The carbon footprint of cataract surgery in Wellington

INTRODUCTION

Efforts to improve the sustainability of ophthalmic care require methods to measure its environmental impact and a baseline measurement to compare against in the future. We aimed to measure the carbon footprint of cataract surgery in Wellington.

METHODS

We used Eyefficiency, an application using established footprinting methods, to estimate the emissions produced by phacoemulsification surgery in two public and two private hospitals. We measured (1) power consumption, (2) procurement of disposable items and pharmaceuticals, (3) waste disposal emissions and (4) travel (other potential sources were excluded). Where possible we used New Zealand emissions coefficients.

RESULTS

We recorded data from 142 cataract surgeries. The average emissions produced by cataract surgery in the region was estimated to be 152kg of carbon dioxide equivalent. This is equivalent to 62L of petrol and would take 45m2 of forest one year to absorb. The great majority of emissions were from procurement, mostly disposable materials, and the second greatest contribution was from travel (driving).

CONCLUSION

Estimating the carbon footprint of cataract surgery is becoming easier, but improved methods for measuring the footprint of procured supplies are needed. There are significant opportunities for emissions reduction in the most common surgical procedure in New Zealand.

Using Optical Quality Analysis System for predicting surgical parameters in age-related cataract patients

The Optical Quality Analysis System (OQAS, Visiometrics) provides objective measurements of image formed onto retina, by combining quantification of ocular media transparency and of optical aberrations. In order to evaluate its contribution in the assessment of age-related cataract, we conducted a monocentric clinical study to determine the relationships between clinical grading of lens opacity, OQAS parameters, and parameters required for cataract surgery by phacoemulsification with ultrasound (called “phacodynamics”). Clinical parameters were: best-corrected visual acuity (BCVA, expressed as Log of minimal angle resolution (logMAR)) and the lens opacity classification system III (LOCS III) as a gold standard determined by two independent observers who graded total cataract and nuclear, cortical and posterior sub capsular components. The OQAS provided an objective scatter index (OSI), a modulation transfer function (MTF, expressed in cycle per degree (cpd)) and a Strehl ratio (SR) used as an aberration marker. Patients were operated on by the same surgeon using a phacoemulsification machine that provided the cumulative dissipated energy (CDE) and total ultrasound time (US time) necessary to extract the lens. Patients with poor compliance, corneal or retinal diseases impairing OSI, or who required surgical settings variation, were excluded. Twenty-one eyes of 21 patients aged 76±8 years were analyzed. They were 11 pure nuclear, 3 pure cortical, and 7 mixed cataracts. Mean LOCS III and OSI were respectively: 4.86 ±2.03 and 6.12 ±3.07 (mean±SD). Medians (10°-90° percentiles) were: for BCVA 0.30 (0.10–0.70) logMAR, for MTF cutoff 9.31 (1.54–30.57) cpd, for SR 0.071 (0.042–0.146), for CDE 8.04 (5.74–23.29) and for US time 58 (39–116) seconds. LOCS III was significantly correlated (spearman r, r_s) with BCVA (r_s = 0.561, p = 0.008), CDE (r_s = 0.457, p = 0.038) and US time (r_s = 0.647, p = 0.002). The three OQAS parameters significantly correlated (all r_s ≥ 0.526, p<0.05) with BCVA, and LOCS III grading, but the strongest correlations were found with OSI for cortical components and with MTF for nuclear components: only OSI may be used objectively to assess the effect of cortical components on optical quality, and MTF cutoff—integrating scattering and aberrations—seems the best objective parameter for clinical assessment of nuclear cataracts. The three OQAS parameters were also significantly correlated (r_s) with CDE, and with US time only for pure nuclear cataracts: OSI had the strongest correlations with phacodynamics (r_s = 0.693, p = 0.022 with CDE and r_s = 0.703, p = 0.019 US time). OSI increased with cortical components not requiring higher CDE. When measured in optimal conditions (good compliance, no retinal or ocular surface or tear film diseases), the three OQAS parameters are complementary for objective grading of cataract. In the future, they may help to optimize surgical parameters, especially energy distribution, in femtosecond laser assisted cataract surgery.

Comparison of phacoemulsification parameters in eyes with and without exfoliation syndrome

OBJECTIVE

To evaluate and to compare the phacoemulsification machine parameters in eyes with and without XFS, requiring cataract surgery.

METHODS

Patients who underwent phacoemulsification and in-the-bag IOL implantation for cataract were included in this retrospective study. All surgeries were performed by the same experienced surgeon using the stop & chop technique with the same phacoemulsification device (Infiniti Vision System, Alcon Laboratories, Inc., USA). Patients were divided into two groups according to the presence of exfoliation material (XFM). Each group consisted of consecutive patients. Their characteristics and intraoperative phacoemulsification parameters were compared.

RESULTS

Sixty-eight eyes of 68 patients [29 in the exfoliation syndrome (XFS) (-) group, 39 in XFS (+)] were enrolled. There were no statistical differences regarding preoperative patient characteristics. There was a statistically significant difference in total U/S time, phaco time, aspiration time and estimated fluid used between the XFS (+) and XFS (-) groups (P=0.021, P=0.017, P=0.009 and P=0.002, respectively). Considering that the use of a CTR (capsule tension ring) might be an important factor potentially affecting surgical parameters, the data were analyzed accordingly. Aspiration time and estimated fluid used remained statistically significant (P=0.046 and P=0.017, respectively); however, although the U/S total and phaco time were found to be longer in XFS (+) group compared to XFS (-) group, the difference did not show statistical significance (P=0.061 and P=0.059, respectively). There were no differences between groups regarding endothelial cell loss or any other postoperative complications.

CONCLUSIONS

The presence of XFS results in longer total U/S time, phaco and aspiration time and more estimated fluid used in phacoemulsification, but this prolongation does not result in additional complications.

Visual quality observation of clear lens extraction by ultrasonic phacoemulsification and intraocular lens implantation in a child with microspherophakia: A case report

RATIONALE

Microspherophakia is characterized by a small, spherical crystalline lens with increased sagittal diameter. Because of the uncertainty about the outcome, as well as the complexity of the operation and development of complications, the management and timing of surgical intervention for microspherophakia are still debated. Lens extraction is effective for avoiding the risk of pupillary blockage, but the outcome after operation is controversial. The iTrace (Tracey, USA) report shows the influence of low-order aberrations (LOA) and high-order aberrations (HOA), which may be valuable in predicting postoperative outcome. Our report concerns a child with microspherophakia who underwent lens extraction via the analysis of visual quality by iTrace.

PATIENT CONCERNS

Our report is on the case of a 7-year-old girl whose parents observed she had to bring her papers and books extremely close to her face to read. On examination, the girl was bilaterally diagnosed microspherophakia with a small tremble lens. The objective refraction was -15.0 diopter of spherical power (DS)/-1.00 diopter of cylindrical power (DC) × 180 right eye (OD) and -12.5 DS/-1.50 DC × 20 left eye (OS). The HOA of OD and OS were high up to 0.926 and 0.659, respectively by iTrace. The visual quality remained terrible after correcting LOA (high myopia and astigmatism). According to iTrace report, the patient would get a good visual quality by extracting the clear lens with HOA from cornea after correcting LOA. The girl's parent opted for surgery on the left eye.

DIAGNOSIS

Due to the patient's symptoms, examination results, she was diagnosed with microspherophakia.

INTERVENTIONS

The patient underwent clear lens extraction by ultrasonic phacoemulsification and intraocular lens implantation.

OUTCOMES

The first day after operation, total HOA was decreased to 0.077. Total LOA was 0.713. Corrected distance visual acuity (CDVA) is 20/20. One week after surgery, HOA was 0.110 and LOA was 0.328. CDVA was 20/25. CDVA was still 20/25 one month after surgery. The total HOA was 0.110 and the LOA was 0.334 by iTrace.

LESSONS

ITrace not only plays an important role in analyzing potential reasons of undesirable preoperative visual quality but also can predict postoperative outcomes. All these functions are helpful for determining surgical intervention of microspherophakia cases.

Case Series of Combined iStent Implantation and Phacoemulsification in Eyes with Primary Angle Closure Disease: One-Year Outcomes

PURPOSE

To evaluate the safety and efficacy of combined iStent® trabecular micro-bypass device (Glaukos, Laguna Hills, CA) and phacoemulsification in eyes with primary angle closure disease.

METHODS

A two-center prospective interventional case series of consecutive patients with primary angle closure (PAC) or primary angle closure glaucoma (PACG) on at least one glaucoma medication, who underwent iStent implantation with cataract surgery. Postoperatively, patients were assessed on days 1 and 7, and months 1, 3, 6, and 12. The intraocular pressure (IOP), glaucoma medication use, visual acuity, and the presence of complications were assessed at each visit. Complete success was defined as IOP reduction of at least 20% without the use of glaucoma medications.

RESULTS

Thirty-seven eyes with angle closure disease were included in this study. At 1-year, postoperative mean IOP (14.8 ± 3.94 mmHg) was significantly decreased compared with preoperative medicated (17.5 ± 3.82 mmHg, p = 0.008) and unmedicated (24.6 ± 3.41 mmHg, p < 0.001) IOP. Complete success was achieved in 89.2% of the eyes. The number of glaucoma medications decreased from 1.49 ± 0.77 to 0.14 ± 0.48 (p < 0.001). Preoperative medicated IOP was a risk factor for failure (hazard ratio 3.45, 95% confidence interval 1.52-7.85, p = 0.003), after adjustment for age, gender, and race. The most common postoperative complications were iStent occlusion with iris (27.0%) and hyphema (18.9%). There were no sight-threatening intraoperative or postoperative complications.

CONCLUSION

Combined iStent implantation with cataract surgery was effective in lowering the IOP and the number of glaucoma medications for at least 12 months, with a favorable safety profile.

FUNDING

Glaukos Corporation; NMRC Science Translational and Applied Research (STAR) award.

The Effect of Anterior Chamber Maintainer on Anterior Chamber Contamination

PURPOSE

To evaluate the effect of anterior chamber continuous infusion maintainer system on the contamination of anterior chamber in phacoemulsification surgery.

METHODS

Clear corneal phacoemulsification surgery was performed in 132 eyes of 132 randomly selected patients with cataract who were divided into two groups of 66 eyes according to the use of an anterior chamber maintainer (ACM) system. The fluid specimens were taken from anterior chamber in the beginning and at the end of the surgery. They were transferred under anaerobic conditions and investigated by culturing onto blood agar and thiogluconate broth media. Differences between the two groups with respect to contamination of the specimens were investigated.

RESULTS

The mean age of the group undergoing surgery without a maintainer system (Group A) was 63 +/- 10 years (min = 41, max = 80) versus 59 +/- 10 years (min = 33, max = 80) in the other group (Group B) in which the maintainer was used during surgery. In the postoperative specimen, Micrococcus species were isolated from one eye (1.5%) in Group A and S. pyogenes in one eye (1.5%) from Group B. Mean follow-up interval was 12 +/- 6 (min = 4, max = 28) months.

CONCLUSIONS

The use of ACM system in clear corneal phacoemulsification surgery carries no additional risks as far as contamination is concerned.

Comparison of Vacuum and Aspiration on Phacoemulsification Efficiency and Chatter Using a Monitored Forced Infusion System

PURPOSE

To evaluate the effect of vacuum and aspiration rates on phacoemulsification efficiency and chatter using a monitored forced infusion system.

DESIGN

In vitro animal study.

METHODS

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.

PROCEDURES

Formalin-soaked porcine lenses were divided into 2 mm cubes (tip diameter, 0.9 mm). Vacuum levels were tested at 200, 300, 400, and 500 mm Hg; aspiration rates at 20, 35, and 50 mL/min. Torsional power was set at 60% and intraocular pressure at 50 mm Hg.

RESULTS

Increasing vacuum increased efficiency regardless of aspiration rates (R(2) = 0.92; P = .0004). Increasing aspiration further increased efficiency when vacuum was at 400 and 500 mm Hg (P = .004 for 20 vs 35 mL/min, P = .0008 for 35 vs 50 mL/min). At 200 and 300 mm Hg, efficiency only improved when increasing aspiration to 35 mL/min (P < .0001 with 20 vs 35 + 50 mL/min). Chatter improved with increasing vacuum, up to 400 mm Hg (P = .003 for 200 vs 300 mm Hg and P = .045 for 300 vs 500 mm Hg). A similar trend of improved chatter was seen with increasing levels of aspiration.

CONCLUSIONS

Vacuum improved efficiency up to 500 mm Hg independent of flow. Flow has an additive effect on efficiency through 50 mL/min, when vacuum is at 400 mm Hg or higher, and only up to 35 mL/min at vacuums less than 400 mm Hg. Chatter correlated with both vacuum and flow such that increasing either parameter decreases chatter, up to 400 mm Hg with vacuum.

Heat Generation and Efficiency of a New Modified Phaco Tip and Sleeve

PURPOSE

To compare a modified phacoemulsification tip with the established micro tip, in terms of temperature at the corneal wound, efficiency, and chatter events, using the Centurion® Vision system.

METHODS

Eighty porcine eyes were randomized into 4 groups: 1)sleeveless conventional 45D MiniFlared ABS® Kelman tip (1.1-mm incision); 2)sleeveless new modified 45D ABS® INTREPID® balanced tip(1.1-mm incision); 3) Kelman tip with own sleeve (2.2-mm incision); 4)Balanced tip with modified 4-rib sleeve (2.2-mm incision). Measurements were taken with 2 settings: longitudinal(power 40% and 70%) and torsional mode (power 40% and 100%). Peak temperatures were measured 0, 10, 30, and 60 seconds after continuous ultrasound power. For the efficiency test, porcine lens nuclei were formalin soaked and cut into 2.0 mm3 cubes. Efficiency and chatter were examined.

RESULTS

In all longitudinal settings, the sleeveless groups(1 and 2) showed lower temperatures than the sleeved groups(3 and 4) (P = 0.003). In 100% torsional mode, groups 3 and 4 produced significantly different temperatures(37.13 ± 1.44 and 35.14 ± 0.54, respectively; P = 0.007).The efficiency, in a 100% power torsional setting, was13.52 ± 2.60 sec for group 4, and 44.45± 14.75 sec for group 3 (P<0.001).

CONCLUSIONS

The two different bare tips show no significant differences in thermogenesis. However, the balanced tip with sleeve produces lower temperaturesat100% torsional power and better efficiency than the Kelman tip.

Safety Profile of Venturi Versus Peristaltic Phacoemulsification Pumps in Cataract Surgery Using a Capsular Surrogate for the Human Lens

PURPOSE

To compare the risk of capsular rupture of the human lens during cataract surgery from contact by phacoemulsification needles using different vacuum pumps, ultrasound modalities, and contact angles.

DESIGN

Experimental laboratory investigation.

METHODS

The John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, was the setting for this study. A Signature (Abbott Medical Optics, Inc) phacoemulsification machine was used in peristaltic and Venturi vacuum modes with transversal and micropulsed ultrasound. Contact was made with a capsular surrogate to achieve tip occlusion or tip contact only. Breakage rates were calculated by analyzing the capsular surrogate under a surgical microscope.

RESULTS

Venturi and peristaltic pump modes had similar risk of capsular rupture, regardless of whether the data were analyzed with tip occlusion data included (44.2% peristaltic vs 40.2% Venturi, P = .047) or excluded from the analysis (66.3% peristaltic vs 60.3% Venturi, P = .013). Transversal ultrasound was significantly more likely to cause capsular rupture than micropulsed ultrasound (69.8% vs 56.8%, P < .0001). Tip contact was significantly more likely than tip occlusion to cause capsular rupture (63.3% vs 0%, P < .0001).

CONCLUSIONS

There is no significant difference in risk of capsular rupture using Venturi rather than peristaltic vacuum pumps, while transversal seemed to increase the risk when compared to micropulsed ultrasound. Tip occlusion is not a risk factor for capsular rupture, as all breaks in the capsular surrogate occurred with tip contact.

Impact of micropulsed ultrasound power settings on the efficiency and chatter associated with lens-fragment removal

PURPOSE

To determine the optimum power settings in micropulsed ultrasound (US).

SETTING

John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Experimental study.

METHODS

Pig lenses hardened to be comparable to dense human cataracts were cut into 2.0 mm cubes and removed using micropulsed longitudinal US with previously optimized settings (6 milliseconds on and 6 milliseconds off and using a 0.9 mm 30-degree beveled bent phaco tip). The aspiration was set at 40 mL/min and the vacuum level at 550 mm Hg. Twenty lens cubes were tested with the power set from 10% to 100% in increments of 10%. Primary outcome measures were efficiency time (time to lens removal) and chatter (number of times the lens fragment visibly bounced off the tip).

RESULTS

Efficiency time decreased with increasing power. There was a correlation between power and efficiency time (R(2) = 0.41, P = .046), which was more substantial between 30% and 100% power (R(2) = 0.71, P = .004). The mean number of chatter events did not differ significantly between power settings (R(2) = 0.012, P = .1195).

CONCLUSIONS

There was a 5-fold increase in efficiency between 10% power and 20% power, which likely indicates that there is a minimum power threshold for efficient breakup of the lens. Between 20% and 100% power, there was a linear, strong, and statistically significant improvement in efficiency in these lens fragments. In addition, with micropulsed US there was little chatter or microchatter throughout the power range.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

MY EXPERIENCE OF TEACHING PHACOSURGERY ON VISALIS 100 IN SUDAN AND NIGERIA

At the invitation of the director of The National Eye Center, Kaduna, Nigeria and The Makkah Eye Hospital of Khartoum, Sudan I visited both these institutions to teach phacoemulsification surgery to their aspiring surgeons on Visalis 100 (Carl Zeiss Meditec, Germany). This article highlights the experience of teaching phacoemulsification surgery in foreign African countries like Nigeria and Sudan. In Nigeria I had the opportunity to give training in both wet lab and live surgery settings whereas in Sudan only hands-on live surgery. Sudan being an Islamic nation pigs are not slaughtered there and hence no pig eyes. Goat eyes differ significantly from human eyes and hence have almost no value in wet lab teaching. The training program included theoretical discussions, wet lab, surgery and finally discussions related to the days' surgery. It became clear that quality of learning depends on three main factors. Thorough understanding of theory and observation of senior surgeons in operation room Good wet lab and finally doing the surgery oneself in step by step manner. Dedicated teachers and instructors can make all the difference. The learning curve also significantly shortens if the trainees are exposed to all types of cataract surgery like ECCE, SICS and phacoemulsification surgery. The main problem faced by those surgeons who have done only ECCE/SICS is that they are not used to handling microscope and instruments in both hands at the same time. Hence I strongly recommend them wet lab where they can sit and practice using both hands and feet and microscope simultaneously and in coordinated fashion.

Phacoemulsification with implantation of Morcher aniridia capsular rings for postoperative atonic pupil after iridencleisis--case report

INTRODUCION

Large iris defets, anirdia or wide atonic pupil may cause disturbing photoptic phenomena my require surgical treatment. In acquired iris defects, ophthalmologists have a relatively wide choice of therapeutic strategies, which depend on the size and etiology of the defect and the comorbidities. The goal of treatment is to restore iris diaphragm and to reconstruct the pupil in order to prevent glare and to increase the quality of perceived image.

CASE REPORT

We present a case of cataract and unilateral wide, atonic pupil in a patient 39 years after iridencleisis, who complained of intense glare in the left eye and photophobia ever since. The patient was successfully treated by phacoemulsification through a 2.75 mm clear corneal incision with implantation of two black Morcher aniridia capsular rings. The patient experienced a significant improvement in her subjective quality of vision and a constant glare that she had been experiencing for years resolved.

CONCLUSION

The presented case indicates that Morcher aniridia capsular rings may be a good tool instrument to assist the surgeon in cases of cataract concomitant with wide and atonic pupil. Using these rings reduces glare and improves the subjective quality of patients' vision.

[State-of-the-art cataract surgery and intraocular optical correction]

The paper provides current knowledge on cataract epidemiology worldwide and in the Russian Federation, including issues of cataractogenesis and prevention. An overview of medical equipment for preoperative and intraoperative diagnostics is provided. Key aspects of the conventional ultrasonic phacoemulsification method as well as the most marked trends in correction of aphakia with intraocular lenses and in design of the latter are presented. Major laser-assisted techniques, including those that imply the use of femtosecond laser systems, and results that they yielded to date are discussed in detail.

High-speed cannula detachment into the eye during hydrodissection

Detachment of a hydrodissection cannula during a phacoemulsification procedure appeared to produce no adverse sequelae during surgery. Day 1 postoperatively, two nonpenetrating hemorrhagic retinal lesions were identified; there was no evidence of posterior capsular perforation. Day 6 postoperatively, the pupil was temporally peaked by a fine vitreous strand running to the main-port incision in the superotemporal cornea. This was divided with Nd:YAG laser, and argon laser was applied to encircle the two retinal lesions. Postoperative uncorrected visual acuity remained 6/4 at day 1, day 6, and week 4 (3 weeks after laser application) follow-up visits. Surgeons must accept responsibility for confirming the integrity of the cannula and syringe connection before beginning hydrodissection, which can be highly destructive to intracameral structures.

The use of a 20-gauge valved cannula during pars plana phacofragmentation with a 23-gauge ultrasonic fragmatome

BACKGROUND AND OBJECTIVE

To evaluate the usefulness of a 20-gauge cannula to maintain a self-sealing sclerotomy wound after 23-gauge phacofragmentation.

PATIENTS AND METHODS

This retrospective study compared the suture rates after 23-gauge phacofragmentation when the 23-gauge cannula was temporarily replaced with a 20-gauge valved metal cannula versus when the 23-gauge fragmatome was inserted at the sclerotomy site without a cannula.

RESULTS

Whereas a sclerotomy was sutured in all 31 eyes in the without-cannula group, only one eye of 14 in the cannula group required a sclerotomy suture (P < .0001). However, there was one case of fragmatome tip fracture during fragmentation in the cannula group.

CONCLUSION

A self-sealing sclerotomy wound can be maintained without suturing by using a 20-gauge metal cannula, but fragmatome tip fracture can occur during fragmentation.

Temperature profiles of sleeveless and coaxial phacoemulsification

PURPOSE

To study the temperature profile at the corneal wound during 2 sleeveless techniques versus 2 coaxial phacoemulsification techniques.

SETTING

Department of Ophthalmology, Meir Medical Center, Kfar Saba and Ein-Tal Eye Center, Tel-Aviv, Israel.

DESIGN

Experimental study.

METHODS

Thirty-six porcine eyes were randomized into 4 groups: Group 1: conventional coaxial system (3.0 mm incision); Group 2: coaxial microincision cataract surgery (MICS) system (2.2 mm incision); Group 3: bimanual MICS (1.1 mm incision); Group 4: sleeveless tri-MICS (1.1 mm incision) using a 19-gauge anterior chamber maintainer as the sole fluid source. Temperature measurements were taken using a thermocouple and an infrared thermal imaging system. Measurements were taken in 2 settings; that is, with and without occlusion.

RESULTS

With no occlusion, corneal burns did not occur in any group. However, corneal temperatures were lower with the sleeveless systems (Groups 3 and 4) than with the coaxial systems (Groups 1 and 2) (P=.0003). When occlusion was induced, temperatures were kept constantly low in the sleeveless groups, whereas in the coaxial groups, temperatures increased rapidly, causing corneal burns within seconds. The mean temperature elevations at the incision sites were 39 °C, 48.5 °C, 13.6 °C, and 11.3 °C in Groups 1, 2, 3, and 4, respectively (P<.0001).

CONCLUSIONS

Sleeveless phacoemulsification maintained lower tissue temperatures than sleeved coaxial methods. During occlusion, fluid flow around the naked tip of the sleeveless systems prevented heat accumulation and corneal burns.

A clinical comparison between DisCoVisc and 2% hydroxypropylmethylcellulose in phacoemulsification: a fellow eye study

OBJECTIVE

This study sought to compare the effects and outcomes of two ophthalmic viscosurgical devices, 1.6% hyaluronic acid/4.0% chondroitin sulfate and 2.0% hydroxypropylmethylcellulose, during phacoemulsification.

METHODS

This prospective, randomized clinical trial comprised 78 eyes (39 patients) that received phacoemulsification performed by the same surgeon using a standardized technique. Patients were randomly assigned to receive either 1.6% hyaluronic acid/4.0% chondroitin sulfate or 2.0% hydroxypropylmethylcellulose on the first eye. The other eye was treated later and received the other viscoelastic agent. Preoperative and postoperative examinations (5, 24 and 48 hours; 7 and 14 days; 3 and 6 months) included measurements of the total volume of the ophthalmic viscosurgical device, ultrasound and washout times to completely remove the ophthalmic viscosurgical device, intraocular pressure, central corneal thickness and best-corrected visual acuity. The corneal endothelial cell count was measured at baseline and at six months postoperatively. ClinicalTrials.gov: NCT01387620.

RESULTS

There were no statistically significant differences between groups in terms of cataract density or ultrasound time. However, it took longer to remove 2.0% hydroxypropylmethylcellulose than 1.6% hyaluronic acid/ 4.0% chondroitin sulfate, and the amount of viscoelastic material used was greater in the 2.0% hydroxypropylmethylcellulose group. In addition, the best-corrected visual acuity was significantly better in the hyaluronic acid/ chondroitin sulfate group, but this preferable outcome was only observed at 24 hours after the operation. There were no statistically significant differences between the two ophthalmic viscosurgical devices regarding the central corneal thickness or intraocular pressure measurements at any point in time. The corneal endothelial cell count was significantly higher in the hyaluronic acid/chondroitin sulfate group.

CONCLUSION

The ophthalmic viscosurgical device consisting of 1.6% hyaluronic acid/4.0% chondroitin sulfate was more efficient during phacoemulsification and was easier to remove after IOL implantation than 2.0% hydroxypropylmethylcellulose. In addition, the corneal endothelial cell count was significantly higher following the use of hyaluronic acid/chondroitin sulfate than with hydroxypropylmethylcellulose, which promoted an improved level of corneal endothelium protection.

Trench, lollipop, lift and chop technique for mild to moderate cataracts

No abstract available.DOI: http://dx.doi.org/10.3126/nepjoph.v4i2.6561 Nepal J Ophthalmol 2012; 4 (2): 344-345  

The influence of corneal wound size on surgically induced corneal astigmatism after phacoemulsification

BACKGROUND/PURPOSE

To determine whether there is a difference in surgically induced astigmatism (SIA) after phacoemulsification for unsutured temporal clear corneal incisions of 2.5 mm and 3.5 mm wound sizes.

METHODS

This study comprised 36 eyes of 18 patients who received cataract surgery from a single surgeon. Patients were randomly assigned to receive a one-piece intraocular lens (IOL; Acrysof SA60AT), through a 2.5 mm incision in one eye, and a three-piece IOL (Tecnis Z9000), through a 3.5 mm incision in the contralateral eye. Corneal topography was performed preoperatively and also postoperatively at 3, 6, and 12 weeks. SIA was calculated by means of vector analysis using the Alpins' method.

RESULTS

The mean SIAs of the groups with 2.5 mm and 3.5 mm incisions were 0.57 diopter (D) and 0.86 D respectively (p = 0.04) at 3 weeks postoperatively, 0.60 D and 0.83 D respectively (p > 0.05) at 6 weeks postoperatively, and 0.58 D and 0.58 D respectively (p > 0.05) at 12 weeks postoperatively. At 12 weeks postoperatively, SIAs of <1.0 D were found in all eyes in the 2.5 mm group and 93% of eyes in the 3.5 mm group. Forty-four percent of eyes in both groups demonstrated SIAs > 0.5 D at 12 weeks postoperatively. The largest SIA was 1.36 D in the 3.5 mm group.

CONCLUSION

Mean SIA in the 3.5 mm group was larger than that in the 2.5 mm group in the early postoperative period, but there was no significant difference for the entire observational period.

Comparison of bimanual and micro-coaxial phacoemulsification with torsional ultrasound

PURPOSE

To evaluate the efficacy and postoperative outcomes of bimanual and micro-coaxial phacoemulsification with torsional ultrasound.

METHODS

In this prospective randomized series, eyes with age-related cataract were randomly divided into bimanual phacoemulsification and micro-coaxial phacoemulsification groups. Data included preoperative and postoperative corrected distance visual acuity (CDVA), central/temporal corneal thickness, endothelial cell density and intraoperative ultrasound time, cumulative dissipated energy and balanced salt solution volume.

RESULTS

The study evaluated 89 patients (89 eyes). When compared between micro-coaxial and bimanual phaco groups, ultrasound time (57 ± 24 second versus 85 ± 40 second, p < 0.01), cumulative dissipated energy (10 ± 7 versus 14 ± 7, p = 0.01) and balanced salt solution volume (55 ± 19 ml l versus 75 ± 20 ml, p < 0.01) were significantly lower in micro-coaxial phaco group. At 1 day, there were no statistically significant differences in CDVA (p = 0.68) or central corneal thickness (p = 0.48) between two groups; temporal corneal thickness was statistically significantly thicker in bimanual phaco group (1247 ± 123 μm) than that in micro-coaxial phaco group (1108 ± 131 μm, p = 0.01). There were no statistically significant differences in CDVA, central/temporal corneal thickness, or endothelial cell density between two groups 30 days postoperatively (all p values >0.05).

CONCLUSION

With rapid visual rehabilitation and comparable endothelial cell loss, both bimanual and micro-coaxial phacoemulsification procedures with torsional ultrasound are efficient for moderate nuclear cataract extraction.

[Intracapsular ring in cataract surgery in lens subluxation (15 years exrerience)]

Based on literature and own experience recommendations for intracapsular ring use in cataract surgery in patients with different types of suspensory ligament deficiency were given. Operation technique and prevention of complications during ring implantation with or without retractors in different etiology of subluxation and individual degree of suspensory ligament deficiency were described for every principal step of phacoemulsification.

[Computer-assisted phacoemulsification for hard cataracts]

PURPOSE

to evaluate the efficiency of new torsional phacoemulsification software (Ozil IP system) in hard nucleus cataract extraction.

METHODS

45 eyes with hard senile cataract (degree III and IV) underwent phacoemulsification performed by the same surgeon, using the same technique (stop and chop). Infiniti (Alcon) platform was used, with Ozil IP software and Kelman phaco tip miniflared, 45 degrees. The nucleus was split into two and after that the first half was phacoemulsificated with IP-on (group 1) and the second half with IP-off (group 2). For every group we measured: cumulative dissipated energy (CDE), numbers of tip closure that needed manual desobstruction the amount of BSS used.

RESULTS

The mean CDE was the same in group 1 and in group 2 (between 6.2 and 14.9). The incidence of occlusion that needed manual desobstruction was lower in group 1 (5 times) than in group 2 (13 times). Group 2 used more BSS compared to group 1.

CONCLUSION

The new torsional software (IP system) significantly decreased occlusion time and balanced salt solution use over standard torsional software, particularly with denser cataracts.

Clinical application of 11-deoxycortisol in visualizing prolapsed vitreous body after posterior capsule rupture in cataract surgery

PURPOSE

To evaluate the clinical usefulness of 11-deoxycortisol, a precursor of cortisol in steroid metabolism, in visualizing the vitreous body in the anterior chamber after posterior capsule rupture during cataract surgery.

SETTING

Department of Ophthalmology, Tsukuba University Hospital, Ibaraki, Japan.

METHODS

Eight eyes had anterior vitrectomy during cataract surgery using this new technique. A suspension of 11-deoxycortisol was prepared by dilution in balanced salt solution without preservatives or emulsifying agents. After a posterior capsule rupture, the suspension was injected into the anterior chamber. The visual and anatomical outcomes of surgery were evaluated during a follow-up of 7 to 9 months.

RESULTS

After the 11-deoxycortisol injection, the vitreous body that had prolapsed through the torn posterior capsule, with white particles entrapped on its surface, became clearly visible. Complete removal of the prolapsed vitreous body was achieved easily and safely using an anterior vitrectomy system. No postoperative complications related to the use of 11-deoxycortisol were observed.

CONCLUSION

Injection of 11-deoxycortisol helped visualize the vitreous body in the anterior chamber after posterior capsule rupture. The technique minimized intraoperative and postoperative complications related to posterior capsule rupture and vitreous loss during cataract surgery [corrected]

Decrease in complications during cataract surgery with the use of a silicone-tipped irrigation/aspiration instrument

PURPOSE

To compare rates of vitreous loss during cataract surgery when a silicone-tipped irrigation/aspiration (I/A) instrument is used for cortex removal as opposed to a metal tip.

SETTING

Parkland Memorial Hospital, Dallas, Texas, USA.

METHODS

A retrospective chart review of all patients who had cataract extraction by phacoemulsification by third-year ophthalmology residents between September 2000 and February 2004 was conducted. A silicone-tipped I/A instrument was used to remove cortex for all surgeries beginning in September 2002, whereas a metal I/A tip was used previously.

RESULTS

Of the 1072 cases performed with a metal I/A tip, there were 13 cases of vitreous loss during cortex removal (rate 1.2%) and 26% of all vitreous loss during that time occurred during cortex removal. Of the 805 cases performed with a silicone I/A tip, there was a single case (0.1%) of vitreous loss during cortex removal (P=.004); only 4% of all vitreous loss during that time occurred during cortex removal (P=.011).

CONCLUSION

The overall incidence of vitreous loss during cortex removal and the ratio of vitreous loss during cortex removal to all cases of vitreous loss were significantly decreased using the silicone-tipped I/A instrument.

Outcome of dual infusion through irrigating chopper in conventional phacoemulsification

OBJECTIVE

To determine the operative advantage in terms of minimizing the complications following conventional phaco surgery with dual infusion through irrigating chopper.

METHODS

A Randomized Controlled Clinical Trial (RCCT) was conducted in the Ophthalmology Unit-III, Sindh Government Lyari General Hospital and DUHS and Al-Noor Eye Hospital Karachi, from March 2008 to February 2009. A total of 200 eyes with nuclear/cortico-nuclear cataract on Lens Opacity Classification System III underwent phacoemulsification. In all 100 eyes in group A were randomized to have conventional phacoemulsification with dual infusion technique through irrigating chopper and another 100 eyes in group B by conventional phaco surgery. Outcomes in two groups were judged by amount of Ringer's Lactate used, stability of anterior chamber and number of complications observed.

RESULTS

Rate of intra-operative complications was lower in group A as compared to group B (p=0.002). Anterior chamber depth was maintained in all cases of group A while it collapsed in 9 cases of group B which was highly significant (p=0.003). Mean amount of Ringer's Lactate used in group A was 260.2 +/- 55.07 ml and 195.8 +/- 35.0 ml in group B, which was significantly high (p<0.001).

CONCLUSION

Dual infusion through irrigating chopper serves triple function of irrigation, chopping and additional separate distant infusion. It improves anterior chamber stability and compensates surge and operative advantage to surgeon.

[Intelligent phaco--always necessary?]

PURPOSE

To assess the need of /P system use in soft cataract

METHODS

prospective study--40 eyes with soft cataract (+/++); surgery with Infinity system, Ozil handpiece; in 20 eyes we used low levels (max 70%) of torsional ultrasound power and IP system; in 20 eyes we used higher levels of torsional ultrasound power without IP system; we assessed: the CME value and the presence of cornela edema.

RESULTS

In cases with tosional ultrasound only: average value of CME--2.4; maxim value of CME--4.3; all corneas without edema. In cases with torsional ultrasound and IP system; average value of CME--3.6; maxim value of CME--7.2; 4 eyes with decemetic folds in central cornea.

CONCLUSIONS

In soft cataracts is better to not use IP system

Thermal comparison of Infiniti OZil and Signature Ellips phacoemulsification systems

PURPOSE

To determine thermal characteristics of Signature Ellips (Abbott Medical Optics) and Infiniti OZil (Alcon, Inc.) transverse ultrasound and compare both with longitudinal ultrasound in clinically relevant scenarios.

DESIGN

Laboratory investigation.

METHODS

Temperature increase over baseline after 60 seconds was measured in water at positions in 90-degree increments around the sleeve near the proximal needle shaft in an artificial chamber for Ellips and OZil on continuous ultrasound with aspiration blocked and unblocked. This was also done with Signature using longitudinal ultrasound, with and without micropulse (6 ms on, 12 ms off), with aspiration blocked and unblocked, and at the OZil sleeve tip on continuous transverse mode with aspiration unblocked.

RESULTS

OZil (8.1 +/- 0.3 C) had greater temperature increase than Ellips (5.2 +/- 0.3 C; P < .0001) with aspiration unblocked and blocked (29.3 +/- 1.0 C vs 12.2 +/- 0.7 C; P < .0001). OZil had uneven distribution of heat around the shaft (30.1 +/- 0.5 C vs 28.5 +/- 0.6 C; P < .0001), whereas Ellips did not (P = .57). OZil was cooler at the tip (6.6 +/- 0.2 C; P < .0001). Friction in a cadaver eye incision only increased these numbers by 10% (OZil, irrigation blocked).

CONCLUSIONS

Metal stress probably creates heat at the proximal needle junction for both transverse methods. Heat generation differences between OZil and Ellips result from the manner in which they create needle motion. Incision burns may occur, especially for OZil, under nonpulsed settings during fragment removal with occlusion when reaching across the anterior chamber such that the proximal needle shaft came near the wound.

[Influence AquaLase at corneal endothelial cells]

PURPOSE

To assess the effect of the cleaning of the posterior capsule using pulses of balanced salt solution (BSS) on the corneal endothelial cells.

METHODS

This pilot study involves 43 patients with bilateral cataracts having lens removal using torsional phacoemulsification (Ozil, Infiniti, Alcon) and bimanul irrigation/aspiration (I/A). Posterior capsule of the right eye of each patient was cleaned using pulses of BSS (AquaLase, Infiniti, Alcon). Surgery was performed by one of 2 surgeons (NJ, PR), both eyes of each patient was operated on by the same surgeon. Best corrected visual acuity (BCVA), endotelial cell count and pachymetry were evaluated pre- and postoperatively as well as occurence af peri- and postoperative complications.

RESULTS

Preoperative mean pachymetry (P) was 566 +/- 45 microm in the right eye (RE) and 562 +/- 42 microm in the left eye (LE), mean endotelial cell count (ECC) 2541 +/- 317 cells/mm2 (RE) and 2567 +/- 311 cells/mm2 (LE). Three months after surgery P was 557 +/- 43 microm (RE) and 558 +/- 45 microm (LE) and ECC 2368 +/- 416 cells/mm2 (RE) and 2396 +/- 417 cells/mm2 (LE). There was no statistical difference in postoperative changes of both corneal parameters between right and left eyes. Best corrected visual acuity improved in all eyes and no peri-or postoperative complications occured.

CONCLUSIONS

Cleaning of the posterior capsule using AquaLase is safe for corneal endothelial cells.

Comparison of actual vacuum pressures at the end of 3 phacoemulsification tips in swine eyes

PURPOSE

To compare the actual vacuum pressure at the end of an aspiration bypass system (ABS) phaco tip and a conventional tip in conditions similar to those during human cataract surgery.

SETTING

Kangbuk Samsung Hospital, Seoul, Korea.

METHODS

A 4.0 mm diameter rubber eraser ball was inserted in a phacoemulsified swine eye and engaged to a phaco tip. With a vacuum pressure of 300 mm Hg, the eraser ball was pulled in the opposite direction with the phaco tip. The pulling power separating the eraser ball from the phaco tip was measured using the volume of water dripped into a container connected to the eraser ball. Measurements were taken with an Infiniti ABS tip and 2 conventional tips: Sovereign (conventional tip S) and Infiniti (conventional tip I). Measurements were taken alternatively at random in the same eye.

RESULTS

The mean pulling power was 17.35 mL +/- 5.01 (SD) with conventional tip S and 16.85 +/- 4.45 mL with conventional tip I. The mean pulling power of the ABS tip was 13.35 +/- 4.32 mL, which was a mean 20.8% lower than that of conventional tip I (P = .016) and 23.1% lower than that of conventional tip S (P = .010).

CONCLUSIONS

The actual vacuum pressure of the phaco tip was significantly influenced by the presence of the ABS hole. To compensate for the decrease in actual vacuum pressure, surgeons should be aware of the characteristics of the ABS tip being used and change the standard settings accordingly.

[The first results of cataract phacoemulsification made by bimanual technique]

The results of 112 operations of bimanual ultrasound lens extraction through microincisions in cataracts of varying severity and origin are assessed in patients aged 46 to 85 years. The parameters of operation of ultrasound devices, the designs of accessory instruments (cataract hydrochoppers), and a nuclear scission procedure are considered. It is noted that this procedure is convenient in complicated cases: rigid iris and lens dislocation. The operations were observed to show a high efficiency: no postoperative astigmatism and rapid rehabilitation.

Cataract surgery (phacoemulsification) in difficult cases

By presenting three cataract surgeries, we discuss the difficulties of the interventions and the key moments. Case I: Mature cataract surgery on a patient with corneal opacities (maculas). Case II: Posterior polar cataract. Case III: Small pupil, shallow anterior chamber (dilating with Malyugin ring).

CONCLUSIONS

The surgery of a mature cataract on an eye with corneal opacities can be performed by a surgeon with enough experience. The final visual acuity depends on the clarity of the center of the cornea. During the operation of a posterior polar cataract we have to be prepared to the rupture of the posterior capsule, which is more frequent than in other cases. These interventions are better to be made in centers with posterior pole surgery capabilities. The Malyugin ring is a novel PMMA device, which dilates the pupil, creating decent conditions for a cataract surgery This device can be inserted and pulled out through a standard 2,8 mm incision.

Macular thickness and volume after uncomplicated phacoemulsification surgery evaluated by optical coherence tomography. A one-year follow-up

OBJECTIVE

To evaluate changes in the macular thickness and volume using optical coherence tomography in patients after phacoemulsification and intracapsular implantation of a foldable intraocular lens.

MATERIALS AND METHODS

The study included 82 patients (37 males and 45 females) after phacoemulsification and intracapsular implantaion of the same type of a foldable intraocular lens, without any other eye disease. Phacoemulsification was performed with an INFINITI machine. In all patients, macular thickness and volume were measured with an optical coherence tomograph (Stratus OCT) using the Fast Macular Thickness Map. The OCT evaluation was performed on days 1, 7, 30 and 90 postoperatively. In 58 patients (71%), it was additionally performed at 12 months after surgery and in 52 patients (63%) the macular parameters in the healthy and operated eyes were compared.

RESULTS

A statistically significant increase in the minimal retinal thickness was observed on days 30 (p<0.0005) and 90 (p<0.005) postoperatively compared to post-operative day 1. A statistically significant increase in the foveal volume was seen on days 30 (p<0.00005) and 90 (p<0.0005). A statistically significant increase in the volume of the entire macula was found on days 7, 30 and 90 (p<0.00005).

CONCLUSION

Uncomplicated cataract phacoemulsification is followed by increases in the central retinal thickness, foveal volume and volume of the entire macula on days 30 and 90 and at 12 months postoperatively. Further observation of patients is required to confirm whether the macular parameters will return to their values on day 1 postoperatively and if so, when this will occur.

Use of Malyugin pupil expansion device for intraoperative floppy-iris syndrome: results in 30 consecutive cases

PURPOSE

To evaluate a new disposable, small-pupil expansion device in tamsulosin patients with intraoperative floppy-iris syndrome (IFIS) having cataract surgery.

SETTING

Private practice, Los Altos, California, USA.

METHODS

The 5-0 polypropylene Malyugin pupil expansion device (MicroSurgical Technology) was used in 30 eyes from 21 tamsulosin patients having routine cataract surgery. The pupil diameter was measured at the beginning and end of surgery, and the severity of IFIS was graded. Intraoperative and postoperative complications were recorded.

RESULTS

The device maintained a constant 6.0 mm pupil diameter throughout surgery. Although iris prolapse was still possible, there were no significant intraoperative or postoperative complications despite the fact that 93% of the eyes had moderate to severe IFIS. All eyes achieved a best corrected visual acuity of at least 20/25. There was a tendency for ring deformation if flash sterilization was used without sufficient cooling time.

CONCLUSIONS

The disposable Malyugin pupil expansion device was highly effective at maintaining an adequate pupil opening in eyes with IFIS. It is easier and faster to use than iris retractors and other pupil expansion rings and represents an excellent small-pupil strategy.

A fluidics comparison of Alcon Infiniti, Bausch & Lomb Stellaris, and Advanced Medical Optics Signature phacoemulsification machines

PURPOSE

To compare three phacoemulsification machines for measurement accuracy and postocclusion surge (POS) in human cadaver eyes.

DESIGN

In vitro comparisons of machine accuracy and POS.

METHODS

Tip vacuum and flow were compared with machine indicated vacuum and flow. All machines were placed in two human cadaver eyes and POS was determined.

RESULTS

Vacuum (% of actual) was 101.9% +/- 1.7% for Infiniti (Alcon, Fort Worth, Texas, USA), 93.2% +/- 3.9% for Stellaris (Bausch & Lomb, Rochester, New York, USA), and 107.8% +/- 4.6% for Signature (Advanced Medical Optics, Santa, Ana, California, USA; P < .0001). At 60 ml/minute flow, actual flow and unoccluded flow vacuum (UFV) was 55.8 +/- 0.4 ml/minute and 197.7 +/- 0.7 mm Hg for Infiniti, 53.5 +/- 0.0 ml/minute and 179.8 +/- 0.9 mm Hg for Stellaris, and 58.5 +/- 0.0 ml/minute and 115.1 +/- 2.3 mm Hg for Signature (P < .0001). POS in an 32-year-old eye was 0.33 +/- 0.05 mm for Infiniti, 0.16 +/- 0.06 mm for Stellaris, and 0.13 +/- 0.04 mm for Signature at 550 mm Hg, 60 cm bottle height, 45 ml/minute flow with 19-gauge tips (P < .0001 for Infiniti vs Stellaris and Signature). POS in an 81-year-old eye was 1.51 +/- 0.22 mm for Infiniti, 0.83 +/- 0.06 mm for Stellaris, 0.67 +/- 0.01 mm for Signature at 400 mm Hg vacuum, 70 cm bottle height, 40 ml/minute flow with 19-gauge tips (P < .0001).

CONCLUSIONS

Machine-indicated accuracy, POS, and UFV were statistically significantly different. Signature had the lowest POS and vacuum to maintain flow. Regarding POS, Stellaris was close to Signature; regarding vacuum to maintain flow, Infiniti and Stellaris were similar. Minimizing POS and vacuum to maintain flow potentially are important in avoiding ocular damage and surgical complications.

The influence of viscoelastic substances on the corneal endothelium during cataract surgery by phacoemulsification

PURPOSE

To compare the ability of different ophthalmic viscoelastic devices to protect the corneal endothelium following in-the-bag phacoemulsification with posterior chamber intraocular lens (IOL) implantation.

MATERIAL & METHODS

We studied 50 patients with soft to moderately dense (Grade 1-3) cataract and corneal endothelial cell density of >2000 cells/mm2. The corneal response to surgery was evaluated by measuring the endothelial cell loss, the variation in the mean cell area of the endothelial cells (CV), and the central corneal thickness, all that by using a TOPCON SP 2000P noncontact, specular microscope. Data were recorded preoperatively and postoperatively.

RESULTS

Preoperatively no statistical significant difference was observed in cell count, CV or pachymetry among groups. Postoperatively, all the groups had a statistically significant decrease (p < 0.001) in endothelial cell count. There was an equal and significant (p < 0.001) increase in visual acuity. Between groups there was no statistically significant difference (p > 0.17) in any of the parameters we studied.

CONCLUSIONS

Between the OVDs we used, either DisCoVisc or ProVisc & VisCoat, there was no statistical significant difference neither in surgical outcome nor in endothelial layer aspect and function. DisCoVisc protected better the endothelium cells even if it was not statistically significant, and is the one that can be used for the entire surgical procedure.

Visual acuity in patients having foldable and non-foldable intra-ocular lens for cataract surgery

BACKGROUND

Intra-ocular lens (IOLs) is the most commonly use organ substitute worldwide. Question of different type of IOLs which would offer different post operative visual acuity (VA) has been asked.

OBJECTIVES

To compare the pre-operative and post operative visual acuity (VA) of cataract patients operated-patient and the use of non foldable and foldable IOLs in different age groups.

METHOD

Retrospective study of post operative VA of cataract patients-operated from Priest, Lerdsin Hospital in Bangkok and Lampang Hospital in northern part of Thailand. Methods to operate and type of IOLs implantation were recorded. The cases with pre-operative and intra-operative complications were excluded.

RESULTS

Post operative VA of cataract patients was better than pre-operation VA with statistically significant at p-value less than 0.05 and the results persisted for every age group. With phacoemulsification (PE) techniques, non-foldable IOLs offered better post operative VA than foldable IOLs in every age group except in age group of less than 40 and age group over 59 that showed statistically significant different at p-value less than 0.05.

CONCLUSION

Due to the nature of retrospective study, the cause of poor post operative VA was due to astigmatism which the pre-operative astigmatism were not recorded to fulfill complete analysis.

Modified capsular tension ring for cortical removal after implantation

We describe a modification of the original 14C Morcher capsular tension ring. The new ring, the Henderson capsule tension ring (HCTR, Morcher), is an open C-shaped loop made of poly(methyl methacrylate). It has 8 equally spaced indentations of 0.15 mm to improve the ease of removing nuclear and cortical material while maintaining equal expansion of the capsular bag. The HCTR is currently under review by the U.S. Food and Drug Administration.

Cataract surgery using the bimanual phacoemulsification technique with an Accurus system and Mackool microphaco tip

PURPOSE

To investigate the safety and effectiveness of the Accurus vitreoretinal and phacoemulsification system (Alcon, Inc.) for bimanual phacoemulsification surgery.

SETTING

Kosei Chuo Hospital, Tokyo, Japan.

METHODS

Phacoemulsification for age-related cataract was performed using a bimanual technique in 55 eyes and a coaxial technique in 31 eyes. The Accurus system with a venturi pump and a sleeveless ultrasonic tip or a Mackool microphaco tip was used in all cases. The 2 techniques were compared. In bimanual phacoemulsification, the 2 tips were evaluated to determine whether either reduced ocular tissue impairment.

RESULTS

The mean best corrected visual acuity 1 day after the surgery was 20/20 in both groups. There was no significant difference between the bimanual group and coaxial group except in ultrasound output (bimanual 22%, coaxial 28%; P = .01). Iris impairment was observed only in the bimanual group but was reduced by the use of the Mackool sleeved microphaco tip.

CONCLUSION

Bimanual phacoemulsification for cataract surgery using the Accurus system with a venturi pump and a Mackool microphaco tip was safe and effective and may provide a means of performing combined or successive cataract and vitreoretinal surgery.

Weight effect of saline accumulation in surgical drapes

BACKGROUND

Positive vitreal pressure during phacoemulsification is a known risk factor for posterior capsule rupture. Knowledge of modifiable causes of positive vitreal pressure is imperative to aid in its management intraoperatively. The aim of our study was to determine whether the weight from the accumulation of a large volume of saline in the surgical drapes could have an effect on intraocular pressure in patients. Such an effect could indicate a source of posterior vitreal pressure in patients undergoing prolonged phacoemulsification.

METHODS

In 23 adult patients undergoing phacoemulsification at the Jones Eye Institute at the University of Arkansas for Medical Sciences, intraocular pressure readings were taken before and after the addition of 500 cc of saline to the surgical drapes and taken again after removal of the saline.

RESULTS

Statistically significant differences in intraocular pressure were found between the baseline measurement, the measurement with saline, and the measurement after saline removal. No differences in the rise in intraocular pressure were found according to age, race, sex, or which eye was tested.

INTERPRETATION

Accumulation of a large volume of saline in surgical drapes has a modest effect on intraocular pressure. This may indicate a contributing cause of posterior vitreal pressure during prolonged phacoemulsification.

[Prospective randomized trial comparing Discovisc versus Healon in phacoemulsification]

OBJECTIVE

To compare the intraoperative behaviour of both, DisCoVisc and Healon used as viscoelastics in cataract surgery.

METHOD

We prospectively evaluated 35 patients with cataracts who underwent phacoemulsification and intraocular lens implantation. Patients were randomized into two groups. Group A included 17 patients in where Healon was used as a viscoelastic, whereas group B included 18 patients in where the viscoelastic used was DisCoVisc. After each procedure, the surgeon filled in a questionnaire describing the behaviour of the viscoelastic during the different stages of phacoemulsification.

RESULTS

DisCoVisc behaved as both cohesive and dispersive viscoelastic during capsulorrhexis, phacoemulsification and viscoelastic aspiration, whereas Healon acted as a cohesive substance during all surgical stages. DisCoVisc enabled better visualization and transparency during all the surgical stages and maintains the capsular bag better during the intraocular lens implantation. Viscoelastic aspiration was easier with Healon.

CONCLUSIONS

DisCoVisc is a new viscosurgical device with both cohesive and dispersive properties, which avoids using two different viscoelastics to improve the performance at different surgical stages. DisCoVisc has been shown to be more transparent and provides better anterior chamber maintenance when compared with Healon. Healon was more easily aspirated due to its cohesive character.

[Results of modified one-stage operation for cataract and glaucoma]

The paper analyzed the immediate and late results (the state of intraocular pressure and visual functions) of combined surgery for cataract and glaucoma, by using the developed instrument. Eighteen patients (19 eyes) aged 54 to 92 years who had open-angle glaucoma or phacotopic glaucoma (dislocation of the lens to the vitreous body) and cataract underwent combined surgery involving extraction of cataract, its phacoemulsification with intraocular lens (IOL) implantation through the scleral tunnel, and sinus trabeculectomy (STE) performed with a perforator, the instrument developed by the authors. The findings confirm the efficiency of the combined surgery (STE) with cataract extraction through variously extended scleral tunnels in patients with open-angle glaucoma, normalizing intraocular pressure and improving visual functions by one-stage surgery. Combined surgery for cataract extraction with IOL implantation through the scleral tunnel and STE, which is performed with the instrument proposed by the authors, has been put into practice.