CLINICAL OUTCOME OF MANUAL SMALL INCISION CATARACT SURGERY IN SMALL PUPIL

Abstract

Background and Objective Small pupil is one of the most significant risk factors that can lead to a variety of difficulties both during and after the cataract surgery. Poor pupil dilation can be caused by many factors, such as diabetes and the consumption of certain pharmaceutical drugs such as terazocin and doxazocin. Even for an experienced cataract surgeon, the intraoperative small pupil continues to provide a number of obstacles. Preoperative and intraoperative measures, such as 2.5% phenylephrine drops, sphincterotomy, iris hooks, pupil expansion rings can reduce the likelihood of miosis occurring during the surgery. Limited data is available regarding visual outcome and the rates of complications in patients with small pupils undergoing cataract surgery. Therefore we investigated the visual outcome, intraoperative complications and post-operative complications following cataract surgery in small pupils. METHODOLOGY This is hospital-based, cross-sectional study, involving 40 eyes who attended ophthalmology OPD at R.L Jalappa Hospital attached to Sri Devaraj Urs Medical College, Tamaka, Kolar from September 2022 to December 2023. Pupils are measured in mesopic luminance under torch light or slit lamp graticule. Patients with pupil size of less than or equal to 3mm were taken for the study. Following this, the patient was dilated using dilating drop tropicamide(0.8%) +phenylephrine(0.5%) one drop in both eyes every 5-10minutes for 3 times after 15-20minutes see the pupil size if the pupil size of 6mm and less then the patient is considered. On the day of surgery, patient is dilated half an hour before the surgery. And operation is done by single surgeon intraoperative complications while operating like Posterior capsular rent, iris trauma, difficulty in delivering the nucleus are noted. If complications while delivering the nucleus to anterior chamber are anticipated xv phenylephrine(2.5%)is used, if dilation is not adequate 2%viscoelastic is used even after this if pupil fails to expand sphincterotomy is done. Postoperative visual outcome is assessed on the 1st, 7th and 30th postoperative day. RESULTS We examined 40 patients in total who is undergoing MSICS with small pupils. Majority of patients were aged between 61-70 years, comprising 47.5% of the sample, followed by those over 71 years (35.0%), and the smallest group being those aged 50-60 years (17.5%). Gender distribution was fairly even, with 52.5% female and 47.5% male patients. Pre-operative visual acuity varied, with the most common category being counting fingers close to face (CF CF) observed in 27.5% of patients. Other notable pre-operative visual acuities included 1/60-2/60 in 17.5% of patients and counting fingers at 2 meters (CF 2mt) in 15.0% of patients. Regarding pupil size, before dilation, the majority of patients (77.5%) had a pupil size of 3 mm, while 22.5% had a pupil size of 2 mm. Post-dilation, the most common pupil size was 5 mm (47.5%), followed by 4 mm (32.5%), 6 mm (15.0%), and 3 mm (5.0%). Intraoperative complications were notable, with trauma to iris (microbleeds, sphincter tears, iris chafing) occurring in 27.5% of cases and posterior capsule rupture (PC rent) in 28.0% of cases. Difficulty in delivering the nucleus was encountered in 12.5% of surgeries. Postoperative slit lamp examinations on day 1 revealed that 42.5% of patients experienced corneal edema, while Descemet's membrane folds (DM folds) were observed in 27.5% of patients. Anterior chamber (AC) reaction was noted in 10.0%, and 7.5% of patients had clear findings. Visual acuity outcomes showed that on postoperative day 1, the most common uncorrected visual acuity was 6/24 (22.5%), with 15.0% of patients achieving 6/60 and hand movements xvi (HM) vision. On postoperative day 7, 25.0% of patients achieved BCVA of 6/6 vision, followed by 20.0% with 6/12 and 17.5% with 6/18. By postoperative day 30, the most common best corrected visual acuity was 6/6 (30.0%), with 32.5% of patients achieving 6/9 and 25.0% achieving 6/12. Statistical analysis revealed significant associations between intraoperative events, postoperative visual acuity, and pupil size after dilation. Difficulty in delivering the nucleus was significantly associated with smaller pupil sizes (p = 0.03). Furthermore, postoperative visual acuity on day 1 showed a statistically significant association with pupil size after dilation (Chi-Square: 56.42, P Value: 0.007). CONCLUSION AND INTERPRETATION: Small pupil presents significant challenges, particularly in intraoperative complications like PC rent, iris trauma, and many more. Despite these challenges study shows the importance of meticulous surgical technique and careful management which can lead to favourable visual outcomes. There was significant associations found between small pupil size and increased surgical difficulty. Through tailored approach, we were able to reach maximum visual acuity of 6/6 in most of patients.