Now-a- days, it is further improved to small incision cataract surgery rather than extra capsular cataract extraction. The main improvement behind SCIS was that no suture is required where extra capsular cataract extraction required stitches.
Recent advances of cataract surgery is highly sophisticated and give the person early visual outcome, with less or no astigmatism, with no hospital staying, after undergoing cataract surgery. Phaco emulsification is the ultimate choice for new generation due to very small incision cataract surgery called micro incision cataract surgery. Only 2-3 mm or less incision is required and in this case nucleus of lens is emulsified by a titanium needle which vibrates on an average frequency of 28,000 to 40,000 hertz, and Amplitude is 5 -15 micron due to a signal from ultra–sound phaco emulsification machine.
However, this device has some limitations in the context of the poverty and health care in under developed and developing countries, such as Bangladesh.
First of all, it is very expensive. Cost of each machine is 40,000 -50,000 US dollars. Moreover, we need to change cassette, needle etc time to time, prior to surgery. This requires huge financial involvement to complete an operation. So very less number of surgeons in third world country are using this device for cataract operation.
He tried a simple rotating device, thinking that if he could drill a tooth, he could drill away a cataract .This only made the lens spin inside the animal’s eye, denuding the endothelium. He then added suction and irrigation, in an attempt to keep the lens from rotating. However, this did not prevent the lens from spinning, so he introduced other instruments in an attempt to hold the lens in place while it was being drilled. This attempt was unsuccessful too. So, he took two needles rotating in opposite directions, similar to a food blender. This approach was exceedingly dangerous, since it set up eddy currents which drew the iris to the needles, causing a complete disinsertion of the iris with hemorrhage [1].
The Machine has three parts – namely Body, Tube and Yousuf’s Needle.
•Body contains a motor and a wire connecting the power source with a foot-switch. The motor has a shaft enabling the needle to spin.
•The tube has a broad base attached with body and a tapered end containing Yousuf’s Needle.
Unlike other phaco device, this device will not produce much more temperature causing damage to the surrounding structures. So this device can be used without any sleeve! So tapered end of tube will be 2.4 mm in its outer diameter and inner diameter will be 2 mm. So operation can do with only 2.8 or 3.2 mm clear corneal incision.
•Easy penetration to the lens fibers
•Quick cutting lens fibers by increasing cutting surfaces of needle
•Arrangements of needles are in such a fashion that cutting surfaces will be outside the circle
2. Diameter of Yousuf’s Needle is little bit higher than the existing phaco tip. So if you consider about cutting lens fibers, then my device has advantages over existing phaco device. Existing device has a sleeve. With this sleeve total diameter of phaco tip is 2 mm which is more than my device. Due to production of very low temperature no need of this sleeve in my device. So with more diameter of needle it will easily enter into the anterior chamber with 2.8 mm clear corneal tunnel.
3. Size of needle will depend upon the nature of device.
•Device without irrigation and aspiration system – in that system size of needle will be 20 gauze needles. Total diameter of needle will be 1.85 mm.
•Device with only aspiration system – in that system size of needle will be 22 gauze needles. Total diameter of needle will be 1.45 mm.
•Device with irrigation and aspiration system – in that system size of needle will be 23 gauze needles. Total diameter of needle will be 1.2 mm.
4. Generate very low temperature – less than 2’C during emulsifying lens, due to sharp cutting surface and also move slowly - it generate very low temperature. See table below (Table-1)
Time (s) |
Temp of Lens (◦C) |
00 |
28.3 |
05 |
28.6 |
10 |
28.6 |
15 |
28.9 |
20 |
29.2 |
25 |
28.8 |
30 |
28.6 |
35 |
28.7 |
6. Conform the needle in lens fibers. (Figure 1)
On the basis of irrigation and aspiration systems, this device will be of 3 types.
Experimented on goat’s eye – Second experiment was carried out with goat’s eye. It is widely practiced to experiment on goat (ref no 2), sheep (ref. no. 3), or pig’s (ref. No.4) eye before going experiment on human eye. Hence, this procedure was experimented on goat’s eye. 50 cases were used for this clinical trial. Method was random but purposive method.
The traditional experiment runs with this device with goat’s eye. After peritomy, we enter into anterior chamber by making scleral tunnel, then doing capsulotomy of anterior lens capsule, hydro dissection, and also hydro desalination was carried out. Lens was brought to anterior chamber. Then nucleus of lens of goat’s eye was close to this device for emulsification of lens. After rotating of device lens turned into broken particles and afterwards became jelly like substance. Some portion of lens decayed, the process created a hole in the middle of operating portion. Afterwards the broken part of the lens was brought near the needle with the help of a phaco chopper. The device and again started to operate until, the total lens emulsified fully after a period of few minutes at a stretch.
On human crystalline lens in vitro – After operation of small incision cataract surgery, 50 lenses are collected immediately after delivery of lens and preserved it in visco- elastic substances, and balanced salt solution which is identical to aqueous humor. Lens was held with the lens holding forceps. Then this device started to rotate after penetration through lens. Three different experiments were done, after taking three different types of lenses. First was immature, another was matured and last one was hyper matured cataractous lenses. Method was random but purposive method.
All lenses were cadaveric lens which are collected after doing SICS operation.
b) Second experiment with goat’s eye-gives the clear cut idea about the utility of this device. Main idea is tried to evaluate how much efficiency is shown by this device, and also indicate any type of complications do occur or not? Lens of goat’s eye was emulsified successfully with this device repeatedly. No spinning of the lens at all denuding corneal endothelial damage. No severe complication like posterior capsular rupture, vitrious prolaps, no corneal endothelial injury, and no wound burn occurred. Initially one minor complication was observed in anterior chamber of goat’s eye, that is iris was injured by the needle but the Problem was overcome by exercising caution.
• When the process was applied to matured lens it has turned into jelly like substances. The procedure was in accordance with the expected rate. That is to say that the lenses have been emulsified optimally as expected.
• However, in case of hyper mature cataract, the process was time prolonged accordance with the expected rate and the lens was jelly like substance.
See table below (Table: 2,3,4) (Figure: 2,3,4)
Time (s) |
Temp. of Water (◦C) |
Temp of Lens (◦C) |
00 |
28.2 |
29.5 |
10 |
27.9 |
29.1 |
20 |
27.9 |
28.2 |
30 |
27.8 |
28.1 |
40 |
27.7 |
28.1 |
50 |
27.7 |
28.1 |
1:00 |
27.6 |
28.0 |
1:10 |
27.6 |
27.8 |
1:20 |
27.6 |
27.9 |
1:30 |
27.6 |
28.8 |
1:40 |
27.8 |
27.9 |
1:50 |
27.9 |
28.0 |
2:00 |
27.8 |
28.2 |
2:10 |
27.8 |
28.1 |
2:20 |
27.8 |
28.2 |
2:30 |
27.8 |
28.2 |
2:40 |
27.7 |
28.1 |
2:50 |
27.9 |
28.4 |
3:00 |
28.1 |
30.6 |
3:10 |
28.2 |
28.8 |
Time (s) |
Temp of Lens (◦C) |
00 |
29.7 |
05 |
29.6 |
10 |
29 |
15 |
29.1 |
20 |
29.9 |
25 |
27.9 |
30 |
29.1 |
35 |
29.1 |
40 |
29.2 |
45 |
29.2 |
50 |
29.2 |
Time (s) |
Temp. of Cornea (◦C) |
Temp of Anterior Chamber (◦C) |
00 |
29.8 |
28.8 |
10 |
29.9 |
29.0 |
20 |
29.9 |
29.2 |
30 |
29.9 |
29.4 |
40 |
29.9 |
29.6 |
50 |
29.9 |
29.1 |
1:00 |
29.9 |
28.9 |
1:10 |
29.9 |
29.1 |
1:20 |
29.9 |
29.2 |
1:30 |
29.9 |
29.4 |
1:40 |
29.9 |
29.5 |
1:50 |
29.9 |
29.5 |
2:00 |
30.0 |
29.7 |
2:10 |
30.0 |
29.7 |
2:20 |
30.0 |
29.8 |
2:30 |
30.0 |
30.0 |
2:40 |
30.1 |
29.8 |
2:50 |
30.1 |
29.9 |
3:00 |
30.1 |
30.0 |
3:10 |
30.1 |
30.0 |
But my device is a simple device; no raise much temperature to cause thermal injury to surrounding structure during operation. Efficacy is almost same to phaco machine. I have used mechanical energy to rotate a needle which will emulsify lens material successfully and lens fibers will convert into a jelly like substances and then it will evacuated by two way irrigation aspiration canola. So, by using my proposed device we want to decrease severe complications during surgery which will be cost effective as well. The basic mechanism of new device is different than phaco machine. Proposed device will work by rotating a special type of needle (Yousuf’s needle) at the rate of less than 2,000 rpm where phaco machine works by vibrating a needle which is made of titanium. This low rotation can be achieved by using a ‘DC’ motor where voltage will be between1.5 to12 volts.
- Charles D. kelman, MD phako, phakonit and laser phako- a Quest for the best(highlights of ophthalmology. 2002:1-8.)
- Dada VK, Sindhu N. Cataract in enucleated goat eyes: training model for phacoemulsification. J Cataract Refract Surg. 2000;26(8):1114-1116.
- Mohammadi SF, Mazouri A, Jabbarvand M, Rahman-A N, Mohammadi A. Sheep practice eye for ophthalmic surgery training in skills laboratory. J Cataract Refract Surg. 2011;37(6):987-991. doi: 10.1016/j.jcrs.2011.03.030
- Van Vreeswijk, Pameyer JH. Inducing cataract in postmortem pig eyes for cataract surgery training purposes. J Cataract Refract Surg. 1998;24(1):17-18.






