Evaluation of Endothelial Cell Loss After Cataract Surgery in Patients with Pseudoexfoliative Syndrome

Introduction: Despite modern techniques and technologies for cataract surgery, pseudoexfoliative syndrome poses a challenge to surgeons due to weakness of the zonular apparatus and limited pupillary dilation. Quantitative and qualitative morphological changes in the corneal endothelium have been demonstrated by several studies. An accumulated risk of endothelial cell loss can be expected in these patients following more complicated and prolonged surgery, often requiring complex manipulation of the cataract, iris, and IOL. Our present work aims to compare the loss of endothelial cells after uncomplicated phacoemulsification in patients without and with pseudoexfoliative syndrome. Materials and methods: We conducted a prospective comparative study collected at the Rabat specialty hospital , spanning from August to December 2023. Were included in this study 60 candidates for cataract surgery:


Introduction:
Despite modern techniques and technologies for cataract surgery, pseudoexfoliative syndrome poses a challenge to surgeons due to weakness of the zonular apparatus and limited pupillary dilation.
Quantitative and qualitative morphological changes in the corneal endothelium have been demonstrated by several studies [1,2].
An accumulated risk of endothelial cell loss can be expected in these patients following more complicated and prolonged surgery, often requiring complex manipulation of the cataract, iris, and IOL.
Our present work aims to compare the loss of endothelial cells after uncomplicated phacoemulsification in patients without and with pseudoexfoliative syndrome.

Materials and methods:
We conducted a prospective comparative study collected at the Rabat specialty hospital, spanning from August to December 2023.
Were included in this study 60 candidates for cataract surgery: -30 patients with pseudoexfoliation syndrome (PXF) and -30 without capsular exfoliation (non-PXF) as a control group.
We excluded from this work diabetic patients, glaucomatous patients, patients with a history of surgery, ocular trauma or uveitis, high myopia, patients with preoperative corneal abnormalities as well as all complicated cataract surgeries.
All patients underwent cataract surgery by phacoemulsification with implantation.Specular microscopy with measurement of endothelial cell density (ECD), central corneal thickness (CCT), hexagonality and coefficient of variation was performed preoperatively and 8 weeks after surgery.(Figure 1).
We used Student's t test to perform the statistical analysis.In the PXF group, men accounted for 40% versus 46.5% in the control group.
Preoperative visual acuity and types of cataracts were similarly distributed between the 2 groups.
Figure 3: distribution of patients in the two groups according to gender.

Preoperative characteristics:
For preoperative characteristics, the difference in mean keratometry and axial length was not significant.There was no statistically significant difference between the 2 groups with regard to the preoperative results of the average density of endothelial cells, the coefficient of variation, the hexagonality as well as the central corneal thicknes.

Operating characteristics:
Regarding the cumulative dissipated energy used during the gesture, it was higher in the PXF group compared to the control group: 14.5 versus 11.4, this difference was not statistically significant.

Post-operative results:
The mean postoperative endothelial cell density was significantly lower in the PXF group than in the non-PXF group.Mean central corneal thickness was similar between groups throughout the follow-up period.There was no statistically significant difference for the coefficient of variation and the hexagonality.The percentage of endothelial cell loss was significantly higher in the PXF group than in the control group.It was about 46% in the PXF group and 27% in the control group.Other reports have suggested that iris hypoprofusion, anterior chamber hypoxia, and altered aqueous humor composition may also be responsible for endothelial changes.
Pseudoexfoliation as a risk factor for endothelial cell loss after phacoemulsification is a controversial subject.
In our series, we did not find a statistically significant difference in the density of preoperative endothelial cells between the 2 groups, this result is similar to that obtained by KALJURAND et al [3], on the other hand for ken hayashi et al [4,5 ], and wirbelauer et al, the difference between the 2 groups was statistically significant.

Statistically significant difference
Regarding postoperative cell loss, our results agreed with those obtained by Ken Hayashi et al [4], who also reported greater endothelial cell loss in the PXF group compared to the control, unlike Wirbelauer et al [5], for whom the loss of endothelial cells was similar between the 2 groups.
In the study by Kaljurand et al [3], the average percentage loss was 18% in the PXF group versus 11.6 in the control group, this difference had a statistically low significance.
Table 7: Comparison between our study and other studies regarding postoperative cell loss.

Conclusion:
In conclusion the loss of corneal endothelial cells after phacoemulsification in eyes with capsular pseudoexfoliation was significantly greater than in eyes without PXF, these results suggest that corneal endothelial cells of patients with pseudoexfoliation syndrome are more vulnerable to cataract surgery than healthy endothelial cells.
To prevent serious endothelial lesions, a precise preoperative evaluation of the corneal endothelial state by specular microscopy seems necessary in these patients, with more precision and precautions during the procedure.

Figure 1 :
Figure 1: Specular microscopy device used in the study Results: Age: Concerning the results, the mean age of the patients was 71 years in the PXF group, versus 68 years in the control group, this difference was not statistically significant.

Figure 2 :
Figure 2: Mean age of patients in the two groups Gender:

Table 1 :
Distribution of mean keratometry, axial length and implant power in the two groups of patients preoperatively.

Table 3 :
Cumulative dissipated energy used in the two groups intraoperatively.

Table 4 :
Distribution of endothelial cell density, coefficient of variation, hexagonality and central corneal thickness in the two groups postoperatively.

Table 5 :
Losses of endothelial cells between the two groups of patients.

Table 6 :
Comparing between our study and other studies with respect to preoperative endothelial cell density.