Cataract is the leading cause of treatable blindness worldwide.1 Around the world, there are more than 190 million people suffering from visual impairment, 32 million of whom are blind.2 Cataract is responsible for over 47% of total cases of blindness worldwide.3
Phacoemulsification with intraocular lens (IOL) implantation is the most common surgical procedure performed for the treatment of cataract, with benefits of causing less surgically induced astigmatism and early and better visual rehabilitation.4,5 Despite all the potential benefits of phacoemulsification, corneal endothelial cell loss remains one of the major concerns especially in patients with already compromised corneal endothelium.
Several studies have indicated an increased corneal vulnerability in diabetic subjects to intraocular surgical stress.6 The diabetic cornea suffers from cellular dysfunction and dysfunctional repair mechanisms leading to decreased corneal endothelial cell density (CED).7 This makes cornea vulnerable to surgical insults as corneal endothelium lacks the ability to regenerate. Moreover, the diabetic patients opting for cataract surgery are usually old aged and have less CED since the number of endothelial cells decreases with age. As a result, it is recommended to evaluate the corneal endothelium routinely prior to phacoemulsification, particularly in diabetic patients.8
A study conducted by Khalid et al. evaluated the changes in corneal endothelial cells density (CED) after phacoemulsification and reported significant change in endothelial cells density; CED 2639.89±331.99 Cells/mm2 before phacoemulsification versus 2250.37±426.68 Cells/mm2 after 2 weeks of phacoemulsification in diabetic patients. The authors concluded that phacoemulsification has significantly negative effects on CED in diabetic patients.9
The aim of present study is to determine the effect of phacoemulsification on CED in diabetic patients undergoing cataract surgery. Because corneal endothelial cells are responsible for maintaining the clarity of the cornea by actively removing the water and any disturbance in the endothelial homeostasis might therefore have a profound effect on the clarity of the cornea. So the present study results will help us to determine the effect of phacoemulsification on CED in diabetic patient, if higher effect is found then it will create an alarm for ophthalmologists and will provoke them to look for a safer method of cataract management in diabetic patients.
To determine the mean endothelial cell density before and after phacoemulsification in patients with diabetes mellitus.
Final diagnosis of cataract will be made using slit-lamp examination. Patients with cataract density of grade 2 and grade 3 (as seen on slit-lamp images, see annexure-II) according to Lens Opacity Classification System III and Axial Lenght (AL) between 23 and 25mm (measured using ultrasound biometry) will be labelled as having cataract.
Patients taking anti-diabetic medication from atleast last 2 years will be labelled as having diabetes mellitus.
Corneal Endothelial Cell Density (CED):
CED will be measured in all patients using Topcon SP 3000P Specular Microscope (Topcon Corporation, Tokyo, Japan) system by consultant ophthalmologist. Specular microscopy is a non-invasive photographic technique that analyzes the size, shape and population of the endothelial cells. It will be noted in cells/mm2. CED will be measured one day before surgery and after 2 weeks of phacoemulsification.
MATERIALS AND METHODS:
Study Design : Pre & post-op study design.
Settings : Department of ophthalmology, Nishtar Hospital Multan.
Duration of Study : 06 months after approval of synopsis.
Sample Size : A sample size of N=16 diabetic patients is calculated by formula of paired sample t-test, using STAT 15.0. Where
Pre-treatment ECD 2639.89±331.99 Cells/mm2.9
And post-treatment ECD 2250.37±426.68 Cells/mm2.9
Corellation between SD for pre and post treatment endothelial cell density =0.1
However we will be taking total sample size N=30 in diabetic patients undergoing phacoemulsification.
Sampling Technique: Non-probability, consecutive sampling.
⦁ Patients of cataract as per operational definitions.
⦁ Adult patients of age 30 years to 60 years.
⦁ Known case of diabetes mellitus.
⦁ Both male and female patients.
⦁ Patients having previous history of ocular trauma.
⦁ Patients having previous history of intra-ocular surgery.
⦁ Patients with bilateral cataract.
DATA COLLECTION PROCEDURE:
After approval of synopsis from hospital ethical committee and REU of CPSP, a total number of 30 patients who will present for cataract extraction fulfilling the inclusion criteria of the study will be selected after written informed consent. Data regarding patients age, gender, duration of diabetes Mellitus and side of cataract will be collected after inclusion in study.
One day before surgery, CED will be measured in all patients using Specular Microscope by consultant ophthalmologist having a minimum of three years post-fellowship experience. In all patients, phacoemulsification cataract surgery will be done by a single experienced surgeon using same phaco machine for all patients. After 2 weeks of surgery, CED will be measured again. All study relevant information will be noted on a pre-designed Proforma (Annexure-I).
DATA ANALYSIS PROCEDURE:
Date analysis will be carried out using SPSS version 23 Software. Qualitative variables such as gender and side of cataract will be presented as frequency and percentage. Quantitative variables such as age, duration of diabetes mellitus, pre-op CED and post-op CED will be presented as mean ± standard deviation (S.D.). Paired sample t-test will be used to compare pre-op and post-op CED values. Affect modifiers such as age, gender, duration of diabetes and side of cataract will be controlled through stratification. Post-stratification paired sample t-test will be applied again. P-value <0.05 will be considered as significant difference.
⦁ Mohammadi SF, Hashemi H, Mazouri A, Rahman AN, Ashrafi E, Mehrjardi HZ, et al. Outcomes of cataract surgery at a referral center. J Ophthalmic Vis Res. 2015;10(3):250-6.
⦁ Jonas JB, Bourne RR, White RA, Flaxman SR, Keeffe J, Leasher J, et al. Visual impairment and blindness due to macular diseases globally: a systematic review and meta-analysis. Am J Ophthalmol. 2014;158(4):808-15.
⦁ Leasher JL, Bourne RR, Flaxman SR, Jonas JB, Keeffe J, Naidoo K, et al. Global estimates on the number of people blind or visually impaired by diabetic retinopathy: a meta-analysis from 1990 to 2010. Diabet Care. 2016;39(9):1643-9.
⦁ Hugod M, Paulsen AS, Norregaard JC, Nicolini J, Larsen AB, Thulesen J. Corneal endothelial cell changes associated with cataract surgery in patients with type 2 diabetes. Cornea. 2011;30(7):749-753.
⦁ Gogate P, Optom JJ, Deshpande S, Naidoo K. Meta-analysis to compare the safety and efficacy of manual small incision cataract surgery and phacoemulsification. Middle East Afr J Ophthalmol. 2015;22(3):362-9.
⦁ Ganesan N, Srinivasan R, Babu KR, Vallinayagam M. Risk factors for endothelial cell damage in diabetics after phacoemulsification. Oman J Ophthalmol. 2019;12(2):94-8.
⦁ ELKady MS, Saleh MM, Aboalhamd AS. Corneal endotheleal cells changes after phacoemulsification in type ii diabetes mellitus. Egypt J Hosp Med. 2017;69(3):1-9.
⦁ Yang R, Sha X, Zeng M, Tan Y, Zheng Y, Fan F. The Influence of Phacoemulsification on Corneal Endothelia Cells at Varying Blood Glucose Levels. Ophthalmology. 2016 Aug 24;26(2):91-5.
⦁ Khalid M, Hanif MK, Qamar ul Islam, Mehboob MA. Change in corneal endothelial cell density after phacoemulsification in patients with type II diabetes mellitus. Pak J Med Sci. 2019;35(5):1366-9.
Changes in Corneal Endothelial Cells Density After Phacoemulsification in Patients with Diabetes Mellitus
Hospital Regd. No. : ________________________________________________
Address : ________________________________________________
Age : ——————- Years
Gender : Male
Side of Cataract : Right
Duration of Diabetes : ——————————Years
Pre-op CED : —————————— Cells/mm2
Post-op CED : —————————— Cells/mm2