|Year : 2021 | Volume
| Issue : 3 | Page : 254-258
Phacoemulsification without manual hydrodissection: “Passive-Hydro Phaco”
Mithun Thulasidas, Keya Barman
Centre for Sight Eye Institute, New Delhi, India
|Date of Submission||09-Apr-2021|
|Date of Decision||08-Jun-2021|
|Date of Acceptance||26-Jun-2021|
|Date of Web Publication||09-Sep-2021|
Dr. Mithun Thulasidas
Centre for Sight Eye Institute, Plot No. 9, Sector 9, Dwarka, New Delhi - 110 075
Source of Support: None, Conflict of Interest: None
Purpose: The aim of this study was to describe a technique, “Passive-Hydro Phaco” and to evaluate the outcomes of this technique in eyes with visually significant cataract. Design: This was a retrospective interventional study. Materials and Methods: We conducted a single-center study including eyes with visually significant cataract that had undergone the technique of phacoemulsification without manual hydrodissection during a period of 3 months. The functional outcomes were assessed based on postoperative corrected distance visual acuity (CDVA) at 3 weeks and 3 months, intraoperative complications, and endothelial cell count (ECC) at 3 months of follow-up. Results: The study included 112 patients (112 eyes) with a mean age of 69.2 ± 8.8 years. The mean preoperative logarithm of the minimal angle of resolution (logMAR) CDVA improved from 0.60 ± 0.20 to 0.08 ± 0.12 at 3 weeks of follow-up (P < 0.001) and remained the same till 3 months. One hundred and six eyes (94.6%) had a CDVA of logMAR <0.3 and six eyes (5.4%) had a CDVA of logMAR 0.3–0.6 at 3 weeks postoperatively. The mean difference between pre- and post-operative ECC at 3 months was 5.46 ± 26.72 cells/mm2 (P = 0.928). No posterior capsule rupture or significant intraoperative complications occurred in any of the cases. Conclusion: Passive-Hydro Phaco technique is an effective solution to avoid hydrodissection-related complications in high-risk cases.
Keywords: Cataract, hydrodissection, hydrodissection-related complication, Passive-Hydro, phacoemulsification
|How to cite this article:|
Thulasidas M, Barman K. Phacoemulsification without manual hydrodissection: “Passive-Hydro Phaco”. TNOA J Ophthalmic Sci Res 2021;59:254-8
| Introduction|| |
Phacoemulsification cataract surgery usually includes manual hydrodissection, which is a highly effective procedure to separate the lens cortex and the capsule for easy removal of the lens. Hydrodissection needs an injection of an adequate volume of a fluid stream. In a case with posterior polar cataract, pre-existing capsular tear, or continuous curvilinear capsulorhexis (CCC) tear, hydrodissection can cause a sudden difference in intraocular pressure (IOP), leading to posterior capsule rupture and fissures to develop in the posterior chamber–anterior hyaloid membrane barrier, which is a risk factor for endophthalmitis.,, Further, in a case with central corneal dystrophy or degeneration, hydrodissection can hamper surgeon's visibility, and further phacoemulsification becomes difficult. Other complications associated with the high-pressure hydrodissection include capsular block syndrome, pseudoexpulsive hemorrhage, zonular dehiscence or dialysis (pseudoexfoliation syndrome and old trauma), and even optic disc damage in glaucoma patients.,, Although the rate of incidence is low, surgeons should be careful and ensure that such complications do not occur.
Modern phacoemulsification surgery can be performed quickly and safely without manual hydrodissection. We introduce a technique of phacoemulsification surgery without manual hydrodissection, which we refer to as Passive-Hydro Phaco.
| Materials and Methods|| |
We conducted a retrospective study at Centre for Sight, New Delhi, India, including eyes with significant cataracts that had undergone the technique of phacoemulsification without manual hydrodissection between October 2019 and December 2019. The study was approved by the institutional ethics committee and adhered to the tenets of the Declaration of Helsinki. Informed consent was obtained from all patients before undergoing the procedure. The confidentiality of patients was maintained throughout at all stages of the data analysis.
Patients with visually significant cataract including complicated cases such as pseudoexfoliation, posterior polar cataract, poorly dilating pupil, corneal opacity, shallow anterior chamber, and phacodonesis that had undergone Passive-Hydro phacoemulsification were included in the study. Exclusion criteria included soft cataracts (less than grade 2 nuclear sclerosis) and patients with less than 3 months of follow-up data. A complete ophthalmologic examination including corrected distance visual acuity (CDVA), subjective refraction, slit-lamp examination, IOP measurement using a noncontact tonometer, dilated fundus examination, and specular microscopy (Topcon SP 3000P) for counting the corneal endothelial cells was performed. All surgeries were performed by a single surgeon.
Under topical anesthesia, a clear corneal incision is made in the temporal or superior side after a conventional CCC. No manual hydrodissection is done.
The phacoemulsification is performed using the Whitestar Signature Pro (Abbott Medical Optics, Inc.) machine. The Phaco probe is inserted into the anterior chamber, and the chopper is introduced through the side port.
- First step: The superficial cortex within the rhexis area is grasped and shaved using the phaco tip [Figure 1]
- Second step: Using direct-chop or stop-chop technique, the phaco tip (bevel sideway) holds the nucleus with a requisite vacuum and is then cracked into two pieces by chopping [Figure 2] (vacuum pressure – 400 mmHg, aspiration flow rate – 38 cc/min, and ultrasound power – 40%)
- Third step: The phaco tip now holds the right half of the nucleus at 7 o'clock position and pulls it a little to the center. The held nucleus is then chopped to create a triangular piece and devoured [Figure 3]. In a similar way, the left half of the nucleus is held at 4 o'clock position, chopped, and devoured [Figure 4] (vacuum pressure – 450 mmHg, aspiration flow rate – 38 cc/min, and ultrasound power – 50%)
- Fourth step: A Sinskey hook replaced the chopper, and the cracked nucleus is then moved 180° toward the opposite side of the phaco probe tip. Because of complete cortical capsular separation, nucleus rotation can be done without causing any stress on the zonules. The remaining nucleus pieces are then emulsified.
|Figure 1: Shaving of the superficial cortex within the rhexis area using phaco tip|
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|Figure 3: Chopping the right half of the nucleus at 7 o'clock position and devouring|
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|Figure 4: Chopping the left half of the nucleus at 4 o'clock position and devouring|
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This completes the Passive-Hydro Phaco technique [Video 1]. After nucleus emulsification, cortical wash and intraocular lens (IOL) implantation are performed.
Demographic data collected from the records of the patients included age, gender, type of cataract, and relevant anterior segment findings. Preoperative data included CDVA (using Snellen's chart), and corneal endothelial cell count (ECC; using Specular Microscopy Topcon SP 3000P). Postoperative data included CDVA at 3 weeks and 3 months and ECC at 3 months follow-up. Any intraoperative complications during the surgery were also noted.
The primary outcome measure was CDVA at 3 weeks and 3 months postoperatively, which were graded according to the World Health Organization International Statistical Classification of Diseases, and the secondary outcome measures included intraoperative complications and ECC at 3 months postoperatively.
The CDVA measured by Snellen's visual acuity chart was converted to logarithm of the minimal angle of resolution (logMAR) scale for statistical analysis.
Statistical analysis was performed on the Statistical Package for the Social Sciences (SPSS) version 24.0 for Windows. Descriptive statistics, such as frequency and percentage for qualitative data and mean for quantitative data, were used. The normality of data was tested by Kolmogorov–Smirnov test. Paired t-test was performed to compare the quantitative variables and Wilcoxon rank test was used for nonparametric variables. P < 0.05 considered as significant at 95% confidence level.
| Results|| |
Passive-Hydro Phaco with single-piece IOL implantation was performed in 112 consecutive eyes by a single surgeon. The demographic characteristics of the study population are shown in [Table 1]. The patients included 58 males and 54 females, with a mean age of 69.2 ± 8.8 years old (range 43–84 years). Relevant anterior segment findings included pseudoexfoliation in 19 eyes, posterior polar cataract in 15 eyes, poorly dilating pupil in 9 eyes, shallow anterior chamber in 4 eyes, corneal opacity in 3 eyes, and phacodonesis in 2 eyes. Significant posterior segment findings included glaucoma in 18 eyes, diabetic retinopathy in 12 eyes, epiretinal membrane in 8 eyes, dry age-related macular degeneration in 4 eyes, and one previously vitrectomized eye. The nucleus hardness was grade 2 in 32 (28.6%) eyes, grade 3 in 63 (56.2%) eyes, and grade 4 in 17 (15.2%) eyes, based on Lens Opacities Classification System III.
The mean preoperative and postoperative data are displayed in [Table 2]. The mean preoperative logMAR CDVA improved from 0.60 ± 0.20 to 0.08 ± 0.12 at 3 weeks of follow-up (P < 0.001) and remained the same till 3 months. One hundred and ten eyes (98.2%) showed a gain of more than two lines of visual acuity. At 3 weeks, 106 (94.6%) eyes had a CDVA of logMAR < 0.3 and 6 (5.4%) eyes had a CDVA of logMAR 0.3–0.6. The mean difference between pre- and post-operative ECC at 3 months was 5.46 ± 26.72 cells/mm2 (P = 0.928).
Two eyes had a CCC tear, but Passive-Hydro phacoemulsification was done successfully in these eyes without causing the tear to extend to the posterior capsule. No posterior capsule rent happened in any of the cases, and the IOL was implanted inside the capsular bag in all the cases.
| Discussion|| |
Passive-Hydro Phaco utilizes the principle of “natural or passive” hydrodissection. The technique involves the creation of a space between the capsule and the nuclear–epinuclear complex. The irrigation fluid flows from the sleeve of the phaco tip into the cortical–capsular layers, creates a dynamic pressure, and separates the cortical–capsular connection. In the first step, shaving of the superficial cortex within the rhexis area results in the formation of clefts through which irrigation fluid makes way to passive hydrodissection. In the second step, cracking the nucleus into two pieces creates space between the capsule and the nuclear–epinuclear complex. The third step again creates spaces, thus allowing more ingress of irrigating fluid.
The rise in IOP during hydrodissection depends both on the fluid inflow and outflow, which is affected by the size of the incision, volume, and viscoelastic used. Newer phacoemulsification techniques prefer to make small incisions, which indicate that hydrodissection-related complications may happen more often. Different techniques are being introduced instead of manual hydrodissection to avoid these high-pressure complications.,,
In the present study, the technique was successfully performed in high-risk cases with posterior polar cataract, pseudoexfoliation, hard cataract, shallow anterior chamber, small pupil size, and post-pars plana vitrectomy. The postoperative CDVA at the end of 3 weeks and 3 months was better than 20/40 (logMAR <0.3) in 106 eyes (94.6%) and 20/40–20/80 (logMAR 0.3–0.6) in 6 eyes (5.4%). These results are comparable to those reported by other studies of phacoemulsification without manual hydrodissection.,, The impaired visual acuities in six patients were related to corneal opacity, glaucoma, epiretinal membrane, and amblyopia. However, in our study, no patient had a postoperative vision worse than 20/80, in contrast to the reports by Masuda et al., This could be due to difference in the demographic characteristics of the study population. In the present study, the average percentage of endothelial cell loss at 3 months postoperatively was only 1%, which is much lesser than the endothelial cell loss of 7.7% reported by Soda and Yaguchi.
Masuda et al. described a technique of mechanical cortical cleaving dissection by applying circumferential rotational pressure using the phacoemulsification tip and a hook, followed by emulsification of the nucleus by rotating it clockwise and counterclockwise. However, they experienced posterior capsular rent in six eyes. This technique uses mechanical force to separate and rotate the nucleus, which might weaken the capsule–zonule complex and cannot be performed in cases with capsule-zonule disorders. In contrast, the Passive-Hydro Phaco technique does not include exertion of mechanical pressure and is safely performed even in eyes with phacodonesis. We did not encounter any case of posterior capsular rent, though there is a difference in sample size between both the studies.
Soda and Yaguchi introduced a semi-crater and split technique in which the crater sculpting is done in half the nucleus and emulsified before nucleus rotation. The remaining half of the nucleus is freed from the capsule and then rotated to the opposite side of the phaco tip and emulsified. However, creating a wide semi-crater in one half of the nucleus and a deep central trench in another half will definitely require more ultrasound time and energy when compared to our technique, though we have not assessed the ultrasound time and energy in the present study.
Masuda et al. also described an irrigation dynamic pressure-assisted hydrodissection technique that uses the phaco tip to intentionally vacuum the intraocular fluid to induce the irrigation dynamic pressure for cortical–capsular cleavage. This technique uses both anterior and posterior irrigation dynamic pressure to cleave the cortical–capsular layers, and a bottle-height-dependent limited peak pressure to avoid high-pressure complications. They observed posterior capsular tear in two eyes. The placement of the phacoemulsification tip under the capsulorhexis edge in the anterior approach and close to the posterior capsule in the posterior approach needs significant surgical expertise. We believe that our technique is relatively more manageable and can be easily adopted by a wide range of cataract surgeons.
The major limitation of the study is its retrospective design. Prospective studies including more high-risk cases may provide more meaningful results.
| Conclusion|| |
Passive-Hydro Phaco technique is an effective solution that reduces manual hydrodissection-related complications and helps cataract surgeons to perform safe and secure phacoemulsification.
The authors like to express their gratitude to Dr. Narayan Bardoloi, the pioneer of this technique.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]