|Year : 2018 | Volume
| Issue : 2 | Page : 82-89
Outcomes of bimanual microincision cataract surgery and 2.2-mm coaxial phacoemulsification
Tarek R El-Lakkany, Ashraf M Swellam, Hamza Abd El-Hameed, Hossam T Al-Sharkawy, Rania K Farag
Mansoura Opthalmic Center, Mansoura University, Egypt
|Date of Submission||01-Oct-2017|
|Date of Acceptance||01-Nov-2017|
|Date of Web Publication||30-Aug-2018|
Tarek R El-Lakkany
Mansoura Opthalmic Center, Mansoura University
Source of Support: None, Conflict of Interest: None
Purpose To compare the efficacy and safety outcomes of bimanual microincision cataract surgery (B-MICS) versus 2.2-mm coaxial phacoemulsification (C-MICS).
Patients and methods This prospective, interventional, randomized, comparative clinical study was carried out on 60 cataractous eyes. Thirty patients were managed surgically by C-MICS through a 2.2 mm mean incision and 30 patients were managed surgically by B-MICS through a 1.2–1.4 mm trapezoidal incision. The main outcomes measures were postoperative best-corrected distant visual acuity, postoperative spherical equivalent, higher-order aberrations, corneal thickness, corneal endothelial cell loss (ECL), and complications during and after surgery. Both groups were compared for all variables preoperatively.
Results The visual rehabilitation in group B was faster than that in group A (nonsignificant). There were nonstatistically significant differences, in the best-corrected visual acuity, between both groups throughout the postoperative period. The mean ECL was statistically significantly higher in group A (221.2±44.1) compared with group B (167.5±67.9) (P<0.001). The mean central corneal thickness change was significantly greater in group A than group B (P=0.01). The surgically induced astigmatism was statistically significantly improved in B-MICS (group B) than C-MICS (group A) (P=0.001). For the other corneal aberrations, there were nonsignificant differences between the two groups. No differences were found in the complications during surgeries between the two groups of cataract surgery.
Conclusion The two techniques are reliable, functional, effective, and yield good visual outcomes and low complication rates. B-MICS with the smallest incision induces less astigmatism (surgically induced astigmatism), less ECL, fewer central corneal thickness changes, and enables earlier visual rehabilitation.
Keywords: bi-manual microinscion cataract surgery
|How to cite this article:|
El-Lakkany TR, Swellam AM, Abd El-Hameed H, Al-Sharkawy HT, Farag RK. Outcomes of bimanual microincision cataract surgery and 2.2-mm coaxial phacoemulsification. J Egypt Ophthalmol Soc 2018;111:82-9
|How to cite this URL:|
El-Lakkany TR, Swellam AM, Abd El-Hameed H, Al-Sharkawy HT, Farag RK. Outcomes of bimanual microincision cataract surgery and 2.2-mm coaxial phacoemulsification. J Egypt Ophthalmol Soc [serial online] 2018 [cited 2018 Sep 21];111:82-9. Available from: http://www.jeos.eg.net/text.asp?2018/111/2/82/240127
| Introduction|| |
First introduced in Spain by Alió et al.  as a new technique, microinscion cataract surgery (MICS) gain popularity these days, depending on bimanuality, fluidics, and micro tools. Currently, the typical incision size in bimanual microincision cataract surgery (B-MICS) is 1.5 mm. The surgery is performed depending on the presence of appropriate tools like the proficient phaco machine, and an appropriate surgical procedure. The use of pressurized inflow of fluid is essential for MICS along with the use of precise irrigating choppers and the small I/A headpiece that is suitable for the microinscion.
Klonowski et al.  reported the benefits of the B-MICS surgery technique over the previous techniques as follows:
- A smaller incision has a low influence on corneal biomechanics, less surgically induced astigmatism (SIA), and superior postoperative corneal optical values, and also minimizes the risk of endophthalmitis and the risk of iris prolapse during the surgery.
- The separation of irrigation and aspiration of the fluid stream managing, increases efficiency of the fluid managing system, increases access to nuclear fragments, and leads to phaco energy savings procedures.
- There is flexibility of the biaxial incisions bilateral access to nuclear fragments, better access to the anterior chamber, and easier capsulorhexis and hydrodissection. The small size of the instruments yields a better intraocular view. The separate irrigation steam may be used to protect the posterior capsule and maintain stable anterior chamber (AC) during the entire surgery.
| Patients and methods|| |
A prospective, interventional, randomized, and comparative clinical study was carried out on 60 cataractous eyes during 2015–2016. All patients agreed to participate, fulfilled the inclusion criteria, and signed an informed consent agreement before undergoing any procedure. Patients were assigned to microcoaxial phacoemulsification (C-MICS) by a 2.2 mm mean incision, the C-MICS group, and/or B-MICS through a 1.2–1.4 mm trapezoidal incision, the B-MICS group.
Inclusion criteria were men and women 35 years of age or older, with a clear central cornea and dilated pupil at the preoperative examination of 7 mm, grade I–IV nuclear cataract using the Lens Opacities Classification System, no glaucoma, normal fundus, absence of previous ocular surgery, and absence of any other ocular or neurological disease that could affect the surgical outcomes. The patients were distributed randomly to undergo either the C-MICS or the B-MICS technique.
Exclusion criteria were as follows: conditions that may prevent full visual rehabilitation after successful surgery, for example, related medical or neurological disorders, congenital, traumatic, or complicated cataract, previous intraocular surgery or ocular malformation, preoperative endothelial count less than 1500, pathologic eye conditions other than cataract such as anterior segment pathology, uveitis, iridocyclitis, rubiosis iridis, pseudoexofoliation, defective zonules, or edema of the cornea, keratitis, keratouveitis, or clinically significant corneal dystrophies, uncontrolled glaucoma, optic atrophy, diabetic retinopathy, and macular degeneration, either wet or dry.
Preoperative and postoperative patient examination
A full ophthalmic examination was performed including assessment of history and visual acuity assessment for uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) by the Snellen chart; values were expressed in decimal values. A kerato-refractometer (Auto-Refractometer AR-1s; Nidek Co. Ltd, Tokyo, Japan) and slit-lamp examination were performed to assess the cornea, anterior chamber, iris, lenticular status with opacity grading and anterior vitreous, a Goldmann applination tonometer (Haag-Streit AT 900; HS Wedel, Germany), Stereoscopic Biomicroscopy of the macula and fundoscopy with a 90 D lens or 20 D with an indirect ophthalmoscope, Biometry for intraocular lens evaluation with IOL Master (IOL Master 500; Carl Zeiss Meditec, Jena, Germany), the Sheimpflug imaging system (Pentacam; Oculus Inc., Wetzlar, Germany), and assessment of the endothelial cell count by noncontact specular microscopy (Tomey EM-3000 Specular Microscopy; Tomey GmbH, Erlangen, Tennenlohe, Germany).
Postoperatively, we used the same standard examination protocol at 1, 7, 30, and 90 days to assess postsurgical BCVA (UCVA and BCVA), corneal and anterior chamber changes: increase in postsurgical central corneal thickness (CCT) and anterior chamber flare were assessed by slit-lamp examination and Pentacam evaluations, IOP, SIA, higher order aberrations (HOAs), and CCT were assessed by postoperative Pentacam studies, and endothelial cell count was determined by specular microscopy after 3 months to calculate the total endothelial cell loss (ECL).
The following standard dilation regimen was used in both the groups: tropicamide 1.0% and phenylephrine hydrochloride 2.5%; in all groups, conjunctival sac antisepsis was performed using povidone–iodine 5.0%. The same surgeon performed all operations using topical anesthesia of lidocaine hydrochloride 2% (xylocaine gel) plus benoxinate hydrochloride 0.4 mg (benox eye drops) and mild sedation with midazolam.
Coaxial microincision cataract surgery through a 2.2 mm mean incision (group A)
A 2.2 mm mean clear corneal incision (CCI) was created on the axis of the positive corneal meridian with a stainless-steel microkeratome 2.2 (Alcon Intrepid ClearCut Dual Bevel Slit Knives, Angled, 2.2 mm). Side ports smaller than 1.2 mm were made 90° from the primary incision with MVR 20 G (ClearCut Sideport Knives by Alcon Labs, Dual bevel angled knives, 1.2 mm). Dispersive ophthalmic viscosurgical devices were used to stabilize the anterior chamber during capsulorhexis. The capsulorhexis was created using (Capsulorhexis Forceps without ridge G-31301). Hydrodissection and hydrodelineation were performed using a 27 G hydrodissection cannula and nuclear rotation. Phacoemulsification was performed using the stop-and-chop technique using (Infiniti phacoemulsification system with Ozil by Alcon Laboratories Inc., Fort Worth, Texas, USA), which uses torsional ultrasound. The AcrySof IOL single piece (Alcon Inc.) was injected using a Monarch III injector and a D-cartridge system (Alcon Inc.). The IOL was implanted as in the MICS group without enlarging the incision. Incision closure was performed with stromal hydration using irrigating solution (BSS).
Bimanual microincision cataract surgery (group B)
By the use of stainless-steel knife (ClearCut Sideport Knives by Alcon Labs, Dual bevel angled knives, 1.2 mm), an incision was made in the positive meridian. The incision was trapezoidal, ∼1.2 mm in width internally near the Descemet membrane and 1.4 mm externally near the epithelium. A side-port incision was created 90°–110° from the main incision using the same knife. This wound has been made to ensure water tightness of the incision; facilitates manipulation of tools in the eye without distortion, deformation, or maceration of wound architecture; and reduces cylinder by 30%. A dispersive ophthalmic viscosurgical device was instilled to fill the anterior chamber and maintain its stability during capsulorhexis. A capsulorhexis of around 5.5 mm was made using a 23-G [MICS Capsulorhexis Forceps (IsoClean), Cystotome Teeth Katalyst surgical, LLC]. With as few movements as possible, the surgeon tore the capsule clockwise or counterclockwise. Hydrodissection was used to completely separate the lens from the cortex and to enable chopping.
Direct chopping (horizontal chopping) was performed to reduce the total energy distributed within the anterior chamber during nuclear breakdown. An irrigating chopper, Walker irrigating chopper Duckworth & Kent Ltd, was inserted just under the anterior capsule rim while holding the nucleus with the sleeveless phaco Tip after applying vacuum. The hook of the irrigating chopper was positioned parallel to the anterior lens capsule, after which the chopper was positioned smoothly along the axis until it was on the edge of the capsulorhexis. Using both hands, the surgeon simultaneously and symmetrically crossed the chopper and the sleeveless phaco tip against each other, fracturing the lens with minimal zonular stress. The nucleus was then rotated 90° and the chopping process was repeated until complete fracture of four quadrants was achieved. Phacoemulsification was performed using (Infiniti phacoemulsification system with Ozil by Alcon Laboratories Inc.), which uses torsional ultrasound. The MICS settings were dependent on the cataract grade as reported in a previous study.
An Akreos AO monofocal IOL (Bausch & Lomb microincision IOL) was folded and inserted into a 1.8 mm hydraulic injector (Viscoject injector set). The incision was enlarged with a 1.5 mm×1.7 mm slit knife. The tip of the cartridge was introduced partly into the outer portion and IOL was implanted in a capsular bag. The outer portion of the IOL was positioned in the capsular bag from the side-port incision using an Alió intraocular manipulator (Katena Products Inc.). Incision closure was performed with stromal hydration by BSS.
Details of the surgical parameters for C-MICS and B-MICS are shown in [Table 1].
The following intraoperative parameters were recorded: the time between the creation and the closure of the corneal incision by stromal hydration was recorded as the total time of the surgery, phaco time, mean phaco power, effective phaco time (EPT), Mean pupil diameter, and Mean capsulorhexis diameter (corneal capsulorhexis marker). The factors affecting the time to use phaco, and intra-operative complications were recorded in detail.
All patients received topical antibiotics (moxifloxacin ED), topical corticosteroids (prednisolone acetate 1% ED), topical nonsteroids (nepafenac 0.1% ED), and artificial tears.
Analysis and data entry were carried out using SPSS version 20 (Statistical Package for the Social Sciences versions, 2015). First, a test of distribution was performed. Then, normally distributed data were expressed as mean and SD. Non-normally distributed data were expressed as median (minimum–maximum). An independent t-test was used to compare the means of two different groups. A paired t-test was used to compare preoperative and postoperative variables with a normal distribution. For non-normally distributed data, the Mann–Whitney U-test was used to compare continuous variables in two different groups. Also, the Wilcoxon sign rank test was used to compare preoperative versus postoperative variables. Finally, the P value was considered statistically significant when less than 0.05.
| Results|| |
This study focused on 60 eyes with immature senile cataract; 30 eyes were managed by C-MICS (group A) and the other 30 eyes were managed by B-MICS (group B), with male:female ratio 34:26. Group A and group B were similar in all demographic and preoperative data ([Table 2]).
The average pupil diameter was 7.68±0.69 mm in group A and 7.80±0.78 mm in group B. The planned incision size was 2.2 mm in group A and 1.2 mm in group B. The planned capsulorhexis size in both groups was 5.0–5.5 mm.
Posterior capsular rupture in one (3.3%) eye was reported in each C-MICS and B-MICS group. Difficulty during lens implantation was reported in one case in group B with the risk to tear the posterior capsule. This complication was not reported in group A. In all eyes, intraocular lens implantation was successful and no vitreous loss was recorded in any case.
Best-corrected visual acuity
Improvement in the BCVA distance was observed postoperatively in both groups. The visual rehabilitation in group B was faster than that in group A (nonsignificant). There were nonstatistically significant differences, related to the BCVA, between both groups throughout the postoperative period ([Table 3]).
|Table 3 Comparison between the mean values of the differences in best-corrected visual acuity readings in both groups throughout the postoperative period|
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Endothelial cell loss
The mean endothelial cell density for the 30 eyes in the C-MICS was 2525.16±152.7 preoperatively and statistically significantly decreased postoperatively to 2303.9±154.04 (P<0.001). The mean endothelial cell density for 30 eyes in the B-MICS group was 2546.2±172.8 cells/mm2 preoperatively and statistically significantly decreased postoperatively to 2378.7±178.9 (P<0.001). The mean ECL was statistically significantly higher in group A (221.2±44.1) compared with group B (167.5±67.9) (P<0.001) ([Table 4]).
Central corneal thickness
The mean CCT for the 30 eyes in the C-MICS was 522.5±23.1 preoperatively and statistically significantly increased postoperatively to 537.4±34.9 (P<0.001). The mean ECL in group A (C-MICS) was 14.8 μm (−15–64.0). The mean CCT for the 30 eyes in the B-MICS was 525.8±23.3 preoperatively and showed nonsignificant changes postoperatively (526.4±26.8) (P<0.7). The mean ECL in group B (B-MICS) was 0.6 μm (−15–16.0). The mean CCT change was significantly greater in group A than in group B (P=0.01). There was a statistical difference between the two groups in the CCT changes; B-MICS (group B) showed statistically significantly fewer CCT changes than C-MICS (group A) (P=0.001) ([Table 5]).
|Table 5 Comparison of central corneal thickness changes among the groups studied|
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On analysis of the preoperative and postoperative pentacam data and comparing both groups, the median SIA in group A measured by a simulated keratometer (ΔSimK) was 1.15 (0.5–4.4) and that in group B was 0.8 (0.2–2.2). The SIA was statistically significantly improved in B-MICS (group B) than C-MICS (group A) (P=0.001). For the other corneal aberrations, there were no significant differences between the two groups ([Table 6]).
|Table 6 Comparison of the groups in corneal aberrations and surgically induced astigmatism|
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| Discussion|| |
The present study showed better efficiency, and equal acuity and safety outcomes in the C-MICS and B-MICS groups.
The analysis of our results indicated better efficiency, less use of phaco energy, and less volume of irrigating fluid circulating through the eye in the B-MICS group, which indicated minimal tissue trauma in the B-MICS group and faster rehabilitation.
The values recorded in our study, with a statistically significant reduction in EPT, ultrasound results, and irrigating fluids in the B-MICS group, confirmed the benefits of the microincision technique in cataract surgery. The B-MICS technique is useful for protecting the tissue intraoperatively and enabling faster rehabilitation.
Alio and colleagues, carried out a 50-patient, 100-eye, prospective randomized study comparing the outcomes of B-MICS with a 1.7 mm incision to small incision cataract surgery (SICS) with a 3.1-mm incision and a 3-month follow-up. Although more favorable BCVA results were found on day 1 using B-MICS, these were not statistically significant at this or the 1 and 3-month follow-up visits. Kurz et al.  studied 70 eyes of 70 patients using B-MICS with less than 1.5-mm incision and SICS with a 2.75-mm incision and BCVA as the main outcome measure. The BCVA with B-MICS was statistically significantly better than the coaxial control at 1 day, 3 days, and 8 weeks after surgery. In a later study of 94 complicated cases, Kurz and colleagues looked at both techniques and 1.5-mm (B-MICS) and 2.8-mm (SICS) incisions and found no statistically significant differences in corrected distance visual acuity at the 8-week follow-up. Elkady and colleagues compared B-MICS (1.7-mm incision; 25 eyes of 16 patients) and C-MICS (2.2-mm incision; 25 eyes of 18 patients). The BCVA and UCVA results approached but did not achieve statistical significance at 1 week (P=0.09) and 1 month (P=0.06) with B-MICS surgery.
The meta-analysis of Yu et al.  showed no significant between-group differences in CDVA at 3 months, and both techniques were equally efficient. The B-MICS technique seems to enable faster improvement in CDVA compared with the C-MICS technique. Can et al.  found that although there was no significant between-group difference in the mean CDVA at 90 days or in the mean increase in CDVA (P=0.05), the mean visual rehabilitation rate (recovery time to reach best CDVA) was statistically significantly shorter in the B-MICS group than in the coaxial group (25.1 vs. 40.9 days; P=0.040). Dick  reported that improvement in BCVA over the baseline logarithm of the minimum angle of resolution (logMAR) was statistically significantly better with B-MICS than C-MICS at one day. The mean improvement in UCVA from the baseline was better with B-MICS at 1 day, 3 days, 1 week, and 2 months.
In the present study, analysis of our data, compared between the mean values of the BCVA of both groups throughout the postoperative period, showed an improvement in BCVA postoperatively in both groups, and a nonsignificantly faster visual rehabilitation in the B-MICS group than in C-MICS patients (P=0.07). There was no statistically significant difference between the postoperative BCVA in both groups throughout the postoperative period (P=0.3).
ECL: the phacoemulsification energy insults the corneal endothelial cells and is directly proportionate to the ECL. A study of the ECL by Wilczynski et al.  found that there was a nonstatistically difference between the B-MICS group and the C-MICS group. Kahraman et al.  evaluated the ECL in the B-MICS and C-MICS groups; the results showed a nonstatistical difference between both groups. There were no statistically significant differences between the preoperative and postoperative anterior chamber flare and ECL. No significant differences in corneal ECL or endothelial morphology were found between MICS and standard incision techniques in the study by Mencucci et al. . The morphology of the cells was not different in the MICS and coaxial group in the study by Mencucci et al.  or Kahraman et al. . The study of Crema et al.  recorded lower ECL in the C-MICS group. The mean corneal ECL at 3 months was 4.66±6.10% in the C-MCS group and 4.45±5.06% in the B-MICS group and 6.00±6.72 and 8.82±7.39% at 1 year, respectively. Postoperative anterior chamber flare studied by laser flare photometry was the same in both groups in different studies. The studies by Wilczynski et al.  and Yu et al.  did not find significant differences between both groups in ECL. Alió et al.  reported that ECL is directly proportionate to the value of fluid circulating in the anterior chamber during phacoemulsification and that additional changes should be suggested in fluid control and in minimizing incision leakage to reduce the volume of fluid used in B-MICS during phocoemulsification surgery.
In our study, we recorded a statistically significant difference in ECL among the two groups postoperatively, with P=0.001. The mean endothelial cell density for the 30 eyes in the cox small incision cataract surgery (C-SICS) was 2525.16±152.7 preoperatively and statistically significantly decreased postoperatively to 2303.9±154.04 (P<0.001). The mean endothelial cell density for the 30 eyes in the B-MICS group was 2546.2±172.8 cells/mm2 preoperatively and statistically significantly decreased postoperatively to 2378.7±178.9 (P<0.001). The mean ECL was greater in group A (221.2±44.1) compared with group B (167.5±67.9), with a statistically significant difference (P<0.001).
Lundberg et al.  found that corneal thickness on the first day after surgery correlated with intraoperative trauma to the endothelium and with the ECL 3 months postoperatively.
CCT was found to be similar in both groups at the 3-month follow-up ,,.
Berdahl et al.  found that at 6 months, phacoemulsification using a torsional hand-piece through a microincision (2.20 mm) used less total energy and caused less ECL than phacoemulsification through a standard incision (2.8 mm). Wylegała et al.  noted less CCT in the B-MICS group than in the C-MICS group, which could be attributed to less effective phaco time.
In our study, the mean CCT for the 30 eyes in the C-SICS was 522.5±23.1 preoperatively and statistically significantly increased postoperatively to 537.4±34.9 (P<0.001). The mean CCT for the 30 eyes in the B-MICS was 525.8±23.3 preoperatively and showed nonsignificant changes postoperatively, 526.4±26.8 (P<0.7). The difference between the two groups in the CCT changes was significant (P=0.01). Moreover, the early postoperative corneal edema in the biaxial group could have been related to longer surgery time, prolonged aspiration, and more corneal trauma because of microincisions and reduced total phacoemulsification energy.
The major benefit of B-MICS is the lowering of SIA and the fact that the microincisions do not result in an increase in postoperative astigmatism compared with standard 3 mm phacoemulsification. The shorter the incision, the less the SIA. It was found that the value of the SIA obtained by vector analysis was 0.44–0.88 D and increased as the size of the incision increased. This is very useful as cataract surgery today is considered an effective and valuable refractive technique.
In our study, significantly less SIA was observed in the B-MICS group at 1 and 3 months than with the C-MICS technique. We found that there was a statistically significant reduction in SIA in B-MICS, with a median 0.8±0.2–2.2 D, than C-MICS, with a median 1.15±0.5–4.4 D (P=0.001).
The results of the studies on corneal changes with microincisions parallel ours. In their 50-patient study of 1.7 mm B-MICS and 3.1 mm coaxial incisions, SIA was calculated by vector analysis ; a mean vectorial astigmatic change of 0.36±0.23 D was induced in the B-MICS group and 1.2±0.74 D in the coaxial group (P<0.001). Widening the corneal incision from 1.5 to 2.0 mm for IOL implantation produced astigmatism of 0.44±0.36 D.
Wang et al.  evaluated postoperative astigmatism values. For 2.2 mm incisions, the value was 0.5±0.5 D, for 2.6 mm incisions, the value was 0.6±0.5 D, and for 3.0 mm incisions, the value was 0.9±0.9 D. The difference between 2.2 and 2.6 mm was insignificant; there was a significant difference between 2.2 and 3.0 mm. They confirmed that 2.2 and 2.6 mm incisions minimize SIA and lead to earlier refractive stabilization, which enabled faster postsurgical rehabilitation. Also, Can et al.  compared coaxial C-MICS, microcoaxial, and B-MICS; the recorded postoperative astigmatism values were 0.46, 0.24, and 0.13 D astigmatism for 2.83, 2.26, and 1.89 mm, respectively, and these values were statistically significantly different. Also, better clinical outcomes in the B-MICS versus the C-MICS group were confirmed in the study by Dick . He recorded better and earlier improvement in BCVA and less SIA among B-MICS patients.
In our study of parameters of corneal changes, when the aberrations were evaluated by Zernike analysis, we found that both techniques significantly altered the HOA (P=0.001), which is most probably related to corneal incisions. ΔSimK changed significantly in the B-MICS group (P=0.001), whereas other aberrations changed insignificantly. On comparing both groups, there was no statistically significant difference in the aberration induced (total root mean square value (RMS), HOA, limit of agreement (LOA), spherical aberrations) between biaxial and coaxial groups (P=0.82, 0.7, 0.7, and 0.8, respectively). On comparing ΔSimK in both groups, it was significantly less in B-MICS [0.8 (0.2–2.2)] than in C-MICS [1.15 (0.5–4.4)] (P=0.001). This is in agreement with the results of Elkady et al.  that coaxial SICS significantly increased the coma and RMS of total HOA (P=0.001). This finding is in agreement with other studies on coma, but not total HOA.
This finding is also in agreement with Yao et al. , who measured the change in ΔSimK values, which was obtained from a corneal wave front aberration map. The mean postoperative ΔSimK value was 0.78±0.38 D for the B-MICS group and 1.29±0.68 D for the standard group. The difference between the two groups was statistically significant (P=0.001). The incision in both group is on the top of the table.
The corneal aberrations induced after 2.2 mm C-MICS and 1.8 mm B-MICS surgery showed that the safe perimeter of the corneal degradation was a 2 mm incision. B-MICS significantly produced lower changes among different corneal aberrations, including coma and HOAs, compared with C-MICS Alió et al. .
Can et al.  compared 1.8 mm B-MICS with 2.2 mm C-MICS. They confirmed that the B-MICS group did not show increased corneal aberrations during the follow-up period, and therefore, they considered that B-MICS surgery as non aberration inducing surgery.
In our study, posterior capsular rupture in one (3.3%) eye was reported in each C-MICS and B-MICS group. Difficulty during lens implantation was reported in one patient in group B with the risk of tearing of the posterior capsule. This complication was not reported in group A. No eye showed vitreous loss and intraocular lens implantation was successful in all eyes. No differences were found in the complications during surgeries between the two groups of cataract surgery. Furthermore, the B-MICS group showed statistically significant CCT changes and less ECL.
Our results confirmed those of Kurz et al. , who reported that MICS was a safe procedure in complicated cataract cases. They recorded nearly the same percentage of complications in both B-MICS and C-MICS groups. EPT was significantly less in B-MICS than in the C-MICS groups. Kim et al.  also reported the same percentage of intraoperative complications for both B-MICS and C-MICS techniques of hard cataract surgery with 180 eyes. They also confirmed less statistically significant endothelium loss and CCT in the B-MICS group.
| Conclusion|| |
The two techniques are reliable, functional, and effective, and yield good visual outcomes and low complication rates. B-MICS with the smallest incision induces less astigmatism (SIA), less ECL, and fewer CCT changes, and enables earlier visual rehabilitation.
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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]