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

Corneal Effect of Air Bubble After Phacoemulsification

Objectives

The aim of the study was to investigate the effect of air bubble on the cornea at the end of the cataract surgery with phacoemulsification.

Methods

This prospective and case-control study included 71 patients with air bubble injected into the anterior chamber at the end of the operation and 63 age-sex-matched control patients without air bubble. Endothelial cell density (ECD), coefficient of variation (CV), hexagonality rate (HEX), and central corneal thickness (CCT) measurements were taken using non-contact specular microscopy preoperatively and at 1-day, 1-week, and 1-month postoperatively.

Results

No significant difference was determined between the groups preoperatively in respect of mean visual acuity, anterior chamber depth, ECD, CV, HEX, and CCT values (p>0.05). The intraoperative average ultrasound power, effective phaco time, and ultrasound time values were similar (p>0.05). The CCT value was lower in the study group than in the control group on post-operative day 1 (p=0.012), but similar at 1 week and 1 month (p=0.102, p=0.330, respectively). No significant difference was determined between the groups in mean visual acuity, anterior chamber reaction, ECD, CV, and HEX values at 1-day, 1-week, and 1-month postoperatively (p>0.05).

Conclusion

Air bubble may be used as an alternative method to reduce corneal edema on the 1st post-operative day. According to the results, although air bubble has no detrimental effect, there is also seen to be no protective effect on the corneal endothelium.

Effect of Reformation of the Anterior Chamber by Air or by a Balanced Salt Solution (BSS) on Corneal Endothelium after Phacoemulsification: A Comparative Study

Aim

To study the effect of reformation of the anterior chamber by air or by a balanced salt solution, after smooth phacoemulsification on the corneal endothelial count and morphology.

Methods

A prospective interventional nonrandomized comparative study included 500 eyes of 500 patients with age range between 50 and 60 years, prepared for cataract surgery and presented to the Ophthalmology department of Sohag University Hospital in the period from October 2016 to May 2017. Corneal endothelial morphology and count were examined, and the results were recorded for all cases before the surgery. Patients were divided into two groups, and both groups were diagnosed with grade 2 cataract and underwent uncomplicated phacoemulsification performed by well-trained surgeons. At the end of the surgery, group 1 was subjected to a reformation of the anterior chamber via a balanced salt solution (BSS) injection while group 2 was subjected to a reformation of the anterior chamber via air injection. Corneal endothelial morphology and count were evaluated in the first and 3rd month postoperatively.

Results

The study included 500 patients (250 in each group), 220 males (44%) and 280 females (56%) with no significant statistical age differences. Both preoperative and postoperative (3 months after the operation) recorded parameters of the corneal endothelium did not show any significant statistical differences. The cumulative dissipated energy was recorded, for all cases of both groups, during phacoemulsification with no significant statistical differences (P = 0.7).

Conclusion

There is no difference between the effect of reformation of the anterior chamber after phacoemulsification, using air or using a BSS injection, on the corneal endothelial count and morphology.

Corneal endothelial morphology and function after torsional and longitudinal ultrasound mode phacoemulsification

PURPOSE

To study the endothelial cell morphology and corneal thickness changes after phacoemulsification by using the OZil torsional and longitudinal ultrasound techniques (Infiniti Vision System, Alcon Laboratories).

SETTING

Department of Ophthalmology, Clinical Center, University of Debrecen, Debrecen, Hungary.

METHODS

52 patients with cataract were randomly assigned to longitudinal ultrasound and torsional mode group. All surgeries were performed through a 2.2 mm clear corneal incision, the method employed being divide and conquer. The endothelial morphometry such as cell density (ECD), mean cell area, coefficient of variation of cell area, and central corneal thickness were examined with specular microscopy (EM-1000, Tomey) preoperatively and 4, 8 weeks postoperatively.

RESULTS

ECD values decreased significantly in both surgical groups (P < .001, repeated- mesures ANOVA), the postoperative endothelial cell loss was higher in the longitudinal ultrasound mode group (3.5% and 6.5%, at 4 and 8 weeks after surgery) than in the torsional group (3.3% and 5.5%, at 4 and 8 weeks after surgery), the difference not being significant between the two groups (P = .164 and P = .479, at 4 and 8 weeks after surgery, Mann-Whitney test). There was no statistically significant difference in any of the assessed parameters between the two surgical groups (P > .05). No significant correlation was found between the endothelial cell loss and the nucleus density.

CONCLUSIONS

Both phacoemulsification techniques were safe and effective. The torsional handpiece performs oscillatory movements and delivers less energy into the eye than the longitudinal ultrasound technique, therefore providing more favorable energy and thermal safety profile.

Comparison of corneal endothelial changes following phacoemulsification with transversal and torsional phacoemulsification machines

AIM

To compare and evaluate the phacoemulsification parameters and postoperative endothelial cell changes of two different phacoemulsification machines, each with different modes, but also to assess the relationship between postoperative endothelial cell loss and the phacoemulsification parameters, as well as the other factors in both groups.

METHODS

This prospective observational study was comprised of consecutive eligible cataract patients operated with phacoemulsification technique performed by the same surgeon using either a WHITESTAR Signature Ellips FX (transversal, group 1) or Infiniti OZil IP (torsional, group 2) machine.

RESULTS

The study included 86 patients. Baseline characteristics in the groups were similar. The median nuclear sclerosis grade was 3 (2-4) in the first group and 2 (2-4) in the second group (P=0.265). Both groups had similar phacoemulsification needle times (group 1: 60.63±36 s; group 2: 55.98±30 s; P=0.789). The percentage of endothelial cell loss 30d after surgery ranged from 3% to 15% with a median of 7% in group 1, and from 2% to 13% with a median of 6% in group 2; however, there was no statistically significant difference between the groups (P=0.407). Hexagonality (P=0.794) and the coefficient of variation (CV; P=0.142) did not differ significantly between the groups before and 30d after surgery. A significant positive correlation was found between the endothelial cell loss and nuclear sclerosis grade (group 1: P<0.001; group 2: P<0.001) and between the endothelial cell loss and average phacoemulsification power (group 1: P=0.007; group 2: P=0.008).

CONCLUSION

Both of these machines were efficient, with similar endothelial cell loss. This endothelial cell loss was related to the increased nuclear sclerosis grade and increased phacoemulsification power.

Ozil® versus conventional ultrasound phacoemulsification: a randomized comparative study

The purpose of this study is to compare and assess the performance and the postoperative outcomes of torsional mode and ultrasound (US) mode performed in the phacoemulsification of cataract with different nuclear densities. This is a randomized comparative clinical study. Two groups of 75 eyes (the first operated by Ozil(®) and the second by US) were comparable in age, gender, cataract density, corneal incision size, and intraocular lens type. We assessed peroperative parameters: US time (UST) and cumulative dissipated energy (CDE). Postoperative outcome measures were corneal edema and final best-corrected visual acuity. The UST was significantly lower in the ozil(®) group for all nucleus grades (73.43 s ± 8.3 with US vs. 46.02 s ± 23 with Ozil(®)) (p = 0.0003). The CDE was lower in the Ozil(®) group for grade III and IV cataract (p = 0.005). However, no significant difference was noted for grade II cataract (p = 0.07). Immediate postoperative corneal edema was significantly harder in the US group (p = 0.00002). The mean one month postoperative visual acuity was 0.2 ± 0.03 logMAR and 0.15 ± 0.07 logMAR, respectively, in the US group and the Ozil(®) group (p = 0.06). Ozil(®) mode seems to dissipate less energy in the eye than US mode. The visual outcome at one month is comparable in the two groups.