|Year : 2015 | Volume
| Issue : 3 | Page : 124-128
Effect of torsional versus longitudinal phacoemulsification on the corneal endothelium
Ibrahim F Abdelrasoul MSc 1, Hosny H Mohammad2, Hisham F Khalil2, Mohamed A Mahdy2
1 National Research Centre, Dokki, Giza, Egypt
2 Ophthalmology Department, Al-Azhar University, Cairo, Egypt
|Date of Submission||02-Apr-2015|
|Date of Acceptance||25-Jun-2015|
|Date of Web Publication||30-Oct-2015|
Ibrahim F Abdelrasoul
National Research Centre, Dokki, Giza
Source of Support: None, Conflict of Interest: None
The present study aims to compare postoperative endothelial outcome after cataract surgery performed with longitudinal phacoemulsification with that performed with torsional phacoemulsification in patients with senile cataract.
Patients and methods
In this prospective observational study, 20 eyes with senile cataract of different grades of nuclear hardness underwent phacoemulsification by means of a 2.8-mm clear corneal incision using Ozil IP, 10 of which underwent torsional phacoemulsification and 10 underwent longitudinal phacoemulsification. Central endothelial cell counts were taken in all patients preoperatively, at 1 week, 1 month, and 3 months postoperatively.
The study included 20 patients with age-related cataract whose ages ranged from 55 to 64 years. There was highly statistically significant endothelial cell loss throughout the study in the two groups and also significant endothelial cell loss between the two groups by the third month (P = 0.02).
Both torsional and longitudinal phacoemulsification techniques were efficient in removing noncomplicated cataract; however, statistically significant endothelial cell loss was noted, especially with longitudinal phacoemulsification.
Keywords: Cataract, endothelial cells, longitudinal phacoemulsification, Ozil, torsional phacoemulsification
|How to cite this article:|
Abdelrasoul IF, Mohammad HH, Khalil HF, Mahdy MA. Effect of torsional versus longitudinal phacoemulsification on the corneal endothelium. J Egypt Ophthalmol Soc 2015;108:124-8
|How to cite this URL:|
Abdelrasoul IF, Mohammad HH, Khalil HF, Mahdy MA. Effect of torsional versus longitudinal phacoemulsification on the corneal endothelium. J Egypt Ophthalmol Soc [serial online] 2015 [cited 2022 Sep 28];108:124-8. Available from: http://www.jeos.eg.net/text.asp?2015/108/3/124/168682
| Introduction|| |
Cataract is one of the leading causes of preventable and curable blindness worldwide. Recently, especially with the advancement of technology, there has been a trend toward making cataract surgery not simply a procedure to remove the opaque lens, but additionally to achieve the best possible visual outcome with optimal safety and minimum invasiveness. These goals have created a trend toward using a smaller wound during phacoemulsification that is associated with less surgically induced astigmatism, better fluidics, and phaco power modulation to allow for faster recovery with less tissue damage and inflammation. The problem facing ophthalmic surgeons after performing cataract surgery with intraocular lens (IOL) implantation may be corneal decompensation due to endothelial cell loss .
Torsional ultrasound (US) using a torsional handpiece that produces side-to-side rotary oscillations has been recently introduced ,. Torsional US has a lower resonant frequency and slower needle movement than conventional US, which allows for optimized cutting efficiency with reduced heat generation ,,. Torsional US at different vacuum levels, like conventional US, leads to differences in parameters such as phaco time, US efficiency, and endothelial cell changes. The corneal endothelium is a single layer of polygonal cells lining the back surface of the cornea. Relative corneal dehydration and transparency is controlled by active endothelial ionic pumps, which maintain a low level of stromal hydration . In the human eye, the endothelial cell density decreases with aging from 4000 cells/mm 2 in childhood to ∼2500 cells/mm 2 at age 80 years . When the endothelial cell count (ECC) drops below 600-800 cells/mm 2 , corneal decompensation and corneal edema occur as a result of the compromised pump function. Endothelial cells are nonreplicative, and cell loss is compensated by enlargement and migration of residual cells ,,. This naturally occurring process is exacerbated when there is additional cell loss resulting from intraocular surgery, caused by both the heat generated and the turbulence of fluids within the anterior chamber that occur during phaco surgery. Despite the fact that cases with low endothelial cell density could be at greater risk of developing corneal decompensation, no significant correlation was found between the preoperative endothelial cell density and the percentage of postoperative endothelial cell loss .
| Patients and methods|| |
Twenty patients with cataract were divided equally into two groups: the first group, consisting of 10 patients, had five men and five women, whose ages ranged from 55 to 64 years; these patients underwent torsional phacoemulsification. The second group, also consisting of 10 patients, had six men and four women, and their ages ranged from 55 to 61 years; these patients underwent longitudinal phacoemulsification. An ethical approval was obtained from the local ethical committee and all patients signed informed consent for the surgical procedure. All surgeries were performed using the Infiniti Vision System (Alcon Laboratories Inc., Fort Worth, Texas, USA). Patients with nuclear or corticonuclear cataract of grades II-III according to the Lens Opacities Classification System III (LOCS III) scale were included in the study . Exclusion criteria included coexisting ocular disease, pseudoexfoliation, and poor pupillary dilatation. Corneal exclusion criteria included corneal dystrophy, corneal scarring, and an ECC less than 1500 cells/mm 2 . Patients with age-related macular degeneration and glaucoma and eyes with a history of trauma or surgery were excluded.
A complete ocular examination, biometry for IOL power calculation, and an ECC were performed preoperatively (ECC-pre). Keratometric power was obtained using a Bausch and Lomb manual keratometer (Bausch and Lomb, Rochester, New York, USA) and axial length was measured using an ultrasonic A-Scan (Alcon Laboratories Inc.).
Central corneal ECC was performed using KONAN NONCON-ROBO (Konan Medical, Inc, Hyogo, Japan).
Preoperative medications included topical administration of an antibiotic (ofloxacin 0.3% eye drops) five times daily for 2 days before surgery. Pupillary dilatation was started 2 h before the scheduled time for the surgery and this was achieved with one drop each of 1% tropicamide and 1% cyclopentolate instilled every 15 min.
Surgeries were performed under local peribulbar anesthesia using xylocaine 1% and bupivacaine 0.5%.
Two micro vitreo retinal (MVR) incisions using a 20-G MVR blade were made at 3 and 9 o'clock positions. Viscoelastic (Healon) was injected through the side port into the anterior chamber, and a keratome incision using keratome 2.8 mm was made at the 12 o'clock position. Capsulorhexis was performed using a pair of rhexis forceps, followed by hydrodissection using balanced salt solution. Phacoemulsification of the nucleus was carried out by means of the divide and conquer technique with a Kelman flared tip (in the longitudinal group we used a power of 50 in phaco 1 and of 40 in phaco 2, and used 100% torsional phaco in the torsional group). Irrigation/aspiration followed to remove the soft cortex using a bimanual technique. Healon was injected to fill the anterior chamber once more and a foldable IOL was introduced by means of an injector into the anterior chamber and placed in the capsular bag. This was followed by irrigation/aspiration again to remove the viscoelastic using a bimanual technique and the two sideports were hydrated. Gentamicin 20 mg and 2 mg of dexamethasone phosphate in a volume of 0.5 ml were injected subconjunctivally into the lower fornix.
Topical steroid and antibiotic eyedrops were administered six times daily for 1 week and then tapered gradually over a month. Topical steroid ointment was applied at bedtime.
Complete ocular examination was carried out after 1 week, 1 month, and 3 months postoperatively, including slit-lamp biomicroscopy for corneal edema, anterior chamber flare, and cell count. The state of the IOL was examined, as well as refraction and specular microscopy.
| Results|| |
This study included 20 eyes of 20 patients who were divided into two groups. In group A, 10 eyes (10 patients) underwent longitudinal phacoemulsification and in group B 10 eyes (10 patients) underwent torsional phacoemulsification, pre-operative data of the two groups is shown in [Table 1].
|Table 1: Comparison of preoperative data between the two groups showing no significant difference|
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No significant differences were noted as regards ECC, hexagonality, pachymetry, maximum cell size, minimum cell size, average cell size, coefficient of variation, and SD at 1 week postoperatively, as shown in [Table 2].
No significant differences were noted as regards ECC, hexagonality, pachymetry, maximum cell size, minimum cell size, average cell size, coefficient of variation, and SD at 1 month postoperatively, as shown in [Table 3].
|Table 3: Comparison of 1-month postoperative data between the two groups|
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There were no significant differences in any of the parameters except for ECC at 3 months postoperatively, as shown in [Table 4].
|Table 4: Comparison of 3-month postoperative data between the two groups|
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In the torsional phacoemulsification group there was significant endothelial cell loss and significant increase in the maximum and average cell size between preoperative and 1-week postoperative, preoperative and 1-month postoperative, and preoperative and 3-month postoperative values.
There was no significant difference in other parameters, as shown in [Table 5].
|Table 5: Comparison between endothelial cell parameters throughout the study in the torsional group|
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In the longitudinal phacoemulsification group there was significant endothelial cell loss and significant increase in the maximum and average cell size between preoperative and 1-week postoperative, preoperative and 1-month postoperative, and preoperative and 3-month postoperative values.
There was no significant difference in other parameters, as shown in [Table 6].
|Table 6: Comparison between endothelial cell parameters throughout the study in the longitudinal group|
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| Discussion|| |
In the current study, there was no statistically significant difference in endothelial cell loss between the two groups at 1 week or 1 month postoperatively. However, 3 months postoperatively there was statistically significant difference in endothelial cell loss between the two groups, with the torsional group showing less endothelial cell loss. Our study suggested a better efficiency for the torsional mode compared with the longitudinal mode. This result is in agreement with earlier reports by Kim et al. , Vasavada et al. , and Fakhry and El Shazly  (P < 0.001). Kim et al.  found that in patients with moderate cataract the percentage of endothelial cell loss at 1 week postoperatively was 13.18% in the longitudinal group and 5.12% in the torsional group, which turned out to be not significantly different 1 month postoperatively (7.9% in the longitudinal group and 3.19% in the torsional group), whereas in the hard cataract group the percentage of endothelial cell loss was 13.45% in the longitudinal group and 23.52% in the torsional group, which is statistically insignificant. They reported that it is possible that the shearing effect might not be as effective as the jackhammer effect in hard cataract, because US power in torsional phaco does not act on the nucleus perpendicularly, Our results also matched those of Liu et al. , who reported that the torsional mode may provide more effective lens removal with less endothelial cell loss compared with the longitudinal mode at 7 days and 30 days (P < 0.001).
Reuschel et al.  in their study on grade III nuclear opacity found that there was no statistically significant difference in central endothelial cell loss between the torsional group and the longitudinal group (6.6% in the longitudinal group and 6.9% in the torsional group; P = 0.34); this was in contrast to our results, which may be attributed to the larger sample size in their study (72 patients in the torsional group and 76 patients in the longitudinal group). These results are similar to those of Bozkurt et al. , who concluded that the torsional mode appears to cause less loss of corneal endothelial cells, although not statistically significant (4.2% in the torsional group and 6.7% in the longitudinal group). This is also in contrast with our results, which may be attributed to restriction of the follow-up to only 1 week postoperatively in their study.
| Conclusion|| |
The torsional mode provides an effective and safe method for cataract removal with lower energy usage as compared with longitudinal traditional phacoemulsification. Our study suggested a better efficiency by the torsional mode rather than the longitudinal mode. It has been demonstrated that endothelial cell loss in torsional mode was lower than that in the conventional mode in cataract of medium density. This result implies that torsional phacoemulsification is more efficient and is at least equally safe as compared with conventional phacoemulsification in moderate cataract. However, this study is limited by a small sample size. Nevertheless, the findings have meaningful clinical relevance to support the efficiency and safety of torsional phacoemulsification in medium-density cataract.
| Acknowledgements|| |
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]