Author: Mehmet Demir
Co-authors: Cetin Akpolat, Turgay Ucak, Isil Karagoz, Tugce Dursun
Abstract
Aim: Effects of iatrogenic iris tissue manipulation via iris vacuum application on central macular thickness (CMT) and visual acuity in the postoperative periodMethods: This comparative study included 41 eyes of 41 patients (study group= 21 eyes, control group= 20 eyes) diagnosed with age-related cataracts and underwent uncomplicated phacoemulsification surgery. The patients were followed-up at least 45 days in the postoperative period. The study group included patients who underwent iris vacuum procedures during phacoemulsification surgery, and the control group included patients without iris tissue manipulation. The vacuum was applied under 300 mmHg with an aspiration cannula at 3-8 points on iris tissue for reduction of the pupil size to prevent IOL (intraocular lens) capture. Patients were examined in the preoperative period and on days 1, 7, 30 and 45 of the postoperative period. Patients had detailed ophthalmic examinations at pre-and postoperative visits. The ophthalmic examinations included best-corrected visual acuity assessment (BCVA, in Snellen), slit-lamp biomicroscopic evaluation, indirect fundoscopic assessment with + 78 D lens, and intraocular pressure (IOP, mm Hg) measured with Goldmann applanation tonometry. Spectral-domain optical coherence tomography (OCT) was used for the scan of the macula to evaluate CMT, and IOL diopter was calculated with an optical biometer. Patients with >± 3.0 D spherical equivalent, < 50 years age, history of the vitreoretinal disease, retinopathy, neovascular glaucoma, previous intravitreal injection, and intraocular surgery were excluded. All phacoemulsification surgeries were performed by the same experienced surgeon (>15 years) in sterile conditions under topical (proparacaine hydrochloride 0.5 %) and retrobulbar (lidocaine hydrochloride 2 % and bupivacaine hydrochloride 0.5 %) anesthesia. The gravity fluidics torsional phacoemulsification system (Constellation, Alcon Laboratories Inc.) was used the phacoemulsification surgeries.
Results: The patients in the study and control groups had similar mean age values (69.7± 8; 72. 6 ± 6.5, p>0.05, respectively). The mean preoperative and postoperative BCVA values were similar between the groups (p=0.152, p=0.469, respectively). The preoperative BCVA values (0.34±0.15; 0.27±0.15: 0.27+/-0.15) were significantly improved at last postoperative visits in both groups ( 0.66±0.23; 0.72±0.22 respectively), (p<0.001 in all groups).
Similar mean IOP values were noted in the inter-and intragroup analysis (p>0.05 for all). The mean CMT value of the study group increased from 198.00±31.31 to 346.65±59.95 um (p<0.001). The mean CMT value of the control group increased from 201.71±29.16 to 231.86±66.75 um (p=0.016). While the mean preoperative CMT values were similar (p=0.696) between the groups, the postoperative values were different (p=0.004). Postoperative CMT in the study group had a significant correlation with the iatrogenic vacuum manipulation (r=+0.423, p=0.006).
Conclusion: Iatrogenic vacuum on iris tissue may lead to an increase in CMT. Therefore, manipulation of the iris tissue during surgery should be avoided. In this study, this negative effect was not observed on BCVA, which may be attributed to the small number of cases.
