Post operative astigmatism following extracapsular cataract extraction and small incision cataract surgery: A comparative study

Anuradha, T R (2007) Post operative astigmatism following extracapsular cataract extraction and small incision cataract surgery: A comparative study. Masters thesis, Stanley Medical College, Chennai.


Download (186kB) | Preview


INTRODUCTION: Cataract is a major cause of avoidable blindness and world wide, an estimated 17 million are blind from this condition. In the absence of any preventive measure the only resource is surgery. In the field of cataract surgery, IOL implantation after extra capsular cataract extraction was a major breakthrough. However delayed rehabilitation was the major drawback with this procedure and it produced high induced astigmatism and ocular discomfort due to sutures. Invention of phacoemulsification by “Charles Kelmann” (1965) and learning the technique of self sealing wound (1980) resolved the above mentioned problems associated with ECCE and begun the era of sutureless small incision cataract surgery. AIM OF THE STUDY: This is a study carried out to analyse post operative astigmatism between the two operative procedures-small incision cataract surgery and extracapsular cataract extraction. ECCE with PCIOL implantation using five 10-0 nylon interrupted sutures. Small incision cataract surgery with PCIOL implantation without sutures. This study also analyses post operative astigmatism in small incision cataract surgery group with varying length and shape of incisions. MATERIALS AND METHODS Hundred cases of uncomplicated mature and immature cataract were selected for the study. Corneal curvature was measured with keratometer preoperatively. Extracapsular cataract extraction with PCIOL implantation was done for 50 cases and the wound was closed with 10-0 nylon, 5 interrupted sutures. Scleral tunnel with PCIOL Implantation was done for the remaining 50 patients and no suturing was done. Three types of scleral tunnel incisions – linear, frown and smile were made. All incisions were made in the upper quadrant. Post operative evaluations included keratometry at 2 weeks, 4 weeks, 6 weeks and at 3 months. Refraction and spectacle correction was done at 6 weeks. Corneal topography was done in selected patients at 3 months. In this study, cases which had post operative complications, fundus pathology has been deleted from the list as our main aim was to study the nature and amount of post operative astigmatism in detail. SUMMARY One hundred cases of uncomplicated cataract with clear cornea and V/A ranging from PLPR + to 6/36 underwent cataract surgery by two methods, 1) ECCE with PCIOL implantation 2) SICS with PCIOL implantation, each having a sample size of 50. In SICS group, surgery was done using 3 shapes of incisions. Linear in 32 patients, Frown in 16 patients and Smile in 2 patients. The incision length in SICS group varied from 6.5 – 8.5mm. The patients were divided into two groups based on the length of incision, 6.5 - 7.5mm and 7.6 – 8.5 mm. Preoperatively keratometry was done in all these patients and post operatively patient was followed up at 2 weeks, 4 weeks, 6 weeks and at 3 months. This study was done to evaluate the post operative astigmatism by keratormetry in 100 cases of cataract surgery by the two surgical techniques, to find out which surgery produced less post operative astigmatism. This study also analyse if the use of smaller incision in SICS group produced less post operative astigmatism and to find out the shape of incision which produced lesser post operative astigmatism. It was found in this study that the SICS with PCIOL, produced less degree of post operative astigmatism and in the same group, use of smaller incision and using frown incision produced lesser post operative astigmatism. It was also found that placing the incision on the steeper meridian, reduces the preexisting astigmatism. This study also revealed that there was greater shift to ATR and Oblique astigmatism in ECCE with PCIOL group, whereas in SICS with PCIOL group shift was less. It was also found that 0.53 D of astigmatic decay occurred in ECCE group at 3rd month but there was no such decay in SICS group. CONCLUSION: The length, location, shape of incision, suturing technique and number of sutures have effect on post operative astigmatism. Longer incision, curvilinear to limbus and suturing produces greater post operative astigmatism and a drift towards ATR/Oblique astigmatism as in ECCE. Small, posteriorly placed incision produces less post operative astigmatism. Frown shaped incision in SICS produces less post operative astigmatism. It is inferred and concluded that SICS using frown incision could be the preferred mode of cataract surgery resulting in minimal post operative astigmatism.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Post operative astigmatism; extracapsular cataract extraction; small incision cataract surgery
Subjects: MEDICAL > Ophthalmology
Depositing User: Devi S
Date Deposited: 13 Sep 2017 12:03
Last Modified: 18 Sep 2017 02:46

Actions (login required)

View Item View Item