Intraoperative trypan blue central landmark and its use in capsulotomy and capsulorhexis centration.

PURPOSE: To compare 3 capsulotomy centration methods. SETTING: Private clinic, Zlin, Czech Republic. DESIGN: Prospective, consecutive case series. METHODS: 180 eyes undergoing cataract surgery had anterior capsule staining with microfiltered 0.4% trypan blue solution before selective laser capsulotomy. The first 60 eyes (Group 1) had mydriatic dilated pupil centered capsulotomies. The next 60 eyes (Group 2) were centered on the trypan blue central landmark (TCL). The final 60 capsulotomies (Group 3) were centered on the patient fixated coaxial Purkinje reflex (CPR). Measurements between key anatomical landmarks and the TCL, CPR capsulotomies, and implanted intraocular lens (IOL) center were made. RESULTS: The TCL, observed in >94% of eyes in the study, coincided with the CPR with a displacement of <0.1 ± 0.1 mm. Group 1 capsulotomies were noticeably decentered on the IOLs by 0.3 ± 0.2 mm. The Group 2 symmetrical IOL relationship was maintained with a decentration of 0.15 ± 0.1 mm. Group 3 had a similar decentration with the IOLs with 0.15 ± 0.1 mm. Verification with IOLMaster 700 data and CALLISTO Eye System showed that the CPR and the TCL were coincident with the measured visual axis. CONCLUSIONS: The clearly visible TCL served as an alternate landmark to the patient fixated CPR, and being on the anterior capsule was not sensitive to tilt. Further patient compliance was not required. Both were superior to dilated pupil centration, to achieve symmetric IOL coverage. This has application for both capsulotomies and capsulorhexes.

Clear corneal incision, an important step in modern cataract surgery: a review.

A clear corneal incision (CCI) is the most commonly used entrance site in modern phacoemulsification cataract surgery. Despite some initial concerns about increased endophthalmitis rates through a self-sealing CCI, recent literature suggests that the risk of infection with proper wound construction and all other necessary precautions is minimal. The technique of creating a clear corneal incision has, with recent developments in corneal imaging, undergone critical appraisal leading to a better understanding of incision architecture. Many surgeons operate through smaller incisions, and they have a wide choice of surgical instruments to create their corneal incisions. The aim of this review is to discuss the history and the current status of clear corneal incision creation, the design and materials of surgical blades, and the current trends in manufacturing and sustainability. Although disposable instruments have some advantages and are very popular, recycling, if possible, and avoiding unnecessary plastic waste are important considerations. In any case, the step of CCI is a small one for the surgeon, but a big one for the eye. That is why it has to be done with the utmost precision and in-depth knowledge is important.

Comparison between using INTEGRA and manual method in determining axis for intraocular lens implantation: Preliminary retrospective study.

The aim of this study was to explore the efficacy, repeatability, and efficiency of a new intraoperative contactless device (INTEGRA Optomed, Chorzów, Poland) for determining the axis for toric intraocular lens implantation and then to compare this with that determined using a manual method.This study was conducted at the Ophthalmological Center for Children and Adults Optomed, Chorzów, Poland.This nonrandomized, retrospective, observational study included 20 eyes of 12 patients (5 males and 7 females) who had toric intraocular lens implanted. A video recording of each surgery using the INTEGRA system was made showing the analysis. The surgeon and one of the researchers then independently assessed the location of the implant axes determined with both digital and manual slit-lamp methods, and compared them.The implantation axes suggested for both the manual and INTEGRA methods were similar. The median axis disparities were 0.0 degree and 0.5 degree, and standard deviations were 0.61 and 0.81 for researcher 1 and 2, respectively. The dominant value was 0.0 in both groups. The INTEGRA axis designation was not statistically different from the manual method (level of significance: α < 0.01).The INTEGRA system is a digital ink-free device for image tracking scleral vessels. It was helpful for determining the implantation axis in a precise and repeatable manner, and measurements were comparable with a manual technique.

Comparison of anterior capsulotomy techniques: continuous curvilinear capsulorhexis, femtosecond laser-assisted capsulotomy and selective laser capsulotomy.

PURPOSE: To compare the anterior capsulotomy edge tear strength created by manual continuous curvilinear capsulorhexis (CCC), femtosecond laser-assisted capsulotomy (FLACS), and selective laser capsulotomy (SLC). SETTING: Singapore National Eye Centre, Singapore and Excel-Lens, Livermore, California, USA. DESIGN: Three armed study in paired human eyes. METHODS: Capsulotomies were performed in 60 cadaver eyes of 30 donors using CCC, Victus Femtosecond Laser, (Bausch & Lomb, Rochester, New York, USA) or CAPSULaser, (Excel-Lens, Los Gatos, California, USA). Three pairwise study groups each involved 10 pairs of eyes. Study group 1: SLC eyes compared with fellow eyes with CCC. Study group 2: CCC eyes compared with fellow eyes with FLACS. Study group 3: FLACS eyes compared with fellow eyes with SLC.A shoe-tree method was used to apply load to the capsulotomy edge, and Instron tensile stress instrument measured distension and threshold load applied to initiate capsule fracture. Relative fracture strengths and distension of CCC, FLACS and SLC were determined. Scanning electron microscopy (SEM) of capsule edges were reviewed RESULTS: Anterior capsulotomies behave as non-linear elastic (elastomeric) systems when exposed to an external load. The pairwise study demonstrated that the SLC fracture strength was superior to that of CCC by a factor of 1.46-fold with SLC 277±38 mN versus CCC with 190±37 mN. Furthermore, CCC fracture strength was superior to that of FLACS by a factor of 1.28-fold with CCC 186 + 37 mN versus FLACS 145 ± 35 mN (p < 0.001). This was determined by statistical analysis utilising the Wilcoxon matched-pairs signed-ranks test and in accordance with the Consolidated Standards of Reporting Trials guidelines. The capsule edge of SLC on SEM demonstrated a rolled over edge anteriorly and an alteration of collagen. CONCLUSIONS: The strength of the capsulotomy edge for SLC was significantly stronger than that of CCC which and both were significantly stronger than FLACS. The relative strengths can be explained by SEM of each type of capsulotomy.

Efficacy and safety of a new selective laser device to create anterior capsulotomies in cataract patients.

PURPOSE: To compare the efficacy and safety of anterior capsulotomy creation with a new selective laser device (CAPSULaser) with those of manual capsulotomies. SETTING: GEMINI Eye Clinic, Zlin, Czech Republic. DESIGN: Prospective case series. METHODS: Patients were placed in cohorts based on age and cataract grade and randomly allocated to have laser capsulotomy or manual continuous curvilinear capsulorhexis (CCC). The anterior capsule was stained with microfiltered trypan blue 0.4%. The anterior capsulotomy was created with the laser device focused on the anterior capsule through a custom patient interface lens. Intraoperative video analysis with the use of an intraocular ruler and postoperative examinations were used to assess safety and efficacy (accuracy of capsulotomy size, circularity, centration). RESULTS: No intraoperative complications occurred in the laser group or the manual group. All capsulotomies in the laser group were free-floating with no tags or tears. The mean capsulotomy diameter was 5.03 mm overall (range 4.8 to 5.2 mm, laser group; 4.4 to 5.8 mm, manual group). In the laser group, all the capsulotomies were within 0.1 mm ± 0.1 (SD) of the target. The circularity accuracy was greater than 99.0% ± 1.0%; the mean centration of the capsulotomy in relation to the intraocular lens (IOL) was 0.1 ± 0.1 mm. All parameters were statistically significant (P < .01). The IOL-capsulotomy overlap was 360 degrees in all laser cases. CONCLUSIONS: Selective laser capsulotomy using a new proprietary trypan blue formulation was safe and effective in cataract surgery. The sizing, circularity, and centration of the laser capsulotomy were more accurate than those of the manual CCC, resulting in consistent 360-degree IOL coverage.

The evolution of the anterior capsulotomy.

The paper describes the development of the anterior capsulotomy from its early crude beginnings in the 18th century to the possibility of automated surgery today via continuous curvilinear capsulorhexis (CCC). The reasons for the opening of the capsule have changed from a roughly made tear to allow access to the nucleus for its extraction, to the creation of more regular openings to allow support for intraocular lenses. With the development of continuous circular tears it was possible to be certain to contain the intraocular lens (IOL) in the capsular bag. In recent times we have the ability to achieve precision in size and location with lasers and other technologies. This means the capsulotomy can be used to hold the IOL, which will improve the centration of the optic. This is important in premium lenses and should improve predictability of the effective lens position. All of these changes will be highlighted with appropriate illustrations.

Parameters affecting anterior capsulotomy tear strength and distension.

PURPOSE: To study the effects of anterior capsulotomy diameter and discontinuity on tear threshold load and distension for the technique of continuous curvilinear capsulorhexis (CCC). SETTING: Singapore National Eye Centre, Singapore, and CapsuLaser Inc., Livermore, California, USA. DESIGN: Two separate randomized pairwise cadaver eye preclinical studies. METHODS: Capsulotomies were performed in 40 cadaver eyes of 20 donors using CCC. The pairwise comparisons were divided into 2 study groups: Study A: Continuous versus discontinuous capsulotomies; Study B: Capsulotomy diameter of 5.0 mm and smaller versus diameters of 5.2 mm and larger. A shoe-tree method was used to apply load to the capsulotomy rim, and the Instron tensile stress instrument measured threshold load and distension to initiate a capsular tear. Wilcoxon matched-pairs signed-rank tests were performed to assess statistical superiority. RESULTS: In Study Group A, all pairs demonstrated that continuous capsulotomies were better than discontinuous capsulotomies for both the anterior tear threshold load and distension (P < .01). In Study Group B, 80% of the pairs demonstrated that diameters of 5.2 mm and larger were better than those of 5.0 mm and smaller diameter (P < .05). CONCLUSIONS: Anterior capsulotomies behave as nonlinear elastic (elastomeric) systems when exposed to an external load and distension. This study demonstrated that continuous circular capsulotomies were more resistant to anterior tears than discontinuous capsulotomies. A point of irregularity or a defect in a capsulotomy rim has a high probability of being the tear initiation point. Furthermore, larger diameter capsulotomies were more resistant to anterior tears than smaller capsulotomies.

Combined occlusion-triggered longitudinal and torsional phacoemulsification during coaxial microincision cataract surgery: effect on 30-degree mini-flared tip behavior.

PURPOSE: To study the impact of a new power-delivery option using occlusion-triggered bursts of longitudinal phaco energy in addition to torsional tip movement in the performance of the 30-degree mini-flared tip to minimize tip clogging with dense nuclei. SETTING: Prince Charles Eye Unit, King Edward VII Hospital, Windsor, United Kingdom. DESIGN: Comparative case series. METHOD: The cumulative dissipated energy (CDE) and time in foot pedal position 3 (FP3) to phacoemulsify each half of the nucleus with and without use of the new power-delivery option (Intelligent Phaco) were compared. RESULTS: Fifty consecutive cataract operations were reviewed. The mean CDE was 1.79 with the new power-delivery option and 2.03 without the option (P=.08). For grades I, II, III, and IV nuclei, the corresponding values were 0.41 and 0.51 (P=.16), 1.43 and 1.23 (P=.31), 2.32 and 2.92 (P=.12), 3.82 and 5.03 (P=.005). The mean FP 3 time was 5.40 seconds with the new power-delivery option and 6.35 seconds without it (P=.03). For grades I, II, III, and IV nuclei, the corresponding values were 1.53 seconds and 1.98 seconds (P=.13), 4.47 seconds and 4.26 seconds (P=.69), 6.51 seconds and 8.77 seconds (P=.05), 11.81 seconds and 16.49 seconds (P=.008). CONCLUSIONS: The new power-delivery option appeared to reduce the CDE and FP 3 time when a 30-degree mini-flared tip was used. The benefit accrued by preventing clogging of the needle was significant only in cases with a denser nucleus.

Adherent ocular bandage for clear corneal incisions used in cataract surgery.

PURPOSE: To assess an adherent ocular bandage for clear corneal incisions (CCIs) in cataract surgery using optical coherence tomography (OCT). SETTING: Prince Charles Eye Unit, Windsor, United Kingdom. DESIGN: Case-control study. METHODS: Patients having coaxial microincision cataract surgery (MICS) were allocated to an adherent ocular bandage group or to a control group. The CCIs were examined postoperatively within 2 hours and at 24 hours and 7 days using OCT imaging and a slitlamp fluorescein 2% Seidel test. RESULTS: The ocular bandage group comprised 22 eyes and the control group, 23 eyes. The mean intraocular pressure (IOP) in the immediate postoperative period was significantly lower in the control group (13.4 mm Hg ± 5.28 [SD]; range 5 to 23 mm Hg) than in the bandage group (19.4 ± 5.94 mm Hg, range 11 to 29 mm Hg) (P<.001, t test). In the bandage group, all incisions were Seidel negative. In the control group, 1 main incision was Seidel positive. In 2 cases, the bandage successfully captured a micro-leak and thus maintained an intact anterior chamber. Differences in OCT architectural features between the bandage group and control group were noted. CONCLUSIONS: The adherent ocular bandage protected the incisions, selectively adhering to deepithelialized areas and rapidly clearing from reepithelialized areas. The bandage helped maintain a more desirable IOP in the immediate postoperative period, likely by preventing micro-leaks.

dc superconducting quantum interference device based neodymium magnet displacement sensor for superfluid experiments.

A new displacement sensor that uses a rare-earth magnet attached to a flexible diaphragm is demonstrated for superfluid experiments. Its construction, calibration, and performance are described.

ASCRS White Paper: clinical review of intraoperative floppy-iris syndrome.

Intraoperative floppy-iris syndrome (IFIS) is associated with the use of systemic alpha(1)-antagonists, and tamsulosin in particular. The incidence and severity of IFIS are variable; however, the syndrome is associated with a higher rate of cataract surgical complications, especially when the condition is not recognized or anticipated. Questioning cataract patients preoperatively about current or previous use of alpha(1)-antagonists is therefore important. Intraoperative floppy-iris syndrome surgical management strategies include pharmacologic measures, the use of high-viscosity ophthalmic viscosurgical devices, and mechanical dilating devices. However, sphincterotomies and pupil stretching are ineffective. Whether used alone or in combination, these small-pupil techniques improve the surgical success rate in these cases. Stopping the alpha(1)-antagonist preoperatively is of questionable value.

Superfluid 4He quantum interference grating.

We report the first observation of quantum interference from a grating structure consisting of four weak link junctions in superfluid 4He. We find that an interference grating can be implemented successfully in a superfluid matter wave interferometer to enhance its sensitivity while trading away some of its dynamic range. We also show that this type of device can be used to measure absolute quantum mechanical phase differences. The results demonstrate the robust nature of superfluid phase coherence arising from quantum mechanics on a macroscopic scale.

Clinical experience with intraoperative floppy-iris syndrome. Results of the 2008 ASCRS member survey.

According to an online survey, most members of the American Society of Cataract and Refractive Surgery believe that tamsulosin makes cataract surgery more difficult (95%) and increases the risks of surgery (77%). Commonly reported complications of intraoperative floppy-iris syndrome (IFIS) were significant iris trauma and posterior capsule rupture, with 52% and 23% of respondents, respectively, reporting these complications at a higher rate than in non-IFIS eyes. There was no single preferred surgical method for managing IFIS; 33% of respondents routinely used multiple strategies. Of respondents with sufficient experience, 90% believe that IFIS is more likely with tamsulosin than with nonspecific alpha1-antagonists. Ninety-one percent believe that physicians prescribing alpha1-antagonists should become better educated about IFIS, and 59% would recommend a pretreatment ophthalmic evaluation for patients with cataracts or decreased vision. If they themselves had mildly symptomatic cataracts, 64% of respondents would avoid taking tamsulosin or would have their cataract removed first.