Phaco one-chop nucleotomy

Comparison of phaco time parameters in eyes with and without glaucoma filtration surgery due to pseudoexfoliation glaucoma

PURPOSE

To compare the phaco time parameters including ultrasound time (UST), effective phaco time (EPT), and average phaco power (APP) in eyes with pseudoexfoliation glaucoma (PEG) and had or had not glaucoma filtration surgery.

METHODS

In this retrospective comparative study, Group 1 was constructed with 84 PEG patients who had not operated previously, and Group 2 was constructed with 49 PEG patients who had glaucoma filtration surgery. The mean values of UST, EPT, and APP were compared. The preoperative clinical characteristics and surgical manipulations were also compared.

RESULTS

The mean ages and male-to-female ratios of the groups were similar (p > 0.05, for both). There was no difference in the preoperative clinical characteristics, including biometric values between the groups (p > 0.05, for all). Some surgical manipulations, including pupillary stretching (p = 0.004), pupillary membrane peeling (p = 0.021), iris hook using (p = 0.041), and capsular tension ring implantation (p = 0.041), were significantly performed more commonly in Group 2. Although the mean UST and EPT values were similar (p > 0.05, for both), the mean APP value was significantly lower in Group 2 (p = 0.011).

CONCLUSION

The lower APP parameter was observed in PEG patients having had glaucoma filtration surgery. Needing more surgical manipulation to overcome poor pupillary dilation and weak zonular instability can be a reason for this result.

The phaco hemi-flip: a method of lens removal in nuclei of soft to moderate density

Although endocapsular nuclear fragmentation chopping techniques have allowed surgeons to decrease the amount of dissipated phaco energy in the anterior chamber and improve lens removal efficiency when compared with previous techniques, chopping maneuvers carry a small risk of capsular and zonular injury. Furthermore, in softer lenses, chopping techniques may be limited in providing sufficient nuclear cracking. Additionally, with torsional phaco technologies, adequate lens purchase may be suboptimal and lead to inefficient chopping. Supracapsular phaco techniques improve capsular safety, but may be challenging in small pupil/capsulorrhexis cases and place the corneal endothelium and anterior chamber tissues at greater risk to trauma from ultrasound energy. The phaco hemi-flip technique combines the advantages of these two approaches with a single endocapsular quick chop, followed by phacoaspiration removal of each heminucleus in the iris plane without further chopping or segmentation.

The comparison between torsional and conventional mode phacoemulsification in moderate and hard cataracts

Purpose

To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts.

Methods

Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thickness, and central endothelial cell counts) were performed for each patient. Cataracts were subdivided into moderate and hard, according to the Lens Opacities Classification System III grading of nucleus opalescence (NO). Eyes in each cataract group were randomly assigned to conventional and torsional phaco-mode. Intraoperative parameters, including ultrasound time (UST), cumulative dissipated energy (CDE), and the balanced salt solution plus (BSSP) volume utilized were evaluated. Best corrected visual acuity (BCVA) was checked on postoperative day 30; mean central corneal thickness and central endothelial cell counts were investigated on postoperative days 7 and 30.

Results

Preoperative BCVA and mean grading of NO showed no difference in both groups. Preoperative endothelial cell count and central corneal thickness also showed no significant difference in both groups. In the moderate cataract group, the CDE, UST, and BSSP volume were significantly lower in the torsional mode than the longitudinal mode, but they did not show any difference in the hard cataract group. Torsional group showed less endothelial cell loss and central corneal thickening at postoperative day seven in moderate cataracts but showed no significant differences, as compared with the longitudinal group, by postoperative day 30.

Conclusions

Torsional phacoemulsification showed superior efficiency for moderate cataracts, as compared with longitudinal phacoemulsification, in the early postoperative stage.

Torsional mode phacoemulsification: effective, safe cataract surgery technique of the future

Purpose:

To compare various outcome measures using torsional mode and longitudinal mode in the phacoemulsification of cataract with different nuclear densities.

Setting:

Magrabi Eye Hospitals, Kingdom of Saudi Arabia.

Design:

A randomized comparative clinical study.

Materials and Methods:

This study includes 200 eyes of 156 patients (100 in the ultrasound longitudinal “US” group and 100 in the torsional group). All eyes received AcrySof^® single piece intraocular lens (Alcon Surgical, Fort Worth, TX). The primary outcome measures were ultrasound time (UST), cumulative dissipated energy (CDE), and surgical complications. Postoperative outcome measures were the degree of corneal edema on the first postoperative day and final best corrected visual acuity (BCVA) and CCT (central corneal thickness).

Results:

The differences in UST and CDE between subgroups of nucleus hardness were statistically significant (P < 0.01). The UST and CDE consistently increased in eyes with higher grades of nucleus density. On day one, the mean BCVA was 0.61 ± 0.13 decimals in the ultrasound (US) group and 0.67 ± 0.11 decimals in the torsional group (significant P < 0.05). Corneal edema was significantly less in the torsional group (P < 0.05). At 30 days, the mean BCVA was 0.94 ± 0.22 decimals in the US group and 1.0 ± 0.12 decimals in the torsional group but this difference was not statistically different (P > 0.05).

Conclusions:

The torsional mode provides an effective and safe method for cataract removal with lower energy usage as compared to longitudinal traditional phacoemulsification. However, the final visual outcome was similar for both study groups.

In situ nuclear disassembly: efficient phacoemulsification without nuclear rotation using lateral sweep sculpting and in situ cracking techniques

We describe an in situ nuclear disassembly technique using a simplified form of sculpting and cracking, enhanced by phacoemulsification technology with a Kelman-style tip. The technique does not require mobilization or rotation of the nucleus within the capsular bag, and hydrodissection is optional. The technique requires a Kelman-style curved tip and Kuglen hook and takes advantage of the versatility of the curved phacoemulsification needle for sculpting and cracking. Since in situ nuclear disassembly requires no rotation of the nucleus for extraction, it is useful in cases in which zonules are compromised or the surgeon suspects posterior lenticonus and the potential for loss of integrity of the posterior capsule.

Torsional mode versus conventional ultrasound mode phacoemulsification: randomized comparative clinical study

PURPOSE

To compare the intraoperative and short-term postoperative outcomes of cataract surgery performed with torsional mode and conventional ultrasound mode using the Infiniti Vision System (Alcon Laboratories).

SETTING

Cataract Service, Zhongshan Ophthalmic Center, Sun-Yat-Sen University, Guangzhou, China.

METHODS

In this randomized comparative study, 525 eyes were assigned to phacoemulsification by torsional mode or conventional ultrasound (US) mode. The surgery was performed by an experienced surgeon, and the outcomes were evaluated by an examiner who was masked to treatment assignments. Primary outcome measures were US time (UST), cumulative dissipated energy (CDE), and surgical complications. Patients were seen 1, 7, and 30 days after surgery. Postoperative outcome measures were the final best corrected visual acuity (BCVA) and the change in corneal clarity, central corneal thickness (CCT), and endothelial cell count.

RESULTS

The US group had 262 eyes and the torsional group, 263 eyes. All patients completed the follow-up visits. In the eyes with nucleus density grades of 1, 2, 3, and 4, the mean UST was 10.25 seconds +/- 7.4 (SD), 25.14 +/- 5.5 seconds, 36.45 +/- 8.3 seconds, and 61.44 +/- 17.8, respectively, in the US group and 8.32 +/- 6.8 seconds, 18.45 +/- 7.2 seconds, 29.48 +/- 12.4 seconds, and 48.39 +/- 20.3 seconds, respectively, in the torsional group (P<.001); the mean CDE was 1.25 +/- 0.5, 4.18 +/- 1.2, 8.59 +/- 6.5, and 16.51 +/- 9.6, respectively, in the US group and 0.94 +/- 0.3, 3.13 +/- 2.7, 7.47 +/- 12.6, and 14.08 +/- 8.3, respectively, in the torsional group (P<.001). At 1 day and 7 days, the mean BCVA was 0.23 +/- 0.12 logMAR and 0.00 +/- 0.10 logMAR, respectively, in the US group and 0.18 +/- 0.11 logMAR and -0.08 +/- 0.05 logMAR, respectively, in the torsional group (P<.001). At 30 days, the mean BCVA was -0.10 +/- 0.07 logMAR and -0.12 +/- 0.06 logMAR in the US group and the torsional group, respectively (P>.01). At 1 day and 7 days, the mean CCT was 625 +/- 80 microm and 568 +/- 37 microm, respectively, in the US group and 601 +/- 35 microm and 559 +/- 40 microm, respectively, in the torsional group (P<.001). At 30 days, the mean CCT was 531 +/- 30 microm in the US group and 529 +/- 39 microm in the torsional group (P>.01). At 7 days and 30 days, the mean central corneal endothelial cell count was 2135 +/- 858 cells/mm(2) and 2084 +/- 527 cells/mm(2), respectively, in the US group and 2004 +/- 656 cells/mm(2) and 1953 +/- 615 cells/mm(2), respectively, in the torsional group (P<.001).

CONCLUSION

The torsional mode may provide more effective lens removal with a lower level of phacoemulsification time and energy.

Hydro-chop technique for soft lenses

Chopping techniques were initially developed to expend the least amount of phacoemulsification power inside the eye to remove a lens and to improve efficiency. Soft nuclei are not generally conducive to traditional chopping techniques and have required alternate, energy-consuming techniques, such as sculpting, to be removed. We describe a modified chopping technique that can be used to mechanically cleave soft nuclei into distinct fragments before phaco power is required, reducing total power and energy expended in the eye.