Evaluation of Parameters and Nozzle Tip Damage after Clinical Use of Three Hydrophilic Intraocular Lens Injector Models.

Purpose: To assess the nozzle tip damage and the parameters of three different hydrophilic intraocular lens (IOL) injector models. Methods: After routine cataract surgeries at the University Eye Hospital Heidelberg, all the used IOL injectors were collected from the operating room and sent to our laboratory. Nozzle tip damage was assessed under a microscope and graded as follows: no damage (grade 0), slight scratches (1), deep scratches (2), extensions (3), cracks (4), and bursts (5). Each damage grade was assigned a score from 0 to 5, and the total damage score for each injector system was calculated and compared. Nozzle tip parameters (diameters and areas), plunger tip parameters, and tip angles were also measured in each model. Results: The damage scores were (median, Q3-Q1): 1 (1-1) for Accuject, 1 (1-1) for Bluemixs, and 1 (1-1) for RayOne. There was no statistically significant difference in the damage scores between the study groups (P > 0.05). The outer cross-sectional vertical and horizontal diameters were 1.69 and 1.69 mm for Accuject, 1.69 and 1.69 mm for Bluemixs, and 1.70 and 1.71 mm for RayOne. Plunger tip areas were 0.78 mm2 for Accjuect, 0.74 mm2 for Bluemixs, and 0.43 mm2 for RayOne. Plunger tip area/inner cross-sectional area of the nozzle tip (%) was 31.2% for RayOne, 66.7% for Accuject, and 63.8% for Bluemixs. The tip angles for three injector models were 56° (Accuject), 56° (Bluemixs), and 44° (RayOne). Conclusions: All the injector models showed mild to moderate damage to the nozzle tip after IOL implantation, even with smaller diameter tips. RayOne resulted in the lowest ratio between plunger tip area and inner cross-sectional area of the nozzle tip and a better distribution of damage categories than the other two groups. All three injector models had relatively small tip parameters. If smaller incisions are required in certain patients, smaller tip parameters should be considered.

Intraocular lens calcification in a patient with Ehlers-Danlos syndrome.

Introduction: Calcification of hydrophilic intraocular lenses (IOL) is a rare complication following cataract surgery. Secondary calcification is described as due to host factors or changes in the IOL environment and uveitis, proliferative diabetic retinopathy and sequelae of ocular surgery are recognised potentiators. The impact of systemic connective tissue disease on IOL opacification is yet to described. Purpose: To describe the clinical presentation and management of a young patient, with a rare subtype of Ehlers-Danlos syndrome, who presented with secondary IOL calcification 14 years after primary IOL insertion. Observations: Floret-like lesions were observed on the IOL surface. Positive staining for calcification was observed with Alizarin red and von Kossa method on laboratory analysis. Conclusions and importance: Patients with systemic connective tissue disease, such as a subtype of Ehlers-Danlos, may present with secondary IOL calcification many years after primary lens insertion. This poses an additional consideration when implanting IOLs in these patients.Good visual acuity can be achieved with IOL exchange.

Forward Light Scattering of the Vitreous Gel After Enzymatic Aging: An In Vitro Model to Study Vitreous Opacification.

Purpose: Symptomatic vitreous opacifications, so-called floaters, are difficult to objectively assess majorly limiting the possibility of in vitro studies. Forward light scattering was found previously to be increased in eyes with symptomatic floaters. Using an objective setup to measure forward light scattering, we studied the effects of enzymatically digesting the components of the vitreous body on straylight to develop an in vitro model of vitreous opacifications. Methods: Fifty-seven porcine vitreous bodies were digested using hyaluronidase, collagenase, trypsin, and bromelain, as well as using a combination of hyaluronidase + collagenase and hyaluronidase + bromelain. A modified C-Quant setup was used to objectively assess forward light scattering. Results: Depletion of hyaluronic acid majorly increased vitreous straylight (mean increase 34.4 deg2/sr; P = 0.01), whereas primarily digesting the vitreous gel with collagenase or trypsin did not significantly affect straylight. When collagenase or bromelain is applied in hyaluronic acid depleted vitreous gels, the increase in forward light scattering is reversed partially. Conclusions: The age-related loss of hyaluronic acid primarily drives the increase in vitreous gel straylight induced by conglomerates of collagen. This process can be reversed partially by digesting collagen. This in vitro model allows the objective quantification and statistical comparison of straylight burden caused by vitreous opacities and, thus, can serve as a first testing ground for pharmacological therapies, as demonstrated with bromelain.

Ectasia Detection by Anterior Segment Optical Coherence Tomography in Scheimpflug Tomographically Normal Keratoconus Fellow Eyes.

PURPOSE: The purpose of this study was to determine whether the Scheimpflug tomographically normal fellow eyes of keratoconus patients are also classified as normal using an ectasia screening algorithm based on anterior segment optical coherence tomography (AS-OCT). METHODS: This monocentric cross-sectional study included 22 very asymmetric ectasia patients with tomographically significant keratoconus in 1 eye and normal Scheimpflug tomography in the fellow eye. Twenty-two eyes of 22 healthy subjects served as a control group. We performed corneal tomography using Pentacam AXL (Oculus, Wetzlar, Germany) and used Belin/Ambrósio Enhanced Ectasia total deviation index as well as Belin ABCD keratoconus classification to identify Scheimpflug tomographically normal eyes. We also performed AS-OCT using Anterion (Heidelberg Engineering, Heidelberg, Germany) and analyzed for the presence of ectasia using the Screening Corneal Objective Risk of Ectasia (SCORE) algorithm, with positive values indicating ectasia suspect tomography. RESULTS: The SCORE value was positive in 9.1% (n = 2) of the healthy eyes, in 45.5% (n = 10) of the Scheimpflug tomographically normal eyes of keratoconus patients and in all eyes (n = 22) with tomographically significant keratoconus. The Scheimpflug tomographically normal eyes of keratoconus patients had higher SCORE values compared with healthy controls (P < 0.001). The median (interquartile range) SCORE value was -1.7 (1.3) in healthy controls, -0.5 (2.2) in Scheimpflug tomographically normal eyes of keratoconus patients, and 11.1 (11.0) in tomographically significant keratoconus eyes. CONCLUSIONS: The Scheimpflug tomographically normal fellow eyes of keratoconus patients had higher AS-OCT-based SCORE values than healthy controls, with positive SCORE values found in 46% of the eyes, indicating early tomographic ectatic changes.

7-Year Efficacy and Safety of iStent inject Trabecular Micro-Bypass in Combined and Standalone Usage.

INTRODUCTION: This study evaluated 7-year effectiveness and safety of second-generation trabecular micro-bypass implantation (iStent inject) either in combination with cataract surgery or as a standalone procedure (Combined or Standalone subgroups, respectively) in eyes with open-angle glaucoma. METHODS: This prospective, non-randomized, unmasked, longitudinal study included 125 consecutive iStent inject cases of a single surgeon at a large German academic hospital. Patients had considerable preoperative disease burden, with mean intraocular pressure (IOP) of 23.5 mmHg, 84.8% of eyes on ≥ 2 medications, and 38.4% of eyes with prior glaucoma surgery. IOP, medications, adverse events, and secondary surgeries were assessed through 7 years in the Overall cohort and in Combined (n = 81) and Standalone (n = 44) subgroups. RESULTS: Over 7-year follow-up, mean IOP decreased by 36.2-40.0% in Overall eyes, 34.1-38.9% in Combined eyes, and 39.5-43.5% in Standalone eyes (p < 0.001 at all timepoints for all groups). Meanwhile, mean medications decreased by 59.3-71.3% in Overall eyes, 57.9-69.0% in Combined eyes, and 62.1-76.2% in Standalone eyes (p < 0.001 at all timepoints in all groups). At last follow-up (mean 77.4 months; 92.8% of patients with last visit at 6 or 7 years), 83.7% of Overall eyes, 82.3% of Combined eyes, and 86.4% of Standalone eyes had achieved ≥ 20% IOP reduction vs preoperative. At last follow-up vs preoperative, 100% of eyes in all groups had the same or lower IOP and 100% had the same or lower medication regimen. Safety outcomes were favorable, with no filtration surgeries and only 4.84% of eyes experiencing clinically significant visual field loss over 7 years of follow-up. CONCLUSION: iStent inject implantation with or without phacoemulsification produced significant and durable 7-year reductions in IOP (~ 34-44% reduction) and medications (~ 58-76% reduction) while preventing filtering surgery in this cohort of patients with relatively high preoperative disease burden. Combined and Standalone cases had similarly favorable effectiveness and safety.

In-vitro assessment of a novel intraocular lens made of crosslinked polyisobutylene.

PURPOSE: To describe and analyse the particularities of the material and the optical quality of the first intraocular lens (IOL) (Eyedeal® lens) made of crosslinked polyisobutylene (xPIB). METHODS: We assessed the material quality using an accelerated ageing process (to provoke glistenings) and compared values with a control, AcrySof® lens. Using the sessile drop method, the contact angle of the new IOL was measured. Images of the lens surface were recorded by scanning electron microscopy (SEM). Optical quality was assessed by measuring the labeled power and modulation transfer function (MTF) using standard metrology equipment (OptiSpheric IOL PRO2). RESULTS: The Eyedeal® lens had an average glistening density result of 7.46 ± 3.78 MV/mm2 compared to the control AcrySof® whose glistenings number was 142.42 ± 72.47 MV/mm2. The contact angle was 97.2° whereas the angle of AcrySof material is between 73.3 ± 2.4° and 84.4 ± 0.1°. Using SEM, Eyedeal® lenses were examined and all appeared to be comparable to modern IOLs made of acrylic materials. The power and MTF values were normal and conformed to ISO standards. CONCLUSIONS: In the laboratory, the new Eyedeal® lens showed equivalence to current hydrophobic- or hydrophilic-acrylic lens models. It showed superiority in its glistening density result compared to the control lens.

Refractive outcomes of small lenticule extraction (SMILE) Pro® with a 2 MHz femtosecond laser.

PURPOSE: To evaluate the initial visual outcomes of Small Incision Lenticule Extraction (SMILE) Pro® using a 2 MHz femtosecond laser (VisuMax 800, Carl Zeiss Meditec) and to assess the efficacy, safety, predictability, accuracy, and complication rate. METHODS: This retrospective analysis included eyes which underwent the SMILE Pro® procedure using VisuMax 800 femtosecond laser to correct myopia. All surgeries were performed by one surgeon (DB). Follow-up was conducted 3 months postoperatively to evaluate visual outcomes after neuroadaptation, corrected visual acuity (CDVA) and intra- and postoperative complications. RESULTS: One hundred and fifty-two eyes of 82 patients (mean age 31 ± 6 years) results at 3 months are presented. The mean spherical equivalent (SE) was - 4.44 ± 1.86 D preoperatively while -0.24 ± 0.32 D postoperatively. 99% of eyes achieved SE within ± 1.0 D of attempted correction and 91% were within ± 0.5 D. Efficacy index was 0.93 while the safety index was 1. No complications occurred intra- or postoperatively. No eyes lost more than 1 line of their preoperative CDVA. All highly myopic eyes (- 6.25 to - 10.00 D; n = 18) achieved 20/20 at 3 months postoperatively and were within 0.5 D from the attempted SE and no eyes lost more than 1 line of CDVA. CONCLUSION: The SMILE Pro® is a safe, efficient, and predictable procedure for the treatment of myopia and myopic astigmatism, with comparable results of conventional SMILE surgery. High myopic eyes achieve better results than low and moderate myopia. No complications were recorded in our patients.

Blue-Light Filtering Monofocal Intraocular Lenses: A Study on Optical Function and Tolerance to Misalignment.

PURPOSE: To investigate the optical performance and tolerance to misalignment of blue-light filtering monofocal intraocular lenses (IOLs). METHODS: The optical properties of two monofocal IOLs featuring yellow chromophores, CT Lucia 621 PY (Carl Zeiss Meditec AG) and Clareon CNA0T0 (Alcon Laboratories, Inc), were assessed in monochromatic and polychromatic light while introducing spherical aberration (SA). Optical quality metrics derived from the modulation transfer function were assessed after optimal IOL centration at 3- and 4.5-mm pupils. In addition, each IOL's tolerance to misalignment was examined by inducing up to 1 mm of decentration and the effect of tilting it by 5 degrees at 3 mm. RESULTS: The IOLs' resolution and contrast, while tested using a 3-mm aperture and an SA-neutral corneal model, indicated the CT Lucia 621 PY had a slightly higher modulation transfer function (MTF) at 50 lp/mm than the CNA0T0 under monochromatic conditions (0.77 vs 0.69). On introducing SA with (0.49 vs 0.40) and without (0.75 vs. 0.70) chromatic aberration, the CT Lucia 621 PY maintained its minimally better performance. When assessed with a 4.5-mm aperture in monochromatic light, the CT Lucia 621 PY displayed improved MTF with aberration-free cornea (0.71 vs 0.40) but performed worse after introducing SA (0.44 vs 0.62). However, both lenses achieved comparable MTF values under spherical and chromatic aberrations (0.28 vs 0.27). The IOL misalignment test revealed a better tolerance to tilt and decentration of the CT Lucia 621 PY across all conditions. CONCLUSIONS: The CT Lucia 621 PY and CNA0T0 showed similar optical quality in different situations, with equal simulated distance visual acuity for both models. However, the CT Lucia 621 PY's aspheric design offers an advantage when dealing with often imperfect physiological conditions, displaying a more robust performance under tilt and decentration. [J Refract Surg. 2024;40(2):e79-e88.].

Characterizing glare effects associated with diffractive optics in presbyopia-correcting intraocular lenses.

PURPOSE: To objectively quantify glare of intraocular lenses (IOLs) using a diffractive principle to extend the visual range and to identify models with increased susceptibility to inducing glare. SETTING: David J Apple Laboratory, Heidelberg, Germany. DESIGN: Laboratory investigation. METHODS: Glare was assessed by means of a straylight parameter with a standard C-Quant intended for 7 degrees. In addition, 2 C-Quant modifications were used to test lower angles (ie, 2.5 degrees and 3.5 degrees). The following IOL models were assessed: PanOptix, AT Lisa Tri, Synergy, and Triumf, the latter 2 with chromatic aberration correction at distance. Straylight from trifocal IOLs was compared against a monofocal W-60R lens. The C-Quant test was performed through the studied IOLs by using additional optical components attached to their ocular. RESULTS: Straylight (deg 2 sr -1 ) of the control was <1 at all tested angles, with the trifocal models showing comparable straylight at 7 degrees. At 3.5 degrees, Triumf's straylight increased to 15.5 ± 0.6, followed by Synergy (6.2 ± 1.1), PanOptix (4.1 ± 0.3), and AT Lisa Tri (2.0 ± 0.8). The chromatic aberration-correcting models demonstrated correspondingly higher straylight (Synergy: 18.8 ± 1.3; Triumf: 17.3 ± 0.5) at 2.5 degrees compared with PanOptix (4.3 ± 0.4), AT Lisa Tri (2.1 ± 0.1), and monofocal IOLs yielding minimal or no increase. CONCLUSIONS: Trifocal IOLs induced increased straylight, but it was limited to lower angles, which may cause difficulties detecting these effects using a standard clinical approach. The latest IOL designs featuring chromatic aberration correction at far focus seem more susceptible than the established trifocal IOLs to inducing a glare phenomenon.

Longitudinal Evaluation of Biomechanical Indices in Fellow Eyes of Patients With Keratoconus Classified as Having Very Asymmetric Ectasia With Normal Topography.

PURPOSE: To evaluate the biomechanical longitudinal variability and progression of tomographically normal fellow eyes of patients with keratoconus. METHODS: Of 513 patients with keratoconus, 30 patients with tomographically normal fellow eyes were included in this study. Tomographic and biomechanical parameters of the Pentacam and Corvis ST (Oculus Optikgeräte GmbH) were analyzed in multiple follow-up examinations, including the ABCD grading, Belin/Ambrósio Enhanced Ectasia total deviation index (BAD-D), Corvis Biomechanical Index (CBI), Corvis Biomechanical Factor (CBiF), and Tomographic and Biomechanical Index (TBI). A mixed regression model was applied. The results were compared to a healthy control group (n = 17) and a keratoconus group (n = 20). RESULTS: Within a maximum observation period of 3.3 years, no fellow eye (0%) showed a progression to tomographically evident keratoconus. No significant change in tomographic or biomechanical parameters was detected over the study period. The indices BAD-D, CBI, CbiF, and TBI exhibited a certain variability over time, whereas the tomographic ABC parameters and maximum keratometry barely changed. This was also shown in the control group and for all parameters in the keratoconus group, except the TBI. CONCLUSIONS: During the observation period none of the normal fellow eyes progressed to tomographically detectable keratoconus. However, biomechanical parameters CBI, CbiF, and TBI showed pathological values in 43.3% of eyes and certain variability. Subsequent studies with a longer observation period are warranted to confirm the biomechanical trends seen in this study and to rate the ability of single measurements to diagnose early keratoconus. [J Refract Surg. 2024;40(1):e48-e56.].

Endothelial Cell Loss in Patients with Phakic Intraocular Lenses. / Endothelzellverlust bei phaken Intraokularlinsen.

Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.

Material Analysis of Explanted Calcified Silicone Intraocular Lenses in Association with Asteroid Hyalosis.

INTRODUCTION: The aim of this study was to analyze posterior surface opacification in explanted silicone intraocular lenses (IOLs) with clinicopathologic correlation to asteroid hyalosis. METHODS: In a laboratory setup, 12 explanted silicone IOLs underwent laboratory analyses, including light microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy for elemental composition (EDX). Relevant clinical data were obtained for each case, including gender, age at IOL implantation, dates of implantation and explantation, as well as history of neodymium-dopped yttrium aluminum garnet (Nd:YAG) laser treatments or other opacification removal attempts. High-resolution optical coherence tomography (OCT) images were obtained in vitro with an anterior segment OCT device (Anterion, Heidelberg Engineering, Heidelberg, Germany). RESULTS: Calcification located at the posterior optic surface of each lens was identified through SEM and EDX analyses, revealing deposits composed of hydroxyapatite. In all cases, IOL polishing using Nd:YAG laser had been attempted prior to IOL exchange. The clinical functional data showed that this type of IOL opacity led to increase in straylight and subjective symptoms of glare. CONCLUSIONS: Silicone IOLs can develop posterior surface calcification in eyes with asteroid hyalosis. There are mechanical techniques of cleaning the IOL surface but in many cases, IOL explantation is the only sustainable way to reduce the patients' straylight levels and glare symptoms. Due to the risk of posterior surface calcification, silicone IOL implantation should be avoided in eyes with asteroid hyalosis.