Polypseudophakia: from "Piggyback" to supplementary sulcus-fixated IOLs.

Polypseudophakia, the concept of using a second intraocular lens (IOL) to supplement an IOL that has already been placed in the capsular bag, was first used as a corrective measure where the power requirement was higher than that of available single IOLs. Subsequently, the technique was modified to compensate for post-operative residual refractive errors. In these early cases, an IOL designed for the capsular bag would be implanted in the sulcus.  Although these approaches were less than ideal, alternative means of correcting residual refractive errors were not without their limitations: IOL exchange can be traumatic to the eye and is not easily carried out once fibrosis has occurred, while corneal refractive surgical techniques are not suitable for all patients. Piggyback implantation was the term first coined to describe the use of two IOLs, placed together in the capsular bag. The term was later extended to include the procedure where an IOL designed for the capsular bag was placed in the sulcus. Unfortunately, the term piggyback has persisted even though these two approaches have been largely discredited. Intraocular lenses are now available which have been specifically designed for placement in the ciliary sulcus. As these newer IOLs avoid the many unacceptable complications brought about by both types of earlier piggyback implantation, it is time to employ a new terminology, such as supplementary IOL or secondary enhancement to distinguish between the placement of an unsuitable capsular bag IOL in the sulcus and the implantation of an IOL specifically designed for ciliary sulcus implantation. In addition to minimising possible complications, supplementary IOLs designed for the sulcus have expanded the options available to the ophthalmic surgeon. With these new IOLs it is possible to correct presbyopia and residual astigmatism, and to provide temporary correction of refractive errors in growing, or unstable, eyes. This article aims to review the literature available on supplementary IOL implantation in the ciliary sulcus and to summarise the evidence for the efficacy and safety of this intervention. KEY MESSAGES: What is known Polypseudophakia has been used for over 30 years to correct hyperopia or residual refractive error, but early techniques were associated with significant complications. What is new The development of specially designed sulcus-fixated supplementary IOLs significantly reduces the risks associated with these procedures, and has also opened up new opportunities in patient care. The reversibility of the procedure allows patients to experience multifocality, and to provide temporary and adjustable correction in unstable or growing eyes. The terms "secondary enhancement" or "DUET" to describe supplementary IOL implantation are preferential to "piggyback".

Cyclization enhances function of linear anti-arthritic peptides.

This study describes the biophysical and immunomodulatory features of a cyclic peptide termed C1 which consists of alternating d-, l-amino acids and is capable of inhibiting IL-2 production in vitro and reducing the induction and extent of T-cell mediated inflammation in animal models. Solid-state nuclear magnetic resonance demonstrates that the peptide orders the lipid bilayer, suggesting a transmembrane orientation, and this is supported by surface plasmon resonance indicating strong binding affinity of C1 to model membranes. In vitro cell viability and proliferation assays show that C1 does not disrupt the integrity of cell surface membranes. Permeation studies of C1 and analogs across human epidermis cells show that the stability and skin permeability are enhanced by cyclization. Treatment with C1 in an asthma and in an arthritis animal model resulted in a suppressed immune response. Cyclization may be a useful means of enhancing biological linear peptide activity and improving delivery.

Macular hole formation and spontaneous closure after vitrectomy for vitreomacular traction documented in spectral-domain optical coherence tomography.

BACKGROUND: We present a case of a macular hole formation and its spontaneous closure after vitrectomy for vitreomacular traction. To our knowledge, it is the first description of spontaneous closure of the macular hole after vitrectomy for vitreomacular traction. CASE PRESENTATION: A 78-year-old woman presented decreased visual acuity and metamorphopsia in the right eye due to vitreomacular traction. A vitrectomy with internal limiting membrane peeling and an air tamponade was performed in the right eye. Spectral-domain optical coherence tomography was obtained during all visits.Seven days after the vitrectomy, the spectral-domain optical coherence tomography showed a resolved vitreomacular traction and a full-thickness macular hole. Examination after a further three weeks showed that the full-thickness macular hole had spontaneously closed. 5 months later spectral-domain optical coherence tomography showed a normal foveal contour without intraretinal microcystic spaces and a resolution of the photoreceptor and external limiting membrane elevation. CONCLUSIONS: While performing a vitrectomy for vitreomacular traction posterior hyaloid membrane creates anterior-posterior traction on the fovea, and, during detachment, retinal layer damage occurs in the macular area and a full-thickness macular hole may develop. Removal of the anterio-posterior vitreous traction may play the main role and may help the spontaneous closure of the macular hole after vitrectomy for vitreomacular traction.

Potential environmental effect of reducing the variation of disposable materials used for cataract surgery.

PURPOSE: To analyze the cataract package variability in 1 country, Austria. SETTING: Austrian Departments of Ophthalmology. DESIGN: Cross-sectional study. METHODS: The cataract package components of 3 different Austrian hospitals were weighed and life cycle assessment on each product performed. This data was then extrapolated to the sales figures of the main Austrian cataract package suppliers to estimate the carbon footprint of all cataract packages used in Austria in 2021. RESULTS: There were 55 different cataract package compositions in use with an average weight of 0.7 kg. These compositions differ significantly in weight and composition considering that the smallest package was 57% lighter than the largest package. The size of the surgical drapes also showed considerable variation, with a difference of up to 71%. This is substantial, considering that drapes and covers account for about 53% of the package weight. CONCLUSIONS: There was a considerable variation in package composition and product size, which could provide opportunities to save carbon dioxide emissions in cataract surgery. If all Austrian eye departments were to reduce the material quantities and drape sizes to the lower third of the cataract packages used in the Austria in 2021, cataract package associated CO 2 emissions could be reduced by 34%.

Loteprednol etabonate ophthalmic suspension 0.5 %: efficacy and safety for postoperative anti-inflammatory use.

Topical corticosteroids are routinely used as postoperative ocular anti-inflammatory drugs; however, adverse effects such as increased intraocular pressure (IOP) are observed with their use. While older corticosteroids such as dexamethasone and prednisolone acetate offer good anti-inflammatory efficacy, clinically significant increases in IOP (≥10 mmHg) are often associated with their use. Loteprednol etabonate, a novel C-20 ester-based corticosteroid, was retrometabolically designed to offer potent anti-inflammatory efficacy but with decreased impact on IOP. After exerting its therapeutic effects on the site of action, loteprednol etabonate is rapidly converted to inactive metabolites, resulting in fewer adverse effects. Randomized controlled studies have demonstrated the clinical efficacy and safety of loteprednol etabonate ophthalmic suspension 0.5 % for the treatment of postoperative inflammation in post-cataract patients with few patients, if any, exhibiting clinically significant increases (≥10 mmHg) in IOP. Furthermore, safety studies demonstrated a minimal effect of loteprednol etabonate on IOP with long-term use or in steroid responders with a much lower propensity to increase IOP relative to prednisolone acetate or dexamethasone. The anti-inflammatory treatment effect of loteprednol etabonate appears to be similar to that of rimexolone and difluprednate with less impact on IOP compared to difluprednate, although confirmatory comparative studies are needed. The available clinical data suggest that loteprednol etabonate is an efficacious and safe corticosteroid for the treatment of postoperative inflammation.

The forceps-needle: Combining needle and grasping functions in a single instrument.

A new forceps-needle to facilitate intrascleral haptic fixation surgery is described. In an initial series of 10 cases, the forceps-needle was used to grasp and externalize the haptic of a 3-piece intraocular lens (IOL) for transscleral fixation. The site of perforation was marked at 180 degrees 2.0 mm away from the limbus. Then, the IOL with polypropylene haptics was folded and implanted partially into the anterior chamber. A transconjunctival, scleral tunnel of about 2.0 mm length parallel to the limbus was prepared with the forceps-needle on 1 side, with the second hand holding the leading haptic through a side-port incision. The end of the first haptic was grasped and externalized after which the end of the haptic was flanged. Subsequently, a second scleral tunnel was prepared with the forceps-needle, and the second haptic was externalized and flanged. All procedures could be performed without any intraoperative complication.

Visual Outcomes and Patient Satisfaction After Bilateral Sequential Implantation of a Capsular Bag IOL and a Supplementary Sulcus-Fixated Trifocal IOL.

PURPOSE: To assess visual and refractive outcomes and patient satisfaction after bilateral sequential implantation of a primary capsular bag intraocular lens (IOL) and a supplementary sulcus-fixated trifocal IOL. METHODS: All patients had bilateral implantation of a mono-focal IOL in the capsular bag followed by a supplementary trifocal IOL (Sulcoflex 703F, Rayner Intraocular Lenses Limited) in the sulcus. Patients were evaluated for monocular uncorrected and corrected distance visual acuity, binocular uncorrected and corrected distance, intermediate and near visual acuity, photopic and mesopic contrast sensitivity, defocus curves, visual symptoms, spectacle independence, and patient satisfaction at 1 and 6 months postoperatively. RESULTS: Forty eyes of 20 patients were evaluated. Six months after surgery, mean binocular uncorrected visual acuity was -0.07 ± 0.06 logMAR for distance vision (range: -0.2 to 0.0 logMAR), -0.03 ± 0.17 logMAR for intermediate vision (range: -0.1 to 0.6 logMAR), and 0.09 ± 0.08 logMAR for near vision (range: -0.1 to 0.2 logMAR). All patients reported full spectacle independence after 6 months and no adverse events were reported for any of the patients. CONCLUSIONS: Sequential implantation of a monofocal IOL in the capsular bag and a supplementary trifocal IOL in the sulcus provides a safe and effective choice for patients who desire spectacle independence after cataract surgery. [J Refract Surg. 2021;37(2):105-111.].

LIPEMIA RETINALIS DURING CHEMOTHERAPY WITH ADJUNCTIVE GLUCOCORTICOID TREATMENT IN A PATIENT WITH COLON CARCINOMA.

PURPOSE: The purpose of this report is to describe a case of lipemia retinalis due to decompensating hyperlipidemia that occurred during chemotherapy in a patient with metastatic colon carcinoma. METHODS: Retrospective case report. RESULTS: A 55-year-old non-insulin-dependent diabetic man with well-controlled hyperlipidemia presented himself with temporarily blurred vision in both eyes occurring during chemotherapy. He was found to have lipemia retinalis in his both eyes. Blood tests revealed elevated cholesterol and triglyceride levels exceeding 8,200 mg/dL. He received six cycles of FOLFIRI/bevacizumab and accompanying dexamethasone because of colon cancer with pulmonary metastases. Lipemia retinalis had resolved after a 6-week follow-up when chemotherapy was finished, and the patients' triglyceride and glucose levels decreased to normal values. CONCLUSION: Lipemia retinalis associated with visual impairment may occur during chemotherapy under accompanying treatment with dexamethasone. Even if patients with hyperlipidemia are metabolically well-controlled with oral medication, treatment with dexamethasone can potentially lead to decompensation of hyperlipidemia causing secondary lipemia retinalis.

Hypothesis: TCR signal transduction--A novel tri-modular signaling system.

Antigenic peptides initiate an immune response in T cells via the T cell receptor (TCR). The TCR itself is widely regarded as one of the most complex receptors in nature, as it is comprised of at least six different subunits, the antigen recognizing TCRalpha and beta chains, and the signal transmitting CD3deltavarepsilon, gammaepsilon, and zeta2 dimers. In order for a signal to be transmitted from the TCR to the cytoplasm, the CD3 chains must "sense" that an antigenic peptide has been presented to the TCRalpha and beta subunits. After accomplishing this, there are a total of 10 different immunoreceptor tyrosine activation motifs (ITAMs) present within the CD3 chains which effectively activate the T cell and hence the immune response. The importance of each CD3 chain and subsequently each ITAM has been the focus of intense research. However, the precise role(s) played by each CD3 chain has remained elusive. Using the immunomodulatory peptide termed core peptide (CP), which is proposed to inhibit TCR activation by disrupting TCR-CD3 interactions, a tri-modular signaling system for T cell activation is proposed. By contrast to the existing two distinct signaling model (zeta2, CD3epsilongamma/epsilondelta), in this model each of the three dimers, CD3gammaepsilon, deltaepsilon, and zeta2, are proposed to act as three separate and distinct signaling modules, performing both specific and redundant functions.

Therapeutic application of transmembrane T and natural killer cell receptor peptides.

Autoimmune diseases primarily mediated by T-cells effect a significant proportion of the population and include common and distressing conditions such as diabetes, multiple clerosis, inflammatory bowel disease, skin diseases and arthritis. Current treatments are restrictive in terms of range of options and side-effect profiles and new drugs and new approaches are always eagerly sought. With the T-cell antigen receptor (TCR) as a model system we have identified a new approach to inhibit T-cell activation. By means of peptides derived from the transmembrane TCR-alpha chain region we have shown that T-cells, the major effector cells of disease, can be inhibited in vitro and the immune responses leading to disease ameliorated in animal models. The exact molecular mechanism of peptide action is still uncertain and assumed to involve a disturbance in transmembrane protein-protein interactions mediated by amino acid charges that disrupt normal signaling pathways. This chapter summarizes the results to date ofTCR core peptide (CP); the most effective peptide noted so far, in terms of function, behavior in membranes and future development and application as a therapeutic agent. The lessons learned from this model can be applied to other multi-subunit receptors that serve critical cellular functions and open new doors for drug design, development and application.

Anti-vascular endothelial growth factor for unilateral acute idiopathic maculopathy.

PURPOSE: To describe a case of unilateral acute idiopathic maculopathy (UAIM) response to intravitreal therapy with aflibercept (Eylea). METHODS: Retrospective case report. RESULTS: A 36-year-old woman with sudden visual impairment and central scotoma was found to have a UAIM in her left eye. Three weeks after continuous worsening of her visual acuity and central scotoma, the patient was treated with intravitreal injections of aflibercept. The visual acuity increased and the macula lesion regressed, causing macula scarring after 2 injections. CONCLUSIONS: Intravitreal injections of aflibercept could be a therapy option in patients with UAIM without signs of spontaneous resolution of the clinical manifestations and visual improvement.

Randomized controlled European multicenter trial on the prevention of cystoid macular edema after cataract surgery in diabetics: ESCRS PREMED Study Report 2.

PURPOSE: To compare the efficacy of perioperative treatment strategies, in addition to topical bromfenac 0.09% and dexamethasone 0.1%, to reduce the risk for developing cystoid macular edema (CME) after uneventful cataract surgery in diabetic patients. SETTING: Twelve European study centers. DESIGN: Randomized clinical trial. METHODS: Diabetic patients having phacoemulsification cataract surgery were randomly allocated to receive no additional treatment, a subconjunctival injection with 40 mg triamcinolone acetonide, an intravitreal injection with 1.25 mg bevacizumab, or a combination of both. The main outcomes were the difference in central subfield mean macular thickness, corrected distance visual acuity, and the incidence of CME and clinically significant macular edema within 6 and 12 weeks postoperatively. RESULTS: The study comprised 213 patients. At 6 and 12 weeks postoperatively, the central subfield mean macular thickness was 12.3 µm and 9.7 µm lower, respectively, in patients who received subconjunctival triamcinolone acetonide than patients who did not (P = .007 and P = .014, respectively). No patient who received subconjunctival triamcinolone acetonide developed CME. Intravitreal bevacizumab had no significant effect on macular thickness. CONCLUSIONS: Diabetic patients who received a subconjunctival injection with triamcinolone acetonide at the end of cataract surgery had a lower macular thickness and macular volume at 6 and 12 weeks postoperatively than patients who did not. Intravitreal bevacizumab had no significant effect.

European multicenter trial of the prevention of cystoid macular edema after cataract surgery in nondiabetics: ESCRS PREMED study report 1.

PURPOSE: To compare the efficacy of a topical nonsteroidal antiinflammatory drug, topical corticosteroid, and a combination of both drugs to prevent the occurrence of cystoid macular edema (CME) after cataract surgery in nondiabetic patients. SETTING: Twelve European study centers. DESIGN: Randomized clinical trial. METHODS: Nondiabetic patients having uneventful cataract surgery were included in this study. Patients were randomized to receive topical bromfenac 0.09% twice daily for 2 weeks or dexamethasone 0.1% 4 times daily with 1 drop less per day every following week, or a combination of both. The primary outcome was the difference in central subfield mean macular thickness 6 weeks postoperatively. Secondary outcome measures included corrected distance visual acuity as well as the incidence of CME and clinically significant macular edema (CSME) within 6 weeks and 12 weeks postoperatively. RESULTS: This study comprised 914 patients. Six weeks postoperatively, the central subfield mean macular thickness was 288.3 µm, 296.0 µm, and 284.5 µm in the bromfenac group, dexamethasone group, and combination treatment group, respectively (overall P = .006). The incidence of clinically significant macular edema within 12 weeks postoperatively was 3.6%, 5.1%, and 1.5%, respectively (overall P = .043). CONCLUSION: Patients treated with a combination of topical bromfenac 0.09% and dexamethasone 0.1% had a lower risk for developing CSME after cataract surgery than patients treated with a single drug.

Lipidation and glycosylation of a T cell antigen receptor (TCR) transmembrane hydrophobic peptide dramatically enhances in vitro and in vivo function.

A T cell antigen receptor (TCR) transmembrane sequence derived peptide (CP) has been shown to inhibit T cell activation both in vitro and in vivo at the membrane level of the receptor signal transduction. To examine the effect of sugar or lipid conjugations on CP function, we linked CP to 1-aminoglucosesuccinate (GS), N-myristate (MYR), mono-di-tripalmitate (LP1, LP2, or LP3), and a lipoamino acid (LA) and examined the effects of these compounds on T cell activation in vitro and by using a rat model of adjuvant-induced arthritis, in vivo. In vitro, antigen presentation results demonstrated that lipid conjugation enhanced CP's ability to lower IL-2 production from 56.99%+/-15.69 S.D. observed with CP, to 12.08%+/-3.34 S.D. observed with LA. The sugar conjugate GS resulted in only a mild loss of in vitro activity compared to CP (82.95%+/-14.96 S.D.). In vivo, lipid conjugation retarded the progression of adjuvant-induced arthritis by approximately 50%, whereas the sugar conjugated CP, GS, almost completely inhibited the progression of arthritis. This study demonstrates that hydrophobic peptide activity is markedly enhanced in vitro and in vivo by conjugation to lipids or sugars. This may have practical applications in drug delivery and bioavailability of hydrophobic peptides.

Intraindividual comparison of surgical trauma after bimanual microincision and conventional small-incision coaxial phacoemulsification.

PURPOSE: To compare the surgical trauma after microincision phacoemulsification and small-incision coaxial phacoemulsification after implantation of conventional, foldable, hydrophobic acrylic intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: A prospective investigator-masked case series comprised patients with bilateral cataract who had cataract surgery on the same day. Thirty-three patients (66 eyes) were randomized. Microincision cataract surgery (MICS) was performed through 2, 1.4 mm clear corneal incisions (CCIs) using bimanual sleeveless phacoemulsification (cool phaco) in 1 eye. Small-incision cataract surgery (SICS) was performed on the other eye through a 3.2 mm CCI. In all cases, an AcrySof SA60AT IOL was inserted, in the MICS group after the CCI was enlarged. Laser flare photometry, specular microscopy, corneal endothelial cell density, and pachymetry were evaluated preoperatively and postoperatively. Intraindividual comparison and statistical analyses were performed. RESULTS: There were no relevant clinical differences or perioperative complications in either group. There were no statistically significant differences between preoperative and postoperative anterior chamber flare or endothelial cell loss. On the first postoperative day, the MICS group had statistically significantly increased corneal swelling (P = .008). Postoperatively, the mean endothelial cell density loss was higher in the MICS group (6.2%) than in the SICS group (3.10%); however, the difference between groups was not significant (P = .08) CONCLUSIONS: Microincision cataract surgery was a safe and reproducible technique. The postoperative results in the MICS group were comparable to those in the SICS group.

Uveal and capsular biocompatibility after implantation of sharp-edged hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses in eyes with pseudoexfoliation syndrome.

PURPOSE: To evaluate the uveal and capsular biocompatibility of 3 types of sharp-edged foldable intraocular lenses (IOLs) in eyes with pseudoexfoliation syndrome (PEX). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Eighty-five eyes with PEX had implantation of 1 of the following sharp-edged 3-piece IOLs: hydrophilic acrylic (Injectacryl F3000, OphthalMed), hydrophobic acrylic (AcrySof MA60MB, Alcon), or silicone (CeeOn 911, AMO). Postoperative evaluation (flare, cellular reaction, and capsular reaction) was performed at 1, 3, and 7 days as well as 1, 3, 6, and 12 to 18 months. RESULTS: One year after surgery, flare was comparable between the IOLs. In terms of uveal biocompatibility, whereas the Injectacryl had the highest deposition of debris on the IOL surface (P = .04), the CeeOn 911 had significantly more small round cells in the first 6 months (P<.03). The AcrySof had the highest number of foreign-body giant cells (P = .01). In terms of capsular biocompatibility, lens epithelial cell outgrowth was highest in the AcrySof group (P<.02). Anterior capsule opacification was comparable between the 3 groups. Posterior capsule opacification was mild in all groups but was significantly greater in the Injectacryl group (P<.05). There were no cases of clinically significant IOL decentration or capsule contraction. CONCLUSIONS: In general, inflammatory cells accumulated more easily on hydrophobic IOLs than on hydrophilic IOLs; the AcrySof IOL had the highest prevalence of foreign-body giant cells. All 3 IOLs had good biocompatibility, although the AcrySof group had increased inflammatory signs.

Intraindividual comparison of capsule behavior of 2 hydrophobic acrylic intraocular lenses during a 5-year follow-up.

PURPOSE: To evaluate and compare the 5-year postoperative anterior (ACO) and posterior capsule opacification (PCO), the occurrence of glistenings, and the level of anterior capsule retraction after implantation of 2 designs of 1-piece hydrophobic acrylic IOLs. SETTING: Hospital St. John, Vienna, Austria. DESIGN: Randomized controlled prospective case series. METHODS: Patients had an Acrysof SA60AT IOL (Group A) implanted in 1 eye and a Tecnis ZCB00 IOL (Group B) implanted in the fellow eye. At 1, 3, and 5 years, the PCO level was evaluated with the Evaluation of Posterior Capsule Opacification software. The level of ACO and capsule retraction was graded subjectively. Glistenings were scored as present or not present. RESULTS: Fifty eyes of 25 patients were evaluated after 5 years. No significant differences in PCO scores were found between the 2 groups at all follow-up visits (1 year: 0.06 ± 0.12 [SD] versus 0.07 ± 0.13, P = .35; 3 years: 0.23 ± 0.36 versus 0.22 ± 0.32, P = .66; 5 years: 0.36 ± 0.41 versus 0.36 ± 0.54, P = .98). A significant increase in PCO score was found between 3 and 5 years (P < .01). Anterior capsule opacification was present in Group A and Group B in 18.0% and 2.7% of eyes (P = .03), in 92.0% and 24.0% of eyes, and in 100% and 52% of eyes (P < .01) at 1, 3, and 5 years, respectively. Glistenings (5 years 100%) were observed in Group A. CONCLUSION: Both IOLs had a comparable PCO rate 5 years after surgery, although more ACO and retraction as well as glistenings were observed in Group A.

Capsular bag-fixated and ciliary sulcus-fixated intraocular lens centration after supplementary intraocular lens implantation in the same eye.

PURPOSE: To assess capsular bag and sulcus intraocular lens (IOL) centration in eyes that had implantation of a sulcus-fixated supplementary IOL anterior to a preexisting capsular bag IOL. SETTING: Academic Teaching Hospital of St. John, Vienna, Austria. DESIGN: Retrospective case series. METHODS: A sulcus-fixated supplementary IOL (Sulcoflex) was implanted anterior to a preexisting capsular bag IOL. The geometric center of preexisting capsular bag IOLs and newly implanted sulcus-fixated IOLs was evaluated at least 12 months postoperatively and in relation to the geometric center of the pupil and limbus. RESULTS: The study comprised 48 eyes of 43 patients with a mean follow-up of 25 months (range 12 to 84 months). The mean decentration of the capsular bag-fixated IOL was 0.29 mm ± 0.02 (SEM) when compared with the limbus and 0.29 ± 0.03 mm when compared with the dilated pupil. The mean decentration of the sulcus-fixated IOL was 0.23 ± 0.02 mm in relation to the limbus and 0.22 ± 0.02 mm when in relation to the dilated pupil. Sulcus-fixated supplementary IOLs showed significantly better centration than bag-fixated IOLs when compared with the limbus and with the pupil (both P = .03, paired t test). CONCLUSIONS: Implantation of a sulcus-fixated supplementary IOL resulted in good centration of capsular bag-fixated IOLs and ciliary sulcus-fixated IOLs. However, ciliary sulcus-fixated IOLs achieved significantly better centration.

Immunoreceptor transmembrane peptides and their effect on natural killer (NK) cell cytotoxicity.

Short peptides derived from the transmembrane sequence of NK activating receptors and associated molecules were tested in vitro for inhibition of NK cell cytotoxicity using a standard (51)Cr release assay in the absence or presence of peptides. NKL23 cell line was used as the NK effector and the target was the NKL23 sensitive 721.221 cell line. NKp46, NKp30, NKG2D and CD3-zeta peptides inhibited NK activity at higher concentration (100 microM) compared to controls by 6-13% (p<0.05). Modification of one non-effective peptide (NKP44) significantly enhanced inhibition by 30%, 17% and 11% at 100 microM, 50 microM and 10 microM respectively compared to controls. A T-cell antigen receptor-alpha chain transmembrane sequence derived peptide (CP) significantly inhibited NKL cell activation by 20-30% (p<0.05) at 50 microM and 100 microM concentrations compared to the control. The structural similarities between these immuno-receptors, and in particular the need for transmembrane electrostatic interactions for receptor function, provides the basis for current and future targeted therapeutic strategies.