Intraocular pressure after small incision cataract surgery with Healon5 and Viscoat

A primer on ocular viscosurgical devices

PURPOSE

To provide pharmacists with an overview of ocular viscosurgical devices (OVDs) and a comprehensive resource describing characteristics of commercially available agents.

SUMMARY

OVDs are substances that are injected into the eye during ophthalmic procedures, such as cataract surgery, to reduce injury to the endothelium that may result from surgical manipulation. Currently available OVDs are composed of one or more of the following active ingredients: sodium hyaluronate, sodium chondroitin sulfate, and hydroxypropylmethylcellulose. Rheologic properties of OVDs, such as viscosity, elasticity, pseudoplasticity, and cohesion, affect the products' function and performance. Based on rheologic properties, OVDs can be generally classified as cohesive or dispersive. Given each products' unique characteristics, OVDs are not interchangeable. An understanding of OVD characteristics and role in practice allows for improved product selection, which varies based on patient characteristics and procedure. Availability of OVD information and literature is generally lacking since OVDs are regulated by the US Food and Drug Administration (FDA) as medical devices. This primer includes an overview of relevant ophthalmic surgical practices and the landscape of comparative efficacy and safety literature to assist in formulary decision-making. This review also provides a comprehensive guide to commercially available OVDs and a discussion on practical considerations for the pharmacist.

CONCLUSION

Pharmacists may be tasked with handling OVDs in institutional settings. Knowledge about OVD rheologic properties, product characteristics, role in practice, and available literature is necessary for managing formularies and ensuring optimal product selection.

Pure phaco: phacoemulsification without ophthalmic viscosurgical devices

The ophthalmic viscosurgical device (OVD) is an essential part of modern phacoemulsification surgery. Many times, OVDs are blamed for intraocular pressure spikes, toxic anterior segment syndrome, and capsular bag distension syndrome. To avoid these complications, we developed a technique in which phacoemulsification can be done without using OVDs. The irrigating cannula, on a continuous irrigation mode, was introduced through a side port, and capsulorhexis and incision construction were performed under an irrigating balanced salt solution. No hydroprocedure was performed. Phacoemulsification was done by chopping technique. At the end of the procedure, the intraocular lens was implanted by wound assistance technique under a continuous irrigation mode.

Clinical Comparison of the Performance of Two Marketed Ophthalmic Viscoelastic Devices (OVDs): The Bacterially Derived Healon PRO OVD and Animal-Derived Healon OVD

This clinical investigation compared the clinical performance of two marketed ophthalmic viscoelastic devices (OVDs): the bacterially derived Healon PRO OVD (test) and the animal-derived Healon OVD (control) under normal use conditions during cataract removal and lens implantation. This prospective, multicenter, randomized, parallel, participant/evaluator masked, postmarket investigation enrolled 139 subjects (170 eyes), 116 (143 eyes) of which were treated (73 test; 70 control group). Both test and control OVDs were used, at a minimum, to inflate the anterior chamber and protect the endothelium prior to cataract extraction according to the standard procedure. The surgeon completed a postsurgery OVD clinical performance questionnaire, and intraocular pressure (IOP) was measured before surgery and at the 1 day postoperative visit with Goldmann applanation tonometry. Any IOP measurement of 30 mmHg or higher was considered a “spike” and recorded as a study-specific, serious adverse event. The bacterially derived Healon PRO OVD was found to be statistically noninferior to the overall clinical performance of the animal-derived Healon OVD control; thus, the primary hypothesis was satisfied. There were no statistically significant differences between OVD groups for any of the additional endpoints relating to IOP changes or to safety, thus satisfying additional hypotheses. The Healon PRO OVD showed statistically significant improvements in surgeon ratings for ease of injectability, transparency/visibility, and ease of IOL placement. The safety profile was also similar between OVD groups with regards to serious and/or device-related adverse events, as well as medical and lens findings. The results of this clinical investigation support the safety and effectiveness of the bacterially derived, currently marketed Healon PRO OVD and indicate that the intraocular surgical performance was similar between the two OVDs.

Impact of Ophthalmic Viscosurgical Devices in Cataract Surgery

Background

Ophthalmic viscoelastic devices (OVDs) used during small-incision cataract surgery have numerous advantages. However, OVDs have longer retention time in an eye after surgery resulting in intraocular pressure (IOP) spikes. The purpose of this study is to analyze and quantify the effect of various OVDs on both IOP and best corrected visual acuity (BCVA) by systematically reviewing the literature and performing meta-analysis.

Methods

Numerous databases from January 1, 1985, to present were systematically searched. Thirty-six (3893 subjects) of 3313 studies identified were included for analysis. Standardized mean difference (SMD) was computed, and meta-analysis was performed.

Results

A total of 3313 records were retrieved including 1114 from database search and 2199 from grey literature search. Significant increase in postoperative IOP in 1-day follow-up with Healon (SMD = 0.37, CI: [0.07, 0.67]), Viscoat (SMD = 0.29, CI: [0.13, 0.45]), Provisc (SMD = 0.46, CI: [0.17, 0.76]), and Soft Shell (SMD = 0.58, CI: [0.30, 0.86]) was computed. On the other hand, results implied a nonsignificant increase in postoperative IOP with Healon GV (SMD = 0.07, CI: [−0.28, 0.41]), Healon5 (SMD = 0.15, CI: [−0.33, 0.64]), 2% HPMC (SMD = 0.32, CI: [−0.0, 0.64]), and OcuCoat (SMD = 0.26, CI: [−0.37, 0.9]). Additionally, a nonsignificant reduction in postoperative IOP was inferred with Viscoat + Provisc (SMD = −0.28, CI: [−2.23, 1.68]).

Conclusion

Improvement in IOP was shown with Viscoat + Provisc. Additionally, IOP nonsignificant upsurge was observed with Healon GV, Healon5, 2% HPMC, and OcuCoat compared to significant upsurge with Healon, Viscoat, and Soft Shell.

Intraocular pressure variation after conventional extracapsular cataract extraction, manual small incision cataract surgery and phacoemulsification in an indigenous black population

Introduction

intraocular pressure changes have been reported following the various cataract surgical technique. This study aims to compare the intra-ocular pressure (IOP) variation following conventional extra-capsular cataract extraction (ECCE), manual small incision cataract surgery (MSICS) and phacoemulsification in an indigenous black population.

Methods

a comparative cross-sectional study of adult patients aged 40 years and above who had pressure was measured with Goldman’s applanation tonometer pre-operatively and 1^st day, 1^st week, 1^st month as well as 3^rd month post-operative periods and recorded. Data was analyzed using SPSS version 21. Mean IOP changes between study groups were compared using ANOVA. P-value of < 0.05 was taken as statistically significant.

Results

total of 82 patients consisting of 20(24.4%) ECCE, 32(39%) MSICS and 30(36.6%) phacoemulsification with mean preoperative 13.4mmHg, 13.5mmHg and 14.1 mmHg (p = 0.657) respectively was studied. Mean IOP increased from baseline at 1st day post-operative period in the ECCE and MSICS groups (13.4 ± 3.0mmHg to 13.7 ± 4.5mmHg (p = 0.84) and 13.5 ± 3.1mmHg to 15.3 ± 5.1mmHg (P = 0.48) respectively), and decrease in the phacoemulsification group (14.1 ± 2.6mmHg to 13.9 ± 3.5mmHg (p = 0.378). There was a decline in IOP in all the 3 study groups by one week post-operative period; the difference was significant only in the ECCE group (p = 0.032). By 3^rd month postoperatively, there was a reduction in mean IOP when compared with pre-operative IOP the difference being greatest in the ECCE group.

Conclusion

ECCE, MSICS, and Phacoemulsification cause a decline in IOP below preoperative levels at 3^rd month postoperatively in the MSICS group.

A new histological evaluation method to detect residual ophthalmic viscosurgical devices for cataract surgery

Purpose

To establish a new evaluation method to quantify residual ophthalmic viscosurgical device (OVD) volume and corneal endothelium adhesion properties for phacoemulsification surgery.

Methods

We compared the performance of four OVDs (Viscoat®, Healon5®, Healon® and DisCoVisc®) using porcine eyes. First, OVDs were mixed with fluorescent-conjugated dextrans to render them visible under the microscope. A corneal side port was opened, followed by a continuous curvilinear capsulorhexis, and a corneal tunnel incision was made. OVDs were injected, then the lens was removed using one-handed phacoemulsification. After this procedure, the anterior segment of the eye was isolated via an equatorial incision and the tissue was immediately frozen in shimmering liquid nitrogen. Sagittal slices (20 μm) were cut with a Cryostat from limbus to limbus. Every tenth slide was imaged using a fluorescent microscope with a CCD camera. We evaluated the percentage of the corneal endothelium covered by each OVD as the OVD adhesion to corneal endothelium ratio (OAE ratio) and the volume of residual OVD in the anterior chamber.

Results

Viscoat® showed significantly higher endothelium coverage compared with both Healon® and DisCoVisc®. A statistically larger volume of Healon5® remained in the anterior chamber compared with Healon® and DisCoVisc®.

Conclusion

The new evaluation methods used here provide precise quantitative analysis of OAE ratio and residual OVD volume. These results show that Viscoat® and Healon5® have a high potential for coating the corneal endothelium during phacoemulsification and aspiration surgery.

Phacoemulsification of bilateral cataracts in two pet rabbits

Two 3 year-old, healthy, client-owned Lop rabbits presented with bilateral cataracts. After performing a physical examination, bloodwork, ocular ultrasonography and electroretinography, both animals were deemed good surgical candidates for phacoemulsification. Bilateral cataract surgery was performed and both rabbits regained vision in both eyes. Both animals developed post-operative ocular hypertension and one animal developed corneal ulcers immediately after surgery. Both surgical complications resolved with medical management. This case series describes phacoemulsification of bilateral cataracts in 2 companion rabbits and the use of an intraocular lens in 1 rabbit. Surgical treatment of cataracts can be considered as a treatment option whenever a healthy rabbit is visually impaired due to cataracts.

Safety of Polyacrylamide 1.5% Left in Anterior Chamber in Combined Phacoemulsification and Pars Plana Vitrectomy Surgery

PURPOSE

To evaluate safety, efficacy and postoperative characteristics of polyacrylamide 1.5% ophthalmic viscosurgical device (OVD) left in anterior chamber during and at the end of combined phacoemulsification and pars plana vitrectomy surgery.

MATERIALS AND METHODS

This prospective study comprised 20 eyes that received combined phacoemulsification and pars plana vitrectomy performed by the same surgeon. Polyacrylamide 1.5% was left in anterior chamber at the end of the surgery. Preoperative and postoperative examinations (4, 12 and 24 hours; 14 days; 1 and 3 months) included measurement of intraocular pressure (IOP), central corneal thickness (CCT), endothelial cell density and assessment of any ocular adverse reactions.

RESULTS

Four of the 20 patients (20%) showed increased IOP at hours postoperatively and needed medical treatment for IOP control. There was no significant difference in IOP between the preoperative visit and postoperative 3 months (p > 0.05). CCT measurements were similar between preoperative and postoperative visits (p > 0.05). A mean endothelial cell density loss of 6.7% was observed at postoperative day 14, however there was no change after this visit.

CONCLUSION

Polyacrylamide 1.5% is safe, well-tolerated and protective in eyes undergoing combined phacoemulsification and pars plana vitrectomy.

Safety of hydroimplantation: a foldable intraocular lens implantation without the use of an ophthalmic viscosurgical device

PURPOSE

To compare the safety of a single-piece, foldable intraocular lens (IOL) hydroimplantation with that of a standard implantation using an ophthalmic viscosurgical device (OVD).

METHODS

One hundred consecutive patients with bilateral age-related cataract surgery were enrolled into a prospective double-blind study. Each patient's first eye was randomly assigned to a standard implantation technique with an OVD or the hydroimplantation technique, while the fellow eye received the opposite technique. The main outcomes measured were endothelial cell loss, postoperative changes of intraocular pressure (IOP), and the frequency of complications.

RESULTS

The reduction of endothelial cell density 1 month and 6 months after the surgery was 9.76% ± 13.5%, 10.7% ± 12.6%, respectively, in group A (OVD) and 9.07% ± 12.7%, 9.13% ± 13.7%, respectively, in group B (hydroimplantation). The differences were not statistically significant. The mean IOP 2 hours after surgery was 10.19 ± 6.78 mm Hg in group A and 9.92 ± 7.01 mm Hg in group B. Twenty-four hours and 1 month after surgery, the mean IOP was 14.52 ± 5.59 mm Hg and 13.21 ± 3.5 mm Hg, respectively, in group A, and 15.45 ± 5.77 mm Hg and 13.1 ± 3.44 mm Hg, respectively, in group B. The differences between groups A and B were not statistically significant.

CONCLUSIONS

The hydroimplantation technique is a safe technique for single-piece foldable IOL implantation. There was no increase in intraoperative and postoperative complications compared with the standard implantation technique using an OVD.

Effect of prophylactic intraocular pressure-lowering medication on pain during cataract surgery

PURPOSE

This study evaluated the effects of acetazolamide, latanoprost, travoprost, bimatoprost, brimonidine, brinzolamide, and timolol on pain during phacoemulsification cataract surgery.

METHODS

This prospective randomized comparative study included 323 eyes of 323 patients with no history of intraocular surgery or chronic eye disease who underwent uncomplicated phacoemulsification cataract surgery and foldable intraocular lens implantation under topical anesthesia. Patients were divided into 8 groups according to the preoperative prophylactic intraocular pressure (IOP)-lowering medication. The intraoperative pain was assessed postoperatively using a visual analog pain scale. The Kruskal-Wallis test investigated the differences in the visual analog pain-scale scores of the groups, and the Mann-Whitney U test investigated the pairwise comparison of the groups.

RESULTS

The median visual analog pain-scale score of the group that did not receive any IOP-lowering medication was 2.0±1.89. The brimonidine group exhibited the lowest visual analog pain-scale scores, and the prostanoids, especially the bimatoprost group, demonstrated the highest visual analog pain-scale scores (median±standard deviation were 0.0±1.50 and 2.0±1.91, respectively). The median visual analog pain-scale scores of the acetazolamide, latanoprost, travoprost, brinzolamide, and timolol groups were 0.0±1.62, 2.0±1.67, 2.0±1.73, 0.0±1.66, and 1.0±1.54, respectively. A pairwise comparison using the Mann-Whitney U test with Bonferroni correction revealed significant differences between the groups of acetozolamide and travoprost (p=0.001), acetozolamide and bimatoprost (p<0.001), travoprost and brimonidine (p<0.001), bimatoprost and brimonidine (p<0.001), and bimatoprost and timolol (p=0.001).

CONCLUSIONS

Prophylactic application of the IOP-lowering medication may alter the pain sensation during phacoemulsification cataract surgery.

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 four-year prospective study on intraocular pressure in relation to phacoemulsification cataract surgery

AIM OF STUDY

To follow up prospectively the intraocular pressure (IOP) of healthy eyes with senile cataract undergoing phacoemulsification surgery over a duration of 4 years.

PATIENTS AND METHODS

Thirty-five patients entering first eye cataract surgery had IOP measured by applanation tonometry pre-operatively and on day 1, at 1 month, 6 months, 1 year, 2 years and 4 years after surgery at 9 a.m. and again at 2 p.m. in the Department of Ophthalmology, Oulu University Hospital. Thirty-four patients attended the 1-year checkup, and the 2- and 4-year results are available for 31.

RESULTS

The pre-operative IOP was 16.0 (SD 4.3, range 6-25) mmHg in the morning and 16.4 (SD 4.0, range 8-25.5) mmHg in the afternoon. On the first postoperative day, the IOP was 2.1 ± 5.6 mmHg higher than before surgery (p = 0.029). At 1 month, the IOP morning measurement had decreased 2.8 ± 3.6 mmHg, and in the afternoon, the decrease was 3.0 ± 2.7 mmHg from the pre-operative level. At 6 months, the decrease was 3.3 ± 2.7 mmHg in the morning and 3.6 ± 2.7 mmHg in the afternoon, at 1 year, 3.2 ± 3.0 mmHg and 3.5 ± 3.2 mmHg, at 2 years, 3.2 ± 2.4 mmHg and 3.1 ± 2.8 mmHg, and at the 4-year postoperative checkup, 3.6 ± 3.4 mmHg and 3.6 ± 2.7 mmHg, respectively (p = 0.000 for all time-points).

CONCLUSIONS

IOP decreases by about 3 mmHg (16-23% from the pre-operative IOP level) after phacoemulsification and remains at this reduced level with no trend towards an increase during 4 years.

Safety, efficacy, and intraoperative characteristics of DisCoVisc and Healon ophthalmic viscosurgical devices for cataract surgery

Purpose

To evaluate the safety and efficacy of DisCoVisc ophthalmic viscosurgical device (OVD, Alcon Laboratories, Inc) with respect to a comparator, Healon OVD (Advanced Medical Optics, Inc).

Patients and methods

In this prospective study, patients with cataracts were randomized to an OVD, and then received phacoemulsification and injection of an intraocular lens. After each surgery, unmasked investigators completed subjective questionnaires about OVD characteristics during each stage of the procedure. Masked technicians evaluated objective safety parameters of intraocular pressure (IOP) and endothelial cell density, with 90 days of follow-up.

Results

The DisCoVisc OVD group (128 eyes) and the Healon OVD group (121 eyes) had statistically similar outcomes for IOP and for endothelial cell loss. Subjectively assessed viscosity was statistically different (P < 0.0001), with Healon OVD most often rated “cohesive” and DisCoVisc OVD most often rated “both dispersive and cohesive”. Workspace maintenance differed between groups (P < 0.0001), with workspace most frequently rated “full chamber maintained” when using DisCoVisc OVD and most frequently rated “workspace maintained” when using Healon OVD. “Flat” or “shallow” workspace ratings occurred only in the Healon OVD group.

Conclusion

DisCoVisc OVD had both cohesive and dispersive properties, and was safe and effective for every stage of cataract surgery.

Use of viscoelastic substance in ophthalmic surgery - focus on sodium hyaluronate

Among viscoelastic substances, sodium hyaluronate has become the most popular for intraocular surgeries since the introduction of Healon^® (sodium hyaluronate 1%, 4 × 10⁶ daltons) in 1979. This review focuses on the recent development of a new generation of sodium hyaluronate agents with new rheologic properties and the relevant new techniques used in cataract, glaucoma, corneal, and vitreoretinal surgeries. The introduction of sodium hyaluronate agents with different rheologic properties has improved the safety and reliability of intraocular surgeries. Although there have been numerous studies reporting the effectiveness of viscoelastic substances in intraocular surgeries, rigorous validation by multi-center randomized control trials is lacking in many cases. At present, no single viscoelastic agent is most suitable to all of the various intraocular surgical techniques. Therefore, ophthalmologic surgeons should keep up with recent developments of viscoelastic agents and relevant surgical techniques for better patient care.

Increased intraocular pressure on the first postoperative day following resident-performed cataract surgery

PURPOSE

The aim of this study was to investigate the incidence of intraocular pressure (IOP) elevation after resident-performed cataract surgery and to determine variables, which influence postoperative day 1 (POD1) IOP.

METHODS

In all, 1111 consecutive cataract surgeries performed only by training residents between 1 July 2001 and 30 June 2006 were included. Elevated IOP was defined as ≥23 mm Hg. Surgeries were classified according to the presence of POD1-IOP elevation. Fisher's exact test and Student t-test were used to compare both groups. Multivariate analyses using generalized estimating equations were performed to investigate predictor variables associated with POD1-IOP elevation.

RESULTS

The average preoperative IOP was 16.0±3.2 mm Hg and the average POD1-IOP was 19.3±7.1 mm Hg, reflecting a significant increase in IOP (P<0.001, paired t-test). The incidence of POD1-IOP elevation ≥23 mm Hg was 22.0% (244/1111). Presence of glaucoma and ocular hypertension, higher preoperative IOP, and longer axial length were frequently encountered variables in the POD1-IOP elevation group (all P<0.05). Using a multivariate analysis, presence of glaucoma (P=0.004, OR=2.38; 95% confidence interval (95% CI)=1.31-4.30), presence of ocular hypertension (P=0.003, OR=6.09; 95% CI=1.81-20.47), higher preoperative IOP (P<0.001, OR=3.73; 95% CI=1.92-7.25), and longer axial length (P=0.01, OR=1.15; 95% CI=1.03-1.29) were significant predictive factors for POD1-IOP elevation.

CONCLUSIONS

IOP elevation on the first postoperative day following resident-performed cataract surgery occurred frequently (22.0%). Increased early postoperative IOP was associated with presence of glaucoma and ocular hypertension, higher preoperative IOP, and longer axial length.

Subjective evaluation of intraoperative performance of DisCoVisc in complex ocular environments

PURPOSE

To subjectively evaluate the intraoperative characteristics of DisCoVisc during phacoemulsification in complex ocular environments.

PATIENTS AND METHODS

In this prospective observational study, two experienced surgeons (ARV and CZ) performed phacoemulsification on 100 consecutive patients with cataract associated with complex ocular environments. Inclusion criteria were eyes with shallow anterior chambers (anterior chamber depth (ACD) of <2.1 mm), inadequate pupillary dilation (3 mm), dense cataract, and white mature cataract. The surgeons subjectively assessed the endpoints at each phase of phacoemulsification and various behavioural aspects of the ophthalmic viscosurgical devices (OVDs) were subsequently evaluated.

RESULTS

The distribution was as follows: eyes with white mature cataract (n=18), eyes with grades 4 and 5 cataract (n=56), eyes with co-existing shallow ACD <2 mm (n=24), and co-existing small pupil size <2 mm (n=18). DisCoVisc behaved like a moderately cohesive viscoelastic in 94% of the cases. Injection of viscoelastic was easy in 38 (38%) eyes and very easy in 62 (62%) eyes. Visualization after the viscoelastic injection was excellent in 74% of the eyes. During phacoemulsification, DisCoVisc was moderately dispersive at all the stages of emulsification. The bag maintenance during IOL implantation was excellent in 56% eyes; IOL implantation was easy in 26% of the eyes and difficult in 20% of the eyes. Surgeons found viscoelastic removal easy in 68% of the eyes. At the time of OVD removal, DisCoVisc behaved like both a dispersive and a cohesive viscoelastic in 96% of the eyes.

CONCLUSION

DisCoVisc provides both cohesive and dispersive properties. DisCoVisc alone, even in complex ocular environments, enabled the surgeon to achieve good intraoperative performance.

DisCoVisc versus the soft-shell technique using Viscoat and Provisc in phacoemulsification: randomized clinical trial

PURPOSE

To compare the effects and outcomes of DisCoVisc (hyaluronic acid 1.6%-chondroitin sulfate 4.0%) with those of the soft-shell technique using Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%) and Provisc (sodium hyaluronate 1.0%) in phacoemulsification.

SETTING

Iladevi Cataract & IOL Research Centre, Ahmedabad, India.

METHODS

This prospective randomized clinical trial comprised 100 eyes having phacoemulsification by the same surgeon using a standardized technique. Eyes were randomly assigned to DisCoVisc (Group 1) or Viscoat and Provisc (Group 2). Preoperative and postoperative examinations included absolute change in pachymetry, percentage difference in endothelial cell density (ECD) and coefficient of variation (CV), and anterior segment inflammation.

RESULTS

The mean postoperative central corneal thickness (CCT) in Group 1 and Group 2 was 590.96+/-46.05 microm and 586.94+/-50.57 microm, respectively, at 1 day; 554.14+/-35.45 microm and 551.65+/-37.69 microm, respectively, at 7 days; and 533.74+/-29.12 microm and 536.44+/-35.59 microm, respectively, at 1 month. The between-group differences in CCT were not statistically significant. At 3 months, the mean ECD was 2427.06+/-243.26 cells/mm2 and 2475.30+/-222.83 cells/mm2, respectively, and the mean CV, 42.38+/-7.94 cells/mm2 and 41.66+/-7.71 cells/mm2, respectively. There was no significant difference in the mean ECD between preoperatively and 3 months postoperatively or in corneal thickness between preoperatively and 1, 7, and 30 days postoperatively.

CONCLUSION

A single injection of DisCoVisc was effective, and its postoperative outcomes were comparable to those of combined Viscoat and Provisc.

Comparison of the effect of Viscoat and DuoVisc on postoperative intraocular pressure after small-incision cataract surgery

PURPOSE

To evaluate the effect of Viscoat (sodium chondroitin sulfate 4%-sodium hyaluronate 3%) and DuoVisc (Viscoat and Provisc [sodium hyaluronate 1%]) on postoperative intraocular pressure (IOP) after bilateral small-incision cataract surgery.

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This prospective randomized study comprised 60 eyes of 30 consecutive patients with age-related cataract in both eyes. Each patient's eyes were randomly assigned to receive Viscoat or DuoVisc during cataract surgery. DuoVisc is a packet containing 2 ophthalmic viscosurgical devices (OVDs): the dispersive Viscoat, which was used for intraocular lens (IOL) implantation. In the Viscoat group, the Viscoat was used during the entire surgery. The intraocular pressure (IOP) was measured preoperatively as well as 1, 6, and 20 to 24 hours postoperatively.

RESULTS

One and 6 hours postoperatively, the mean IOP was significantly higher in the Viscoat group than in the DuoVisc group (25.8 mm Hg and 20.5 mm Hg, respectively, at 1 hour and 24.7 mm Hg and 21.1 mm Hg, respectively, at 6 hours) (P<.05). At 20 to 24 hours, the mean IOP was not statistically significantly different between the 2 groups. Intraocular pressure spikes to 30 mm Hg or higher occurred in 4 eyes in the DuoVisc group and 11 eyes in the Viscoat group (P<.05).

CONCLUSIONS

Viscoat caused significantly higher IOP increases and significantly more IOP spikes than DuoVisc in the early postoperative period. Therefore, if Viscoat is used during cataract surgery, an additional cohesive OVD should be used for IOL implantation.

Evaluation of intraocular pressure at the end of cataract surgery

PURPOSE

To assess the accuracy of estimating intraocular pressure (IOP) at the end of cataract surgery and to suggest a method of verifying this value.

SETTING

University hospital in a suburban area.

METHODS

Sixty-nine eyes having phacoemulsification cataract surgery without complications were studied. In stage 1, the surgeon estimated IOP using digital pressure at the end of cataract surgery while a second investigator checked the actual IOP using a handheld tonometer. The estimated and true values were compared. In a second group of patients, the IOP was measured at the end of surgery in 30 eyes using a specifically designed tonometer, the Ocular Kasaby Barraquer 20/30 (OKBT-20/30) (Ocular Instruments, Inc.). The true values were then measured using the handheld tonometer to verify the accuracy of the OKBT-20/30.

RESULTS

In stage 1, 37.7% of the estimates were outside the "acceptable" IOP range of 10 mm Hg or higher to 30 mm Hg or lower. Accuracy of estimates decreased toward the extremes of IOP. This suggests that eyes with IOP values outside the acceptable range are likely to be left as such at the end of surgery. In stage 2, when the IOP was measured with the new instrument and rechecked with the electronic tonometer, 93.3% of eyes had an IOP within the reference range of 20 to 30 mm Hg; 62.3% of eyes had an IOP within this range when estimated.

CONCLUSIONS

Because the digital estimate can be misleading, the OKBT-20/30 tonometer or a similar device should be used routinely to ensure each eye is left with a desirable IOP at the end of cataract surgery.

Soft-shell technique using Viscoat and Healon 5: a prospective, randomized comparison between a dispersive-viscoadaptive and a dispersive-cohesive soft-shell technique

PURPOSE

To compare the efficacy of the dispersive-viscoadaptive soft-shell technique using Viscoat and Healon 5 to the dispersive-cohesive soft-shell technique in reducing corneal endothelial cell damage during cataract surgery.

METHODS

In this prospective randomized study, 207 eyes of 171 cataract patients underwent phacoemulsification using the dispersive-viscoadaptive soft-shell technique (V-group, 102 eyes) with Viscoat and Healon5 or the dispersive-cohesive soft-shell technique (C-group, 105 eyes) with Viscoat and a cohesive agent (Opegan-Hi). Each group was divided into two subgroups depending on the amount of ultrasound (%Min) used during phacoemulsification. Corneal endothelial cell density was examined preoperatively and 3 months postoperatively. The endothelial cell loss was compared between the two groups, and also between the subgroups.

RESULTS

The mean endothelial cell loss 3 months after surgery was 8.4 +/- 5.6% standard deviation (SD) in the V-group and 8.2 +/- 6.2% in the C-group (P = 0.787). In the subgroups with ultrasound of 10 %Min or less, the mean endothelial cell loss 3 months after surgery was 6.6 +/- 4.6% in the V-group and 5.5 +/- 5.0% in the C-group (P = 0.104). In the subgroups with ultrasound of over 10 %Min, this value was 10.6 +/- 6.3% in the V-group and 11.9 +/- 5.7% in the C-group (P = 0.413). The correlation coefficient of the endothelial cell loss rate and %Min was 0.245 (P = 0.0129) in the V-group and 0.501 (P < 0.0001) in the C-group.

CONCLUSION

The dispersive-viscoadaptive soft-shell technique is as effective as the dispersive-cohesive soft-shell technique in protecting corneal endothelial cells during phacoemulsification regardless of the amount of ultrasound energy used.

Postoperative course of intraocular pressure after cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing

PURPOSE

To evaluate the natural course of intraocular pressure (IOP) after cataract surgery with combined primary posterior continuous curvilinear capsulorhexis (PPCCC) and posterior optic buttonholing (POBH) of the intraocular lens (IOL) in adult patients.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

Fifty consecutive patients with age-related cataract awaiting cataract surgery under topical anesthesia in both eyes were enrolled prospectively. In randomized order, cataract surgery with combined PPCCC and POBH was performed in 1 eye. In the fellow eye, cataract surgery was performed conventionally with in-the-bag IOL implantation and the posterior lens capsule kept intact. Standardized IOP measurements by Goldmann applanation tonometry were performed 1, 2, 4, 6, 8, and 24 hours postoperatively. Follow-up IOP measurements were taken at 1 week and 1 month. Twenty-five patients received 1-time IOP-lowering medication immediately after cataract surgery; the other 25 did not receive IOP-lowering drops.

RESULTS

During the first 24 hours postoperatively, no significant differences in IOP were observed between the PPCCC-POBH group and the conventional surgery group (P>.05). No IOP peaks greater than 27 mm Hg were observed in any eye. One week and 1 month postoperatively, no significant differences in IOP were found between groups (P>.05). The use of IOP-lowering drops significantly reduced postoperative IOP. However, no IOP spikes >27 mm Hg were found with and without the use of IOP-lowering drops.

CONCLUSION

The course of IOP after cataract surgery with combined PPCCC and POBH showed the technique to be as safe as conventional cataract surgery with in-the-bag IOL implantation.

Intraocular pressure and foveal thickness after phacoemulsification

PURPOSE

To evaluate the natural course of intraocular pressure (IOP) and foveal thickness during the postoperative period, and the correlation between them.

DESIGN

Prospective observational case series.

METHODS

This institutional study comprised 30 eyes of 30 cataract patients scheduled for phacoemulsification. IOP and foveal thickness by optical coherence tomography (OCT) were measured preoperatively and three, six, nine, 12, 15, 18, 21, 24 hours, five days, one month, and two months postoperatively.

RESULTS

The IOP was 4.7 +/- 2.4 mm Hg at three hours postoperatively. The IOP increased to 23.4 +/- 8.1 mm Hg at six hours and 23.5 +/- 7.3 mm Hg at nine hours postoperatively. The IOP was 1.9 mm Hg lower at one month or two months postoperatively than preoperatively. The foveal thickness was 202.1 +/- 19.2 microm and significantly higher at three hours postoperatively, and was 182.3 +/- 20.5 microm, 183.2 +/- 22.3 microm, and significantly lower at nine and 12 hours postoperatively than preoperatively. The correlation between mean IOP and mean foveal thickness is statistically significant. Fovea thickness (microns) = 207.0476 - 1.019759 x IOP (mm Hg), P value < .0001, adjusted R(2) = .8699.

CONCLUSIONS

We found initial hypotony, an IOP spike during six to nine hours, and a decrease of IOP at one month and two months postoperatively. An initial increase of the foveal thickness, a significant reduction at nine hours and 12 hours, and an equivocal increase at one month or two months postoperatively were also noted. A significant negative correlation between IOP and foveal thickness was shown.

Natural course of intraocular pressure after cataract surgery with sodium hyaluronate 1% versus hydroxypropylmethylcellulose 2%

PURPOSE

To investigate the natural course of intraocular pressure (IOP) after small-incision cataract surgery with sodium hyaluronate 1% versus hydroxypropylmethylcellulose 2%.

DESIGN

Randomized clinical trial.

PARTICIPANTS

Eighty eyes of 40 consecutive patients with bilateral age-related cataract.

METHODS

The patients were assigned randomly to receive sodium hyaluronate 1% or hydroxypropylmethylcellulose 2% during cataract surgery in the first eye. The second eye received the other ophthalmic viscosurgical device. The IOP was measured preoperatively and 30 minutes; 1, 2, 3, 4, 6, 8, and 20 to 24 hours; and 1 week postoperatively.

MAIN OUTCOME MEASURE

Postoperative IOP increase.

RESULTS

The highest mean IOP increase occurred at 8 hours postoperatively (5.3+/-6.4 mmHg) in the sodium hyaluronate 1% group and at 2 hours postoperatively (7.8+/-6.1 mmHg) in the hydroxypropylmethylcellulose 2% group. Overall, the IOP increase was higher with hydroxypropylmethylcellulose 2% (P = 0.005). Intraocular pressure spikes to > or =30 mmHg occurred in 5 eyes (13%) in the sodium hyaluronate 1% group and 13 eyes (33%) in the hydroxypropylmethylcellulose 2% group.

CONCLUSIONS

Sodium hyaluronate 1% and hydroxypropylmethylcellulose 2% caused significant IOP increases during the first 8 hours after cataract surgery. A single measurement at 6 hours postoperatively could detect all IOP spikes in the sodium hyaluronate 1% group. In the hydroxypropylmethylcellulose 2% group, a single measurement at 2 hours postoperatively could detect two thirds of IOP spikes.

Effect of bimatoprost on intraocular pressure after phacoemulsification in eyes with exfoliation syndrome

PURPOSE

To evaluate the effect of bimatoprost 0.03% on intraocular pressure (IOP) after phacoemulsification in eyes with exfoliation syndrome.

METHODS

This prospective, randomized, masked study comprised 90 eyes of 90 patients scheduled for phacoemulsification. The patients were divided into three groups (group 1 = without exfoliation, group 2 = with exfoliation syndrome, group 3 = exfoliation syndrome + bimatoprost). Immediately after phacoemulsification, one drop of bimatoprost was instilled in eyes in group 3. Baseline IOP was measured 1 day before surgery and routine follow-ups were performed at 6 hours, 20-24 hours and 1 week postoperatively.

RESULTS

Preoperative IOP was 15.0 +/- 2.7 mmHg in group 1, 15.6 +/- 3.2 mmHg in group 2 and 16.1 +/- 3.2 mmHg in group 3 (p = 0.372). Six hours postoperatively, there was a significant difference between the groups (p = 0.013): IOP in group 2 (22.4 +/- 7.3 mmHg) was higher than in group 1 (18.4 +/- 4.4 mmHg) (p = 0.018) and group 3 (18.9 +/- 4.9 mmHg) (p = 0.044). In all groups, IOP values at 6 hours postoperatively were higher than preoperative values (p < 0.001), but IOP values at 20-24 hours and 1 week after surgery were not significantly different from baseline values (p > 0.05). The change in IOP in group 2, from baseline to 6 hours postoperatively, was greater than the equivalent changes in group 1 (p = 0.048) and group 3 (p = 0.016).

CONCLUSIONS

Transient IOP increase and spikes were more common in eyes with exfoliation syndrome. Postoperative application of bimatoprost was effective in reducing IOP and preventing IOP spikes >/= 30 mmHg in eyes with exfoliation syndrome in the early postoperative period.

Change in intraocular pressure within 1 week of phacoemulsification and intraocular lens implantation using Adatocel

PURPOSE

To examine the change in intraocular pressure (IOP) within 1 week of phacoemulsification and foldable posterior chamber intraocular lens (PC IOL) implantation using Adatocel (hydroxypropyl methylcellulose 2% [HPMC]).

SETTING

Department of Ophthalmology, University of Sciences, Faculty of Medicine, Pécs, Hungary.

METHODS

In this prospective study, the IOP in 118 eyes of 118 patients (57 men, 61 women, mean age 68 years +/- 7.8 [SD]) with no history of glaucoma was assessed by Goldmann applanation tonometry 2 to 3, 6 to 8, and 22 to 24 hours and 1 week after uneventful phacoemulsification and PC IOL implantation. The effect of the removal of Adatocel ("partial removal" from the anterior chamber [AC] only versus "complete removal" from behind of the IOL as well), the lens type (Medicontur 601 HP versus Bausch & Lomb Hydroview), and the type of anesthesia (topical versus parabulbar) were compared. Statistical analysis was performed using the Student t test, and P< or =.05 was considered statistically significant.

RESULTS

The mean preoperative IOP was 13.83 +/- 2.5 mmHg. There were no significant differences at any time in postoperative IOP measurements between the 2 IOL types and the 2 modes of anesthesia. At 2 to 3 hours, 6 to 8 hours, and 22 to 24 hours, the IOP was significantly higher in the 30 eyes in which the Adatocel was partially removed (from the AC only) than in the 88 eyes in which it was completely removed (from behind the PC IOL as well) (P< or =.05, P< or =.01, and P< or =.001, respectively).

CONCLUSION

Severe postoperative IOP spikes in nonglaucomatous patients after uneventful phacoemulsification cataract surgery are rare. The type of implanted PC IOL and the mode of anesthesia had no significant effect on postoperative IOP. Total removal of the ophthalmic viscosurgical device, even when using HPMCs such as Adatocel, is necessary to prevent postoperative IOP spikes.

Corneal Endothelial Cell Protection With Viscoat and Healon or Healon Alone During Penetrating Keratoplasty

PURPOSE

To determine the influence of dispersive ophthalmic viscosurgical products (OVPs) on corneal endothelial cell (CEC) density during penetrating keratoplasty (PKP) and on the postoperative intraocular pressure (IOP).

METHODS

In 117 eyes of 113 patients, PKP was performed by a single surgeon from April 1, 1998 to April 30, 2002. Loss of CECs and postoperative IOP were evaluated retrospectively after use of Viscoat (sodium hyaluronate 3.0%, chondroitin sulfate 4.0%) plus Healon (sodium hyaluronate 1.0%) (Viscoat/Healon group) or Healon alone (Healon group) during surgery.

RESULTS

The average CEC loss was 14.6 +/- 15.5% and 9.0 +/- 10.5% at 1 month, 18.1 +/- 14.6% and 10.1 +/- 7.3% at 3 months, 20.1 +/- 16.3% and 12.2 +/- 10.9% at 6 months, and 31.7 +/- 21.4% and 18.1 +/- 15.5% at 12 months in the Healon (n = 74) and Viscoat/Healon (n = 43) groups, respectively. Patients were stratified into groups with corneal leukoma (n = 61) or bullous keratopathy (n = 56). Loss of CECs was significantly smaller in the Viscoat/Healon group compared with the Healon group irrespective of whether patients had corneal leukoma or bullous keratopathy at 3, 6, and 12 months postoperatively. There was no significant difference of postoperative IOP between the Healon and Viscoat/Healon groups over 12 months of follow-up.

CONCLUSION

These results suggest that the addition of Viscoat to Healon decreases CEC loss during PKP and does not affect postoperative IOP.

Natural Course of Intraocular Pressure after Cataract Surgery with Sodium Chondroitin Sulfate 4%–Sodium Hyaluronate 3% (Viscoat)

PURPOSE

To investigate the natural course of intraocular pressure (IOP) and its peak after small-incision cataract surgery with chondroitin sulfate 4%-sodium hyaluronate 3% (Viscoat, Alcon Laboratories, Inc., Fort Worth, TX).

DESIGN

Observational case series.

PARTICIPANTS

This prospective study comprised 40 eyes of 40 consecutive cataract patients scheduled for small-incision cataract surgery.

METHODS

Cataract surgery was performed with sodium chondroitin sulfate 4%-sodium hyaluronate 3% as the ophthalmic viscosurgical device, which was removed as completely as possible from the eye at the end of surgery. The IOP was measured preoperatively and 30 minutes; 1, 2, 3, 4, 6, 8, and 20 to 24 hours; and 1 week postoperatively.

MAIN OUTCOME MEASURES

Postoperative IOP increase.

RESULTS

The mean IOP increased significantly at all observation times during the first 20 to 24 hours, with a peak increase of 13.4+/-9.4 mmHg after 1 hour (P<0.05). In all, 28 eyes (70%) had an IOP spike to 30 mmHg or higher. Sixty-eight percent of these spikes occurred at 30 minutes as well as at 1 hour and 2 hours postoperatively. At 20 to 24 hours, no eye had an IOP spike to 30 mmHg or higher.

CONCLUSIONS

Significant IOP increases were found during the first 24 hours, peaking at 1 hour after surgery. With a single postoperative IOP measurement, between 30 minutes and 2 hours after surgery, two thirds of these IOP spikes could be detected. To detect all IOP spikes, a second measurement between 4 and 6 hours after surgery would be necessary.

Intraocular pressure rise after phacoemulsification surgery in glaucoma patients

PURPOSE

To examine the changes in intraocular pressure (IOP) and the incidence of substantial rises in IOP in the early period after cataract surgery in eyes with open-angle glaucoma (OAG).

SETTING

Hayashi Eye Hospital, Fukuoka, Japan.

METHODS

The study included 32 eyes of 32 patients with OAG and 31 control eyes of 31 age-matched patients scheduled for phacoemulsification surgery. The IOP was measured preoperatively and 1, 2, 3, 5, 7, 14, and 28 days postoperatively. The incidence of a substantial rise in IOP postoperatively was evaluated, with the criterion being an IOP higher than 30 mm Hg.

RESULTS

In the OAG group, the mean IOP increased 1, 2, and 3 days postsurgery and then decreased, whereas in the control group, it decreased from day 1 postsurgery. Although no significant differences were found between groups preoperatively, the mean IOP in the OAG group was significantly higher than in the control group postoperatively. Furthermore, the mean IOP decrease was also less in the OAG group than in the control group. A substantial increase in IOP occurred at day 1 postsurgery in 4 eyes (12.5%) in the OAG group, whereas no eyes in the control group showed such an increase; this difference was significant (P =.0419).

CONCLUSIONS

A substantial increase in IOP occurred in an approximately 13% of eyes with OAG 1 day after phacoemulsification surgery. The IOP shortly after surgery was significantly greater in the eyes with OAG than in nonglaucomatous eyes.

Empty-bag technique for acrylic intraocular lens implantation using Healon5

PURPOSE

To determine how often the empty-bag technique (EBT) for injecting an acrylic foldable intraocular lens (IOL) into the capsular bag using Healon5 (sodium hyaluronate 2.3%) will require a 2-compartment technique to remove the ophthalmic viscosurgical device (OVD) and compare this with that of a standard injection method using Healon5.

SETTING

Cincinnati Eye Institute and Ambulatory Surgical Center, Cincinnati, Ohio, USA.

METHODS

Forty-one eyes of 40 patients were randomly assigned to 1 of 2 groups. In Group A, standard capsular bag expansion was performed with Healon5 before implantation of an acrylic posterior chamber (PC) IOL. In Group B, Healon5 was placed in the anterior chamber followed by balanced salt solution expansion of the capsular bag before acrylic PC IOL implantation. In all patients, complete OVD removal was attempted with the automated aspiration tip anterior to the optic (rock 'n roll technique). The number of patients in each group who required placement of the aspiration tip posterior to the optic for complete removal was compared. Early postoperative intraocular pressure (IOP) was also compared.

RESULTS

In Group A, 15 (75%) of 20 eyes required placement of the aspiration tip posterior to the optic for complete OVD removal and in Group B, 1 (0.05%) of 20 eyes. The postoperative IOP was similar in both groups.

CONCLUSIONS

The EBT decreased the likelihood that a 2-compartment OVD removal method would be necessary when using Healon5 for acrylic PC IOL implantation. The limitations of this new technique must be fully understood before it is used.

Survey of ophthalmic viscosurgical devices

PURPOSE OF REVIEW

Cataract treatment is evolving, thanks to new phaco systems and innovative surgical techniques. Recent ophthalmic viscosurgical devices (OVDs) play an important role in the development of new approaches to surgery. Knowledge of the new techniques and advances in new OVDs is crucial to performing routine and complicated surgeries.

RECENT FINDINGS

Viscoadaptive substances have been introduced as a particular kind of OVD and are distinguished by high viscosity at a low flow rate and a tendency to fracture at higher flow rates, assuming pseudodispersive behavior. The ultimate soft shell technique emphasizes the rheology of viscoadaptive OVDs to perform phacoemulsification procedures, exploiting all the useful properties of these OVDs in terms of space maintenance and tissue protection. Recent studies have highlighted some new and interesting aspects of the use of OVDs. Current reports suggest that the association of lidocaine and OVD seems to be safe and useful in providing anesthesia during cataract surgery. Concern has been expressed in other studies regarding the presence of contaminants, such as endotoxins, which may be responsible for postoperative uveitis-like reactions. Finally, OVDs are widely known to protect the corneal endothelium during cataract surgery. Their role is also assuming relevance in vitreoretinal surgery.

SUMMARY

New OVDs and related techniques represent an advancement in cataract surgery.

Relationship of immediate intraocular pressure rise to phaco-tip ergonomics and energy dissipation

PURPOSE

To evaluate the rise in intraocular pressure (IOP) after phacoemulsification using a straight microtip or a Kelman microtip and its relationship to phaco energy delivered to the eye.

SETTING

Iladevi Cataract & IOL Research Center, Ahmedabad, India.

METHODS

This prospective randomized study comprised 48 consecutive age- and sex-matched patients with senile cataract. Inclusion criteria included older than 45 years and presence of any type of cataract from grade I to III. The patients were divided into 2 groups: straight microtip and Kelman microtip. Each group comprised 13 men and 11 women. The mean age was 58.29 years +/- 6.46 (SD) in the straight microtip group and 60.05 +/- 8.45 years in the Kelman microtip group. The IOP was measured preoperatively and postoperatively with a pneumotonometer and applanation tonometer. One surgeon performed all operations using a standardized surgical technique and topical anesthesia. The intraoperative mean phaco power and ultrasound (US) time were noted. The effective phaco time (EPT), percentage of IOP rise, and wound-site thermal injury (mild, moderate, or severe) were calculated. The correlation between the EPT and percentage of rise in IOP was evaluated using correlation coefficients and the paired t test.

RESULTS

The mean preoperative IOP was 13.73 +/- 2.89 mm Hg in the straight microtip group and 15.14 +/- 2.60 mm Hg in the Kelman microtip group. The mean US time was 239.4 +/- 1.61 seconds and 238.2 +/- 1.48 seconds, respectively. The mean phaco power was 17.37% +/- 3.28% in the straight microtip group and 17.10% +/- 5.26% in the Kelman microtip group and the mean EPT, 39.06 +/- 2.28 seconds and 40.08 +/- 0.24 seconds, respectively (P =.412). The mean rise in IOP was 111.60% +/- 37.83% in the straight microtip group and 91.29% +/- 31.85% in the Kelman microtip group. The difference between groups was significant (P<.05). The correlation coefficient between the EPT and percentage of IOP rise was significant in both groups: 0.3823, straight microtip group (P<.05); 0.514, Kelman microtip group (P<.01). Wound-site thermal injury was noted in 3 patients in the straight microtip group and 1 patient in the Kelman microtip group.

CONCLUSIONS

Although the amount of phaco energy dissipated in the eye was the same between the 2 groups, the percentage of IOP rise was greater with the straight microtip. The rise in IOP was correlated with the dissipated phaco energy.

Effect of a fixed dorzolamide–timolol combination on intraocular pressure after small-incision cataract surgery with Viscoat

PURPOSE

To evaluate the effect of a fixed dorzolamide-timolol combination (Cosopt) on intraocular pressure (IOP) after small-incision cataract surgery with sodium chondroitin sulfate 4%-sodium hyaluronate 3% (Viscoat).

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This prospective randomized study comprised 76 eyes of 38 patients scheduled for small-incision cataract surgery in both eyes. Patients were randomized to receive 1 drop of the fixed dorzolamide-timolol combination in 1 eye or no treatment (control) immediately after cataract surgery. The fellow eye received the other assigned treatment. Cataract surgery was performed with Viscoat in an identical fashion in both eyes. The IOP was measured preoperatively and 6 hours, 20 to 24 hours, and 1 week postoperatively.

RESULTS

Six hours after surgery, the mean increase in IOP was significantly lower in the dorzolamide-timolol group than in the control group (4.3 mm Hg +/- 5.6 [SD] versus 8.4 +/- 6.1 mm Hg; P =.003). Two eyes in the dorzolamide-timolol group and 9 in the control group had IOP spikes of 30 mm Hg or higher (P =.022). Twenty to 24 hours after surgery, the mean IOP change was -2.6 +/- 3.3 mm Hg in the dorzolamide-timolol group and 1.5 +/- 3.2 mm Hg in the control group (P<.001).

CONCLUSIONS

The fixed dorzolamide-timolol combination was effective in reducing IOP 6 hours and 20 to 24 hours after cataract surgery. However, it did not prevent Viscoat-induced IOP spikes of 30 mm Hg or higher.

Efficacy of anterior chamber decompression in controlling early intraocular pressure spikes after uneventful phacoemulsification

PURPOSE

To determine the efficacy of anterior chamber decompression in the management of intraocular pressure (IOP) spikes in the early period after uneventful phacoemulsification.

SETTING

Royal Free Hospital, Department of Ophthalmology, Royal Free and University College London Medical School, London, United Kingdom.

METHODS

This prospective case series comprised 11 consecutive patients with otherwise healthy eyes who an IOP of at least 40 mm Hg 4 to 6 hours after phacoemulsification. After anterior chamber decompression, the IOP was measured at 0, 15, 30, 45, and 60 minutes or until it exceeded 40 mm Hg.

RESULTS

The mean IOP 4 to 6 hours postoperatively was 47.09 mm Hg +/- 7.92 (SD) (range 40 to 68 mm Hg). After decompression, the IOP dropped significantly to a mean of 4.73 +/- 3.00 mm Hg at 0 minutes (P<.001) and then increased progressively to 23.36 +/- 10.80 mm Hg at 15 minutes (P<.001), 33.82 +/- 11.74 mm Hg at 30 minutes (P=.005), 35.00 +/- 6.53 mm Hg at 45 minutes (P=.015), and 38.50 +/- 2.51 mm Hg at 60 minutes (P=.041).

CONCLUSIONS

Marked IOP spikes developed in eyes without glaucoma or ocular hypertension after uneventful phacoemulsification. Anterior chamber decompression immediately lowered IOP, but the effect was transient.

Same-day versus first-day review of intraocular pressure after uneventful phacoemulsification

PURPOSE

To compare the incidence and the spectrum of postoperative complications detected when the intraocular pressure (IOP) is reviewed 4 to 6 hours or the day after uneventful phacoemulsification cataract extraction and intraocular lens (IOL) implantation.

SETTING

Royal Free Hospital, London, United Kingdom.

METHODS

The study cohort consisted of 141 patients who had uneventful phacoemulsification and IOL implantation under regional (peribulbar/topical) or general anesthesia. Postoperative evaluation of the patients was performed by an ophthalmologist using a standard form at 4 to 6 hours or 24 hours.

RESULTS

The mean IOP at 4 to 6 hours and 24 hours was 22.85 mm Hg +/- 9.56 (SD) and 19.44 +/- 7.04 mm Hg, respectively. The IOP was more likely to be greater than 30 mm Hg when measured on the same day, resulting in a significantly higher intervention rate than on the first day (P =.037). The best corrected visual acuity was significantly better at 24 hours than at the same-day review (P <.001). There was no significant difference in the extent of anterior chamber activity, patient comfort, or state of the wound between the same- or next-day follow-up. All patients attended a follow-up appointment 3 weeks after surgery, had an IOP of 21 mm Hg or less, and were subsequently discharged.

CONCLUSIONS

The results indicate that moderate IOP spikes (<40 mm Hg) can be left untreated if they are not associated with corneal edema or patient discomfort as they decline spontaneously. Before they are discharged, patients with compromised optic discs or predisposed to retinal or optic nerve pathology should be carefully evaluated the day after surgery to treat IOP elevations.

Corneal endothelial cell protection during phacoemulsification: low- versus high-molecular-weight sodium hyaluronate

PURPOSE

To compare the efficacy of low- and high-molecular-weight sodium hyaluronate in protecting corneal endothelial cells during phacoemulsification.

SETTING

Miyata Eye Hospital, Miyakonojo, Miyazaki, Japan.

METHODS

One hundred forty-nine eyes of 136 cataract patients were randomly assigned to have cataract surgery using sodium hyaluronate 1% with a low molecular weight (0.6 to 1.2 million d, Opegan) or sodium hyaluronate 1% with a high molecular weight (4 million d, Healon) during phacoemulsification. Each group was divided into 2 subgroups depending on the amount of ultrasound (% min) used during phacoemulsification, which was defined as the mean phacoemulsification energy (%) multiplied by phacoemulsification time (minutes). Corneal endothelial cell density was examined preoperatively and 3 months after surgery. The rate of cell loss was compared between the subgroups in the Opegan group and the Healon group.

RESULTS

In the subgroups with ultrasound of 50% min or less, the mean rate of endothelial cell loss 3 months after surgery was 3.2% +/- 4.1% (SD) in the Opegan group and 5.9% +/- 5.3% in the Healon group (P =.0214). In the subgroups with ultrasound over 50% min, the mean rate of endothelial cell loss 3 months after surgery was 7.5% +/- 10.6% in the Opegan group and 14.8 +/- 9.0% in the Healon group (P =.0029).

CONCLUSIONS

The results suggest that Opegan is more effective than Healon in protecting corneal endothelial cells during phacoemulsification regardless of the amount of ultrasound energy used.

Efficacy and safety of the soft-shell technique in cases with a hard lens nucleus

PURPOSE

To evaluate the efficacy and safety of the soft-shell technique in reducing corneal endothelial cell damage during cataract surgery in patients with a hard lens nucleus.

SETTING

Miyata Eye Hospital, Miyakonojo, Miyazaki, Japan.

METHODS

Sixty eyes of 57 cataract patients with a hard lens nucleus (Emery-Little classification grade 3 or higher) had phacoemulsification using the soft-shell technique with Healon((R)) (sodium hyaluronate 1%) and Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%) (soft-shell group) or with Healon alone (control group). The visual acuity, intraocular pressure (IOP), flare intensity in the anterior chamber, central corneal thickness, and corneal endothelial cell density were evaluated postoperatively.

RESULTS

There were no significant IOP elevations in either group. The mean central corneal thickness in the control group was 539 microm +/- 26.0 (SD) preoperatively and 578 +/- 52.0 microm 1 day after surgery; the increase was significant (P =.0154). There was no significant change in the central corneal thickness in the soft-shell group. There were no statistically significant differences between the 2 groups in uncorrected visual acuity, best corrected visual acuity, IOP, flare intensity in the anterior chamber, and central corneal thickness throughout the follow-up. The rate of endothelial cell loss 3 months after surgery was 6.4% +/- 9.6% in the soft-shell group and 16.3% +/- 9.8% in the control group (P =.0003).

CONCLUSION

The results suggest that the soft-shell technique is safe and effective in protecting corneal endothelial cells during cataract surgery in patients with a hard lens nucleus.

Healon5: comparison of 2 removal techniques

PURPOSE

To evaluate the effect on intraocular pressure (IOP) of the rock 'n roll and behind-the-lens techniques of removing Healon(R)5 (sodium hyaluronate 2.3%).

SETTING

St. Erik's Eye Hospital, Stockholm, Sweden.

METHODS

In a prospective randomized study of 159 patients, 2 techniques to remove Healon5--rock 'n roll and behind-the-lens--were compared during cataract surgery. Cataract surgery included identical phacoemulsification performed by 1 surgeon and implantation of a silicone intraocular lens (IOL) in the capsular bag. The removal time of Healon5 was recorded. The IOP was measured preoperatively and 5 and 24 hours postoperatively.

RESULTS

The mean IOP before surgery was 15.7 mm Hg +/- 2.8 (SD) in the rock 'n roll group and 15.9 +/- 2.7 mm Hg in the behind-the-lens group. Five hours postoperatively, the mean IOP was 25.6 +/- 10.4 mm Hg and 22.4 +/- 7.6 mm Hg, respectively; the difference between the groups was statistically significant. By 24 hours postoperatively, the mean IOP was at preoperative levels in both groups. The mean removal time of Healon5 was 50 seconds in the rock 'n roll group and 39 seconds in the behind-the-lens group; the difference between the groups was statistically significant.

CONCLUSIONS

Results indicate that the behind-the-lens technique for removing Healon5 is quicker and safer than the rock 'n roll technique.

Effect of topical brimonidine on intraocular pressure after small incision cataract surgery

PURPOSE

To evaluate the effect of brimonidine 0.2% on intraocular pressure (IOP) after small incision cataract surgery.

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

This prospective randomized study comprised 80 eyes of 40 patients scheduled for small incision cataract surgery in both eyes. In each patient, 1 eye was randomly assigned to receive 1 drop of brimonidine 0.2% or no treatment (control) immediately after surgery. The fellow eye received the other assigned treatment. All patients had standardized surgery by the same surgeon with sodium hyaluronate 1%, a temporal 3.5 mm sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable intraocular lens. The IOP was measured preoperatively as well as 6 and 20 to 24 hours and 1 week postoperatively.

RESULTS

Six hours after surgery, the mean increase in IOP was 4.7 mm Hg +/- 6.1 (SD) in the brimonidine group and 4.6 +/- 5.3 mm Hg in the control group. In each group, 17 eyes (43%) had an IOP increase of 5 mm Hg or more. Twenty to 24 hours after surgery, the mean increase in IOP was 1.5 +/- 4.2 mm Hg in the brimonidine group and 1.6 +/- 4.4 mm Hg in the control group. There were no statistically significant between-group differences at any measurement.

CONCLUSIONS

In both groups, IOP significantly increased 6 hours and 20 to 24 hours after small incision cataract surgery. Brimonidine 0.2% failed to reduce the IOP increase observed after small incision cataract surgery.