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Abstract Background The removal of high-viscosity silicone oil in retinal surgery is time-intensive. In this laboratory and porcine eye study, we evaluated the efficiency of novel extraction techniques, namely shortened polyimide-cannulas, an extraction sleeve and an experimental luer-trocar system, for commercially available silicone oils. Methods The volume of silicone oil after a 5-min removal time was quantified. The feasibility of all studied techniques was additionally tested in vitrectomized porcine eyes. Siluron 1000, 2000, 5000 and Xtra, as well as Densiron 68 and Densiron Xtra were examined. Results Shortening the 23G-polyimide-cannula from 6 mm up to 1.5 mm led to a significantly higher mean aspirated volume (e.g., 1 ml/min to 1.7 ml/min for Siluron Xtra). The extraction sleeve and luer-trocar increased the flow threefold compared to the shortest polyimide cannulas at 23G (5.2 ml/min and 5.2 ml/min vs 1.7 ml/min for Siluron Xtra, respectively). The extraction sleeve and luer-trocar system reached a similar flow at 27G as the best performing 23G-cannula. Angulation and movement of the eye was possible with the 2 mm-cannula, no angulation was possible when using the extraction sleeve. Stability and control were not impaired with the experimental luer-trocar setup. Conclusion Shorter polyimide-cannulas and extraction sleeves increase the extraction flow but may decrease stability during surgery. The luer-trocar system facilitates rapid removal while offering great stability and control. Small 27G silicone oil removal is possible and time efficient.

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.

Abstract Purpose To assess the nozzle tip damage of IOL injectors in three generations from the same manufacturer using the self-developed system—the Heidelberg Score for IOL Injector Damage. Setting David J Apple Center for Vision Research, Department of Ophthalmology, University Hospital Heidelberg, Heidelberg, Germany Design Experimental laboratory study Methods The nozzle tip damage of three injector models (Emerald, iTec, and Simplicity) was determined using the Heidelberg score for IOL injector damage. Damage to the nozzle tip was examined under a microscope and graded as follows: no damage (score 0), slight scratches (1), deep scratches (2), extensions (3), cracks (4) and bursts (5). The total scores for each injector system were the sum of scores for all injectors in this model. Total scores of the three injector systems were evaluated and compared. The nozzle tip parameters (diameters, tip angles) were also measured in each group. Results The Emerald system achieved the highest total scores, while the other two systems achieved similar total scores. There was no statistically significant difference in the total scores between the study groups (P > 0.05). The outer cross-sectional diameters were 2.10 and 2.10 mm for Emerald, 1.80 and 1.78 mm for iTec, and 1.78 and 1.80 mm for Simplicity. The thickness of the nozzle tips was 0.13 mm (Emerald), 0.17 mm (iTec) and 0.17 mm (Simplicity). The tip angle for three injector models was 35° (Emerald), 45° (iTec), and 45° (Simplicity). Conclusions Although different injector models exhibited varying degrees of damage to the nozzle tip, all injector models generally showed relatively good results. Newer generations of IOL injector models tend to perform better in terms of nozzle tip damage after IOL implantation.

Abstract During intraocular lens (IOL) implantation it is not uncommon for the injector’s nozzle-tip to get damaged. However, the damage has not been systematically described or evaluated using an objective scale. In this study we developed our own system—the Heidelberg Score for IOL Injector Damage (“HeiScore”), which was used to grade 60 injectors from four generations of injector models (Monarch III D, AcrySert C, UltraSert, AutonoMe) made by the same manufacturer. (Alcon Laboratories Inc.) HeiScore has six grades of nozzle-tip damage: no damage (which was graded 0); slight scratches (1), deep scratches (2), extensions (3), cracks (4) and bursts (graded number 5). The score for each injector model was the sum of all grades (total number), and we could compare the four injector models. The injectors showed varying damage profiles, from “no damage” to “crack”. A tendency of a lower damage score in the newer generations of IOL injectors was noted. However, a statistically significant difference was observed only between Monarch III D and AutonoMe. The “Heidelberg Score for IOL Injector Damage” could efficiently and effectively evaluate the damage to IOL injector systems, which might help manufacturers optimize the positioning of the IOL in the injector during pre-loading.

To treat certain vitreoretinal diseases, the vitreous body, a hydrogel composed of mostly collagen and hyaluronic acid, must be removed. After vitrectomy surgery, the vitreous cavity is filled with an endotamponade. Previously, pre-clinical hydrogel-based vitreous body substitutes either made from uncrosslinked monomers (1st generation), preformed crosslinked polymers (2nd generation), or in situ gelating polymers (3rd generation) have been developed. Forward light scattering is a measure of Stray light induced by optical media, when increased, causing visual disturbance and glare. During pinhole surgery, the hydrogels are injected into the vitreous cavity through a small 23G-cannula. The aim of this study was to assess if and to what extent forward light scattering is induced by vitreous body replacement hydrogels and if Stray light differs between different generations of vitreous body hydrogel replacements due to the different gelation mechanisms and fragmentation during injection. A modified C-Quant setup was used to objectively determine forward light scattering. In this study, we found that the 1st and 3rd generation vitreous body replacements show very low stray light levels even after injection (2.8 +/− 0.4 deg2/sr and 0.2 +/− 0.2 deg2/sr, respectively) as gel fragmentation and generation of interfaces is circumvented. The 2nd generation preformed hydrogels showed a permanent increase in stray light after injection that will most likely lead to symptoms such as glare when used in patients (11.9 +/− 0.9 deg2/sr). Stray light of the 2nd generation hydrogels was 3- and 2-fold increased compared to juvenile and aged vitreous bodies, respectively. In conclusion, this significant downside in the forward light scattering of the 2nd generation hydrogels should be kept in mind when developing vitreous body replacement strategies, as any source of stray light should be minimized in patients with retinal comorbidities.

Aim: To determine the clinical risk factors that may increase the occurrence of intraocular lens (IOL) calcification in patients who had undergone pars plana vitrectomy (PPV). Methods: The medical records of 14 patients who underwent IOL explantation due to clinically significant IOL opacification after PPV were reviewed. The date of primary cataract surgery, technique and implanted IOL characteristics; the time, cause and technique of PPV; tamponade used; additional surgeries; the time of IOL calcification and explantation; and IOL explantation technique were investigated. Results: PPV had been performed as a combined procedure with cataract surgery in eight eyes and solely in six pseudophakic eyes. The IOL material was hydrophilic in six eyes, hydrophilic with a hydrophobic surface in seven eyes and undetermined in one eye. The endotamponades used during primary PPV were C2F6 in eight eyes, C3F8 in one eye, air in two eyes and silicone oil in three eyes. Two of three eyes underwent subsequent silicone oil removal and gas tamponade exchange. Gas in the anterior chamber was detected in six eyes after PPV or silicone oil removal. The mean interval between PPV and IOL opacification was 20.5 ± 18.6 months. The mean BCVA in logMAR was 0.43 ± 0.42 after PPV, which significantly decreased to 0.67 ± 0.68 before IOL explantation for IOL opacification (p = 0.007) and increased to 0.48 ± 0.59 after the IOL exchange (p = 0.015). Conclusions: PPV with endotamponades in pseudophakic eyes, particularly gas, seems to increase the risk for secondary IOL calcification, especially in hydrophilic IOLs. IOL exchange seems to solve this problem when clinically significant vision loss occurs.

Background. In vitro assessment of silicone oil adhesion to a new hydrophobic acrylic intraocular lens (IOL) material, the Clareon model CNA0T0, compared with the established AcrySof model SN60WF was carried out. Methods. Silicone oil adhesion was assessed for two types of IOLs, Clareon CNA0T0 (n = 10) and AcrySof SN60WF (n = 10). Lenses were immersed in an aqueous sodium chloride solution for 12 hours and then incubated at room temperature in silicone oil for 12 hours. The lenses were washed with distilled water and photographed at 25x magnification using a microscope. The percent coverage was calculated by dividing the area of oil coverage by the total surface area of the lens. Results. Silicone oil adhesion to the surface of the CNA0T0 lens ranged from 4% to 22%, with a mean ± SD coverage of 8% ± 4%. Silicone oil adhesion to the surface of the SN60WF lens ranged from 1% to 17%, with a mean coverage of 9% ± 4%. The silicone oil adhesion of CNA0T0 was equivalent to that of SN60WF (P>0.05). Conclusions. The new Clareon model CNA0T0 IOL has silicone oil adhesion and interaction that are equivalent to the established AcrySof IOL.