Comparison of endothelial cell loss and phacoemulsification energy during endocapsular phacoemulsification surgery

Femtosecond laser-assisted cataract surgery for complex cataracts - A review

Since its inception in 2009, femtosecond laser-assisted cataract surgery (FLACS) has become an alternative to conventional phacoemulsification cataract surgery (CPCS). Clinical studies were unable to demonstrate superior visual outcomes, but revealed reduced endothelial cell loss. More recently, the cost-effectiveness of FLACS over CPCS in routine cataract surgeries has been challenged. However, the unique abilities of FLACS to customize anterior capsulotomies precisely, soften and fragment the nucleus without capsular bag stress, and create corneal incisions may have special utility in complex cataract and less-common scenarios. In this article, we review the unique role of FLACS in complex cataract surgeries and how it could play a role to improve the safety and predictability of nonroutine cataract surgery.

Narrative review after post-hoc trial analysis of factors that predict corneal endothelial cell loss after phacoemulsification: Tips for improving cataract surgery research

PURPOSE

Identifying pre/perioperative factors that predict corneal endothelial-cell loss (ECL) after phacoemulsification may reveal ways to reduce ECL. Our literature analysis showed that 37 studies have investigated one or several such factors but all have significant limitations. Therefore, the data of a large randomized controlled trial (PERCEPOLIS) were subjected to post-hoc multivariate analysis determining the ability of nine pre/perioperative variables to predict ECL.

METHODS

PERCEPOLIS was conducted in 2015-2016 to compare two phacoemulsification techniques (subluxation and divide-and-conquer) in terms of 3-month ECL. Non-inferiority between the techniques was found. In the present study, post-hoc univariate and multivariate analyses were conducted to determine associations between ECL and age, sex, cataract density, preoperative endothelial-cell density, phacoemulsification technique, effective phaco time (EPT), and 2-hour central-corneal thickness. The data are presented in the context of a narrative review of the literature.

RESULTS

Three-month data were available for 275 patients (94% of the randomized cohort; mean age, 74 years; 58% women). Mean LOCSIII cataract grade was 3.2. Mean EPT was 6 seconds. Mean ECL was 13%. Only an older age (beta = 0.2%, p = 0.049) and higher EPT (beta = 1.2%, p = 0.0002) predicted 3-month ECL. Cataract density was significant on univariate (p = 0.04) but not multivariate analysis. The other variables did not associate with ECL.

CONCLUSIONS

Older age may amplify ECL due to increased endothelial cell fragility. EPT may promote ECL via cataract density-dependent and -independent mechanisms that should be considered in future phacoemulsification research aiming to reduce ECL. Our literature analysis showed that the average ECL for relatively unselected consecutively-sampled cohorts is 12%.

Corneal endothelial cell loss and intraocular pressure following phacoemulsification using a new viscous-cohesive ophthalmic viscosurgical device

PURPOSE

To compare results of two ophthalmic viscosurgical devices (OVDs)-Viscoat (a dispersive OVD, Alcon) and FR-Pro (a viscous-cohesive OVD, Rayner), in phacoemulsification surgery.

METHODS

A prospective randomized controlled study. Patients undergoing phacoemulsification were randomly assigned to receive one of the two OVDs. Exclusion criteria were age under 40, preoperative endothelial cell count (ECC) below 1,500 cells/mm2 and an eventful surgery. The primary outcome was change in ECC from baseline to postoperative month one and month three. Secondary outcomes were the difference between ECC at postoperative month one and month three, changes in IOP and occurrence of an IOP spike ≥ 30 mmHg after surgery.

RESULTS

The study included 84 eyes-43 in the Viscoat group and 41 in the FR-Pro group. Mean cell density loss at month one and month three was 17.0 and 19.2%, respectively, for the Viscoat group and 18.4 and 18.8%, respectively, for the FR-Pro group, with no statistically significant difference between the groups (p = 0.772 and p = 0.671, respectively). The mean ECC difference between the month one and month three visits was 50.5 cells/mm2 and was not statistically significant (p = 0.285). One eye in each group had an IOP spike ≥ 30 mmHg, both normalized by postoperative week one.

CONCLUSIONS

Viscoat and FR-Pro have comparable results following phacoemulsification surgery, suggesting that while FR-Pro is not a dispersive OVD, its endothelial cell protection may be comparable to one, perhaps due to the addition of sorbitol. Furthermore, a one-month follow-up of ECC seems sufficient in such trials.

Efficacy and safety of the eight-chop technique in phacoemulsification for patients with cataract

PURPOSE

The aim of this study was to estimate the efficacy of the 8-chop technique in phacoemulsification surgeries of patients with cataract.

SETTING

Sato Eye Clinic, Chiba-ken, Japan.

DESIGN

Prospective study.

METHODS

Patients were classified into 3 groups (Grade II, Grade III, and Grade IV; n = 50 each) according to the firmness of their lens nuclei. The Eight-chopper I was used for Grade II, Eight-chopper II for Grade III, and Lance-chopper for Grade IV. The best-corrected visual acuity, intraocular pressure (IOP), and endothelial cell density were evaluated at 7 and 19 weeks postoperatively. The primary outcome measures were the mean operative time, mean phaco time, cumulative dissipated energy (CDE), and volume of fluid used.

RESULTS

150 cataract surgeries were performed. The operative time (minutes), phaco time (seconds), CDE, and volume of fluid used (milliliters) differed significantly among the 3 groups, increasing in the following order: Grade II, Grade III, and Grade IV ( P < .01). The corneal endothelial cell density did not decrease significantly in the 3 groups at 19 weeks postoperatively ( P = .09). The rate of endothelial cell loss was 0.9% ± 5.9%, 1.0% ± 10.3%, and 5.3% ± 11.1% in the Grade II, III, and IV groups at 19 weeks postoperatively, respectively. There were significant reductions in the IOP at 7 and 19 weeks postoperatively compared with the preoperative IOP in the 3 groups ( P < .01).

CONCLUSIONS

The 8-chop technique was effective and safe in phacoemulsification for patients with cataracts with lens nuclei of varying hardness.

Comparison of femtosecond laser-assisted cataract surgery and conventional phacoemulsification on corneal impact: A meta-analysis and systematic review

This meta-analysis aims to compare corneal injuries and function after femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS). A comprehensive literature search of PubMed, EMBASE, and the Cochrane Controlled Trials Register was conducted to identify randomized controlled trials (RCT) and high-quality prospective comparative cohort studies comparing FLACS with CPS. Endothelial cell loss percentage (ECL%), central corneal thickness (CCT), endothelial cell density (ECD), endothelial cell loss (ECL), percentage of the hexagonal cell (6A), and coefficient of variance (CoV) were used as an indicator of corneal injury and function. Totally 42 trials (23 RCTs and 19 prospective cohort studies), including 3916 eyes, underwent FLACS, and a total of 3736 eyes underwent CPS. ECL% is significantly lower in the FLACS group at 1-3 days (P = 0.005), 1 week (P = 0.004), 1 month (P<0.0001), 3 months (P = 0.001), and 6 months (P = 0.004) after surgery compared to CPS. ECD and ECL appeared no statistically significant difference between the two groups, except for the significant reduction of ECD at 3 months in the CPS group (P = 0.002). CCT was significantly lower in the FLACS group at 1 week (P = 0.05) and 1 month (P = 0.002) early postoperatively. While at 1-3 days (P = 0.50), 3 months (P = 0.18), and 6 months (P = 0.11), there was no difference between the FLACS group and the CPS group. No significant difference was found in the percentage of hexagonal cells and the coefficient of variance. FLACS, compared with CPS, reduces corneal injury in the early postoperative period. Corneal edema recovered faster in the FLACS group in the early postoperative period. In addition, FLACS may be a better option for patients with corneal dysfunction.

Eye-Related Factors That Can Be Associated With the Plane of Phacoemulsification

Purpose: To evaluate the effect of eye-related factors such as biometric and surgical parameters, nuclear sclerosis (NS) grade, and pupil and capsulorhexis diameters on the plane of phacoemulsification (PP).

Material and Methods: This prospective study included 328 eyes of 328 patients who underwent phacoemulsification surgery. The phaco-chop technique was performed in all patients and changes in PP that occurred during surgery were recorded. Patients were grouped as follows: Group 1, > 75% of lens nucleus emulsified in the capsular bag; Group 2, > 75% of lens nucleus emulsified at the pupillary plane; and Group 3, > 50% of lens nucleus emulsified in the anterior chamber. The association between PP and eye-related factors was evaluated.

Results: There were 153 patients (46.7 %) in Group 1, 104 patients (31.7 %) in Group 2 and 71 patients (21.6 %) in Group 3. The factors associated with PP were anterior chamber depth (ACD) (p = 0.020) and NS grade (p = 0.028). No significant relationship was detected between PP and age, surgical parameters or other biometric values. Moreover, PP was found to be more anterior in patients with soft cataracts and deeper ACD values (p values were 0.002 and 0.036, respectively).

Conclusion: The present study has reported that PP may move to more anterior, as softer cataracts may increase the fear of posterior capsule rent. Moreover, PP may move to more posterior due to shallow anterior chambers or high-grade cataracts that could potentially increase the fear of endothelial injury.

Effect of Intracameral Epinephrine and Indocyanine Green Use on Corneal Endothelium during Cataract Surgery

Purpose: To investigate the safety of single and combined use of epinephrine and indocyanine green during cataract surgery by evaluating the effects on corneal endothelial cells.Methods: From January 2017 to October 2021, 121 patients (132 eyes) who underwent cataract surgery were enrolled. Patients were divided into 4 groups: epinephrine (n = 20), indocyanine green (n = 49), epinephrine and indocyanine green combination (n = 12), and control (n = 51). Retrospective medical chart findings and endothelial cell count change data were compared among study groups before and after operation.Results: Endothelial cell count change (△ECC) decreased for all groups; however, a significant difference among groups was not observed (p = 0.822). Univariate linear regression showed that △ECC was associated with postoperative hexagonality, nuclear sclerosis grade, ultrasound time, and cumulative dissipated energy (beta = -0.216, 0.254, 0.368, 0.351 and p = 0.013, p = 0.003, p < 0.001, p < 0.001). Multivariate linear regression showed that △ECC was associated with postoperative hexagonality and ultrasound time (beta = -0.215, 0.367, p = 0.010, p < 0.001).Conclusions: Factors closely associated with postoperative endothelial cell loss were postoperative hexagonality and ultrasound time. No significant damage to the corneal endothelium was observed when epinephrine and indocyanine green were used alone or in combination. Thus, these agents appear safe for use in this context.

Factors impacting cumulative dissipated energy levels and postoperative visual acuity outcome in cataract surgery

Purpose

To determine factors impacting cumulative dissipated energy (CDE) and postoperative best-corrected visual acuity (BCVA) in phacoemulsification.

Design

Review of 1102 cases at University of California, San Francisco (UCSF) and at Zhongshan Ophthalmic Center (ZOC), China.

Subjects

Patients who underwent cataract surgery at UCSF 03/2014–03/2019 and at ZOC 10/2018–05/2019.

Methods

Patient demographics, medical history, routine ocular examination, and surgical information, including disassembly method, complications, and surgeon training level were recorded. Univariable and multivariable regression models were used to determine factors associated with CDE and good postoperative BCVA (20/40 or better) at 1 month.

Outcome measures

CDE, postoperative BCVA.

Results

In multivariable analysis, patient age at time of surgery, diabetes, degree of nuclear sclerosis (NS), white-to-white corneal diameter, disassembly method, preoperative BCVA, surgeon training level, and surgical center were significantly associated with CDE. Log₁₀CDE increased by 0.20–0.31 for patient age ≥ 70 years, by 0.07 if the patient had diabetes, by 0.12–0.41 for NS grade ≥ 2, by 0.48 per 10 mm increase in white-to-white corneal diameter, by 0.34–0.47 for disassembly method other than non-stop chop, by 0.16 per unit increase in preoperative logMAR BCVA, and by > 0.09 when phacoemulsification was performed by residents early in their training. Log₁₀CDE was 0.33 higher at UCSF than ZOC. In multivariable analysis, worse baseline visual acuity and age above 90 years at time of surgery decreased the odds of good BCVA (OR = 0.26 per unit increase in preoperative logMAR BCVA; OR = 0.12 for age > 90); comorbid retinal issues decreased the odds of good postoperative BCVA (OR = 0.13–0.39); greater anterior chamber depth (ACD) or shorter axial length (AL), increased the odds of good postoperative outcome (OR = 2.64 per 1 mm increase ACD, OR = 0.84 per 1 mm increase AL).

Conclusions

Cataract grade determined by slit lamp exam and, for the first time, older patient age, were noted to be important predictors of high CDE. CDE was not a risk factor for postoperative BCVA measured at postoperative 1 month. When surgery was performed by trainees under supervision, lower training level was associated with higher CDE, but not with worse postoperative BCVA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02205-w.

Comparing Resident Outcomes in Cataract Surgery at Different Levels of Experience

Purpose

To evaluate outcomes of resident-performed cataract surgeries in different training levels in a retrospective case series.

Patients and Methods

A total of 730 surgeries performed by residents were evaluated into three groups: surgeries performed during residents’ first semester of training in phacoemulsification (Level 1 – L1), surgeries performed during the second semester (Level 2 – L2), and surgeries performed during the third semester (Level 3 – L3). The primary outcome was the incidence of intraoperative complications in each group. Secondary outcomes were the comparisons between initial and final corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), and central corneal thickness (CCT) in each group. Descriptive statistical analyses were employed in the presentation of the results using central tendency and variance measurements.

Results

The rate of complications within six weeks of follow-up was 24 out of 102 eyes (23.53%) in the L1 group, 63 out of 301 eyes (20.93%) in the L2 group, and 37 out of 327 (11.31%) in the L3 group (p=0.001). Posterior capsule rupture (PCR) was the most frequent intercurrence observed in all three semesters: it occurred in 12.7% of the surgeries in the first semester (13/102), 16.9% of surgeries in the second semester (51/301), and 9.5% of surgeries in the third semester (31/327). There was no significant difference in CDVA (p=0.298), ECD (p=0.067), IOP (p=0.217), or CCT (p=0.807) between the groups.

Conclusion

When measured by rates of complications and by the aforementioned parameters, surgical competency was found to improve as surgical experience and frequency increased. Therefore, this study identified some patterns of skill development that can be applied to teaching strategies and better assist surgeons in training.

Comparison of the Effect of Sodium Hyaluronate (Ophthalin®) and Hydroxypropylmethylcellulose (HPMC-Ophtal®) on Corneal Endothelium, Central Corneal Thickness, and Intraocular Pressure after Phacoemulsification

PURPOSE

To prospectively evaluate the effects of 2% hydroxypropyl-methylcellulose (HPMC-Ophtal) and sodium hyaluronate 1% (Ophthalin) on intraocular pressure, corneal thickness, and endothelial cell loss in small incision cataract surgery with implant.

METHODS

A total of 110 patients undergoing routine phacoemulsification with implant received either 2% hydroxypropyl methylcellulose or sodium hyaluronate 1% as ophthalmic viscosurgical device. Pre- and postoperative slitlamp examination, intraocular pressure measurement (preoperatively and at 1-4 hours, 1 day, and 7 days postoperatively), ultrasonic pachymetry (preoperatively and at 1 week, 4-6 weeks, and 12 weeks post operatively), and corneal endothelial cell count (preoperatively and 12 weeks postoperatively) were performed. Data were analyzed using two-way analysis of variance.

RESULTS

All measurements were comparable between the two groups preoperatively. Intraocular pressure was significantly lower in the Ophthalin group at 1 day post operatively, while no significant difference was found between the two groups on the 1-4 hours and 7 days examination. The central corneal thickness was not significantly different between the two groups at any postoperative visit . However, the mean cell density demonstrated a significant fall of 11.76% for Ophthalin and 4.27% for HPMC-Ophtal at 12 weeks post-operatively, the difference between the two being significant (p=0.009).

CONCLUSIONS

2% Hydroxypropyl methylcellulose, compared with sodium hyaluronate 1%, is superior in protecting the corneal endothelial cells, has the same effect on central corneal thickness, and is associated with slightly higher intraocular pressure 1 day post operatively. It compares favorably with sodium hyaluronate 1% and can be used as an effective and cheaper alternative in routine small incision cataract surgery with implant.

Impact of Ophthalmic Surgeon Experience on Early Postoperative Central Corneal Thickness After Cataract Surgery

PURPOSE

To assess the impact of surgeon experience on early postoperative central corneal thickness (CCT) in eyes that have undergone phacoemulsification-based cataract surgery.

METHODS

One hundred sixty eyes underwent phacoemulsification-based cataract surgery performed by an experienced surgeon (n = 110; senior group) or a surgically less experienced ophthalmic assistant (n = 50; junior group), using the divide-and-conquer or tilt-and-tumble technique for cataractous lens extraction. The primary endpoint was postoperative corneal edema 2 hours after surgery, determined by pachymetry-based CCT.

RESULTS

Mean age of patients was 71.5 ± 9.1 years. Mean CCT at postoperative hour 2 was 622.8 ± 69.3 μm: an increase of 14.3% ± 10.8 from 545.3 ± 33.7 μm preoperatively (P = 0.0028). Mean CCT at postoperative hour 2 and postoperative corneal edema were significantly higher for the junior group than the senior group, with mean respective increases of 105.8 ± 81.4 μm (19.3% ± 14.2%) and 66.4 ± 3.7 μm (12.3% ± 8.3%), P = 0.0001. After adjustment for confounding factors, surgical experience was the only factor significantly associated with corneal edema: β = 39.58; SD = 11.05; P = 0.0005. Other intergroup differences observed included significantly longer mean operating and mean ultrasound times in the junior group than in the senior group. A final corneal suture was used more frequently in the senior than in the junior group, at rates of 32.7% and 2.0%, respectively, P < 0.0001.

CONCLUSIONS

Greater surgical experience was found to be associated with reduced early postoperative corneal edema, shorter operative time, and shorter ultrasound time. This suggests that beyond mastering the initial learning curve of phacoemulsification, surgical experience enables faster and safer surgery.

Comparing the Curative Effects between Femtosecond Laser-Assisted Cataract Surgery and Conventional Phacoemulsification Surgery: A Meta-Analysis

PURPOSE

To compare the outcomes of femtosecond laser-assisted cataract surgery (FLACS) with those of conventional phacoemulsification surgery (CPS) for age-related cataracts.

METHODS

A comprehensive literature search of PubMed, EMBASE, and the Cochrane Controlled Trials Register was conducted to identify randomized controlled trials (RCT) and comparative cohort studies comparing FLACS with CPS. Endothelial cell loss percentage (ECL%), central corneal thickness (CCT), corrected and uncorrected distant visual acuity (CDVA and UDVA), and mean absolute error (MAE) of refraction were used as primary outcomes. Secondary outcomes included surgically induced astigmatism (SIA), mean effective phacoemulsification time (EPT), phacoemulsification power and circularity of the capsulorhexis.

RESULTS

Nine RCTs and fifteen cohort studies including 4,903 eyes (2,861 in the FLACS group and 2,072 in the CPS group) were identified. There were significant differences between the two groups in ECL% at one week, about one month and three months postoperatively, in CCT at one day, about one month postoperatively and at the final follow-up, in CDVA at one week postoperatively, and in UDVA at the final follow-up. Significant differences were also observed in MAE, EPT, phacoemulsification power, and the circularity of capsulorhexis. However, no significant differences were observed in CDVA at one week postoperatively or in surgically induced astigmatism.

CONCLUSIONS

Compared to CPS, FLACS is a safer and more effective method for reducing endothelial cell loss and postoperative central corneal thickening as well as achieving better and faster visual rehabilitation and refractive outcomes. However, there is no difference in final CDVA and surgically induced astigmatism between the two groups.

Evaluating the different laser fragmentation patterns used in laser cataract surgeries in terms of effective phacoemulsification time and power

PURPOSE

To evaluate the effects of the different fragmentation patterns for the lens nucleus in terms of the effective phacoemulsification time (EPT) and power.

SETTING

Shinagawa LASIK Center, Tokyo, Japan.

DESIGN

Comparison study.

METHODS

Seventy-one eyes of 71 patients had preoperative lens opacity grading based on the Emery-Little Classification (Grade 1 and Grade 2). Eyes underwent femtosecond laser-assisted cataract surgery (Catalys™ Precision Laser System), for capsulotomy and lens fragmentation. For the lens fragmentation, either the quadrants softened (Quadrant) or the quadrants complete (Complete) pattern was used. The mean EPT and phacoemulsification (phaco) power for each cutting pattern of Grades 1 and 2 cataracts were evaluated.

RESULTS

The mean EPT was 28.96 seconds in the Quadrant Group and 16.31 seconds in the Complete Group (P=0.006). The mean phaco power was 8.07% in the Quadrant Group and 4.77% in the Complete Group (P=0.0002). Comparing the Quadrant and Complete Groups of Grade 1 cataract showed no significant difference in EPT (P=0.16), but showed a significant difference in phaco power (P=0.033). Comparing the Quadrant and Complete patterns of Grade 2 cataract showed significant differences in both EPT (P=0.012) and phaco power (P=0.003). Using the Complete pattern showed a 44.7% reduction in EPT and a 40.9% reduction in phaco power when compared to the Quadrant Group.

CONCLUSION

Using the smaller fragmentation pattern in femtosecond laser cataract surgery, the phaco time and power were reduced significantly when compared to the procedure with the larger fragmentation pattern.

Transient corneal edema is a predictive factor for pseudophakic cystoid macular edema after uncomplicated cataract surgery

PURPOSE

To report transient corneal edema after phacoemulsification as a predictive factor for the development of pseudophakic cystoid macular edema (PCME).

METHODS

A total of 150 eyes from 150 patients (59 men and 91 women; mean age, 68.0 ± 10.15 years) were analyzed using spectral domain optical coherence tomography 1 week and 5 weeks after routine phacoemulsification cataract surgery. Transient corneal edema detected 1 week after surgery was analyzed to reveal any significant relationship with the development of PCME 5 weeks after surgery.

RESULTS

Transient corneal edema developed in 17 (11.3%) of 150 eyes 1 week after surgery. A history of diabetes mellitus was significantly associated with development of transient corneal edema (odds ratio [OR], 4.04; 95% confidence interval [CI], 1.41 to 11.54; p = 0.011). Both diabetes mellitus and transient corneal edema were significantly associated with PCME development 5 weeks after surgery (OR, 4.58; 95% CI, 1.56 to 13.43; p = 0.007; and OR, 6.71; CI, 2.05 to 21.95; p = 0.003, respectively). In the 8 eyes with both diabetes mellitus and transient corneal edema, 4 (50%) developed PCME 5 weeks after surgery.

CONCLUSIONS

Transient corneal edema detected 1 week after routine cataract surgery is a predictive factor for development of PCME. Close postoperative observation and intervention is recommended in patients with transient corneal edema.

Comparative analysis of corneal morphological changes after transversal and torsional phacoemulsification through 2.2 mm corneal incision

Purpose

This paper compares and evaluates the corneal morphological changes occurring after cataract surgery through a 2.2 mm corneal incision. We use two platforms for comparison and evaluation, transversal and torsional phacoemulsification.

Patients and methods

This study includes 139 consecutive cataractous eyes (nuclear color 2–4, according to the Lens Opacities Classification System III [LOCSIII]) of 82 patients undergoing cataract surgery through a 2.2 mm corneal incision. Two different phacoemulsification platforms were used and assigned randomly: we used the WhiteStar Signature^® system with the Ellips™ FX transversal continuous ultrasound (US) mode for group I (mean age: 65.33 ± 6.97 years), and we used the Infiniti^® system with the OZil^® Intelligent Phaco (IP) torsional US mode for group II (mean age: 64.02 ± 7.55 years). The corneal endothelium and pachymetry were evaluated preoperatively and at 1 month postoperatively. Incision size changes were also evaluated.

Results

All surgeries were uneventful. Before intraocular lens implantation, the mean incision size was 2.24 ± 0.06 mm in both groups (P = 0.75). In terms of corneal endothelial cell density, neither preoperative (I vs II: 2304.1 ± 122.5 cell/mm² vs 2315.6 ± 83.1 cell/mm², P = 0.80) nor postoperative (I vs II: 2264.1 ± 124.3 cell/mm² vs 2270.3 ± 89.9 cell/mm², P = 0.98) differences between the groups were statistically significant. The mean endothelial cell density loss was 1.7% ± 1.6% and 2.0% ± 1.4% in groups I and II, respectively. Furthermore, no significant differences between groups I and II were found preoperatively (P = 0.40) and postoperatively (P = 0.68) in central pachymetry. With surgery, the mean increase in central pachymetry was 28.1 ± 23.6 μm and 24.0 ± 24.0 μm in groups I and II, respectively (P = 0.1).

Conclusion

Ellips™ FX transversal and OZil^® IP torsional phacoemulsification modes are safe for performing cataract surgery, inducing minimal corneal thickness and endothelial changes.

Long-Term Comparison of Endothelial Changes Between Torsional and Longitudinal Phacoemulsification

PURPOSE

The objective of this study was to evaluate endothelial changes between torsional and longitudinal phacoemulsification 2 years after cataract surgery.

DESIGN

This was a prospective, randomized, controlled clinical trial.

METHODS

We enrolled 200 patients with senile cataract between August 2008 and December 2009 for surgery using either torsional (group A, n = 100) or longitudinal (group B, n = 100) phacoemulsification. Outcomes were central endothelial cell density and corrected distance visual acuity (CDVA) 3 months and in this follow-up 2 years after surgery. Statistical evaluation of endothelial cell loss (ECL) was performed according to statistical guidelines by creating a primary analysis (substitution of missing values by the median) and a secondary analysis (actual data).

RESULTS

The mean age was 71 (SD, 7.3) years. We were able to reexamine 46 patients in group A and 54 in group B 2 years after surgery. The median CDVA before surgery was 0.3 logMAR in group A and 0.35 logMAR in group B, improving to 0 logMAR postoperatively in both groups. The median ECL in the primary analysis was 6.9% after 3 months and 10.3% 2 years after surgery in group A. In group B, we found a loss of 6.6% after 3 months and 8.6% 2 years postoperatively. In the secondary analysis, the loss was 10.0% in group A and 8.5% in group B after 2 years. The difference was statistically not significant.

CONCLUSIONS

There is no difference between the ECL between torsional and longitudinal phacoemulsification up to 2 years after cataract surgery.

Long-term follow-up of changes in corneal endothelium after primary and secondary intraocular lens implantations in children

BACKGROUND

To evaluate long-term changes in corneal endothelial cell count and morphology after congenital cataract extraction and intraocular lens implantation.

METHODS

Cataract extraction and posterior chamber intraocular lens (IOL) implantation was performed on 54 congenital cataract patients (83 eyes). The corneal endothelial cell density (ECD), coefficient of variation (CV), hexagonality, and central corneal thickness (CCT) were measured for a retrospective analysis of long-term changes in corneal endothelial characteristics.

RESULTS

The mean age at the time of IOL implantation was 5.00 (3.62) years [mean (SD)], and the mean follow-up period was 8.83 (1.49) years. In a comparison of the treated and normal eyes of patients who underwent unilateral surgery, the treated eyes showed a significantly greater CCT (p < 0.05), and there was no significant difference in ECD, CV, and hexagonality (p > 0.05). In addition, there was no statistically significant difference in the ECD and CCT between the primary and secondary IOL implantation groups.

CONCLUSIONS

Our results did not show any significant corneal endothelial cell loss in congenital cataract patients; however, their CCTs were increased.

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.

Torsional ultrasound mode versus combined torsional and conventional ultrasound mode phacoemulsification for eyes with hard cataract

Purpose

To compare torsional versus combined torsional and conventional ultrasound modes in hard cataract surgery regarding ultrasound energy and time and effect on corneal endothelium.

Settings

Kasr El Aini hospital, Cairo University, and International Eye Hospital, Cairo, Egypt.

Methodology

Ninety-eight eyes of 63 patients were enrolled in this prospective comparative randomized masked clinical study. All eyes had nuclear cataracts of grades III and IV using the Lens Opacities Classification System III (LOCS III). Two groups were included, each having an equal number of eyes (49). The treatment for group A was combined torsional and conventional US mode phacoemulsification, and for group B torsional US mode phacoemulsification only. Pre- and post-operative assessments included best corrected visual acuity (BCVA), intraocular pressure (IOP), slit-lamp evaluation, and fundoscopic evaluation. Endothelial cell density (ECD) and central corneal thickness (CCT) were measured preoperatively, 1 day, 7 days, and 1 month postoperatively. All eyes were operated on using the Alcon Infiniti System (Alcon, Fort Worth, TX) with the quick chop technique. All eyes were implanted with AcrySof SA60AT (Alcon) intraocular lens (IOL). The main phaco outcome parameters included the mean ultrasound time (UST), the mean cumulative dissipated energy (CDE), and the percent of average torsional amplitude in position 3 (%TUSiP3).

Results

Improvement in BCVA was statistically significant in both groups (P < 0.001). Comparing UST and CDE for both groups revealed results favoring the pure torsional group (P = 0.002 and P < 0.001 for UST; P = 0.058 and P = 0.009 for CDE). As for %TUSiP3, readings were higher for the pure torsional group (P = 0.03 and P = 0.01). All changes of CCT, and ECD over time were found statistically significant using one-way ANOVA testing (P < 0.001).

Conclusion

Both modes are safe in hard cataract surgery, however the pure torsional mode showed less US energy used.

Endocapsular carousel technique phacoemulsification

We describe an approach to cataract phacoemulsification that uses the carouseling technique within the capsular bag. This is made possible by a newly designed phacoemulsification tip with 3 unique modifications: a 20-degree right bend in the tip, a semicircular opening, and a third irrigation port. These 3 features facilitate the carouseling technique of phacoemulsification without expressing the lens into the anterior chamber. The method decreases corneal endothelial injury by maximizing the distance between the delivered thermal energy and the corneal endothelium. The preoperative and postoperative pachymetry and endothelial cell counts in the first 8 patients treated using this technique are reported.

Comparison of endothelial changes and power settings between torsional and longitudinal phacoemulsification

PURPOSE

To compare the intraoperative and postoperative outcomes of conventional longitudinal phacoemulsification and torsional phacoemulsification.

SETTING

Department of Ophthalmology, University of Leipzig, Germany.

DESIGN

Randomized single-center clinical trial.

METHODS

Eyes with senile cataract were randomized to have phacoemulsification using the Infiniti Vision System and the torsional mode (OZil) or conventional longitudinal mode. Primary outcomes were corrected distance visual acuity (CDVA) and central endothelial cell density (ECD), calculated according to the Conference on Harmonisation-E9 Guidelines in which missing values were substituted by the median in each group (primary analysis) and the loss was then calculated using actual data (secondary analysis). Secondary outcomes were ultrasound (US) time, cumulative dissipated energy (CDE), and percentage total equivalent power in position 3. Postoperative follow-up was at 3 months.

RESULTS

The mean preoperative CDVA was 0.41 logMAR in the torsional group and 0.38 logMAR in the longitudinal group, improving to 0.07 logMAR postoperatively in both groups. The mean ECD loss was 7.2% ± 4.6% in the torsional group (72 patients) and 7.1% ± 4.4% in the longitudinal group (76 patients), with no statistically significant differences in the primary analysis (P = .342) or secondary analysis (P = .906). The mean US time, CDE, and percentage total equivalent power in position 3 were statistically significantly lower in the torsional group (98 patients) than in the longitudinal group (94 patients) (P<.001).

CONCLUSION

The torsional mode was as safe as the longitudinal mode in phacoemulsification for age-related cataract.

Torsional ultrasound modality for hard nucleus phacoemulsification cataract extraction

AIM

To evaluate the efficacy and safety of phacoemulsification using torsional modality with different parameter settings for hard nucleus cataract extraction.

DESIGN

A prospective, randomised clinical study.

METHODS

A clinical practice study conducted at the Cataract Service, Zhongshan Ophthalmic Center, Sun-Yat-Sen University, and Guangzhou. One eye each from 198 consecutive patients with cataract density grade IV according to the Emery-Little system classification system, requiring phacoemulsification and intraocular lens implantation, was included. Eyes were randomly assigned to the Linear Torsional combined with Ultrasound power group (Linear Tor+US group, n = 66), 100% Fixed Torsional group (Fixed Tor group, n = 65) and conventional Ultrasound burst group (US group, n = 67). All surgeries were performed by a single experienced surgeon and outcomes evaluated by another surgeon masked to treatment. Intraoperative parameters were Ultrasound Time (UST), Cumulative Dissipated Energy (CDE) and surgical complications. Patients were examined on post-op days 1, 7 and 30. Postoperative outcomes were final best corrected visual acuity (BCVA), average central and incisional corneal thickness and central endothelial cell counts.

RESULTS

The mean UST was lower in the Fixed Tor group than in the US group and in the Lin US+Tor group (p0.01), greater average central corneal and incisional thickness on days 1, 7 (p0.01), and higher average corneal endothelial cell losses on day 7 and 30 days (p

CONCLUSIONS

Torsional combined with ultrasound power or high fixed torsional amplitude can yield more effective hard nucleus phacoemulsification than conventional ultrasound modality.

Collapse

Key Words Collapse

MESH Headings

• Aged
• Aged, 80 and over
• Cornea/pathology
• Endothelium, Corneal/pathology
• Female
• Humans
• Lens Nucleus, Crystalline/surgery
• Male
• Middle Aged
• Phacoemulsification/methods
• Prospective Studies
• Tomography, Optical Coherence
• Treatment Outcome
• Ultrasonic Therapy/methods
• Visual Acuity

Collapse

Grants Collapse

Affiliation(s)

M Zeng Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China The Second Affiliated Hospital of Guangzhou Medical College, Guangzhou, People’s Republic of China
X Liu Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China
Y Liu Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China
Y Xia Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China
L Luo Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China
Z Yuan Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China
Y Zeng Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China
Y Liu Zhongshan Ophthalmic Center, Sun-Yat-Sen University Guangzhou, People’s Republic of China

Collapse

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.

Determining Factors for Corneal Endothelial Cell Loss by Using Bimanual Microincision Phacoemulsification and Power Modulation

PURPOSE

To determine risk factors for central corneal endothelial cell loss in bimanual microincision cataract surgery by using power modulation.

METHODS

Prospective study: 79 eyes (70 subjects) with uncomplicated bimanual cataract surgery by using power modulation. Cataracts were graded with the LOCS III system. Specular microscopy was performed preoperatively and postoperatively (5 weeks). Endothelial cell density was calculated (CD; cells/square millimeter). Endothelial cell loss (ECL = preoperative CD - postoperative CD; cells/square millimeter) and proportional loss of cells [PLC = (ECL/preoperative CD) x 100; %)] were calculated. Phacoemulsification time (seconds) and average phacoemulsification power in foot position 3 (%) were recorded.

RESULTS

Cataracts were moderate to high density, nuclear color = 3.96, and nuclear opalescence = 3.91. Endothelial cell loss = 196 cells/square millimeter (P < 0.0001). Proportional loss of cells = 8.12% (P < 0.0001). Average phacoemulsification power in foot position 3 was low (8.17%). Increased nuclear color and opalescence were correlated with more phacoemulsification time and higher average phacoemulsification power in foot position 3 (P < 0.0001). Endothelial cell loss and proportional loss of cells, respectively, were affected by increased nuclear color (P < 0.004, P < 0.003) and opalescence (P < 0.006, P < 0.004) but were not affected by phacoemulsification time. Average phacoemulsification power in foot position 3 had a mild effect on endothelial cell loss and proportional loss of cells (P = 0.02, P = 0.02).

CONCLUSIONS

Despite the need for longer phacoemulsification time and increased power to emulsify denser cataracts, the amount of endothelial cell loss was only mildly affected by the average phacoemulsification power in foot position 3 and unaffected by total phacoemulsification time, showing that bimanual phacoemulsification with power modulation is an efficient and effective technique for performing cataract surgery.

Intraindividual comparison of surgical trauma after bimanual microincision and conventional small-incision coaxial phacoemulsification

PURPOSE

To compare the surgical trauma after microincision phacoemulsification and small-incision coaxial phacoemulsification after implantation of conventional, foldable, hydrophobic acrylic intraocular lenses (IOLs).

SETTING

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

METHODS

A prospective investigator-masked case series comprised patients with bilateral cataract who had cataract surgery on the same day. Thirty-three patients (66 eyes) were randomized. Microincision cataract surgery (MICS) was performed through 2, 1.4 mm clear corneal incisions (CCIs) using bimanual sleeveless phacoemulsification (cool phaco) in 1 eye. Small-incision cataract surgery (SICS) was performed on the other eye through a 3.2 mm CCI. In all cases, an AcrySof SA60AT IOL was inserted, in the MICS group after the CCI was enlarged. Laser flare photometry, specular microscopy, corneal endothelial cell density, and pachymetry were evaluated preoperatively and postoperatively. Intraindividual comparison and statistical analyses were performed.

RESULTS

There were no relevant clinical differences or perioperative complications in either group. There were no statistically significant differences between preoperative and postoperative anterior chamber flare or endothelial cell loss. On the first postoperative day, the MICS group had statistically significantly increased corneal swelling (P = .008). Postoperatively, the mean endothelial cell density loss was higher in the MICS group (6.2%) than in the SICS group (3.10%); however, the difference between groups was not significant (P = .08)

CONCLUSIONS

Microincision cataract surgery was a safe and reproducible technique. The postoperative results in the MICS group were comparable to those in the SICS group.

Ultrasound energy and endothelial cell loss with stop-and-chop and nuclear preslice phacoemulsification

PURPOSE

To evaluate ultrasound (US) energy and endothelial cell loss in cataract surgery using the stop-and-chop and nuclear preslice techniques.

SETTING

Vision Institute, Federal University of São Paulo, São Paulo, Brazil.

METHODS

This prospective clinical trial comprised 43 patients (50 eyes) with senile nuclear cataract who were randomly assigned to 1 of 2 groups: stop-and-chop (n=26) or nuclear preslice (n=24). The groups were divided according to nuclear density (NO(3) NC(3) and NO(4) NC(4)) using the Lens Opacity Classification System III. A full ophthalmic examination including biometry, specular microscopy, and pachymetry was performed preoperatively and postoperatively. The following parameters were evaluated: age, anterior chamber depth, lens thickness, axial length, phaco time and power, effective phaco time (EPT), infusion volume, ocular inflammation, endothelial cell loss, and best corrected visual acuity (BCVA).

RESULTS

Phacoemulsification time, power, and EPT were significantly higher in the stop-and-chop group. Infusion volumes did not vary significantly between the groups. A significant decrease in endothelial cell density occurred postoperatively and was similar with both techniques (stop-and-chop, 8.70%; nuclear preslice, 8.72%). The BCVA improved significantly in both groups. No significant correlations were found between endothelial cell loss and either technique.

CONCLUSIONS

Ultrasound energy consumption was lower with the nuclear preslice technique. Both techniques had similar results including endothelial cell loss.

Local corneal thickness changes after small-incision cataract surgery

PURPOSE

To assess whether a temporal limbal-corneal incision approach for phacoemulsification cataract surgery induces a gradient in corneal thickening along the horizontal meridian.

SETTING

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

METHODS

Corneal thickness in 21 eyes of 21 patients was measured preoperatively as well as 1 day, 1 week, and 1 and 3 months after phacoemulsification through a temporal limbal-corneal incision. Measurements were performed using partial coherence interferometry (PCI) with a commercial instrument, the ACMaster (Carl Zeiss Meditec, Jena). Measurements were taken along the horizontal meridian centrally along the visual axis at 1.5 mm, 3.0 mm, and 4.5 mm eccentricity.

RESULTS

Preoperatively, there were slight nasal-temporal differences in corneal thickness at all eccentricities. The mean thickness was 522 microm +/- 34 (SD) at 1.5 mm nasally and 513 +/- 36 microm at 1.5 mm temporally (P<.01). On day 1, there was a significant mean increase in corneal thickness (38 +/- 43 microm) along all locations. The thickening was slightly more pronounced in the periphery than in the center, a difference not reaching statistical significance. At 1 week, corneal thickness returned almost to baseline at all locations except for 3.0 mm temporally, where it was slightly, but not significantly, thicker (mean 8 +/- 14 mum). At 1 month, corneal thickness at the 3.0 mm temporal location returned to baseline.

CONCLUSIONS

A nasal-temporal difference in corneal thickness was found preoperatively in all patients. Phacoemulsification through a temporal limbal-corneal incision caused an increase in corneal thickness along the horizontal meridian 1 day after surgery. The prolonged corneal thickening at 3.0 mm eccentricity temporally could be a result of the proximity to the incision site.

Corneal endothelial function after phacoemulsification using the fluid-based system compared to conventional ultrasound technique

AIM

To quantitatively assess corneal endothelial changes after phacoemulsification with the fluid-based system compared to conventional ultrasound technique.

METHODS

This prospective, randomized clinical study included patients with cataract who were randomly assigned either to have phacoemulsification with the fluid-based system (30 eyes of 30 patients--Group 1) or with traditional ultrasound (30 eyes of 30 patients--Group 2). Patients who were available at each follow-up visit (25 eyes in both groups) were enrolled in the statistical analysis. Endothelial function was evaluated by measuring central corneal thickness, central endothelial cell density (ECD), mean cell size, and coefficient of variation in cell size preoperatively, 10 days, 1 and 3 months, and 1 year after surgery. Statistical analyses were performed using two-way repeated measure ANOVA.

RESULTS

An acute, reversible increase of central corneal thickness (CCT) was found 10 days after surgery, which was similar in both groups (P=0.35). ECD decreased, whereas mean cell size increased significantly immediately after surgery. However, the impairments were finished after 1 month. The alterations were similar in both groups (ECD: P=0.99; mean cell size: P=0.85). The coefficient of variation in cell size remained stable after surgery (P=0.08), and significant difference was not found between groups (P=0.99). The endothelial cell loss (ECL) was 6.5+/-8.4% in Group 1 and 6.5+/-11.7% in Group 2 (P=0.69).

CONCLUSIONS

Corneal endothelial changes were similar using the fluid-based system compared to the traditional ultrasound technique. The fluid-based method proved to be as safe as conventional ultrasound in cataract surgery.

The Implantable Miniature Telescope for macular degeneration

PURPOSE OF REVIEW

The function is described of the Implantable Miniature Telescope, which is completing clinical development for bilateral end-stage macular degeneration, and 6-month results of the Phase II/III IMT002 prospective, multicenter study are presented. Multispecialty patient management and implications of the study's findings are discussed.

RECENT FINDINGS

No medical treatments are currently available for bilateral end-stage age-related macular degeneration (atrophic or disciform scar age-related macular degeneration). The visual prosthetic device discussed in this update is implanted in the posterior chamber to reduce the impact of the scotomata on the patient's central vision. The goal of treatment is to improve the patient's ability to perform everyday activities and participate in roles and hobbies that impact their quality of life. Patients implanted with the device experienced clinically significant gains in visual acuity and quality of life at 6 months. In total, 89% gained two or more lines of best-corrected near or distance visual acuity. The device was generally safe and well tolerated. The surgical technique is important to minimize surgically related reduction in endothelial cell density.

SUMMARY

This age-related macular degeneration visual prosthesis has been shown to improve visual acuity and quality of life for the bilateral end-stage age-related macular degeneration patient population that at present has no other acceptable options. Endothelial cell density from baseline to 6 and 12 months after device implantation was reduced due to trauma from the surgical procedure, but was compatible with a healthy cornea. Meticulous surgical technique and a comprehensive, multispecialty approach to preoperative and postoperative patient management are essential for successful outcomes.

Prospective evaluation of phacoemulsification in adults younger than 50 years

PURPOSE

To evaluate intraoperative performance and long-term outcome of phacoemulsification in patients younger than 50 years.

SETTING

Iladevi cataract and IOL Research Centre, Ahmedabad, India.

METHODS

A prospective observational study was conducted comprising 54 patients (35 men and 19 women) under age 50 who had phacoemulsification. Preoperative evaluation included specular microscopy. Phacoemulsification with implantation of an AcrySof MA30BA intraocular lens (IOL) was performed. Intraoperatively, peripheral extension of capsulorhexis, intraoperative posterior capsule opacification (PCO; plaque), and serious complications (eg, posterior capsule rupture, vitreous loss) were noted. Postoperatively, endothelial cell loss, postoperative PCO, neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate, and best corrected visual acuity (BCVA) were assessed for 3 years. Patients with intraoperative PCO were analyzed separately.

RESULTS

Mean patient age was 42.7 years +/- 5.2 SD (men) and 43.1 +/- 3.25 years (women). Continuous curvilinear capsulorhexis was achieved in 49 patients (90.7%). Intraoperative PCO was present in 14 (25.92%) patients. An Nd:YAG laser posterior capsulotomy was performed in 4 patients (28.5%). Posterior capsule rupture leading to vitreous loss occurred in 1 patient (1.85%). At 3-year follow-up, endothelial cell loss was 5.9%. Postoperative PCO developed in 8 patients (22.2%), and Nd:YAG laser posterior capsulotomy was performed in 5 patients (13.8%). The BCVA was > or = 20/40 in 47 patients (94%).

CONCLUSION

Young patients pose a challenge in creating a capsulorhexis and display significant incidence of intraoperative and postoperative PCO.

Corneal edema and intraocular pressure after cataract surgery: randomized comparison of Healon5 and Amvisc Plus

PURPOSE

To compare the protective effect of Healon5 (sodium hyaluronate 2.3%) and Amvisc Plus (sodium hyaluronate 1.6%) against corneal edema and their association with postoperative intraocular pressure (IOP) spikes in patients having phacoemulsification and intraocular lens (IOL) implantation.

SETTING

Ophthalmology department of a general hospital.

METHODS

One hundred forty patients were randomly assigned to have surgery with Healon5 (n = 70) or Amvisc Plus (n = 70). One eye of each patient was analyzed. Data collected preoperatively included best corrected visual acuity (BCVA) and IOP. Central ultrasonic pachymetry was performed in all patients. The same ophthalmologist performed all surgeries. The IOP and central corneal thickness (CCT) were measured 1 and 4 days and 1 month after surgery. The BCVA was also assessed at 1 month.

RESULTS

There were no significant preoperative differences between the Healon5 and Amvisc Plus groups in sex, age, ocular pathology, BCVA, IOP, or CCT. Intraoperative variables were similar between groups, but it took significantly longer to remove the Healon5. Postoperatively, there were no differences between groups in the evolution of CCT or of IOP. Intraocular pressure spikes over 30 mm Hg were detected at 1 day in 7 patients in the Healon5 group and 2 patients in the Amvisc Plus group (10.0% versus 2.9%; P = .165).

CONCLUSIONS

Both OVDs were beneficial in a wide range of cataract patients. However, the results suggest a tendency toward a higher complication rate with Healon5.

Corneal endothelial cell damage after lens extraction using the fluid-based system compared to ultrasound phacoemulsification in human cadaver eyes

PURPOSE

To compare the endothelial cell damage after lens removal using a fluid-based system to conventional ultrasound.

METHODS

Twenty human cadaver eyes were randomized to undergo phacoemulsification using either a fluid-based system or conventional ultrasound. After surgery, each corneoscleral button was removed, stained and damaged endothelial cells per square millimeter were assessed using light microscopy.

RESULTS

Fluid-based system mean damaged endothelial cells/mm was 60.2 +/- 24.1 compared with 60.4 +/- 42.6 when using conventional ultrasound (P = 0.248).

CONCLUSION

The fluid-based system is as safe for the corneal endothelium as conventional ultrasound during cataract removal in human cadaver eyes.

Risk factors for endothelial cell loss after phacoemulsification surgery by a junior resident

PURPOSE

To assess the risk factors for endothelial cell loss after phacoemulsification cataract surgery performed by a junior resident.

SETTING

Ophthalmic teaching hospital, Dublin, Ireland.

METHODS

This prospective study included 40 eyes having divide-and-conquer phacoemulsification cataract surgery by a junior resident under the supervision of an experienced surgeon. Nine variables were examined to assess the risk for corneal endothelial cell loss postoperatively.

RESULTS

The mean overall endothelial cell loss was 11.6%. Longer surgery time, longer absolute and effective phaco time, higher mean ultrasound power, and higher cataract density were significantly associated with endothelial cell loss on univariate analysis. Multivariate analysis identified a grade 3 nucleus (severely dense) and long absolute phaco time as independent predictors for endothelial cell loss, with longer absolute phaco time the stronger predictor.

CONCLUSIONS

Divide-and-conquer phacoemulsification cataract surgery was a safe technique in the hands of an ophthalmic trainee. This study supports advice to junior surgeons to choose cases with less dense cataracts as this will help reduce the absolute phaco time and thus minimize endothelial cell loss.

Corneal endothelial cell protection with a dispersive viscoelastic material and an irrigating solution during phacoemulsification: low-cost versus expensive combination

PURPOSE

To evaluate the protective effect on corneal endothelial cells of a low-cost and an expensive combination of a dispersive viscoelastic material and an irrigating solution during phacoemulsification.

SETTING

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

METHODS

This prospective randomized examiner- and patient-masked study comprised 90 eyes of 45 consecutive patients with age-related cataract in both eyes. For each patient, the first eye was randomly assigned to receive hydroxypropyl methylcellulose 2% (Ocucoat) and Ringer's solution (low-cost combination) or sodium chondroitin sulfate 4%-sodium hyaluronate 3% (Viscoat) and an enriched balanced salt solution (BSS Plus) (expensive combination) during phacoemulsification. The contralateral eye received the other treatment. Endothelial cell function was evaluated by measuring corneal thickness (CT) using partial coherence interferometry, morphology assessment, and endothelial cell counts.

RESULTS

The acute postoperative increase in CT was +9.8 microm in the low-cost group and +10.9 microm in the expensive group; the difference between groups was not significant. After 1 month, the CT still differed significantly from baseline in the low-cost group. Three months after surgery, the CT had returned to baseline values in both groups. There was no significant between-group difference in endothelial cell counts or morphology.

CONCLUSIONS

During phacoemulsification in a nonselected patient population, there was no difference in acute postoperative corneal edema and endothelial cell morphology after 3 months between a Viscoat and BSS Plus combination and an Ocucoat and Ringer's solution combination. Eyes receiving the expensive combination had marginally faster recovery of corneal swelling by 3 months. However, the cost of Viscoat and 500 mL BSS Plus is 5 times that of Ocucoat and Ringer's solution.

Corticocapsular adhesions and their effect during cataract surgery

PURPOSE

To identify the types of corticocapsular adhesions by their preoperative clinical appearance and evaluate the difficulties they pose during cataract surgery.

SETTING

Iladevi Cataract & IOL Research Center, Ahmedabad, India.

METHODS

Seventy-six eyes with age-related senile cataract scheduled for phacoemulsification were identified as having corticocapsular adhesions. Preoperatively, the eyes were assessed at the slitlamp to determine the type of corticocapsular adhesions present. During surgery, the surgeon graded nucleus rotation after single-site cortical-cleaving hydrodissection as easy, difficult, or not possible. Additional multiquadrant-focal hydrodissection was performed. The surgeon's impressions of the presence of corticocapsular adhesions and visualization of the furry surface of the epinucleus were noted.

RESULTS

Corticocapsular adhesions were confirmed in 86.84% of eyes. Equatorial corticocapsular adhesions alone or in combination were present in 72 eyes (94.74%) eyes, anterior corticocapsular adhesions in 40 (52.74%), and posterior corticocapsular adhesions in 42 (56.26%). Rotation of nucleus was not possible in 47.37% eyes, difficult in 39.47%, and easy in 13.16%.

CONCLUSIONS

The surgeon should perform a thorough preoperative slitlamp evaluation in extreme gaze with a fully dilated pupil. Equatorial corticocapsular adhesions, which were present in most eyes, made nucleus rotation difficult. Additional multiquadrant and focal cortical-cleaving hydrodissection helped separate the adhesions and achieve successful rotation.

Transient corneal edema after phacoemulsification: comparison of 3 viscoelastic regimens

PURPOSE

To evaluate the effect of different viscoelastic substances on the grade and time course of postoperative corneal edema.

SETTING

Department of Clinical Sciences/Ophthalmology, Umeå University Hospital, Umeå, Sweden.

METHODS

This study comprised 62 patients with otherwise healthy eyes who had routine phacoemulsification and intraocular lens (IOL) implantation. Patients were divided into 3 groups. Group 1 was given Healon GV (sodium hyaluronate 1.4%) at phacoemulsification and IOL implantation. Group 2 was given Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%) at phacoemulsification and Healon GV at IOL implantation. Group 3 was given Viscoat at phacoemulsification and Provisc (sodium hyaluronate 1.0%) at lens implantation. The central corneal thickness was measured with ultrasonic pachymetry before surgery and 5 and 24 hours, 1 week, and 1 month after surgery.

RESULTS

The mean increase in corneal thickness was significantly greater in Group 1 than in the other 2 groups 5 and 24 hours and 1 week after surgery.

CONCLUSIONS

The transient postoperative increase in central corneal thickness was greater in patients receiving Healon GV during phacoemulsification than in patients receiving Viscoat. The use of Provisc or Healon GV for IOL implantation did not affect the postoperative corneal thickness when Viscoat was used for phacoemulsification. The time course of the edema may be explained by a difference between the 2 agents in endothelial protection from ultrasonic, mechanical, or irrigation trauma.

Corneal impact of ultrasound and bevel position in phacoemulsification

PURPOSE

To investigate the amplitude of ultrasound waves that reach the cornea with the phacoemulsification tip at different angles.

SETTING

Institute for Applied Mechanics and Control Engineering, University of Siegen, Siegen, Germany.

METHODS

A model eye was constructed with an ultrasound tip (angle 45 degrees) in the typical position during the procedure and a sensor mounted in the apex of the artificial cornea. The sensor measured the incoming ultrasound waves. Thirty bursts of ultrasound energy were set at 100% power with the bevel of the tip facing up toward the cornea, and 30 bursts were set with the bevel facing down toward the lens.

RESULTS

There was no statistically significant difference in the measurements with the tips bevel up and bevel down.

CONCLUSIONS

There was no significant difference in the corneal load from ultrasound waves with the phacoemulsification tip in a bevel-up or bevel-down position.

Long-term evaluation of endothelial cell loss after phacoemulsification

PURPOSE

To check whether three months' follow-up is sufficient to determine endothelial cell loss after cataract surgery and whether this value depends on preoperative central endothelial cell density.

METHODS

A two-year prospective assessment of central endothelial cell density was done in 60 eyes after phacoemulsification. In 30 eyes a 3.5 mm corneal incision closed with a single crossed suture was made, and the other 30 had a 3.5 mm scleral tunnel no-stitch incision. Central endothelial cell density was measured before surgery and 1, 3, 6 months and 2 years after.

RESULTS

The mean rate of endothelial cell loss even two years after surgery was significantly higher than the physiological rate, amounting to 0.9% per year. There was no correlation between preoperative central endothelial cell density and postoperative cell loss.

CONCLUSIONS

Even two years' follow-up is not sufficient to establish the total endothelial cell loss after cataract surgery. The amount of cell loss does not depend on the preoperative density.

Phacoemulsification of brunescent and black cataracts

PURPOSE

To evaluate the efficacy and safety of a step-by-step, chop in situ, lateral separation technique to remove brunescent and black cataracts.

SETTING

Iladevi Cataract and IOL Research Center, Ahmedabad, India.

METHODS

In this prospective study conducted between May 1997 and June 1998, 167 consecutive eyes were divided into 2 groups: Group 1, brunescent cataract (n = 123), and Group 2, black cataract (n = 44). Preoperative assessment included axial length (AL), slitlamp examination, corneal pachymetry, tonometry, and specular microscopy. During phacoemulsification performed by a single surgeon, a step-by-step, chop in situ, lateral separation technique was used to divide the nucleus. Intraoperatively, hydroxypropyl methylcellulose 2% was used and irrigation was by balanced salt solution (BSS). Postoperatively, all eyes were assessed at 1, 7, 30, 90, 180, and 360 days. The results were evaluated using regression analysis, the chi-square test, and the Student t test.

RESULTS

The mean follow-up was 14.4 months (range 6 to 35 months) in Group 1 and 13.0 months (range 6 to 32 months) in Group 2. The AL was significantly greater in Group 2 (P =.02). Corticapsular adhesions were present in 17.82% in Group 1 and 31.82% in Group 2. The mean cumulative dissipated energy was 2.03 and 3.12, respectively (P =.0005). Wound site thermal injury occurred in 16 eyes (13.01%) in Group 1 and 4 eyes (9.09%) in Group 2. No serious intraoperative or postoperative complications were noted. One day postoperatively, the mean rise in intraocular pressure was 1.76 mm Hg in Group 1 and 4.15 mm Hg in Group 2 (P =.012), and transient corneal edema was present in 24.40% and 34.10%, respectively. At 1 month, the endothelial cell loss was 10.06% in Group 1 and 9.22% in Group 2.

CONCLUSION

The step-by-step, chop in situ, lateral separation technique was effective and did not produce serious complications such as zonulysis or posterior capsule rupture. However, the incidence of wound site thermal injury and endothelial cell loss was greater than after emulsification of standard cataracts.

Laser cataract surgery : A prospective clinical evaluation of 1000 consecutive laser cataract procedures using the Dodick photolysis Nd:YAG system

BACKGROUND

To evaluate the safety and efficacy associated with the clinical use of a Q-switched neodymium:yttrium-aluminum-garnet (ND:YAG) laser for cataract removal.

DESIGN

Multicenter, prospective, noncomparative case series.

PARTICIPANTS/INTERVENTION

A total of 1000 consecutive eyes underwent cataract extraction with the photolysis Q-switched ND:YAG laser at 12 international clinical sites.

MAIN OUTCOME MEASURES

Visual acuity improvement; total energy used; mean operative time for cataract removal; complications, both intraoperative and postoperative; with a minimum follow-up of 3 months.

RESULTS

The mean values were visual acuity improvement from 20/70.2 to 20/24.4. Mean intraocular energy used was 5.65 J per case. Mean operative photolysis time among the surgeons was for up to +1 nuclear sclerosis, 2.15 minutes; up to +2 nuclear sclerosis, 4.8 minutes; and for up to +3 nuclear sclerosis, 9.8 minutes. Three cases were completed by intraocular lens implantation through the original sub-2-mm incision, using a prefolded, by dehydration, acrylic intraocular lens. Minor complications were encountered in 18 cases.

CONCLUSIONS

These data suggest this photolysis laser technology may be a safe and effective alternative for cataract extraction in human eyes. By use of small clear cornea incisions, the ability to perform cataract extraction and intraocular lens implantation with incisions less than 2 mm has been shown for the first time.