(My learning curve, first 100 cases.)
Aim of the study: To evaluate the technique of scleral tunnel Cataract surgery and I.O.L. implantation that is Phacoless and sutureless.
Introduction: To switch over to sutureless cataract surgery, ie phacoless is quite exciting and interesting also. The reason behind this is (i) It is cost effective. Not only most of our patients can not afford phaco surgery but also most of us (surgeons) can not afford a good phacoemulsifier and its allied expenditure in developing countries. (ii) this procedure produces similar results such as faster and satisfactory visual rehabilitation. One can achieve the same goal that of phaco simply avoiding long and risky learning curve of phacoemulsification.
Materials and methods: One hundred consecutive cases of various cataract, attending to ophthalmology OPC of R.M.Medical College Hospital,Annamalai University, were taken up for this study. This includes 79 cases of senile cataract, 5 cases of child- hood cataract and 10 cases of complicated cataract. Thorough preoperative evaluation of anterior segment of the eyes was done by biomicroscopy, posterior segment by B scan ultrasonography. The cases with posterior segment problems were excluded from the study. The keratometry and I.O.L. power were calculated using Teknar Image 2000 A and B scan (biometry).The surgeries were performed under peribulbar anaesthesia except for childhood cataracts, which were undertaken with general anaesthesia. Peribular anaesthesia was achieved by giving 2 injections , mixture of 5cc of 2% xylocaine with 5cc of 0.5% bupivacaine by two points technique,1 without adding hylase. Facial N. block was avoided in all the cases. Ocular hypotony was achieved by ocular compresion with pinky ball.
Scleral Tunnel Incision: After Ab externo fornix based conjuctival flap,a frown tunnel incision is given with B.P.blade No.15. The size of incision, the distance between the ends of incision mostly varies from 6.5 to 8.5mm,However if it is nuclear, rock hard cataract incision may be bigger up to 10mm It is to be noted that the incision can be extended at any point of time. The anterior extent of the incision is always more than 2mm behind the limbus and two ends can be 4 to 6 mm behind the limbus.2 The tunnel was dissected with the help of sharp edge tunnel pocket blade angled No 4805(image1) or sharpedge lamellar miniature blade angled no.6600. The incision depth varies from 0.1 to 0.5 mm as the thickness of sclera at 2 mm posterior to limbus is roughly 0.6mm. Ideal depth was 1/3rd to thickness of sclera.
One should be very careful not to be very superficial or too deep to avoid complications like button hole or cyclodialysis respectively. Further the thin flap has always the tendencies to tear. The internal incision which is entry to anterior chamber was made with the help of sharpedge slit blade angled No.5540, 5520 or 5516 and latter extended after capsulorhexis.
Capsulotomy: Continuous curvilinear capsulorhexis which was innovated by Gimbel and Neuhann has revolutionised the modern cataract surgery.This was performed with either 26G bent needle or with the help of Masket Capsulorrhexis forceps. Sometimes it takes 6 months to master this technique. A rhexis of 6 to 7.5mm diameter is essential, how ever if it is nuclear cataract, one or two relaxing incision are made at 4 0’clock or 9 0’clock meridians,or else little larger rhexis can be performed very carefully because it has the tendencies to extend peripheraly.Relaxing incisions were made with the help of 26G bent needle or with vannasscissors.
Hydrodissection: The step is very essential before nucleus delivery. It is carried out with 2 ml syringe using curve 23G west lacrimal cannula, the fluid was injected beneth the anterior capsule in one or two places,however large volume are avoided.Golden ring reflex in case of soft cataract or fluid waves are observed to ensure complete hydrodissection.