Introduction
Pseudoexfoliation (PEX) syndrome is an age-related microfibrillopathy disorder characterized by the deposition of grayish-white flaky exfoliative material in ocular and extraocular tissue [1 2 3 5 6 Phacoemulsification is a preferred type of cataract surgery owing to fewer complications than other types [7 , 8 corneal endothelial cells , thickness, and density that may result in corneal decompensation and subsequent corneal transplantation [3 , 4 phacoemulsification complications [2 , 9 10
The aim of the study was to compare the corneal endothelial cell changes after phacoemulsification in PXF patients relative to healthy adults using specular microscope.
Patients and methods
This prospective, nonrandomized comparative, interventional study was performed on 100 eyes of 100 patients who were divided equally into two groups (pseudoexfoliative and control). Patients who aged above 50 years and with nuclear cataract grades II, III, clear cornea, and endothelial cell density (ECD) more than 1000/mm2 were included in this study. Also, patients with normal anterior chamber depth, dilatable pupil, and with no active ocular disease or inflammation were included. Pseudoexfoliative patients who had glaucoma were excluded from the study.
The study is conducted in accordance with Helsinki standards as revised in 2013. All patients signed an informed written consent. Also, approval from the ethical committee of Faculty of Medicine Al-Azhar University Assiut was obtained before the study.
All patients were subjected to full medical history taking, general examination, and ophthalmic evaluation, including the best-corrected visual acuity using Landolt C chart. Intraocular pressure (IOP) (Goldman applanation tonometer) was also evaluated and measured at the same time of the day (from 10 am to 2 pm) to eliminate the effect of diurnal variation. Slit-lamp anterior-segment examination using slit lamp (LS3-450) besides fundus biomicroscopy to assess retina and optic disc by +90 D Volk noncontact lens was also conducted. Specular microscopy (NIDEK CEM 530, NIDEK Incorporation (eye & health care), California, USA) was done for all patients preoperatively, and data for central corneal ECD, hexagonal cells (HEX), and coefficient of variation (CV) were taken after exclusion of cases with abnormal specular parameters. Similar data were also assessed at 1 week, 1 month, and 6 months postoperatively.
All surgeries in the current study were done by the same technique (divide and conquer), same phaco machine, and single expert surgeon. Methyl cellulose was used as viscoelastic substance. Postoperative treatment was kept the same in all patients, including eye patch daily for 5 days, Moxifloxacin eye drops, Prednisolone 1% eye drops, and Tobramycin-dexamethasone eye ointment. On the first postoperative day, slit-lamp evaluation (to assess AC reaction and depth) and IOP was measured by Goldman applanation tonometer for early detection and management of early postoperative complications.
This study was carried out at a specialized eye center (modern eye center) in Assiut and took place between September 2019 and January 2021 after approval of its administration.
Statistical analysis
The mean and SD values were calculated for each group in each test. Data were explored for normality using Kolmogorov–Smirnov and Shapiro–Wilk tests and showed nonparametric (not normal) distribution.
Categorical variables were described by number and percent, where continuous variables were described by mean and SD. For parametric variables, independent samples and paired samples t test were used to compare between two groups in nonrelated and related samples, respectively. For nonparametric variables, Mann–Whitney and Wilcoxon t test were used to compare between two groups in nonrelated and related samples, respectively. The significance level was set at P value less than or equal to 0.05. Statistical analysis was performed with IBM SPSS Statistics, New York, USA version 26 for Windows.
Results
This was a prospective, nonrandomized, comparative, interventional study carried out on 100 patients divided into two groups. The mean age in group I (pseudoexfoliative group) was 55.52±2.94, while in group II (control group) was 55.12±2.96. In total, 26 (52%) patients of group I were males and 24 (48%) patients were females compared with 30 (60%) males and 20 (40%) females in group II. No significant difference was detected regarding age or sex between the two groups as shown in Table 1 .
Table 1: Demographic data of the studied groups
As regarding cataract grading in group I, 32% were soft, 24% were moderate, and 44% were hard, while in group II, 32% were soft, 40% were moderate, and 28% were hard without a significant difference between the two groups; P value of 0.151.
The preoperative evaluation of our patients revealed nonsignificant difference between the two groups regarding visual acuity and ECD (P =0.930, 0.356, respectively). However, the significant difference was detected in IOP of both groups (P =0.020) (Table 2 ).
Table 2: Preoperative data of the two studied groups
Regarding the postoperative evaluation of our groups, there were no significant differences between the two groups concerning ECD at 1 week, 1 month, and 6 months (P =0.223, 0.214, and 0.214, respectively) (Table 3 ). However, it is worth mentioning that in each group, there was a significant decline in endothelial cell count over the period of follow-up at 1 week, 1 month, and 6 months compared with the preoperative data as delineated in Table 4 . Moreover, the endothelial cell loss at each visit postoperatively was calculated in each group without a significant difference between the two groups at 1 week, 1 month, and 6 months (P =0.105, 0.087, and 0.082, respectively) (Table 5 ).
Table 3: Endothelial cell density in the studied groups.
Table 4: Multicomparison between all times calculated by paired samples t test
Table 5: Percent of endothelial cell loss 1 week, 1 month, and 6 months postoperatively
Similarly for cell-size changes postoperative, there was no significant difference between the two groups in the CV of cell size preoperatively and at 1 week, 1 month, and 6 months (P =0324,581 and 0.911, respectively) (Table 6 ). However, there was a statistically significant difference between the preoperative and postoperative CV in each group.
Table 6: Coefficient of variation in the studied groups
Also, for hexagonal corneal endothelial cells , no significant difference between the studied groups was detected either preoperative or during the follow-up period, including 1 week, 1 month, and 6 months (Table 7 ). When preoperative and postoperative data were compared in each group, there was a significant difference between preoperative hexagonality and the postoperative one in each group.
Table 7: Hexagonality in the studied groups
Discussion
This prospective case–control randomized study was carried out to compare the corneal endothelial cell changes after phacoemulsification in pseudoexfoliative patients relative to patients with cataract only. The above results showed that ECD significantly declined in both groups over the period of follow-up at 1 week, 1 month, and 6 months compared with the preoperative one. However, ECD and mean endothelial cell loss did not show a statistically significant difference between the PEX and the control group when compared at 1 week, 1 month, and 6 months postoperatively. Moreover, the mean endothelial cell loss at 1 week, 1 month, and 6 months was 10.63±0.88, 10.43±1.05, and 10.38±1.11 in the PEX group, and 10.1±2.14, 9.85±2.12, and 9.81±2.13 in the control group with no statistically significant difference between the two groups.
Similarly, in the prospective comparative study of Kristianslund et al. [11 cataract surgery, the ECD was not found to be significantly different in PEX eyes compared with other eyes. Also, after 7 years of follow-up of cataract surgery in the study of Østern and Drolsum [12 et al. [13 et al. [14 phacoemulsification and delineated that endothelial cell loss was greater in eyes with PEX after surgery. Erdem et al. [15
In addition to that, this study confirmed the current finding by the nonsignificant difference between the pseudoexfoliative group and the control group when comparing the mean endothelial cell loss at different times of follow-up. Similarly, Aygun et al. [16 12 cataract surgery between PEX and non-PEX eyes.
Regarding cell-size changes, the current study revealed that there was no statistically significant difference between the two studied groups preoperatively and postoperatively. This is in line with Ekici et al. [13 et al. [15 and Demircan et al. [17
Concerning the percent of hexagonal endothelial cells, no statistically significant difference was found between the two studied groups either before or after surgery. However, there was a statistically significant difference between the preoperative and postoperative hexagonality in each group. In the study of Ekici et al. [13
Thus, from the above-mentioned results, it is now obvious that changes in ECD, CV, and HEX could be detected in patients with and without PEX after cataract surgery without a significant difference between them. In the same point of view, Aygun et al. [16 phacoemulsification may be conducted safely in eyes with PEX without a higher rate of complications. Also, Pardasani and Lohiya [18 phacoemulsification surgery since endothelial cells cannot replicate to compensate cell loss.
In our study, we compared between many subgroups regarding the different follow-up evaluations between the pseudoexfoliative and control groups and within the same group. This variety of comparisons was scarcely addressed in previous research work. Therefore, and despite the fact that most of our findings are logical, easy to grasp, and consistent with previous work partly similar to ours, it is recommended to encourage more research work in the same area to confirm or deny the findings in our study.
The limitations of this study, short term of follow-up and low number of cases.
Conclusion
Specular microscopic changes of corneal endothelial cells after phacoemulsification are similar in patients with and without PEX. Thus, phacoemulsification may be performed in eyes with PEX without more susceptibility for complication.
Financial support and ponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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