Ana Prinz

Linear relationship of refractive and biometric lenticular changes during accommodation in emmetropic and myopic eyes.

Aim: Aim of this study was to investigate the relationship between refractive changes in the eye and biometric changes of the human crystalline lens during accommodation. Furthermore, differences in these relationships between young, healthy emmetropic and myopic subjects were analyzed. Methods: Mean relative change in anterior chamber depth (ACD), lens thickness (LT), anterior segment length (ASL  =  ACD + LT) and in objective refraction were simultaneously assessed during near-point-induced accommodation in 10 emmetropic and 10 myopic subjects. Via a beam splitter, measurements were performed simultaneously using partial coherence interferometry (PCI) and infrared (IR) photorefraction. Results: On average, for each diopter of accommodation LT increased by 0.063 mm in emmetropic and by 0.072 mm in myopic eyes, and ACD decreased by 0.047 mm and 0.057 mm, respectively. Mean ASL, indicating the position of the posterior lens pole, increased by 0.009 mm in emmetropic and by 0.013 mm in myopic eyes. The correlation between refractive and biometric changes was found to be essentially linear in both subgroups. Differences in ACD between emmetropic and myopic eyes were statistically significant at an accommodative stimulus of –1 D (p<0.04) and –2 D (p<0.02). Conclusion: The biometric and refractive changes of the human lens are highly correlated and linear in function in both emmetropic and myopic eyes.

Advantage of three dimensional animated teaching over traditional surgical videos for teaching ophthalmic surgery: a randomised study

Background/aim: Owing to the complex topographical aspects of ophthalmic surgery, teaching with conventional surgical videos has led to a poor understanding among medical students. A novel multimedia three dimensional (3D) computer animated program, called “Ophthalmic Operation Vienna” has been developed, where surgical videos are accompanied by 3D animated sequences of all surgical steps for five operations. The aim of the study was to assess the effect of 3D animations on the understanding of cataract and glaucoma surgery among medical students. Method: Set in the Medical University of Vienna, Department of Ophthalmology, 172 students were randomised into two groups: a 3D group (n = 90), that saw the 3D animations and video sequences, and a control group (n = 82), that saw only the surgical videos. The narrated text was identical for both groups. After the presentation, students were questioned and tested using multiple choice questions. Results: Students in the 3D group found the interactive multimedia teaching methods to be a valuable supplement to the conventional surgical videos. The 3D group outperformed the control group not only in topographical understanding by 16% (p<0.0001), but also in theoretical understanding by 7% (p<0.003). Women in the 3D group gained most by 19% over the control group (p<0.0001). Conclusions: The use of 3D animations lead to a better understanding of difficult surgical topics among medical students, especially for female users. Gender related benefits of using multimedia should be further explored.

Rotational stability and posterior capsule opacification of a plate-haptic and an open-loop-haptic intraocular lens

PURPOSE: To compare the rotational stability and posterior capsule opacification (PCO) rate in eyes with a 1‐piece or 3‐piece acrylic intraocular lens (IOL). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. DESIGN: Prospective randomized masked clinical trial. METHODS: Patients with age‐related cataract received a plate‐haptic acrylic IOL (Acri.Smart 46S) in 1 eye and a 3‐piece loop‐haptic acrylic IOL (Acri.Lyc 53N) in the other eye. Retroillumination images were taken 1 hour, 1 week, and 1, 6, and 12 months postoperatively. Intraocular lens rotation was measured using standard software (Adobe Photoshop). The amount of PCO was assessed subjectively at the slitlamp and objectively using an automated image‐analysis software (AQUA). RESULTS: The study enrolled 80 eyes of 40 patients. The IOL rotation measurements showed excellent reproducibility, with a deviation of less than 0.8 degrees. Both IOLs had comparable and good rotational stability; rotation was less than 4 degrees in 71% of eyes 1 year postoperatively. The mean absolute rotation was 2.6 degrees ± 1.9 (SD) in the plate‐haptic IOL group and 3.1 ± 2.4 degrees in the loop‐haptic IOL group. The mean AQUA PCO score (scale 0 to 10) was 0.4 in both IOL groups (P=.7). CONCLUSION: The 2 IOL models had comparable, excellent rotational stability and low PCO intensity 1 year postoperatively. Thus, the plate‐haptic IOL may be a good platform for a toric model. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Influence of severity of nuclear cataract on optical biometry.

PURPOSE: To compare preoperative and postoperative measurements of the axial length (AL) performed with the IOLMaster (Carl Zeiss Meditec) to evaluate the effect of nuclear cataract on the optical biometry. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: In 245 consecutive eyes of 162 patients scheduled for cataract surgery, type and severity of cataract was evaluated using the Lens Opacities Classification System III. Preoperative and postoperative axial length measurements were performed with the IOLMaster. The postoperative readings of AL were corrected for the IOL optic material implanted. RESULTS: The preoperative AL measurements were 0.07 mm ± 0.05 (SD) (range −0.18 to 0.11 mm) longer than the postoperative measurements (P<.001). These differences in AL were only weakly correlated (r = −0.28, P = .01) with the nuclear cataract grade, mean 3.5 ± 0.9. CONCLUSION: In this study, AL measurements with optical biometry using the IOLMaster were not influenced by the severity of nuclear cataract to a clinically relevant degree. Furthermore, it was found that AL in the phakic eye was overestimated by about 0.07 mm because of a slightly too low value of the group refractive index used for the crystalline lens.

Reliability of a video-based noncontact specular microscope for assessing the corneal endothelium.

Purpose: To assess the within- and between-examiner reliability of corneal endothelial cell density (ECD) measurements with 2 noncontact specular microscopes: a video-based system (SeaEagle) and a photographic system (Noncon Robo). Methods: In 57 eyes of 57 subjects, 47 healthy subjects and 10 patients with corneal disease, ECD was measured in the center and at 4 paracentral areas with the video-based system (SeaEagle) and in the center with a photographic system (Noncon Robo). For the between-examiner reliability, a second examiner measured the central ECD with the SeaEagle device in 12 healthy subjects. The video-based system was also used to evaluate the agreement between the automated and the manually corrected (semiautomated) modes of repeated measurements. Results: For central ECD in all eyes, the test-retest reliability assessed by the intraclass correlation coefficient was 0.77, 0.99, and 0.91 for the automated SeaEagle, semiautomated SeaEagle, and Noncon Robo, respectively. Correlation was poor to good between the 3 measurement methods (range, 0.61-0.84). For between-examiner reliability, the upper (lower) limits of agreement were 200 (−384) and 149 (−92) cell/mm2 for the automated and semiautomated SeaEagle, respectively. Conclusions: The best reliability of repeated measurements was found for the semiautomated SeaEagle. However, the semiautomated method showed significantly higher ECD values than the Noncon Robo, and this difference was highly dependent on ECD. Thus, we suggest that these methods should not be used interchangeably. The fully automated mode may need a further refinement of the cell detection algorithm.

Effect of a new cohesive ophthalmic viscosurgical device on corneal protection and intraocular pressure in small-incision cataract surgery.

PURPOSE: To compare the corneal protective and intraocular pressure (IOP) effects of a new cohesive ophthalmic viscosurgical (OVD), Neocrom Cohesive (sodium hyaluronate 1.4%), with those of Healon (sodium hyaluronate 1.0%) in cataract surgery. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This randomized patient‐masked examiner‐masked study with fellow‐eye comparison comprised 29 cataract surgery patients. Surgery was performed with Neocrom Cohesive in 1 eye and Healon in the other eye. Central corneal thickness (CCT) was measured preoperatively and 1 day and 3 months postoperatively; endothelial cell density (ECD), preoperatively and 3 months postoperatively; and IOP, preoperatively and 6 hours and 1 day postoperatively. RESULTS: The mean CCT change from preoperatively to postoperatively in the Neocrom Cohesive, respectively, group and Healon group was +16.0 μm ± 25.7 (SD) (P<.01) and +7.0 ± 17.1 μm (P<.05), respectively, at 1 day and −5.7 ± 10.8 μm (P<.01) and −4.7 μm ± 9.5 μm) (P<.01), respectively, at 3 months. The mean ECD change at 3 months was 8 ± 155 cells/mm2 in the Neocrom Cohesive group (P = .8) and −46 ± 139 cells/mm2 in the Healon group (P = .08). The mean IOP increase was +2.2 ± 3.5 mm Hg (P<.01) and +1.4 ± 4.2 mm Hg (P = .14), respectively, 6 hours postoperatively and +0.9 ± 4.3 mm Hg (P = .37) and 0.0 ± 3.5 mm Hg (P = .77), respectively, at 1 day. CONCLUSION: There was no significant difference between Neocrom Cohesive and Healon in the changes in CCT, ECD, and IOP after cataract surgery.

Comparison of posterior capsule opacification between a 1-piece and a 3-piece microincision intraocular lens

Objective To compare the intensity of posterior capsular opacification (PCO) between a 1-piece and a 3-piece microincision cataract surgery intraocular lens (MICS IOL) in a prospective randomised study. Methods 80 eyes of 40 patients with age-related cataract were enrolled in this study. Each patient received a 1-piece MICS IOL (AF-1 NY-60, Hoya, Tokyo, Japan) in one eye and a 3-piece MICS IOL (AF-1 iMICS Y-60H, Tokyo, Hoya) in the other eye. At the 1-year follow-up, the patients were examined at the slit lamp, visual acuity was determined and standardised high-resolution digital retroillumination images were taken for objective quantification of regeneratory PCO using an automated image analysis software (AQUA). Results The mean regeneratory PCO score (1-piece IOL: 0.2, 3-piece IOL 0.3, p=0.7) and the neodymium:yttrium-aluminium-garnet laser capsulotomy rate (two cases in 3-piece IOL group; p=0.5) were comparable low for both IOLs. Capsular folds occurred significantly more often in the 3-piece IOL group (p=0.02). Conclusions Modification of the MICS IOL from a 3-piece to a 1-piece haptic design caused in short term no significant change in PCO amount. Compared with the 3-piece IOL, the 1-piece IOL led to significantly less capsular folds 1 year after surgery.

Efficacy of ophthalmic viscosurgical devices in maintaining corneal epithelial hydration and clarity: In vitro assessment

PURPOSE: To determine the efficacy of hydroxypropyl methylcellulose (HPMC) and hyaluronic acid (HA) in maintaining corneal hydration and optical clarity. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. DESIGN: Experimental study. METHODS: In porcine autopsy eyes, the effect of 13 ophthalmic viscosurgical devices (OVDs) (5 formulations of HPMC; 8 formulations of HA) in maintaining corneal hydration and optical clarity was tested. The main outcome variables were the time to reach optical clarity of the cornea during dissipation of the OVD and duration of corneal hydration. These variables were assessed after the first application of the OVD, after balanced salt solution application to rehydrate the gel matrix, and after the second application of OVD on top of the first layer. RESULTS: The study used 57 porcine eyes. High‐molecular‐weight HA 1.5% (zero shear viscosity [ZSV] 55 122 millipascal seconds [mPa.s]) took a significantly shorter time to reach optical clarity than HA 1.4% (ZSV 36 882 mPa.s) (P=.04). Hyaluronic acid 1.4% and HA 1.5% maintained corneal hydration significantly longer than HPMC 2.0% (P<.001). CONCLUSIONS: For corneal hydration during short‐lasting surgical procedures such as cataract surgery, the results suggest using HPMC because it distributes quickly and provides an adequate duration of sufficient corneal hydration. For corneal hydration during prolonged surgical procedures, such as vitreoretinal surgery, results suggest using HA 1.5% in the formulation because it provides long‐lasting corneal hydration. Financial Disclosure: Dr. Prinz has a proprietary interest in Croma Pharma GmbH, Leobendorf, Austria. Dr. Findl is a scientific advisor to Croma Pharma GmbH. No other author has a financial or proprietary interest in any material or method mentioned.

Influence of a variable overall diameter hydrophilic acrylic sharp-edged single-piece intra-ocular lens on capsule opacification one year after surgery.

ABSTRACT Background: To investigate the influence of the overall intraocular lens (IOL) diameter on posterior capsule opacification (PCO) formation. Methods: In this prospective randomized clinical trial, 124 eyes of 62 patients with bilateral age-related cataract were included. Each patient received a Corneal A501D IOL in one eye and a Corneal J501D IOL in the fellow eye. Best corrected visual acuity (BCVA) and digital slitlamp photographs were taken a 1 h, 1 week, 1, 3, 6 and 12 months postoperatively. The amount of PCO was assessed subjectively at the slitlamp and objectively using automated image-analysis software. Results: We found a mean BCVA of 0.81 ± 0.2 for the Corneal A501D group and 0.79 ± 0.21 for the Corneal J501D group. There was no significant difference 12 months after surgery between the two IOLs (p > 0.05). Objective PCO assessment resulted in a mean PCO score (scale 0–10) of 1.65 ± 1.71 was found for the Corneal J501D group and a score of 1.54 ± 1.64 was found for the Corneal A501D group (p > 0.05). The subjective PCO assessment at 1 year resulted in a mean PCO score of 2.0 ± 1.74 in the Corneal J501D group and 2.13 ± 1.64 in the Corneal A501D group (p > 0.05). Conclusion: Both investigated IOLs showed good clinical performance regarding PCO and BCVA. Our study suggests that the use of an IOL with variable total diameter seems not to influence the rate of PCO formation.

Effect of primary posterior continuous curvilinear capsulorrhexis with posterior optic buttonholing on pilocarpine-induced IOL shift

PURPOSE: To assess intraocular lens (IOL) shift along the visual axis induced by ciliary muscle contraction with pilocarpine after cataract surgery and to compare primary posterior continuous curvilinear capsulorrhexis (CCC) and posterior optic buttonholing with IOLs implanted in the bag. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. DESIGN: Clinical trial. METHODS: Eyes with age‐related cataract had cataract surgery with implantation of a nonaccommodating IOL (AF‐1 YA‐60BB). Surgery was performed with primary posterior CCC and posterior buttonholing in 1 eye (study eyes) and with conventional in‐the‐bag implantation in the contralateral eye (control eyes). After a minimum of 6 months postoperatively, the anterior chamber depth was assessed with partial coherence interferometry before and after application of pilocarpine 2.0% and, after a washout interval of 1 week, before and after the application of cyclopentolate 1.0%. RESULTS: Forty eyes of 20 patients were enrolled. A slight backward shift of the IOL (+78 μm) in study eyes and in control eyes (+118 μm) was detected after pilocarpine application (both P<.05). No significant difference in IOL shift was found between study eyes and control eyes (P=.19). CONCLUSIONS: Combined primary posterior CCC and posterior optic buttonholing did not affect IOL shift during pharmacologically stimulated ciliary muscle contraction compared with in‐the‐bag implanted IOLs. Capsule fibrosis diminished with primary posterior CCC but did not seem to be the only limiting factor in the accommodative IOL shift. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.