**4. Viscoelastic resistance**

**3. Intracameral suture**

454 Glaucoma - Basic and Clinical Aspects

iris periphery in the area of the MTF track.

about 1 mm from the limbus in the sclera.Air is injected after MTF.

**2.** The pupil is contracted with intracameral carbachol.

verified with a 30 gauge irrigation cannula.

Steps of operation:

O' clock.

complications.

Intracameral sutures have been in use for a long time, mostly in relation to intraocular lens implants and trauma surgery. The tracks they make and the space they occupy are devoid of

In connection with Microtrack filtration surgery, we thought of using intracameral sutures to prevent the iris from moving forward and closing the internal opening.The idea is to have a 10 zero polypropylene suture or a 30 micron stainless steel wire stretched in front of the

**Figure 14.** Transcameral suture is passed once towards the left and then it is returned to the right. The entry point is

**1.** A small pocket incision in the cornea with a 0.75 mm diamond knife, at 3 O' clock or 12

**3.** One two or three iridotomies are done in the periphery of the iris. The iridotomies are

The goal is to create resistance around the filtration track by injecting a viscoelastic material in the anterior chamber or subconjunctivally. NaHa is one such material. Its effectivity is dif‐ ficult to perceive beyond 4-5 hours.

The other material is Healaflow- cross linked sodium hyaluronate, a material of high viscos‐ ity with an ability to stay in place for a long time and getting resorbed slowly. It has been used in all kinds of glaucoma operations as an adjunct since 2008.It has been used in the scleral space,under the scleral flap and under the conjunctiva. Healaflow is reticulated i.e. its architecture is like a network.This makes it a good space former and it has a long life span in situ.

The unique properties of Healaflow, make it particularly suitable as an adjunct in MTF. Un‐ der the conjunctiva, it is used as a "liquid cushion" against excessive flow during the first days and weeks after surgery. It is also our understanding that Healaflow presence under the conjunctiva shall retard the entry of aqueous in to the conjunctival lymphatics, create a sort of back pressure, that may prevent a flat anterior chamber. This reduces/prevents inter‐ nal iris block.

through the limbus in to the anterior chamber. There is only a slight flow of aqueous due to the presence of NaHa in the anterior chamber. The 100 micron Fugo blade tip if activated at high power, makes a precise 250 micron track.At medium power, the track shall be 200

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**Figure 16.** MTF with Healaflow 2 days after surgery. Healaflow compresses the overlying conjunctival lymphatics.The

compression is maximum in the central area and minimum in the periphery

microns.

**Figure 15.** Peripheral iridotomy is made at 12 O' clock. Space is created along the limbus, in which Healaflow is depos‐ ited.MTF is done with 100 micron Fugo blade tip two times.The aqueous does not rush out since there is NaHa in the anterior chamber.

The steps of operation are as follows:


through the limbus in to the anterior chamber. There is only a slight flow of aqueous due to the presence of NaHa in the anterior chamber. The 100 micron Fugo blade tip if activated at high power, makes a precise 250 micron track.At medium power, the track shall be 200 microns.

**Figure 15.** Peripheral iridotomy is made at 12 O' clock. Space is created along the limbus, in which Healaflow is depos‐ ited.MTF is done with 100 micron Fugo blade tip two times.The aqueous does not rush out since there is NaHa in the

anterior chamber.

456 Glaucoma - Basic and Clinical Aspects

The steps of operation are as follows:

**1.** Making a conjunctival hole at 11 O'clock close to the limbus.

**4.** Contract the pupil with intracameral carbachol.

**2.** Raising a large bleb of MMC 0.01% or 0.02 % at the upper limbus.

**3.** Opening the anterior chamber with a pocket incision of 0.75 mm.

**6.** Injecting NaHa in the anterior chamber close to the upper limbus.

**5.** Making one or more peripheral iridotomies at 12 O'clock of the limbus.

**7.** Pushing away the subconjunctival fluid close to the limbus, with a cannula.

through the conjunctival hole, which hole is closed with a single suture.

**8.** Through the existing conjunctival hole, Healaflow is injected along the upper limbus.it appears as a raised transparent strip along the limbus.The excess starts coming out

**9.** MTF is performed with a 100 micron Fugo blade glaucoma tip. With low energy it is passed through the conjunctiva about 7-8 mm from the limbus.It is then pushed towards the limbus unactivated, till the root of the conjunctiva is reached. The transparent raised Hea‐ laflow prominence improves the visibility of Fugo blade tip. Once the position of the tip clearly visualized, it is lifted at an angle of about 30 degrees, kept lightly pressed at the limbus as inactivated. The moment it is activated from the foot switch, it ablates a track

**Figure 16.** MTF with Healaflow 2 days after surgery. Healaflow compresses the overlying conjunctival lymphatics.The compression is maximum in the central area and minimum in the periphery

**10.** The conjunctival hole for MTF being only 150 micron, there is no need to apply a suture to it.

Ologen appears an interesting material to increase subconjunctival resistance to the free

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**1.** Placing a small piece of Ologen in the immediate vicinity or directly over the MTF external

**2.** Placing multiple Ologen pieces some distance from MTF track, with a view to create re‐ sistance to the passage of aqueous, in to the lymphatics.. The swollen Ologen pieces com‐

**1.** Make a 0.75 mm pocket incision close to the limbus. Use carbachol intraocular to contract

**2.** Fugo blade iridotomy/iridotomies,as described earlier, followed by irrigation of the an‐

**3.** Make a hole in the conjunctiva close to the limbus at 10 O'clock. Through this hole a long 30 gauge cannula is introduced under the conjunctiva and is used to loosen the subcon‐

**4.** A small elongated piece of Ologen is brought close to the conjunctival opening.It swells up immediately by the local moisture.The material is spongy and pliable. It can be pushed under the conjunctiva by the tip of a thin cannula.The Ologen piece is taken to 12 O' clock site close to the limbus. It shrinks when the conjunctiva is pressed, and swells up again when the pressure is released.The Ologen piece may be stained with trypan blue before

**5.** A 100 micron Fugo blade glaucoma tip is entered with momentary low energy under the conjunctiva about 7-8 mm from the limbus, in line with the Ologen piece. The tip is then pushed unactivated under the conjunctiva and under the Ologen piece, till it reaches real close to the conjunctival attachment to the limbus. The tip is rested there and is then raised to an angle of 30 degree or over, depending upon of the resistance of the conjunctiva,

**6.** With hand steadily holding the Fugo blade and the tip putting very slight pressure at the limbus, it is momentarily activated from foot switch. It instantly passes through the limbus in to the anterior chamber,as indicated by the formation of cavitation bubbles in the an‐ terior chamber.During passage through the limbus, cavitation bubbles also spread on both

sides of the entry point, which makes the corneal tissue temporarily opaque.

**8.** A balloon of 0.1 to 0.2 ml of Mitomycin 0.01 or 0.02 % is made under the conjunctiva.

flow of aqueous, after MTF. I have used it two ways:

terior chamber to clear the released pigment.

insertion, for better visualization during the entire process.

press the lymphatics in the area.

The steps of operation are as follows:

junctiva close to the limbus.

under which it is working.

**7.** Air is injected in the anterior chamber.

pore.

Anesthesia as usual

the pupil.

The use of NaHa inside the anterior chamber and Healaflow on the outside, provides excel‐ lent control on the flow of aqueous during surgery and for many hours and a few days after surgery. Even though NaHa shall disappear after some hours, Healaflow continues to exert the useful effect of a liquid cushion from the outside.

OCT done in the early postoperative days shows a dome of conjunctiva raised by Heala‐ flow. The dome soon flattens out, after which it is difficult to discern clearly the location of Healaflow. For any dark slit like appearance, we can presume it to be that.

Conjunctival lymphatics act as flood drains for the aqueous and blood under the conjuncti‐ va.Huge quantities of blood can be removed from the field quite efficiently. We have found that subconjunctival silicone oil is not taken away by the lymphatics. We do not know if Healaflow finally gets drained by lymphatics or it gets broken by the natural enzymes.

For delivering a precise amount of Healaflow along the limbus,it is filled in a cannula of de‐ sired size. The cannula is then transferred to NaHa syringe and used. The end point is diffi‐ cult to make out since NaHa and Healaflow are both transparent. The other way is to attach Healaflow carrying cannula to a trypan blue syringe. The moment blue dye is seen, it means that whole of "cannula contained" Healaflow has been delivered. If more Healaflow is de‐ sired, the amount can be delivered direct from Healaflow syringe.

Microtrack Filtration plus Healaflow films are here:

Healaflow only:

http://www.youtube.com/watch?v=2wKcwOYdKfc

Healaflow and trypan blue:

http://www.youtube.com/watch?v=CBnJl2riAso

Failed MTF Ologen case, Re-MTF along with Healaflowhttp://www.youtube.com/watch? v=WTWSK1O1c8g

#### **5. Spongy resistance**

Collagen matrix (available as Ologen) is a sponge like structure having wide bore channels ranging from 20 to 200 microns.It is available as discs of various sizes and shape, the sizes being 6 to 10 mm and the height being 1 to 2 mm. They have been made with a view to cater for the needs of filtration surgery techniques in which scleral flaps are made. The matrix is said to guide the fibroblasts through the pores in a random fashion and thus prevent scar formation.It may also act as a reservoir buffer to prevent shallow or flat anterior chamber. When wetted it swells up like a sponge. Ologen is said to disappear in 3 months time.

Ologen appears an interesting material to increase subconjunctival resistance to the free flow of aqueous, after MTF. I have used it two ways:


The steps of operation are as follows:

Anesthesia as usual

**10.** The conjunctival hole for MTF being only 150 micron, there is no need to apply a suture

The use of NaHa inside the anterior chamber and Healaflow on the outside, provides excel‐ lent control on the flow of aqueous during surgery and for many hours and a few days after surgery. Even though NaHa shall disappear after some hours, Healaflow continues to exert

OCT done in the early postoperative days shows a dome of conjunctiva raised by Heala‐ flow. The dome soon flattens out, after which it is difficult to discern clearly the location of

Conjunctival lymphatics act as flood drains for the aqueous and blood under the conjuncti‐ va.Huge quantities of blood can be removed from the field quite efficiently. We have found that subconjunctival silicone oil is not taken away by the lymphatics. We do not know if Healaflow finally gets drained by lymphatics or it gets broken by the natural enzymes.

For delivering a precise amount of Healaflow along the limbus,it is filled in a cannula of de‐ sired size. The cannula is then transferred to NaHa syringe and used. The end point is diffi‐ cult to make out since NaHa and Healaflow are both transparent. The other way is to attach Healaflow carrying cannula to a trypan blue syringe. The moment blue dye is seen, it means that whole of "cannula contained" Healaflow has been delivered. If more Healaflow is de‐

Failed MTF Ologen case, Re-MTF along with Healaflowhttp://www.youtube.com/watch?

Collagen matrix (available as Ologen) is a sponge like structure having wide bore channels ranging from 20 to 200 microns.It is available as discs of various sizes and shape, the sizes being 6 to 10 mm and the height being 1 to 2 mm. They have been made with a view to cater for the needs of filtration surgery techniques in which scleral flaps are made. The matrix is said to guide the fibroblasts through the pores in a random fashion and thus prevent scar formation.It may also act as a reservoir buffer to prevent shallow or flat anterior chamber. When wetted it swells up like a sponge. Ologen is said to disappear in 3 months time.

Healaflow. For any dark slit like appearance, we can presume it to be that.

sired, the amount can be delivered direct from Healaflow syringe.

Microtrack Filtration plus Healaflow films are here:

http://www.youtube.com/watch?v=2wKcwOYdKfc

http://www.youtube.com/watch?v=CBnJl2riAso

the useful effect of a liquid cushion from the outside.

to it.

458 Glaucoma - Basic and Clinical Aspects

Healaflow only:

v=WTWSK1O1c8g

**5. Spongy resistance**

Healaflow and trypan blue:


pieces.Furthermore, if an Ologen piece is placed at the limbus, MTF track can be made on

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**Figure 18.** MTF and Ologen, 6 months postoperative. Ologen has caught the pigment coming from inside, that would otherwise have been drained away with aqueous.OCT shows good cover for bleb.It is difficult to decide if Ologen has

To treat hypotony after MTF surgery,we have also used/placed a piece of Ologen directly on

The standard 100 micron glaucoma tip has a teflon sleeve of 50 microns thickness.For it to pass through the limbus, the plasma on the tip has to be wider than combined width of the fibre and sleeve. At medium power, the plasma cloud is 50 microns, therefore the track width is 200 microns. At high power setting the plasma cloud is 75 microns on all sides of the filament, therefore the track size is 250 microns. If we use naked filaments of 75, 100 or 120 microns at low energy, we can have smaller widths of MTF tracks. Thinner tracks cause slow decompression during surgery. Since the speed of aqueous out flow gets reduced, the track is less likely to attract the iris.If a block occurs, the iris tissue is small and is easy to

**1.** Pocket incision 0.75 mm parallel to the upper limbus.Inject carbachol to contract the pupil.

**2.** Make a conjunctival opening near 10 O'clock limbus and inject 0.01 or 0.02 % MMC to

Here is a film on MTF with Ologen piece over the filtration track:

http://www.youtube.com/watch?v=NkwuIRjA3aQ

**6. Reducing the width of the filtration track**

dislodge. Some successful cases show no bleb at all.

balloon the conjunctiva along the limbus and beyond.

The steps of mini-MTF operation are as follows:

the over-filtering MTF track, with success.

one side,under it or through it.

been absorbed or not.

**Figure 17.** A thin cannula loosens the subconjunctival space close to the limbus.A piece of Ologen is pushed through the conjunctival opening to the 12 O clock limbus.MTF is performed close to one end of Ologen. Air bubble in the anterior chamber is an indication that MTF track really got made.

Postoperatively, we watch the state of the anterior chamber and the bleb and remain awake to the possibility of internal blockage of the track with the iris, the only problem point of MTF surgery.

We have observed that if there is no free movement of aqueous, the collagen matrix becomes hard and dry and refuses to get absorbed.It also becomes adherent to the overlying conjunc‐ tiva and it becomes difficult to separate the two.

Healaflow and Ologen are two materials, which can increase the subconjunctival lymphatic resistance to the out coming aqueous. This resistance is important in the first few postopera‐ tive weeks. It reduces the chances of shallowing/absence of the anterior chamber. Both mate‐ rials provide resistance, one as a liquid cushion and the other as a soft sponge. The placement of Healaflow is easier than Ologen. Both materials are supposed to disappear with passage of time. It is not easy to find out when the material disappeared or whether it really disappeared. However our main concern is to see if they did the work that was ex‐ pected from them i.e. reducing the incidence and severity of internal blockage of the track with iris. After doing 75-80 surgeries in both groups, it is our perception that there has been a palpable reduction in the use of YAG laser for removing internal MTF iris blocks.

There is only one variation possible with Healaflow, namely the amount of the material de‐ posited. With Ologen many variations are possible, namely number, size and position of the pieces.Furthermore, if an Ologen piece is placed at the limbus, MTF track can be made on one side,under it or through it.

**Figure 18.** MTF and Ologen, 6 months postoperative. Ologen has caught the pigment coming from inside, that would otherwise have been drained away with aqueous.OCT shows good cover for bleb.It is difficult to decide if Ologen has been absorbed or not.

Here is a film on MTF with Ologen piece over the filtration track:

http://www.youtube.com/watch?v=NkwuIRjA3aQ

**Figure 17.** A thin cannula loosens the subconjunctival space close to the limbus.A piece of Ologen is pushed through the conjunctival opening to the 12 O clock limbus.MTF is performed close to one end of Ologen. Air bubble in the

Postoperatively, we watch the state of the anterior chamber and the bleb and remain awake to the possibility of internal blockage of the track with the iris, the only problem point of

We have observed that if there is no free movement of aqueous, the collagen matrix becomes hard and dry and refuses to get absorbed.It also becomes adherent to the overlying conjunc‐

Healaflow and Ologen are two materials, which can increase the subconjunctival lymphatic resistance to the out coming aqueous. This resistance is important in the first few postopera‐ tive weeks. It reduces the chances of shallowing/absence of the anterior chamber. Both mate‐ rials provide resistance, one as a liquid cushion and the other as a soft sponge. The placement of Healaflow is easier than Ologen. Both materials are supposed to disappear with passage of time. It is not easy to find out when the material disappeared or whether it really disappeared. However our main concern is to see if they did the work that was ex‐ pected from them i.e. reducing the incidence and severity of internal blockage of the track with iris. After doing 75-80 surgeries in both groups, it is our perception that there has been

a palpable reduction in the use of YAG laser for removing internal MTF iris blocks.

There is only one variation possible with Healaflow, namely the amount of the material de‐ posited. With Ologen many variations are possible, namely number, size and position of the

anterior chamber is an indication that MTF track really got made.

tiva and it becomes difficult to separate the two.

MTF surgery.

460 Glaucoma - Basic and Clinical Aspects

To treat hypotony after MTF surgery,we have also used/placed a piece of Ologen directly on the over-filtering MTF track, with success.
