The Ultrachopper tip: a wound temperature study.

PURPOSE: To determine the thermal characteristics of the Ultrachopper and its thermal properties in varied viscosurgical substances. DESIGN: Experimental study. PARTICIPANTS: Not applicable. METHODS: The Ultrachopper (Alcon, Inc) tip with the Infiniti (Alcon, Inc) handpiece was attached to a thermistor and placed in a test chamber filled with either an ophthalmic viscosurgical device (OVD) or balanced salt solution (BSS). The thermistor allowed for continuous monitoring of temperature from baseline and the change that occurred over 60 seconds of continuous run time. RESULTS: Mean maximum temperature in each OVD exceeded 50°C over the first 25 seconds of continuous run time. The mean maximum temperature was statistically significantly higher with all OVDs (p < 0.0001) when compared with BSS. A small but statistically significant difference in mean maximum temperature was shown between Healon 5 (AMO, Inc) and Viscoat (Alcon, Inc) (p < 0.05). The linear increase in temperature was statistically significantly different with all OVDs compared with BSS (p < 0.0001). CONCLUSIONS: The thermal properties of the Ultrachopper tip demonstrate a heat-generating capacity that achieves published thresholds for risk for wound burn.

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.

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.

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.

Use of the Unfolder Silver/Sapphire system to inject capsular tension ring during phacoemulsification in cases with subluxated cataract.

Capsular tension rings (CTRs) have proved to be useful devices in cataract surgery in cases of zonular weakness and dialysis. They can be inserted with the help of forceps or commercially available injection systems. We describe use of the Unfolder Silver/Sapphire Series implantation system (Advanced Medical Optics, Inc.) to inject a CTR into the capsular bag during phacoemulsification in cases with subluxated cataract. The implantation system used for CTR insertion can subsequently be used for implantation of a foldable intraocular lens.

Forceps insertion with incisional anesthesia for Sensar intraocular lenses.

This technique to prevent self-adherence of the Sensar acrylic intraocular lens (IOL) optic during forceps insertion with wound stretch includes modifications to the 3-and-9 insertion technique to prevent difficulties that may be encountered with this phenomenon. To decrease patient sensation during IOL insertion and thus improve surgeon control, the corneal tunnel incision is directly anesthetized.

Phacoemulsification and modern cataract surgery.

The techniques and results of cataract surgery have changed dramatically during the past three decades. In the USA, we have moved from intracapsular cataract extraction as the preferred technique to almost exclusively extracapsular techniques. Smaller incisions have become the standard, with phacoemulsification now being the method of choice for most surgeons. Along with these advances have come improved intraocular lens materials and designs, especially well suited for use with smaller incisions. Phacoemulsification as a method to remove the cataractous lens was first proposed more than 20 years ago. Advances in techniques and equipment have led to a dramatic increase in the popularity of phacoemulsification with increased safety and efficiency. Viscoelastic agents have been developed synchronously with modern phacoemulsification techniques, playing an integral role in the success of this new technology. Improved surgical techniques for removing the anterior lens capsule have decreased the incidence of both intraoperative and postoperative capsular complications. Nucleus removal, formerly performed primarily in the anterior chamber, is now performed in the posterior chamber, decreasing damage to the corneal endothelium. Improved wound construction allows many wounds to be left unsutured, and smaller wounds allow shorter recovery time and greater intraoperative control and safety. Intraocular lenses can have smaller optic sizes and still maintain accurate centration. Foldable intraocular lenses can take advantage of the smaller incision, even further shortening the time to visual recovery. Continual evolution of this technology promises to further improve patient outcomes after cataract surgery.

Modified stretch technique for small pupil phacoemulsification with topical anesthesia.

I present an atraumatic technique for small pupil phacoemulsification using topical anesthesia. Fifty consecutive small pupil phacoemulsification cases were performed with topical anesthesia and mild intravenous sedation. Viscoelastic combined with a modified two instrument stretch was used for pupillary enlargement adequate for phacoemulsification. After preoperative cycloplegia, two or more multidirectional stretches were used for 3.0 to 5.0 mm pupils; three or more multidirectional stretches were used for pupils less than 3.0 mm. Pain and proprioceptive responses were avoided by reducing the stretch length, leaving the angle structures and ciliary body untouched. Sodium hyaluronate (Healon GV) created additional expansive power. Of 50 successfully implanted cases, 45 (90%) had acceptable pupillary form and function postoperatively. The 5 (10%) with enlarged, atonic pupils had past injury or inflammatory disease. This technique minimizes anterior segment trauma, instrumentation, and operating time.