COMPARISON OF INTRAOCULAR LENS IMPLANTATION WITH AND WITHOUT VISCOELASTIC SUBSTANCES IN PHACOEMULSIFICATION

COMPARISON OF INTRAOCULAR LENS IMPLANTATION WITH AND WITHOUT VISCOELASTIC SUBSTANCES IN PHACOEMULSIFICATION

By

Hossam Mohamed Khalil Mohamed, Mohamed Zakaria Eid and Sayed Mustafa El-Sayed

Department of Ophthalmology, Faculty of Medicine, Al-Azhar University

Corresponding author: Hossam Mohamed Khalil Mohamed,

E-mail: hossamkhalil323@gmail.com

ABSTRACT

Background: Life expectancy of the population may increase and cataract development may affect all the people with aging. Intraocular lens implantation surgery, a worldwide performed procedure, evolves and progresses. However, different techniques exist, which could be selected for different cases. Any ideal technique should be safe, simple, fast, and easy to learn with good clinical outcome.

Objective: The aim of this work was to compare the efficacy and safety of intraocular lens implantation with and without ophthalmic viscoelastic device after phacoemulsification as well as surgery duration and post-operative intraocular pressure and central corneal thickness.

Patients and methods: This was a prospective, randomized controlled trial conducted on 40 eyes with cataract; to compare the efficacy and safety of intraocular lens implantation with and without ophthalmic viscoelastic device after phacoemulsification of the lens as regard to surgery duration, post-operative intraocular pressure and central corneal thickness. Patients were evaluated 1 day, 1 week, and 1 month postoperatively. Patients were divided into two groups after the completion of lens cortex removal:  Group A (n=20, hydro-implantation): One-piece acrylic intraocular lens implantation was performed with normal saline solution (0.9 solution) irrigation.  Group B (n=20, visco-implantation): using Hydroxy-propyl-methyl-cellulose 2% implantation.

Results: Highly significant increase in phaco operative time in visco-implantation group; compared to hydro-implantation group (p < 0.0001), Non-Significant increase in post-operative IOP, in visco-implantation group; compared to hydro-implantation group (p > 0.05 respectively). Non-significant difference as regards post-operative Central corneal thickness (CCT) (p > 0.05). Non-significant increase in post-operative CCT measurements in visco-implantation group (p > 0.05). Non-significant difference in post-operative IOP measurements in visco-implantation group (p > 0.05). Non-significant decrease in post-operative IOP and CCT measurements in hydro-implantation group (p > 0.05). Non-significant decrease in post-operative IOP in hydro-implantation group; compared to visco-implantation group; during the serial 1st and 2nd measurements. Non-significant increase in post-operative CCT in Visco-implantation group; compared to hydro-implantation group; during the serial 1st and 2nd measurements.

Conclusion: The hydro-implantation had similar clinical outcome to visco-implantation with advantage of reduced surgical time and cost, and no ophthalmic viscosurgical devices (OVD) induced intraocular pressure elevation postoperatively.

Keywords: Intraocular lens implantation, Viscoelastic substances, Phacoemulsification.

INTRODUCTION

     An ophthalmic viscosurgical device (OVD) used to maintain anterior chamber space and prevent damage to intraocular tissue during cataract surgery excellent for protection of corneal endothelial cells (YOON et al., 2019). However, residual OVD in the anterior chamber (AC) may cause postoperative adverse effects and needs to be completely removed at the end of surgery (Bardoloi et al., 2020) some cataract surgeons have preferred the hydroimplantation technique of intraocular lens implantation without OVDs (Studeny et al., 2014).

     Tak (2010) was the first to describe the hydro implantation technique. In this technique, intraocular lens implantation was performed under continuous balanced salt solution irrigation without OVDs.

     Other studies in literature reported safety of hydro implantation technique (Oğurel et al., 2017 and Ozates et al., 2017).

     The aim of this work was to compare the efficacy and safety of intraocular lens implantation with and without ophthalmic viscoelastic device after phacoemulsification as well as surgery duration and post-operative intraocular pressure and central corneal thickness.

PATIENTS AND METHODS

     This was a prospective, randomized controlled trial conducted on 40 eyes with cataract. Patients were evaluated 1 day, 1 week, and 1 month postoperatively.

Ethical considerations: All participant names were hidden & replaced by code numbers to maintain privacy of the patients. An informed consent was obtained from all participants before the study.

Inclusion criteria: Clinically significant cataract with moderate density according to new soft wear Pentacam Nuclear grading System (PNS).(N1-N2)

Exclusion criteria:

1.   Patients having complicated cataract.

2.   Previous ocular surgery, laser procedure or trauma.

3.   Small pupil, shallow anterior chamber, hard cataract (N3-N4).

4.   Coexisting ocular disorders (corneal disorder, glaucoma, pseudoexfoliation, uveitis, and retinal disorder).

Patients were divided into two groups after the completion of lens cortex removal:

•     Group A (n=20, hydro-implantation): One-piece acrylic intraocular lens implantation was performed with normal saline solution (0.9% solution) irrigation.

•     Group B (n=20, visco-implantation): using Hydroxy-propyl-methyl-cellulose 2% implantation.

All patients were subjected to:

1.   All the study participants were undergoing detailed clinical, ophthalmologic examinations including best-corrected visual acuity.

2.   Measurements of IOP (using the goldmann’s applanation tonometry).

3.   Slit-lamp bio-microscopy.

4.   Degree of lens opacification was graded by pentacam nuclear staging (Figure 1) (Pei et al., 2008).

5.   Measurements of central corneal thickness (CCT) were performed before and after the surgery.

6.   Surgery time was recorded.

Figure (1):     Degree of lens opacification was graded by pentacam nuclear staging

Post-operative follow-up:

1.   Patients were evaluated 1 day, 1 week, and 1 month postoperatively.

2.   All patients were undergoing routine ophthalmic examination at every follow-up visit including mainly visual acuity, intraocular pressure and CCT was measured with Pentacam.

Statistical Methodology:

     Data entry, processing and statistical analysis was carried out using MedCalc ver. 18.11.3 (MedCalc, Ostend, Belgium). Descriptive statistics: Mean, Standard deviation (± SD) for parametric numerical data, while Median and Inter-quartile range (IQR) for non-parametric numerical data. Frequency and percentage of non-numerical data.

Analytical statistics: Mann-Whitney's Test (U test) was used to assess the statistical significance of the difference of a non-parametric variable between two study groups. Wilcoxon's test was used to assess the statistical significance of the difference of a non-parametric variable between two (paired) study group means. The ROC Curve (receiver operating characteristic) provides a useful way to evaluate the Sensitivity and specificity.

RESULTS

     The mean age of all patients was 58.1 ± 6.46 years. Regarding gender of the patients, 52.5% of patients were females; while 47.5% were males (Table 1).

Table (1):  Socio-demographic data among 40 eyes

* Mean ± SD.

     Regarding pre and post-operative data, the average IOP of all patients was (17.47 ± 2.35) mmHg; the average CCT was (587.7 ± 55.8) µm, while the average phaco operative time was (14.7 ± 1.8) min. Regarding post-operative outcome data, the average IOP of all patients was (14.7 ± 2.46) mmHg; and the average CCT was (592.37 ± 59.2) µm (Table 2).

Table (2):  Pre and post -operative data among 40 eyes

IOP: Intra-ocular pressure. CCT: Central corneal thickness.

     Comparative study between the 2 groups revealed significant increase in phaco operative time in Visco-implantation group; compared to Hydro-implantation group. Comparative study between the 2 groups revealed non-significant difference as regards pre-operative IOP and CCT. Comparative study between the 2 groups revealed Non-significant increase in post-operative IOP, in Visco-implantation group compared to Hydro-implantation group. Comparative study between the 2 groups revealed non-significant difference as regards post-operative CCT (Table 3).

Table (3):  Comparison between the 2 groups as regards pre and post-operative data using Mann-Whitney's U test

     Comparative study between pre and post-operative measurements revealed Non-significant increase in post-operative CCT measurements in Visco-implantation group. Comparative study between pre and post-operative measurements revealed; non-significant difference in post-operative IOP measurements in Visco-implantation group. Comparative study between pre and post-operative measurements revealed; non-significant decrease in post-operative IOP and CCT measurements in Hydro-implantation (Table 4).

Table (4):  Comparison between Visco-implantation and Hydro-implantation patients as regards serial pre and post-operative assessments

     By using ROC-curve analysis, Visco-implantation usage predicted patient’s short Phaco time, with excellent (96%) accuracy, sensitivity= 95% and specificity= 85% (p < 0.001).

     By using ROC-curve analysis, Visco-implantation usage showed non-significant predictive values in patient’s post-operative IOP and CCT improvement (p > 0.05) (Table 5 and Fig 2 ).

Table (5):  Roc-curve of Visco-implantation usage to predict patient’s post-operative improvement

ROC (Receiver operating characteristic), AUC= Area under curve, SE= Standard Error.

Figure  (2) :   ROC curve of post-operative Phaco time

DISCUSSION

     We found that; the mean age of all patients was (58.1 ± 6.46) years. Regarding gender of the patients, (52.5%) of patients were females; while (47.5%) were males. which came in agreement with Unsal, et al. (2017), Taşkın & Aslan (2018) and Bardoloi et al. (2020).

     Comparative study between the 2 groups revealed non-significant difference as regards pre-operative IOP and CCT, which came in agreement with Taşkın and Aslan (2018).

     Taşkın and Aslan (2018) reported that, the mean preoperative IOP in Group 1 and Group 2 was 15.7 ± 3.5 and 15.3 ± 4.2 mmHg, respectively. The differences of the mean preoperative IOP and CCT measurements of the groups were not statistically significant

     Comparative study between the 2 groups revealed; non-significant increase in post-operative IOP, in Visco-implantation group; compared to Hydro-implantation group, which came in agreement with Taşkın and Aslan (2018) who reported that, the use of OVDs did not have a significant effect on IOP in our cases, since we removed these devices completely through the anterior chamber and from the back of IOL.

     Comparative study between the 2 groups revealed non-significant difference as regards post-operative CCT. Pre and post-operative measurements revealed  non-significant increase in post-operative CCT measurements in Visco-implantation group, which came in agreement with Kamiya et al. (2011) who reported that  the variance of the data was not statistically significant. Multiple comparisons showed no significant differences between preoperative measurements and postoperative measurements at 1 day 1 week, 1 month or 3 months.

     Comparative study between pre and post-operative measurements revealed non-significant difference in post-operative IOP measurements in Visco-implantation group as we washed OVD well after implantation, which came in agreement with Taşkın and Aslan (2018) who reported that, the use of OVDs did not have a significant effect on IOP in our cases, since we removed these devices completely through the anterior chamber and from the back of IOL.

CONCLUSION

     The hydro-implantation had similar clinical outcome to visco-implantation with advantage of reduced surgical time and cost and no OVD-induced intraocular pressure elevation postoperatively.

REFERENCES

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