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Limbal stem cell deficiency (LSCD) is a disease resulting from the loss or dysfunction of epithelial stem cells, which seriously impairs sight. Autologous limbal stem cell transplantation is effective in unilateral or partial bilateral disease but not applicable in total bilateral disease. An allogeneic source of transplantable cells for use in total bilateral disease can be obtained from culture of donated cadaveric corneal tissue. We performed a controlled multicenter study to examine the feasibility, safety, and efficacy of allogeneic corneal epithelial stem cells in the treatment of bilateral LSCD. Patients were randomized to receive corneal epithelial stem cells cultured on amniotic membrane (AM): investigational medicinal product (IMP) or control AM only. Patients received systemic immunosuppression. Primary endpoints were safety and visual acuity, secondary endpoint was change in composite ocular surface score (OSS). Sixteen patients were treated and 13 patients completed all assessments. Safety was demonstrated and 9/13 patients had improved visual acuity scores at the end of the trial, with no significant differences between IMP and control groups. Patients in the IMP arm demonstrated significant, sustained improvement in OSS, whereas those in the control arm did not. Serum cytokine levels were measured during and after the period of immune suppression and we identified strongly elevated levels of CXCL8 in the serum of patients with aniridia, which persisted throughout the trial. This first randomized control trial of allogeneic corneal epithelial stem cells in severe bilateral LSCD demonstrates the feasibility and safety of this approach. Stem Cells Translational Medicine 2019;8:323–331 Patients with severe ocular surface disorder received transplants of amniotic membrane with (black bars) or without (gray bars) cadaveric‐donor‐derived cultured limbal stem cells. All patients received immune suppression. Only patients who received transplants containing limbal stem cells showed sustained significant improvements (reductions) in combined ocular surface scores (5 factors scored 0–3 where 0 is a normal eye score).

Purpose: To evaluate visual performance of a novel full range of vision spiral intraocular lens (IOL) designed with artificial intelligence using preclinical and clinical metrics. Methods: Preclinical visual performance was assessed in healthy individuals using a pseudophakic vision simulation device, comparing monocular corrected distance visual acuity, contrast sensitivity, defocus curve, halo/glare size, and subjective preference between the spiral RayOne Galaxy IOL and diffractive RayOne Trifocal IOL (Rayner). Additionally, postoperative clinical outcomes were subsequently analyzed from 10 sites following bilateral RayOne Galaxy IOL implantation. At 3 months postoperatively, key endpoints included subjective refraction, monocular and binocular uncorrected and corrected distance visual acuity at multiple distances, defocus curves, and patient-reported dysphotopsia. Results: Preclinical evaluation demonstrated comparable range of focus between the Galaxy and diffractive Trifocal IOLs. However, the Galaxy IOL exhibited significantly less halo/glare, with nearly all participants preferring it across all distances. In the clinical study, mean monocular corrected distance visual acuities were −0.03 ± 0.08 logarithm of the minimum angle of resolution (logMAR) for distance, 0.05 ± 0.11 logMAR for intermediate, and 0.08 ± 0.14 logMAR for near, with further improvement observed binocularly. Monocular/binocular defocus curves demonstrated a smooth plateau with binocular defocus maintaining visual acuity of 20/32 (0.2 logMAR) or better from +1.00 to −2.80 diopters (35 cm). Halo and glare symptoms were generally minor (> 95% of patients), with no severe cases. Conclusions: The Galaxy IOL provides excellent monocular and binocular visual acuity across all tested distances, with a smooth and continuous defocus curve ensuring full-range vision. Preclinical testing demonstrated significantly fewer photic phenomena than the tested diffractive trifocal IOL, whereas clinical investigations found no indications of bothersome side effects, together demonstrating high visual comfort.

Background/aims To characterise histopathological changes in corneal buttons associated with deep anterior lamellar keratoplasty (DALK). Methods This was a retrospective, clinical laboratory study. All recipient corneal buttons that underwent DALK in the West of Scotland and were submitted to the regional Ocular Pathology Laboratory (Glasgow, UK) between 2001 and 2010 were examined. Cases affected by artefacts secondary to DALK were highlighted. Keratoconus cases that underwent DALK were compared to those that underwent penetrating keratoplasty (PK). Results 225 DALK corneal buttons were examined. Of these, 61.8% were affected by artefacts or problems related to DALK. Overall, 58.2% of the affected buttons were affected by corneal emphysema related to intrastromal air injection (the ‘big bubble’ technique), 5.3% by epithelial oedema related to the hydrodelamination procedure, which mimicked bullous keratopathy secondary to endothelial cell deficiency, and 0.9% were lost specimens. We were not able to identify any conus, which is a characteristic histopathological feature of keratoconus, in 10 (7.4%) of the DALK-keratoconus cases as opposed to two (1.6%) of the PK-keratoconus cases (p=0.036). Conclusions DALK poses new challenges for histopathological examination of corneal buttons. Awareness of DALK-related histopathological characteristics should be raised among ocular pathologists and ophthalmologists in view of the increasing popularity of this technique.

ABSTRACT PURPOSE: To determine by wavefront analysis the difference between eyes considered normal, eyes diagnosed with keratoconus, and eyes that have undergone penetrating keratoplasty METHODS: The Nidek OPD-Scan wavefront aberrometer was used to measure ocular aberrations out to the sixth Zernike order. One hundred and thirty eyes that were free of ocular pathology, 41 eyes diagnosed with keratoconus, and 8 eyes that had undergone penetrating keratoplasty were compared for differences in root mean square value. Three and five millimeter root mean square values of the refractive power aberrometry maps of the three classes of eyes were compared. Radially symmetric and irregular higher order aberration values were compared for differences in magnitude. RESULTS: Root mean square values were lower in eyes free of ocular pathology compared to eyes with keratoconus and eyes that had undergone penetrating keratoplasty. The aberrations were larger with the 5-mm pupil. Coma and spherical aberration values were lower in normal eyes. CONCLUSION: Wavefront aberrometry of normal, pathological, and eyes after surgery may help to explain the visual distortions encountered by patients. The ability to measure highly aberrated eyes allows an objective assessment of the optical consequences of ocular pathology and surgery. The Nidek OPD-Scan can be used in areas other than refractive surgery. [J Refract Surg 2003;19(suppl): S255-S259]

ABSTRACTPURPOSE: To analyze the efficacy, predictability, stability, and safety of laser in situ keratomileusis (LASIK) to correct myopia and myopic astigmatism using the Nidek EC-5000 CX II laser and the Customized Aspheric Transition Zone (CATz) profile.METHODS: We conducted a retrospective analysis of 100 eyes (50 patients) with myopic astigmatism. A CATz profile was used in all eyes (profile 4) with an ablation zone of 5 mm and a transition zone of 9 mm, using Nidek FinalFit software.RESULTS: Average patient age was 39 years (range 21 to 69 yr). Preoperative mean spherical equivalent refraction was -4.70 ± 2.53 D (range -11.88 to -0.50 D), mean preoperative sphere was -4.31 ± 2.53 D (range -11.25 to -0.25 D), and mean preoperative cylinder was -0.78 ± 0.69 D (range -3.25 to 0). Postoperative mean spherical equivalent refraction at 6 months was 0.12 ± 0.53 D (range -1.63 to +0.88 D), mean postoperative sphere was 0.02 ± 0.56 D (range -1.50 to +2.00 D), and mean postoperative cylinder was -0.29 ± 0.50 D (range 0 to -1.75 D). Uncorrected visual acuity was 6/6 or better in 58% (58 eyes) and better than 6/12 in 93% (93 eyes).CONCLUSION: LASIK with the Nidek EC-5000 CX II laser and the CATz profile was effective, reasonably predictable, stable, and safe for correction of myopic astigmatism with a spherical component between -0.25 and -11.25 D, and a cylindrical component up to 3.25 D, using the techniques in this study. Astigmatism was undercorrected with the current algorithm. [J Refract Surg 2004;20 (suppl): S666-S668]

ABSTRACTPURPOSE: The aim of this study was to quantify how closely the Nidek OPD-Scan objective refraction correlated with subjective refraction.METHODS: A retrospective audit of the preoperative refraction of 80 myopic and myopic astigmatic eyes before laser in situ keratomileusis (LASIK) or laser supepithelial keratomileusis (LASEK) was performed. Objective refraction in the 5-mm zone was performed using a Nidek OPD-Scan. Subjective refraction was performed by a senior optometrist. Statistical analysis of sphere, cylinder, and spherical equivalent refraction measurements was then performed.RESULTS: Spherical measurements correlated well with a linear regression equation, with a correlation coefficient of 0.97. Cylinder measurements correlated less well, with a correlation coefficient of 0.85. Spherical equivalent refraction measurements correlated well, with a correlation coefficient of 0.97. Analyzing the numerical difference between each objective refraction and its corresponding subjective refraction, the majority of values were only 0.50 D apart for sphere, cylinder, and spherical equivalent refraction.CONCLUSION: There was good correlation between objective OPD-Scan and subjective refraction, especially for sphere and spherical equivalent refraction measurements, with regression gradients and correlation coefficients close to 1. [J Refract Surg 2004;20(suppl):S734-S736]

ABSTRACTPURPOSE: To analyze the change in higher order aberrations in myopic and myopic astigmatic eyes following an aspheric ablation profile for laser in situ keratomileusis (LASIK) using a Nidek EC-5000 CX II excimer laser system.METHODS: We performed a retrospective audit of 38 eyes (19 patients) with myopia and myopic astigmatism. A customized aspheric transition zone profile (CATz) was used in all eyes (profile 4) with an ablation zone of 5 mm and a transition zone of 9 mm using FinalFit software and a Nidek EC-5000 CX II excimer laser system.RESULTS: Mean higher order aberrations (RMS) increased from 0.42 µm at baseline to 0.57 µm at 6-month follow-up. Mean spherical aberrations (Z12) increased from 0.02 µm at baseline to 0.33 µm after LASIK. Mean spherical aberration defocus equivalent (DEQ) increased from 0.56 µm at baseline to 1.54 at 6 months after surgery. Mean trefoil (Z6) was -0.11 µm at baseline and -0.14 µm at the 3-month examination. Mean coma (Z7) was -0.09 µm at baseline and -0.10 µm after surgery. Mean coma (Z8) was -0.03 at baseline and 0 at the 3-month examination. Mean trefoil (Z9) was -0.03 at baseline and -0.12 at the 3-month examination.CONCLUSION: The amount of postoperative higher order aberrations in these myopic eyes was acceptable. However, the clinical significance of these numerical changes in aberrations is not known. [J Refract Surg 2004;20(suppl):S659-S662]

[Schachar RA]'s theory,2,3 on the other hand, proposes that the anterior lens curvature increases due to outward movement of the lens, which in turn is due to ciliary muscle contraction that increases the tension in zonulcs.This theory postulates that presbyopia is due to crowding at the lens equator with age-related lens growth causing a decrease in the space between the ciliary muscle and lens equator.

The management of presbyopes is fast becoming the hot topic as the population ages. This year's British Society for Refractive Surgery conference includes a comprehensive session on presbyopic surgical correction. Experts will cover multifocal IOLs, the controversial scierai techniques, and the exciting developments in accommodating intraocular lenses. The conference will take place from May 24-25 at the Birmingham Metropole hotel.