. CONCLUSIONS: This first experience with the combined implantation of a monofocal and a multifocal lens revealed a marked improvement of the uncorrected near visual acuity compared to bilateral monofocal IOL implantation along with a high patient satisfaction.

[Mechanical pupillary dilatation using rings in small pupils during cataract surgery : Video article]. / Mechanische Pupillenerweiterung mit Ringen zur Kataraktoperation bei enger Pupille : Videobeitrag.

OBJECTIVE: The purpose of mechanical pupillary dilatation in small pupils is a sufficient visualization of the lens to be able to perform capsulorhexis, phacoemulsification and intraocular lens implantation. INDICATIONS: The indications for mechanical dilatation are fulfilled in patients where a sufficient pharmacological preoperative pupil dilatation is not possible. SURGICAL TECHNIQUE: During routine cataract surgery specific foldable rings can be employed to dilate the pupil with the appropriate injector under viscoelastic substances. These rings are carefully placed at the pupillary margin until circular pupillary dilatation up to 6-7 mm is achieved. After intraocular lens implantation and before removing the viscoelastic substance the rings are slowly folded into the injector and then removed. The surgical technique is demonstrated in detail with the help of a video of the operation, which is available online. RESULTS: Mechanical pupillary dilatation was possible in all patients studied (n = 14), which allowed uncomplicated phacoemulsification and intraocular lens implantation. For both ring systems studied the mean pupillary dilatation was 6.6 mm. At the end of surgery, the pupillary diameter was 4.89 mm using a Malyugin ring (MST, Redmond, Washington, USA) and 4.93 mm with an I­ring (Visitec, Waltham, MA, USA; P > 0.05). Small lesions at the pupillary margin or pigment dispersion during implantation or explantation depended mostly on the individual patient situation and not on the ring used. CONCLUSION: Mechanical pupillary dilatation with rings allows sufficient dilatation to perform cataract surgery. Both the Malyugin ring and the I­ring achieved smooth and atraumatic pupillary dilatation.

[Refractive long-term results after piggyback intraocular lens implantation]. / Refraktive Langzeitergebnisse nach Huckepackimplantation.

BACKGROUND: Piggyback lens implantation is an alternative to exchange of the original intraocular lens (IOL) to treat high anisometropia in pseudophakic eyes. We present our results. PATIENTS AND METHOD: A second IOL (piggyback) was implanted in 27 patients from 2000 to 2006. Nineteen patients were clinically investigated late postoperatively, and data for the other eight patients were evaluated from the patients' files. RESULTS: The patients were 65+/-9 years old. Follow-up time was 38+/-25 months. The mean preoperative spherical equivalent (SE) in the myopic eyes was -7.86+/-3.82 D and in the hyperopic eyes was 1.64+/-0.74 D. After surgery, the mean SE in the myopic eyes was -1.77+/-1.82 D and in the hyperopic eyes was -0.09+/-0.51 D. Postoperative anisometropia was reduced from 4.64+/-3.3 D. to 0.9+/-0.82 D. CONCLUSION: Piggyback lens implantation is a safe and effective surgical procedure and is less traumatic than exchange of the original IOL.

[Therapy refractory blepharoconjunctivitis in a 90 year old patient]. / Therapierefraktäre Blepharokonjunktivitis bei einer 90-jährigen Patientin.

Sebaceous gland carcinoma can clinically mimic benign conditions such as chalazion and blepharoconjunctivitis. This carcinoma should be histologically excluded for every unilateral, recalcitrant chalazion and every unilateral, therapy refractory blepharitis. Autosomal dominant Muir-Torre syndrome should be considered in patients who develop sebaceous gland carcinoma of the ocular adnexa. In this case, the sebaceous gland carcinoma is combined with visceral carcinoma.

[Optical quality of the cornea following incisional correction of astigmatism]. / Optische Qualität der Hornhaut nach inzisionaler Astigmatismuskorrektur.

BACKGROUND: Unilateral lamellar keratotomy (LKT) and curved dual lamellar keratotomy (BLK) were compared to evaluate the influence of incisional correction of astigmatism on the optical quality of the cornea. PATIENTS AND METHODS: Forty-six patients with a preoperative astigmatism greater than 1.5 D were studied. LKT was performed on 30 eyes during cataract surgery and 20 eyes were treated with a BLK. Preoperatively and 4 weeks after surgery the corneal topographical data were analyzed with ray tracing in a 3-mm optical zone. The potential visual acuity (PVA) and the optical distortion (OD), which is represented by the width of the point spread in the optical center, were calculated as parameters for the optical quality. RESULTS: The mean surgically induced astigmatism was 2.6+/-1.5 D for the LKT group and 3.5+/-1.4 D for the BLK group. The PVA decreased significantly in the LKT group from 1.2+/-0.2 to 1.0+/-0.3 (p=0.008), whereas in the BLK group the PVA remained unchanged (p=0.916). The OD increased from 6.6+/-0.9 microm to 7.9+/-2.0 microm (p=0.007) in the LKT group. In the BLK group the values were stable (p=0.843). CONCLUSIONS: The optical quality of the cornea decreased after unilateral keratotomy in the early postoperative period. Thus, optical quality values should also be considered in incisional correction of astigmatism.

[Influence of age on optical aberrations of the human eye]. / Einfluss des Alters auf die optischen Aberrationen des menschlichen Auges.

BACKGROUND: Currently the influence of age on corneal and ocular aberrations is still insufficiently known. The aim of this clinical study was to compare age-related aberrations of human eyes. METHODS: In a prospective study 98 eyes of 49 healthy patients ranging from 17 to 65 years of age (38.6+/-10.0 years) were consecutively examined. The best corrected visual acuity ranged from 0.8 to 1.6; 48 eyes were emmetropic (SE+/-0.5 D), 42 eyes myopic (SE <-0.5 to -6.75 D), and 8 eyes hyperopic (SE >+0.5 to +3.88 D). The corneal aberrations were derived from corneal topography (Keratron Scout, Optikon). The measurement of ocular aberrations was performed with a Tscherning wavefront aberrometer (ORK, Schwind). The aberrations of the Zernike coefficients and RMS values (1st to 4th order) were determined. RESULTS: The mean corneal and ocular Zernike coefficients of higher order were smaller than 0.2 microm. There was an evident decrease of wavefront aberrations with increasing order. Higher order corneal aberrations were larger than the corresponding ocular aberrations. With increasing age higher optical errors increased in complexity, and the correlation of corneal and ocular aberrations decreased with significant differences. Although the corneal ocular RMS value of the 3rd and 4th order correlated in the younger group (r=0.51, p=0.0001), there was no correlation in the older group (r=-0.48, p=0.832). The influence of age caused a significant increase of ocular aberrations of the 3rd and 4th order, in particular a tenfold extension of coma (C07) (p=0.002), a twofold extension of spherical aberration (C12) (p=0.0001), and an increase of the 3rd and 4th order RMS values (p=0.001). CONCLUSIONS: Increased age induced an increase in optical aberrations of the eye, which demonstrates the influence of the lens on ocular aberrations. The combination of corneal and ocular diagnostic methods is recommendable for a better understanding of visual performance.

[OCT-goniometry before and after iridotomy in angle-closure glaucoma]. / OCT-Goniometrie vor und nach Iridotomie beim Engwinkelglaukom.

PURPOSE: Visualization of the anterior chamber angle is an important diagnostic method in patients with angle-closure glaucoma. In this study, optical coherence tomography (OCT) was used to image the angle width, the iris configuration, and the iris thickness in patients with angle-closure glaucoma. METHODS: Thirteen eyes of 11 patients suffering from angle-closure glaucoma were studied with slitlamp-adapted OCT. All patients were treated with Nd:YAG laser iridotomy. The angle width ( degrees ), the angle opening distance (AOD) (microm), and the iris thickness (microm) were measured with OCT. The configuration of the iris was classified as steeply convex, convex, or flat. RESULTS: The mean angle width was preoperatively 5.1+/-5.0 degrees (0-15 degrees ) and enlarged significantly (p=0.007) to 10.4+/-5.5 degrees (0-19 degrees ) postoperatively. The AOD changed from 71+/-55 microm (0-157 microm) preoperatively to 143+/-74 microm (0-256 microm) postoperatively (p<0.001). The mean iris thickness was 338+/-33 microm. With the exception of two eyes the predominant iris configuration changed from convex to flat. CONCLUSIONS: OCT allowed visualization and noninvasive assessment of the anterior chamber angle region in patients with angle-closure glaucoma. Our results suggest that goniometry with OCT could improve the evaluation in patients with narrow or closed anterior chamber angles.

Screening cDNA expression libraries in lambda gt11 with a T cell hybridoma.

A T cell hybridoma specific for a protein of Plasmodium chabaudi chabaudi has been used to test a system for direct T cell screening of a cDNA library of P. chabaudi in the phage lambda gt11. The technique is based upon the rapid separation of the recombinant beta-galactosidase fusion protein from the bacterial mixtures using polystyrene beads coated with anti-beta-galactosidase antibodies. These coated beads are cultured with antigen-presenting cells and the T cell hybridoma. The technique is sufficiently sensitive to pick up the products of one recombinant phage in a pool of 1000-10,000 other phages. Individual plaques or clones of recombinant phage can be selected after testing of sequential dilutions of pools containing positive recombinant phages. This technique will be generally applicable and should be useful for the identification of important T cell peptides in infectious diseases.

Analysis of T lymphocyte reactivity to complex antigen mixtures by the use of proteins coupled to latex beads.

This report describes a suitable model for analysing heterogeneous T cell responses to complex foreign antigens using coated polystyrene beads. The advantage of this technique is that it allows the simple removal of detergents from bound antigen so that biochemically separated antigens or crude antigen mixtures can be used. Furthermore, due to the enhanced uptake of latex-bound antigens by phagocytic antigen-presenting cells (APC), very small amounts of antigen will suffice for activation of T cells in vitro. The potential use of this technique to analyse relevant T cell responses to antigens which are difficult to obtain purified in bulk quantities, is discussed.

Expression of recombinant human thyroid peroxidase by the baculovirus system and its use in ELISA screening for diagnosis of autoimmune thyroid disease.

The cDNAs coding for human full-length and soluble thyroid peroxidase (TPO) were constructed, cloned into a baculovirus transfer vector and used for infection of Spodoptera frugiperda (Sf9) cells. The soluble TPO lacking 87 amino acids of the C-terminal transmembrane and intracisternal domains was designed as a fusion protein with a histidine-hexapeptide as an affinity ligand at its C-terminus. Whereas the recombinant full-length TPO was expressed mainly in an insoluble form in Sf9 cells, the recombinant soluble TPO was almost completely secreted into the culture medium. Both the full-length and the soluble TPO were purified by conventional methods and by a specific affinity chromatography using metal chelating matrix respectively, and tested for their autoantigenicity towards anti-TPO autoantibodies. The ELISA established with the purified recombinant soluble TPO as antigen demonstrated its specificity, practicability and reproducibility in screening of anti-TPO autoantibodies in sera of autoimmune thyroid patients. High correlation (r = 0.89, n = 175) was obtained between the soluble TPO and natural TPO prepared from human thyroid glands. Pathological sera (n = 200) were positively assayed with a significance of 91%.

Retinal sparing by selective retinal pigment epithelial photocoagulation.

OBJECTIVE: To investigate whether photocoagulation of the retinal pigment epithelium is possible with sparing of the photoreceptors. METHODS: Mild laser effects of a neodymium:yttrium-lithium-fluoride (Nd:YLF) laser (527 nm) were applied to 17 patients. To establish the necessary energy, test exposures were performed to the lower macula (laser variables: 1.7 microseconds, 100 and 500 pulses applied in a train at 500 Hz, 20-130 microJ, 160 microm). Of 179 test lesions, 73 were followed up at various time intervals up to 1 year by performing microperimetry directly on top of the laser lesions. RESULTS: All of the test lesions were at the threshold of retinal pigment epithelial disruption, and none of the laser effects were visible by ophthalmoscopy during photocoagulation; they were detectable only by fluorescein angiography. After exposure with 500 pulses, retinal defects were detected in up to 73% of the patients (100 microJ) after the first day. Most of these defects were no longer detectable after 3 months. After exposure with 100 pulses, no defects could be detected with 70 and 100 microJ after 1 day. The absence of microscotomas in the follow-up period suggests that retinal damage was minimal or, if it occurred, was functionally repaired. CONCLUSION: By choosing proper energy and number of pulses, it is possible to produce retinal pigment epithelial effects with no subsequent retinal damage detectable by microperimetry.