WO2011021225A1

WO2011021225A1 - Scleral incision template and a special blade-knife for eye surgery

Info

Publication number: WO2011021225A1
Application number: PCT/IN2010/000547
Authority: WO
Inventors: Narayan Fakkadrao Avhad
Original assignee: Narayan Fakkadrao Avhad
Priority date: 2009-08-20
Filing date: 2010-08-18
Publication date: 2011-02-24
Also published as: EP2467111A1; EA029263B1; EP2467111A4; EA201270294A1; WO2011021225A4; AP2012006172A0

Abstract

A scleral incision template (SIT) and blade-knife is provided that facilitates adequate, efficient and smooth sclera-corneal tunnel dissection by achieving high quality scleral incision that may be close to ideal. The completed scleral incision has a correct predetermined size, shape, length, site and even depth throughout the length of the incisional groove. The synergetic action of the SIT with blade unit makes the sclero-corneal flaps uniform in thickness and tunnel uniform in depth. This facilitates the passage for the extraction of the cataract nucleus, as well as to implant the IOL inside the eyeball and also reduces complications more efficiently than when an incision is taken with help of blade-knife available.

Description

TITLE

SCLERAL INCISION TEMPLATE AND A SPECIAL BLADE-KNIFE FOR EYE SURGERY.

FIELD OF INVENTION

This invention is related to the Small Incision Cataract Surgery (SICS) especially related to method and equipment used for the said surgery.

BACKGROUND OF THE INVENTION

In the modern era, the treatment for blindness caused by the cataract is removal of the cataract and then implantation of the IOL (Intra ocular lens) in the eye, by various surgical procedures including SICS, or phacoemulsification. SICS is a well established surgical technique in which a scleral incision provides a gateway for adequate, efficient and the smooth sclerocorneal tunnel dissection. It facilitates the passage for the extraction of the cataract nucleus, as well as, to implant the IOL inside the eyeball. However, any irregularities in the scleral incision and the tunnel may result into the tissue insult or cell damage and further complications.

This invention provides devices to an eye surgeon that helps him to achieve scleral incision with far better precision.

SUMMARY

This invention comprises a template and a complementary blade or a cutting device for eye surgery; (a) the said template comprising at least one shape/groove cut in it, and (b) a surgical blade (i) having dimensions complimentary to the dimensions of the said shape/groove in the said template for the purpose of inserting the said blade or the said cutting device through the said cut shape/groove (ii) to take an incision in the sclera for undertaking a further operation.

A template and a complementary cutting device may be constructed in many different ways within the scope of the disclosure in above paragraph. In the illustrated embodiment of this invention, the said template is made meant for positioning in an eye surgery over the globe of an eye and the said surgical blade has dimensions complimentary to the dimensions of the said shape/groove in the said template; the dimensions are complementary to serve the purpose of inserting the said blade through the said cut shape/groove for piercing of the tip of the said surgical blade at one end of the said shape/groove by stabbing into the sclera only up to a depth that is required for the surgery and moving the said blade along the length of the shape/groove without rotating around itself to take an incision useful for a further operation.

The invention also comprises a process or method of an eye surgery comprising use of: (a) a template comprising at least one shape/groove cut in it, for positioning in an eye surgery over the globe of an eye, and (b) a surgical blade or a cutting device having dimensions complimentary to the dimensions of the said shape/groove in the said template for the purpose of inserting the said blade through the said cut shape/groove, piercing of the tip of the said surgical blade into the sclera only up to a depth that is required for the surgery and moving the said blade or said cutting device along the length of the shape/groove to take an incision useful for a further operation.

In one embodiment of the invention, a template is comprised of at least one of the following features: (a) at least one groove or slit on the flat of the surface, (b) an extension and/or a mark that helps alignment, (c) structure/s that help stabilization, (d) structure/s that help anchorage over the globe of the eye preventing accidental slide, skidding or tumbling of the template over the globe and in keeping eye-ball immobile during the incision, (e) comprising a handle (f) the shape of the template such that it can help to achieve juxtaposition with sclera enough to achieve immobilization of the globe.

A template of this invention is further comprised of at least one of the following features: (a) the said groove or a slit is in a shape of a straight line (26) which is formed by front portion of the template between the two antennae or a frown (29), or a Chevron's V shape, (b) the said extensions are two antennae (27-a) and 27-b), and said mark is a triangular or an arrow apex mark (28), (c) the said structure helps stabilization includes two backward projections "tail" (31), and it also works as retractor, when placed over eyeball at the time of taking incision, it retracts the dissected conjunctiva and tenon capsule from the operative area.(d) structures that help anchorage comprise "teeth" (30) on the under-surface which is intended to be placed on the surface of the globe of the eye and are positioned to penetrate the sclera when the template is placed with its undersurface in juxtaposition with the globe of the eye, the said teeth may preferably be in two rows, (e) the said handle is angulated (32), (f) the said shape is toric or ellipsoidal (fig-6-T), (g) the said template is made in a metal sheet or disposable material including plastic, (h) the said template handle can be attached to a blade- holder (38).

A blade of this invention is comprised of at least one of the following features: (a) Tip of the blade (37), (b) the middle portion called as Body (36), (c) the third portion called as Cross-Bar (35), (d) fourth part is stopper (34) and (e) fifth part is a handle (33). A blade of this invention is further comprised of at least one of the following features: (a) a tip that is a semi-circular cutting edge of the blade having a height that is equal to the depth of the incision desired, (b) the said body or middle portion that has a shape and a thickness that precisely fits into the groove of the template such that whenever a proper pressure is applied and pulled in the same direction in which the incision is intended to proceed, it slides into the groove snuggly and smoothly. Because of its unique quadrilateral or oval shape, it prevents self rotation into the slit or groove of the template (c) the said cross bar has a diameter greater than the width of the groove or the slit in the template, to stop over penetration or perforation of the globe, (d) the said stopper stops further progression of the blade when inserted in the blade-holder and provides a surface area on which the tip of the blade-holder rests and enables stable operation of the blade and prevents unintended slight movements of the blade when it is used to take a cut, (e) blade handle can be attached to a blade-holder (38).

Another embodiment of this invention comprises a process or method of taking an incision of claim 2, comprising steps of:

(a) using a template of toric or ellipsoidal shape to help to achieve with sclera a juxtaposition enough to achieve immobilization of the globe, the said template further comprising following features: (i) at least one groove or slit in a shape of a straight line (26) or a frown (29) or a Chevron's V shape on the flat of the surface, (ii) an extension of two antennae (27), and a triangular or an arrow apex mark (28) that helps alignment, (iii) two backward projections "tail" that help stabilization and also work as retractor (iv) "teeth" (30) in two rows on under-surface which is to be placed on the surface of the globe of the eye and are positioned to penetrate the sclera when the template is placed with its under-surface in juxtaposition with the globe of the eye, that help anchorage over the globe of the eye preventing accidental slide, skidding or tumbling of the template over the globe and in keeping eye-ball immobile during the incision, (v) comprising a handle (32) that is angulated and attached to a holder (38),

(b) using a blade further comprising (i) tip of the blade (37) that is a semicircular cutting edge of the blade having a height that is equal to the depth of the incision desired, (ii) the middle portion called as Body (36) that has a thickness that precisely fits into the groove of the template such that whenever a proper pressure is applied and pulled in the same direction in which the incision is intended to proceed, it slides into the groove snuggly and smoothly, (iii) the third portion called as Cross-Bar (35) that has a diameter greater than the width of the groove or the slit in the template, but prevents self rotation, (iv) stopper (34) that stops further progression of the blade when inserted in the holder and provides a surface area on which the tip of the blade holder rests and enables stable operation of the blade and prevents unintended slight movements of the blade when it is used to take a cut, and (v) the handle (33) and attached to a blade-holder (39),

(c) retracting the dissected conjunctiva and tenon capsule by inserting the tails of the template in between, placing both antennae parallel to the limbus and touching the gray-line, bringing the apex mark on the template in alignment with the steeper 'K' or otherwise at 12 O'clock over the scleral incision site, verifying that the distance of the incision groove from the limbus is about 2 mm, (d) burying the teeth smoothly into the sclera by applying firm pressure over the base of the template handle, anchoring the template to the globe and immobilizing the same firmly making the same ready for the incision,

(e) inserting the blade into the selected template incision groove by holding the blade vertical to the template, inserting deep into the groove downwards over the sclera, firmly pressing the handle through the groove, stabbing the blade into the sclera till further insertion of the blade is stopped securely by the cross bar (35), pulling the blade handle slowly and steadily along the shape of the groove keeping the applied pressure constant over the blade - holder, enjoining the other end of the groove, completing and ending the incision, pulling the knife slowly out of the template groove,

(f) repeating the step of (e), if required, before removing the template.

A cutting device mentioned above may also be a laser ray capable of taking a cut useful for eye surgery.

DETAILED DESCRIPTION OF THE INVENTION

FIGURES AND THEIR BRIEF DESCRIPTION

The invention is illustrated with help of figures as follows:

Figure No -1 : Shapes of commonly taken incisions

Figure No - 2: Shows incisions having rugged and normal margins.

Figure No - 3: shows a vertical sectional view of globe of the eye and the positions of shallow, normal and deep grooves

Figure No - 4: Temporal, supra temporal and 12 O' Clock positions of incisions

Figure No - 5: Shows desired scleral incision of correct site, shape, length, margins, depth, and size in relation to the 1OL.

Figure No - 6: Scleral template with F- front view, T- top view, L- lateral view.

Figure No - 7: Special blade and its parts. P - front view, Q - lateral view, R- Bottom view.

Figure No -8: Assembly of Scleral Incision Template and Blade as Unit (SIT- unit) with separate Holders.

Complications can arise in S.I. CS. surgery for a variety of reasons. Invariably it starts from the first scleral incision, in respect to shape, length and its depth. The length of the incision depends mostly upon the size and the material of the 1OL, whether it is folding or rigid. Small incision is preferred for soft I. O. L. materials including folding 1.0. L. in silicon, Acrylic Hydrogel etc., while large incision is necessary for a rigid I. O. L. and PMMA (Polymethyl methacrylate) hard materials.

The surgeon prefers the shape of the incision that is easiest to perform or technically not very complicated. The different shapes of incision are like a straight, parallel to limbus, frown, Blumenthal or Chevron's V shape etc. shown in the figure no.1 with reference to the globe of the eye (eyeball) (1). Straight incision (2) is easiest to make but results in induction of moderate astigmatism post-operatively. Astigmatism results when all the rays from an object do not come to focus at one point over the retina, then it causes blurred image of the object upon the retina. It is a common complication after the post-operative healing of the sclera-corneal wound. "Frown" incision (3) is difficult to make, but results in minimum induction of astigmatism.

Chevron's V incision (4) is also a difficult to make incision but results into least or nil induction of astigmatism. Thus, although a surgeon may prefer to take a straight incision, he would be happy if he could take frown or Chevron's V incision easily and conveniently.

The length of the scleral incision also depends upon the technique used for removal of the cataract that may be by manual technique or by a phaco emulsification technique. Though it is marked by calipers over the sclera during surgery on the table, but its quality in terms of accuracy, smoothness and adequacy varies from surgeon to surgeon and from patient to patient for every surgeon. Therefore the incisions are many a time irregular in shape and length, and their margins are often rugged. The incision that is considered as normal (6) and incisions that have irregular shape (5 a), length (5 b) depth (5 c) and rugged margins (5 d) are shown in the figure No 2.

Further, though externally the scleral incision in present practice looks very clean and smooth, however, the depth of the incision may be uneven (5 c) or rugged because of the uncontrolled force, pressure and direction over the blade during the incision. It may result into either too shallow or too deep scleral groove.

A very deep scleral incision can cause scleral disinsertion i.e. the complete separation of inferior sclera from the sclera superior the incision. This creates a large gap resulting in delayed wound healing, or even the prolapse of the iris or vitreous. Figure 3 shows a vertical sectional view of globe of the eye and the positions of incision -shallow (7), normal (8) and deep (9) grooves. The figure also shows the position of cornea (10), anterior chamber (11), trabecular meshwork (12), Iris (13), ciliary body (14) and lens (15).

Likewise, a too shallow scleral incision results into thinning of scleral and corneal flaps. The too shallow or superficial corneal dissection results into multiple corneal tears or button holing of tissue making further surgical steps very difficult like formation, completion and utilization of the sclero-corneal tunnel. The only remedy in such complications on the table lies in remaking the scleral groove and careful dissection in another plane, which itself is a complicated procedure.

Above mentioned are the multiple factors causing many complications during surgery or during post operative period, viz- shallow anterior chamber, bleeding through scleral tunnel, obstructed cataract nucleus delivery, posterior lens capsule rupture, uveal tissue prolapse, iris tissue prolapse or vitreous prolapse, corneal endothelial damage resulting into corneal edema, bullous keratopathy or total corneal opacity, post-operative astigmatism and blindness due to the phthisis bulbi, also known as the shrunken blind eye.

The object of the invention is to achieve a scleral incision that has controlled size, shape, length, site and the most importantly an equal depth throughout the length of the scleral groove. The objective also includes making a knife useful for achieving the above stated objective.

Above objective has been achieved in present invention by making a mechanical user-friendly device and inventing a method of using it in eye surgery. The said device can be used by a method based on "press & pull" principle. If the surgical device of this invention is made in disposable material, it can also be used on a "use & throw" principle. It gives controlled and predictable results, is dependable, time saver, and very convenient instrument for an eye surgeon to use and handle. This invention facilitates the riskiest action in eye SICS surgery i.e. taking an initial scleral incision.

The instrument and method of using it allows a surgical blade to pierce below into the sclera only for a certain depth, It facilitates predetermination of the length along with its movement after piercing through sclera, pre determination of the shape of the incision, predetermination of the depth of the incision and achieving smooth cut without occurrence of rugged margins or laceration at the cut borders of the tissue.

Although there may be more sites of incision taken by eye surgeons over the sclera , most common site of incision are at temporal (16)supra temporal (17) and 12 O' Clock (18) position, which are shown in Figure 4 with reference to globe of the eye.

In one embodiment of this invention, the objective is achieved by using a scleral template, which is provided with a handle and by providing in its conjunction, a special blade with a special handle. The said special blade may also be replaced by any other cutting device, including but not limited to laser rays.

The said template, which can be placed on the eyeball, carries various shapes of grooves from which the desired one can be selected by the surgeon. The knife of desired depth is designed to slide smoothly when pressed by judicious force by surgeon's hand through the selected groove to achieve desired scleral incision of correct site (19), shape (20), length (21), margins (22), depth (23), and size (24) in relation to the IOL (25) as shown in figure no 5.

It may. be mentioned here that, without getting bound by any particular theory regarding that, the following description includes the possible role/function played by the described part/s of the device/s of this invention in the eye surgery. The materials and dimensions in the description are to be taken as illustrative and not as limiting the scope of the invention. The description of the perceptions of the inventor about the function of various parts of the claimed instruments are to be construed only as inventor's perception of their function, and correctness of the perception or the inventor's perception of the theory behind that and the same is not be construed as binding or limiting the scope of the invention.

One embodiment of this invention incorporated in an illustrative scleral template is shown in figure no. 6 F-Front view, T- Top view, L- Lateral view.

The scleral incision template (SIT), variously called throughout this specification as scleral template or template, is made from a metal plate having a thickness preferably of about 1 mm (1000 μ). The SIT has different parts with unique functions. In the illustrated SIT, two most commonly used shapes of incision are provided as grooves, or slits on the flat surface of the template. The first (26) straight-line is for a phacoemulsification and / or folding IOL and the said groove is located in between two antennae (27), second is for (29) a frown shaped incision. The second incision is a longer incision meant for insertion of a bigger and rigid IOL. The scleral template has two projecting parallel telescopic extensions from its flat end, called as the "antennae" (27). The antennae touch the gray line at two parallel points over the corneal limbus; the gray-line is a junction of cornea and sclera, so as to maintain the correct site for the incision. An arrow mark on the flat of the template is called an "apex" (26). It helps the blade to align along with any meridian or radius of cornea called as K¹ in the keratometry, or simply a superior pole or 12 O' clock, supratemporal or temporal site over the sclera, as shown in figure no. 4. At distal end of the scleral template near the base of the handle (32) are two backward projections called as "tail" (31). These "tails" help to stabilize the instrument over the globe of the eye. In absence of these tails, the base of the handle may act like a fulcrum, causing the instrument to get lifted from the surface of the globe, cause tremors at the apex, and then it may creates poor juxtaposition of the template to the surface of the globe resulting into a gap in between the lower surface of the template and the globe. This may ultimately result into a shallow depth in incision, rugged margins or dragged tissues along the incision. It can be prevented by the firm juxtaposition between tails of the template and the globe, which neutralizes the leverage action of the handle. Possibility of accidental slide, skidding or tumbling of the template over the globe is prevented by two rows of "teeth" (30). When these teeth penetrate into the sclera, by anchoring SIT to the globe, it keeps the eye-ball immobile during the incision.

A small, strong and stout handle is attached to the template. Being angulated (Figure No 6-L); it allows an unobstructed surgical view through the operating microscope during the completion of scleral incision. The shape of the template is toric or made ellipsoidal in such a way that it can also help to achieve juxtaposition with sclera enough to achieve immobilization of the globe (Figure No 6-T Top View). Handling of the template is facilitated by attaching the handle (32) to a blade-holder (38) that is available in market.

Another embodiment of this invention incorporated in the special blade and handle embodies the features shown in figure no. (7).

The unique shape of the blade successfully makes an ideal scleral incision a reality. The blade has five parts and with three step-down thickness variations. A) Tip of the blade (37), B) Body (36), C) Cross-Bar (35), D) Stopper (34) and E) the handle (33) for fixation into the Blade-Holder.

A) Tip of the blade or semi-circular cutting edge of blade (37): The tip of the blade, when inserted in a process of taking an incision through a selected shape of groove of SIT, directly pierces the sclera, and when pushed through the groove from one end to another end, the semicircular tip of the blade cuts a clean, rugged-free and drag-less initial scleral incision.

B) The body (36) of the blade is made a quadrilateral or made oval with round smooth corners that help the body to run frictionless into the groove and it also prevents self-rotation when inserted into the groove of the template. Whenever a proper pressure is applied and pulled in the same direction in which the incision is intended to proceed, it slides into the groove snuggly and smoothly. The shape of the groove of SIT in which the blade moves, is the shape of the incision achieved into the sclera.

C) The cross-bar (35): When cross-bar rests over the surface of the template it acts as a guard to over penetration of the cutting blade and results into the precise depth of incision throughout the scleral incision.

D) Stopper (34): Whenever the blade unit is fixed into the Blade-Holder, it stops further progression and gives stability and firmness during incision maneuver.

E) Blade Handle (33): It is the extension of blade unit to be fixed into the blade-Holder (39).

The blade holder is similar to the holder of the scleral template and is equipped to hold the blade handle into the jaw of the blade holder by screwing or unscrewing the second piece of the blade holder. These are easily available in the market.

Although any material permissible for instruments use in eye surgery can be used, it is preferable, to use disposable material for template and blade to ensure its sterility, razor sharpness of blades, and point sharpness of the teeth and low cost of the instrument, although any other material may also be used which may make the template and knife - blade reusable, whether used in a single surgery or in mass surgeries as in any eye-camp. Further, although the invention is illustrated with multi component handle that holds the scleral template or the blade, it may be possible to produce the scleral incision template with handle and / or blade with handle of this invention in a single piece such that a template is provided through which blade can be inserted and moved such that the shape provided by the template is cut cleanly without rugged margins on the globe of the eye for a width and depth of the incision that is desired for an eye surgery. Such a surgery may include a cataract surgery. Thus, this invention helps to reduce the element of surgeon's individual skill and improves predictability and better control on the cataract eye surgery by ensuring practically ideal scleral incision. Whereas this invention is illustrated and standardized for manually using the scleral template and the blade of this invention, the same may be achieved and adapted for mechanically operated use of the scleral template and the blade, and this mode is also included in the scope of this invention.

While the most prevalent two shapes of scleral incision are incorporated in the illustrated template, any other shape may be considered for the template. Further, shape of the tip of the blade used is semi-circular as in the illustrated example here, and that may be of any shape other than this. Preferred dimensions / specifications, as of now, of the various parts of SIT, are given in the following.

The preferred experimental embodiment SIT is made up from a metal sheet. It is approx.1.00 mm (1000 μ) in thickness and 10 x 20 mm in a rectangular main frame, having 3 pairs of main appendages, e.g. an antenna, tooth and tail. Thickness of the template in preferred embodiment is equal to the thickness of body of the blade (36) which preferably is about 1 mm (1000 μ) in both instruments.

An arrow mark (28) on the flat of the template in the middle of two antennae , helps to maintain alignment with any steeper axis of the cornea or K^* and the center of the scleral template. It contributes to minimize the post operative astigmatism. Two parallel telescopic projecting extensions from left and right hand corners of the flat of the template protruding outward are the antennae (27) they are approximately 1.00 mm in length. They maintain the groove distance and the site of the incision away and parallel to the limbus of the cornea.

First groove (26) in the figure 6 is for phacoemulsification with folding IOL, either at scleral or corneal site. The length of the groove is approx. 3.5mm and is useful for a phacoemulsification probe or any other manual methods used to crack down the cataract-lens nucleus into small fragments and then to implant the folding IOL inside the eye ball. Second groove (29) is for a frown incision. An inverted smile or a frown incision is the most popular among the eye surgeons for the initial scleral incision in the small incision cataract surgery (SICS). It is a small semicircular curve having about 120-130 degree angle between the two ends of the groove. The incision formed is about 6 mm in length, suitable for a rigid lens IOL implantation.

Although only two incisions are illustrated, others shapes of incision are also possible to be made into template, such as 'V shaped incision.

At the left and right hand corner of the posterior end of the flat portion of the template, are the tails (31), about 1 mm extensions projecting backwards. The tails help to maintain juxtaposition between template and the globe securely. There are two rows of teeth (30) which are about 200μ (0.2) mm in length, turned downwards towards the sclera to anchor the template with the globe firmly. Between the two tails is the handle (32) that is a projection starting from the flat of the template and progresses in a posterior and upward direction making an angle of about 90 degree to the flat of the template. This S or Z shape angular handle (figure no 6-L) helps to prevent any accidental obstruction of the view through the microscope due to fingers of the surgeon working in the operative area. The anterior and posterior curvature with medial-and lateral curvature of the eye, being ellipsoidal or toric, is maintained into the template in such a way that juxtaposition between the template and the globe can be achieved.

The blade-knife has five parts with unique functions.

The tip of the blade (37) comprises a semicircular cutting edge. It is about 450μ (0.45mm) in length.

Actually the predetermined (desired) depth of the incision is the length of the semi-circular cutting blade from the tip to the base of blade.

Next to the tip of the blade is body, (36) the middle portion that fits into every template incision groove is quadrilateral or made oval (Figure 7 - R) along its breadth in cross section to run smoothly into the groove, and also it prevents any self rotation on its axis. It guides the cutting blade into the template, vertically and parallel to the thickness of the sclera throughout the length of the incision, replicating the shape of the groove into the sclera. The cross-bar (35) acts as a guard to predetermined depth of the blade and as a stopper to the extra penetration of the blade into the sclera. It also distributes the undue penetrating force and weight of the hand of the surgeon over the template and the globe. The cross-bar helps to prevent any accidental perforation of the globe and also too shallow or too deep dissection of the sclera. The handle (33) is a part that joins the blade to the Blade-Holder by insertion into a complimentary slot of the blade holder (figure 8) and stopper (34) is the part which stops further the insertion into the Blade- holder.

In the following is described an example of how the scleral template and blade of this invention can be used for (S. I. C. S) cataract surgery. This description is illustrative in nature to illustrate the general principles of methods by which an eye surgery can be performed by using the slceral template and blade of this invention and does not limit the scope of the invention. Any variation or further improvement that is obvious to a person skilled in the art and is within the scope of this disclosure is also construed to be included in the disclosed invention. For example, once a scleral incision is taken with help of scleral template and the blade, further steps of surgery may be different than the ones described here. Similarly, the dimensions given here and included in this invention disclosure, and materials used are also illustrative and any reasonable variation in the same in the view of requirements of the type of eye surgery are included in this invention disclosure. Example is given for a manual small incision cataract surgery (SICS) operative procedure. The peribulbar anesthesia is preferred. A mixture of solution of xylocain 2% and bupiracaine 0.50% in 5-7ml in quantity is injected at inferior temporal site of orbit. To keep the surgical field securely under the microscope and for immobilization of the globe, the superior rectus suture is essentially completed. For the purpose of exploration of the scleral incision site, the conjunctiva and tenon capsule dissected into a fornix based flap at the limbus and superficial and minimum wet-field cautery is applied on perforating blood-vessels or large surface vessels, if necessary. Scleral incision depends on several factors. For illustrative example on surgery, an IOL of 5.5 or 6 mm diameter rigid lens was considered. For this purpose, the second scleral incision groove(29) is selected; of 6 mm in length. Length of the blade taken was equal to the desired depth of incision into the scleral groove, e.g. 450μ (0.450mm).

Conjunctiva is dissected. The dissected conjunctiva and tenon capsule were retracted by inserting the tails in between, and then antennae were placed parallel to the limbus and touching the gray-line. The apex mark on the template was brought in alignment with the steeper 'K' or otherwise at 12 O'clock over the scleral incision site. It was verified that the distance of the incision groove from the limbus was about 2 mm.

By applying firm pressure over the base of the template handle, the teeth were got buried smoothly into the sclera, template was anchored to the globe and the globe was immobilized firmly, making the same ready for the incision. The blade-knife was then inserted into the selected template incision groove. The blade was held vertical to the template, keeping length of the semicircular blade tip parallel to the groove, and then inserted deep into the groove downwards over the sclera. The blade stabbed into the sclera till further insertion of the blade was stopped securely by the cross bar (35).

Keeping the applied pressure constant over the blade holder, pull it slowly and steadily along the shape of the groove, enjoining the other end of the groove, completing and ending the incision.. The knife was pulled out of the template groove slowly. The depth of the incision was verified thoroughly. This procedure can be repeated if unsatisfied, before removing the template. Sclero-corneal tunnel was constructed thereafter as follows.

For achieving tunnel construction, a 2.8 mm angled crescent with bevel up of a blade was used. Up to 2 mm of clear of cornea was dissected. Then by tilting the blade laterally to right and left, the scleral side pockets were prepared. In the right or left eye, with a sharp 15 degree-angle blade 1mm first stab incision was completed at 3 or 9 O'clock into the clear cornea, respectively. At 5 or 7.0-clock position another second stab incision was completed for the anterior chamber maintainer (ACM).

The ACM was a hallow steel tube with 0.9 mm outer and 0.65 mm inner diameter, was entered with bevel up and then turned 180 degrees so that the bevel faced the iris. The tube of ACM was attached to BSS (balanced salt solution) bottle suspended 70 cm above the patient^'s eye level.

The continuous circular capsular-rhexis (CCC) was completed with a bend 26 needle. A 3.2 mm bevel down, angled blade was used for the internal corneal incision to enter the anterior chamber at about 2 mm into the clear of cornea.

The hydro-procedures were applied to facilitate the rotation of the cataract nucleus from its capsular bag into the anterior chamber. The shallow anterior chamber with loose lens matter was the indicator to proceed further for nuclear rotation, tilting and displacement into the anterior chamber. Thorough hydro procedures reduced the size of the nucleus which in turn enabled to deliver it out of a small incision. Free nucleus in the AC was then propelled out of AC by hydro pressure generated by ACM. In cases where it did not get propelled out, the nucleus was engaged into the sclerocorneal pocket tunnel with the help of thin vectis instrument to facilitate the nucleus delivery. Rest of the cortex was washed out by irrigation and aspiration using Simcoe cannula.

ACM was removed, capsular bag and AC was filled with visco-elastic solution. The lower haptic and optic of the IOL were guided into the bag and trailing haptic was dialed in using Sinskey^'s hook. Most sclerocorneal pocket tunnel incisions were self sealing. An adequate air bubble and fluid pressure in AC tightly shut off the valvular opening. A figure of "8" suture was taken, whenever necessary. The conjunctiva and tenon capsule repositioned back at the limbus, then antibiotic eye drops were instilled into the eye, and a pressure pad was applied for a day..

Claims

1. A template and a complementary blade or a cutting device for eye surgery;

a. the said template comprising at least one shape/groove cut in it, and

b. a surgical blade (i) having dimensions complimentary to the dimensions of the said shape/groove in the said template for the purpose of inserting the said blade or the said cutting device through the said cut shape/groove (ii) to take an incision in the sclera for undertaking a further operation.

2. A template and a complementary blade of claim 1 , (a) the said template comprising at least one shape/groove cut in it for positioning in an eye surgery over the globe of an eye, and (b) a surgical blade having dimensions complimentary to the dimensions of the said shape/groove in the said template for the purpose of inserting the said blade through the said cut shape/groove for piercing of the tip of the said surgical blade at one end of the said shape/groove by stabbing into the sclera only up to a depth that is required for the surgery and moving the said blade along the length of the shape/groove without rotating around itself to take an incision useful for a further operation.

3. A process or method of an eye surgery comprising use of: a. a template comprising at least one shape/groove cut in it, for positioning in an eye surgery over the globe of an eye, and b. a surgical blade or a cutting device having dimensions complimentary to the dimensions of the said shape/groove in the said template for the purpose of inserting the said blade through the said cut shape/groove, piercing of the tip of the said surgical blade into the sclera only up to a depth that is required for the surgery and moving the said blade or said cutting device along the length of the shape/groove to take an incision useful for a further operation.

4. A template of claim 1 or 3 comprising at least one of the following features: (a) at least one groove or slit on the flat of the surface, (b) an extension and/or a mark that helps alignment, (c) structure/s that help stabilization, (d) structure/s that help anchorage over the globe of the eye preventing accidental slide, skidding or tumbling of the template over the globe and in keeping eye-ball immobile during the incision, (e) comprising a handle (32), (T) the shape of the template such that it can help to achieve juxtaposition with sclera enough to achieve immobilization of the globe.

5. A template of claim 4 further comprising at least one of the following features: a. the said groove or a slit is in a shape of a straight line (26)or a frown (29) or a Chevron's V shape, b. the said extensions are two antennae (27), and said mark is a triangular or an arrow apex mark (28), c. the said structure that helps stabilization includes two backward projections "tail" (31), d. structures that help anchorage comprise "teeth" (30) on the under-surface which is intended to be placed on the surface of the globe of the eye, the said teeth may preferably be in two rows and are positioned to penetrate the sclera when the template is placed with its undersurface in juxtaposition with the globe of the eye, e. the said handle is angulated (32),

f. the said shape is toric or ellipsoidal (Fig 6 T ), g. the said template is made in a metal sheet or disposable material including plastic,

h. the said template handle can be attached to a blade- holder (38).

6. A blade of claim 1 or 3 comprising at least one of the following features: (a) a tip of the blade (37), (b) the middle portion called as Body (36), (c) the third portion called as Cross-Bar (35) (d) stopper (34) and (e) the handle (33).

7. A blade of claim 6 further comprising at least one of the following features: (a) the said tip is a semi-circular cutting edge of the blade having a height that is equal to the depth of the incision desired, (b) the said (body) middle portion has a shape and a thickness that precisely fits into the groove of the template such that whenever a proper pressure is applied and pulled in the same direction in which the incision is intended to proceed, it slides into the groove snuggly and smoothly, and because of its unique quadrilateral or oval shape (36 in Figure 7-R) it prevents self rotation into the slit or groove of the template, (c) the said cross bar has a diameter greater than the width of the groove or the slit in the template, to stop over penetration or perforation of the globe, (d) the said stopper stops further progression of the blade when inserted in the holder and provides a surface area on which the tip of the blade holder rests and enables stable operation of the blade and prevents unintended slight movements of the blade when it is used to take a cut, (e) blade handle can be attached to a blade-holder (38).

8. A process or method of taking an incision of claim 3, comprising steps of :

a. using a template of toric or ellipsoidal shape to help to achieve with sclera a juxtaposition enough to achieve immobilization of the globe, the said template further comprising following features: (a) at least one groove or slit in a shape of a straight line (26)or a frown (29) or a Chevron's V shape on the flat of the surface, (b) an extension of two antennae (27), and a triangular or an arrow apex mark (28) that helps alignment, (c) two backward projections "tail" that help stabilization and act as retractor, (d) "teeth" (30) in two rows on a surface intended to be placed on the surface of the globe of the eye, that help anchorage over the globe of the eye preventing accidental slide, skidding or tumbling of the template over the globe and in keeping eye-ball immobile during the incision, (e) comprising a handle (32) that is angulated and attached to a holder (38), b. using a blade comprising (a) tip of the blade (37) that is a semi-circular cutting edge of the blade having a height that is equal to the depth of the incision desired, (b) a middle portion called as body (36) that has a thickness that precisely fits into the groove of the template such that whenever a proper pressure is applied and pulled in the same direction in which the incision is intended to proceed, it slides into the groove snuggly and smoothly, (c) a third portion called as Cross-Bar (35) that has a diameter greater than the width of the groove or the slit in the template, to prevent any over penetration or accidental perforation of the globe,(d) a stopper (34) that limits and stops further progression of the blade when inserted in the holder and provides a surface area on which the tip of the blade holder rests and enables stable operation of the blade and prevents unintended slight movements of the blade when it is used to take a cut, and (e) a handle (33) that can be attached to a blade-holder (39), c. dissecting and retracting the dissected conjunctiva and tenon capsule by inserting the tails of the template in between, placing both antennae parallel to the limbus and touching the gray- line, bringing the apex mark on the template in alignment with the steeper 'K' or otherwise at 12 O'clock over the scleral incision site, verifying that the distance of the incision groove from the limbus is about 2 mm,

d. burying the teeth smoothly into the sclera by applying firm pressure over the base of the template handle, anchoring the template to the globe and immobilizing the same firmly making the same ready for the incision, e. inserting the blade into the selected template incision groove by holding the blade vertical to the template, keeping length of the semicircular blade tip parallel to the groove, and then inserting deep into the groove downwards over the sclera, firmly pressing the handle through the groove, stabbing the blade into the sclera till further insertion of the blade is stopped securely by the cross bar (35), pulling the blade handle slowly and steadily along the shape of the groove keeping the applied pressure constant over the blade holder, enjoining the other end of the groove, completing and ending the incision, pulling the knife slowly out of the template groove, f. inspecting depth of the incision, g. repeat step (e), before removing the template, if any doubts exist about the depth.

9. A cutting device of claims 1 or 3 when the same is a laser ray capable of taking a cut useful for eye surgery.