Sixteen eyes with absolute glaucoma were treated andfollowed up for a minimum of six months. Goniotomyab interno using the Fugo Blade™ was found to be a safealternative to conventional trabeculectomy, which safelyand effectively reduced intraocular pressure in more than80% of cases.

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INTRODUCTIONGlaucoma is one of the most crippling diseases in oph-thalmology. It is also one of the most expensive tomanage, as medications and repeated visits to the oph-thalmologist are a constant drain on the health care bud-get. Surgical treatment remains the preferred modality,maintaining optimum intraocular pressure (IOP) aroundthe clock.

Presently, trabeculectomy is the most preferred surgi-cal option for management of glaucoma. However,long-term studies of trabeculectomy have shown a lin-ear decrease in success rate with concomitant increasingrequirement for antiglaucoma medications. Goniotomyab interno is a surgical option for glaucoma that is aseffective as trabeculectomy in lowering IOP but withfewer complications.

In all ab externo surgical techniques, penetrating ornonpenetrating, there is a possibility that fibroblastsfrom the conjunctiva can migrate into scleral tissueand proliferate there to block filtration channels.Goniotomy, which is penetrating surgery with an abinterno transcameral approach, prevents this risk andrestores effective internal filtration through internalepiscleral and uveoscleral channel.

Goniotomy ab interno circumvents the trabecularmeshwork resistance by creating a drainage canal in thesclera, where four sclerectomy sites are created using aspecial Fugo blade. These sites are called “Thalami”from the Latin word for “inner chamber.”

DHARMENDRA SINGH, MD,RAJENDRA BUNDELA, MD,ARCHITA AGARWAL, MD,H. K. BIST, MD,S. K. SATSANGI, MD

R E P R I N T SDr. Dharmendra Singh, Department of Ophthalomology, S.N. Medical College,Agra, India 282-003. E-mail: RJFugomd@Fugoblade.com.

Drs. Singh, Bundela, Agarwal, Bist, and Satsangi are from the Department ofOphthalmology, S.N. Medical College, Agra, India.

The authors have stated that they do not have a significant financial interestor other relationship with any product manufacturer or provider of servicesdiscussed in this article. The authors also do not discuss the use of off-labelproducts, which include unlabeled, unapproved, or investigative productsor devices.

Submitted for publication: 4/9/06. Accepted: 4/17/06.

Annals of Ophthalmology, vol. 38, no. 3, Fall 2006© Copyright 2006 by ASCO All rights of any nature whatsoever reserved. 1530–4086/06/38:213–217/$30.00. ISSN 1558–9951 (Online)

O R I G I N A L A R T I C L E

Goniotomy Ab Interno “A Glaucoma FilteringSurgery” Using The Fugo Plasma Blade

A B S T R A C T

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The instrument used is Fugo Plasma Blade (Fig. 1),which is an electrosurgical device, which ablates tissuewithout thermal damage.

MATERIALS AND METHODSThe study was conducted on 16 eyes of 16 patients attend-ing the outpatient Department of Ophthalmology, S.N.Medical College and Hospital in Agra, India, from July2005 to December 2005. Because the technique was new,only patients with absolute glaucoma (compromised visualstatus) were considered. Preoperative evaluation includedage, gender, detailed clinical history with general physicaland systemic examination, record of previous/currentantiglaucoma therapy, slit-lamp biomicroscopy, ophthal-moscopy, intraocular tension by Schiötz tonometry/non-contact tonometery, and gonioscopy.

After topical anesthesia and eye speculum application,a 0.9-mm clear nasal Bent incision at limbus was per-formed. The anterior chamber was then maintained withviscoelastic. A 100-µ Fugo Blade tip was inserted intothe anterior chamber directed to opposite side toward theangle (Fig. 2). The operating field was visualized using afour-mirror goniolens. Using the tip of the probe, four0.3-mm-deep and 0.6-mm-wide sclerectomy sites werecreated (Fig. 3). The tip of probe was withdrawn and vis-coelastic was washed from the anterior chamber.

Postoperatively, antibiotic steroid and pilocarpine areadministered for 10 days. Patients are discharged on firstpostoperative day and assessed at 1 week, 3 weeks,6 weeks, 12 weeks, and 6 months. Postoperative evalua-tion consisted of slit-lamp biomicroscopy, ophthal-moscopy, and IOP measurement (Schiötz/non-contacttonometry). Success was defined as an IOP less than orequal to 21 mmHg.

RESULTSThe study included 16 eyes of 16 patients. Patients weredistribution with respect to age and sex as shown in Table 1.

A 6-month follow-up was performed. The meanpreoperative IOP was 53.58 mmHg range (41.5–64 mmHg). The average postoperative IOP at eachfollow-up visit is detailed in Table 2. Mean postopera-tive IOP at day 1 was 20.25 mmHg (p < 0.01); on fur-ther follow-up there was no significant difference inIOP, which settled to a mean 17.30 mmHg at 6 months.These results show that significant reduction wasachieved at day 1 and we were able to maintain the IOPwithin desirable limits at 6-month follow-up without anyantiglaucoma medication. The results are well displayedin line diagram (Fig. 4) and bar chart (Fig. 5).

As shown in Table 3, we were able to achieve 70–80%reduction in IOP from preoperative levels in 50% of cases.A success rate of 87.5% was obtained. Two cases wererendered failure (IOPs at 6 months were 31.6 and 24.4mmHg). No major complications were encountered duringthe study, as evidenced by Table 4.

Figure 1––Fugo Plasma Blade consisting of console, handpiece, and disposable tip.

Figure 2––A 100-µ Fugo Tip directed to opposite side towardangle.

Figure 3––Using four-mirror goniolens, sclerectomy sites arecreated in trabecular network.

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DISCUSSIONThe usual progression of treatment in primary open-angle glaucoma (POAG) is medical therapy followed bylaser trebeculoplasty, then filtering surgery. Several trialshave shown that filtering surgery is more effective thanmedical therapy.

Trabeculectomy as a filtering surgery has manydrawbacks, one being failure of bleb. Skuta et al.(1887), Panish et al. (1987), and Alvarado et al.(1989) reported that failure of bleb is triggered byproliferation of fibroblasts from the tissue surround-ing the fistula, especially vascularized soft connectivetissue. Other important complications, which have ledto decreased popularity in trabeculectomy is theoccurrence of hypotony. One approach to minimizepostoperative scarring is an ab interno goniotomyapproach, using the Fugo Blade. Because the abinterno approach prevents fibroblast migration fromthe conjunctive, fibrosis does not occur. Unlike tra-beculectomy and deep sclerectomy, ab interno is rarelythe cause of postoperative hypotony. One case wasobserved during this study, probably because of a tran-sient interruption of aqueous humor secretion, whichlasted 4 days. Moreover, goniotomy ab interno is

TABLE 1

Patient Distribution

Age group Male Female

35–45 2 246–55 5 256–65 4 1Total 11 5

Figure 4––Line diagram showing distribution of postoperative intraocular pressure.

Figure 5––Bar diagram showing distribution of postoperative intraocular pressure.

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performed in shorter surgical time. Although tra-beculectomy takes at least 30 minutes, goniotomy abinterno can be carried out in about 5 minutes and it ismuch easier to learn and to perform. Patients can be

discharged on the same day. If goniotomy ab internofails, patients can still be treated because this mini-mally invasive surgery leaves the opportunity forother procedures.

The advantage of goniotomy ab interno lies in itsshorter surgical time, early rehabilitation, high efficacy,and the use of the Fugo Plasma Blade, which employsplasma energy for ablating the incision path in tissue.This plasma ablates in such a fashion that it creates asmooth wall along the ablation path. The Fugo PlasmaBlade also has an important function of non-cauterizinghemostasis in cut tissue.

CONCLUSIONAlthough goniotomy ab interno is a new technique, theinitial results are encouraging. Hence, it offers a

TABLE 3

Distribution of Cases According to Reduction of Intraocular Pressure (% Cases)

Reduction (%) 1st day 1week 3 week 6 week 12 week 6 monthsof IOP from of cases of cases of cases of cases of cases of cases

preoperative (%) (%) (%) (%) (%) (%)

Upto 50 6.25 6.25 0.00 6.25 0.00 0.0050–60 37.50 25.00 18.75 18.75 18.75 12.5060–70 43.75 50.00 50.00 50.00 43.75 37.5070–80 6.251 2.50 31.25 25.00 37.50 50.0080–90 6.25 6.25 0.00 0.00 0.00 0.00

TABLE 4

Complications

Complication No. of patients

Subconjunctival hemorrhage 0Hyphema 3Hypotony 1Shallow anterior chamber 0Corneal edema 0

TABLE 2

Mean and t value of Intraocular Pressure Preoperatively and at Postoperative Follow-Upa

Pre-operative Post-operative

1st day 1 week 3 week 6 week 12 week 6 months

N 16 16 16 16 16 16 16Mean 53.58 20.25 19.51 18.48 18.47 18.03 17.30SD 7.922 6.228 5.505 4.582 4.911 4.551 4.424

t-test for difference in mean between

Pre-op Pre-op Pre-op Pre-op Pre-op Pre-op1st day 1 week 3 week 6 week 12 week 6 months

t value 13.231 14.126 15.341 15.069 15.567 15.994Probability p < 0.01 p < 0.01 p < 0.01 p < 0.01 p < 0.01 p < 0.01

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promising alternative to conventional trabeculectomyand definitely deserves consideration of glaucoma sur-geons for further evaluation.

REFERENCESAddicts EM et al. Histological characteristic of filtering blebs in glau-comatous eyes. Arch Ophthalmol 1983; 101: 795.

Bojan P. Goniotomy ab interno a minimally invasive surgical optionfor glaucoma. Ocular Surg News Europe/Asia Pacific 2005; 16: 5–6. Shields MB. Shield’s Textbook of Glaucoma, 4th Edition. Philadel-phia, PA: Lippincott, Williams and Wilkins, 1998.Skuta GL, Panish RK II. Wound healing in Glaucoma filteringsurgery. Ophthalmology 1987; 149: 170.Watson P. Trabeculectomy and modified ab externo technique. AnnOphthalmol. 1990; 2: 199.Winn MC. Broad application seen for plasma blade. Ocular SurgNews Asia Pacific 2001; 12: 1–5.