A randomised, prospective study comparing trabeculectomy with viscocanalostomy with adjunctive antimetabolite usage for the management of open angle glaucoma uncontrolled by medical therapy

AIMS

To compare trabeculectomy with viscocanalostomy augmented with adjunctive antimetabolite use for the control of intraocular pressure (IOP) in open angle glaucoma (OAG).

METHODS

45 patients (50 eyes) with uncontrolled OAG were randomised to either trabeculectomy (25 eyes) or a viscocanalostomy technique (25 eyes). Preoperatively, all eyes were graded in terms of risk factors for drainage failure and were given intraoperative antimetabolites (5-fluorouracil 25 mg/ml (5-FU), mitomycin C (MMC) 0.2 mg/ml and 0.4 mg/ml) according to a standard protocol.

RESULTS

There were no significant differences between the groups in age, sex, type of OAG, preoperative medications, risk factors for drainage failure, and preoperative IOP. Mean follow up was 20 months (range 3-24 months). It was 12 months or longer in all eyes, except two lost to follow up at 3 months. At 12 months, complete success (IOP<21 mm Hg without antiglaucoma medications) was seen in 91% of eyes undergoing trabeculectomy, but in only 60% of eyes undergoing viscocanalostomy (p<0.02). Similarly, at the last follow up visit (mean 20 months) complete success was seen in 68% of eyes undergoing trabeculectomy and 34% with viscocanalostomy (p<0.05). In terms of qualified success (IOP<21 mm Hg with or without glaucoma medications) and mean IOP measurements postoperatively there were no difference between the groups, although the mean number of antiglaucomatous medications required postoperatively was less with trabeculectomy (0.39) than viscocanalostomy (1.04) (p<0.05). Needling procedures were more commonly required after trabeculectomy (p<0.02). YAG goniotomy was required in three eyes (13%) after viscocanalostomy. Early transient complications such as anterior chamber shallowing and encysted blebs were more common in the trabeculectomy group (p<0.05). Late postoperative cataract formation was similar between the two groups.

CONCLUSION

In terms of complete success and number of antiglaucomatous medications required postoperatively, IOP control appears to be better with trabeculectomy. Viscocanalostomy is associated with fewer early transient postoperative complications.

Prospective study comparing lidocaine 2% jelly versus sub-Tenon's anaesthesia for trabeculectomy surgery

AIMS

To compare the analgesic properties of lidocaine 2% jelly versus sub-Tenon's anaesthesia with lidocaine 2% without adrenaline (epinephrine) for trabeculectomy surgery.

METHODS

A prospective randomised clinical trial. 59 consecutive patients scheduled for trabeculectomy at the Toronto Western Hospital were randomly assigned to topical unpreserved lidocaine 2% jelly or sub-Tenon's anaesthesia with 2% lidocaine. Both groups received a standardised sedative consisting of midazolam, fentanyl. and/or propofol. The visual analogue scale was utilised to measure intraoperative pain. Patient comfort, physician assessment of intraoperative patient compliance, volume of local anaesthetic used, need for supplemental anaesthesia, and any complications were recorded. The two groups were compared using the Student's t test.

RESULTS

The sub-Tenon's anaesthesia group and the lidocaine 2% jelly group did not vary significantly in subjective pain score (18.3 (SD 16.2) v 19.8 (12.4) respectively, p = 0.739) and surgeons' satisfaction scale (3.6 (0.7) and 3.8 (0.6) respectively, p = 0.328). Four patients required additional anaesthesia, all of them in the sub-Tenon's group.

CONCLUSION

Topical lidocaine 2% jelly is as effective as sub-Tenon's anaesthesia for pain control in patients undergoing trabeculectomy. Lidocaine 2% jelly is similar to sub-Tenon's anaesthesia in patient comfort and surgeon satisfaction.

Long-term Outcome of Trabeculotomy for the Treatment of DevelopmentalGlaucoma

OBJECTIVE

To elucidate long-term outcome of trabeculotomy in primary and secondary developmental glaucoma.

METHODS

One hundred forty-nine eyes of 89 patients with developmental glaucoma who underwent trabeculotomy were retrospectively studied. Intraocular pressure (IOP), success probabilities, visual acuities, and visual field were determined during follow-up and at the final visit.

RESULTS

The mean +/- SD IOP of 112 eyes with primary developmental glaucoma at the final visit with an mean +/- SD follow-up period of 9.5 +/- 7.1 years was 15.6 +/- 5.0 mm Hg. The average IOP for 37 eyes with secondary developmental glaucoma was 16.7 +/- 4.2 mm Hg. One hundred eyes (89.3%) with primary developmental glaucoma were defined as achieving success at the final visit. Complete and qualified successes were achieved in 71 eyes (63.4%) and 29 eyes (25.9%), respectively. Visual acuities were 20/40 or better in 78 (59.5%) of 131 eyes examined and were poorer than 20/200 in 32 eyes (24.4%). The causes of poor visual acuities were mainly progression of glaucoma, including delay of detection of onset or surgery and amblyopia. Eyes with glaucoma that existed before 2 months of age or eyes that needed several trabeculotomies were considered to have poor visual acuity. Visual fields were classified as normal or almost normal in 21 (44.7%) of 47 eyes.

CONCLUSIONS

Trabeculotomy for developmental glaucoma is effective over a long time. There is a fairly good prognosis for visual function of eyes with developmental glaucoma with early detection of the onset, proper treatment, and proper management after trabeculotomy.

Trabeculectomy--a review and 2 year follow up

This study reviewed the trabeculectomies (TEs) carried out in University Malaya Medical Center between 1994 to 1998. One hundred and nine of 132 eyes operated were in the primary glaucoma group of which 63 (47.7%) were of the open angle type and 46 (34.8%) were of the angle closure type. Twenty-three eyes belong to the secondary glaucoma group. Sixty-five eyes had plain or non-augmented trabeculectomy (TE) while 20 were augmented with mitomycin C (MMC) and 11 with 5 flourouracil (5FU). In 31 eyes the plain TEs were combined with extracapsular cataract extraction (ECCE) and 4 with phacoemusification. One case had combined ECCE and augmented trabeculectomy with mitomycin-C. The patients were followed up at 1 month, 6 months, 1 year and 2 years. Ninety-four of 132 (71.2%) eyes had successful surgery with intraocular pressure (IOP) of less than 21 mmHg (tonometric success) at the end of 2 years. Four of these patients needed topical medication for the IOP control. More failures were seen in patients with cystic blebs than those with diffuse blebs. Complications include hypotony, shallow anterior chamber, cataracts and hyphaema. The majority of cases (53%) had no complications.

Phacotrabeculectomy in Treatment of Primary Angle-closure Glaucoma and Primary Open-angle Glaucoma

PURPOSE

To evaluate the surgical outcome of combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy (phacotrabeculectomy) in patients with primary angle-closure glaucoma (PACG) or primary open-angle glaucoma (POAG).

METHODS

The records of 57 consecutive patients (65 eyes) with PACG or POAG that were treated with phacotrabeculectomy were reviewed retrospectively. There were 31 eyes with PACG and 34 with POAG. The mean follow-up period was 21.0 +/- 8.3 months. The visual acuity, intraocular pressure (IOP), number of medications, and complications were evaluated.

RESULTS

The mean IOP and the number of glaucoma medications decreased significantly after phacotrabeculectomy in both groups. The mean IOP reduction was significantly greater in eyes with PACG (P < 0.05). The absolute success rates were 87.1% and 70.6% in PACG and POAG, respectively. The difference in the success rates was not significant (P = 0.297). The early postoperative complication rates were similar in both groups.

CONCLUSIONS

Phacotrabeculectomy results in greater IOP reduction in eyes with PACG than in those with POAG, but the overall success rates were not significantly different.

Milling trabeculoplasty for nonpenetrating glaucoma surgery

PURPOSE

To describe the use of a motorized milling drill to perform nonpenetrating glaucoma surgery and to assess its safety.

SETTING

Instituto Oftalmológico de Alicante, Miguel Hernandez University, School of Medicine, Alicante, Spain.

METHODS

This prospective noncomparative study included 16 eyes (13 patients) diagnosed with primary open-angle glaucoma. The eyes were divided into 2 groups. Group 1 (8 eyes) had a milling procedure, and Group 2 (8 eyes) had combined phacoemulsification and milling. A fornix-based conjunctival flap was created, and then the milling procedure was performed using a notched hemispherical metallic tip. Evolution of intraocular pressure (IOP), visual outcomes, and the development of intraoperative and postoperative complications were evaluated.

RESULTS

The mean age of the patients was 67.9 years +/- 10.9 (SD) (range 50 to 80 years). In Group 1, the mean IOP preoperatively was 27.6 +/- 10.1 mm Hg (range 18 to 50 mm Hg) and after 6 months, 15.8 +/- 5.2 mm Hg (range 12 to 24 mm Hg). The mean IOP reduction 6 months postoperatively was 15.4 +/- 10.6 mm Hg, a 55.7% decrease from preoperatively. In Group 2, the mean IOP preoperatively was 21.7 +/- 4.6 mm Hg (range 13 to 30 mm Hg), and after 6 months, 16.2 +/- 3.4 mm Hg (range 13 to 23 mm Hg). The mean reduction in IOP at 6 months was 5.5 +/- 2.8 mm Hg, a decrease of 25.3% from the preoperative value. In Group 1 at 6 months, 5 eyes (62.5%) had a diffuse filtering bleb and 3 (37.5%), localized filtration. In Group 2, 7 eyes (87.5%) had a diffuse filtering bleb and 1 (12.5%) had fibrosis of the bleb and reduction of filtration.

CONCLUSION

The motorized milling drill can be safely used to mill and refine the remaining scleral thickness, eliminating the rupture of trabeculo-Descemet's membrane.

Fornix vs limbus based flap in phacotrabeculetomy with mitomycin C: prospective study

AIM

To compare the efficacy and safety of fornix-based and limbus-based conjunctival flaps of phacotrabeculectomy with mitomycin C in patients with primary open angle glaucoma and cataract.

METHODS

The study included 16 patients (6 men and 10 women) with primary open angle glaucoma and bilateral cataract. In each patient, phacotrabeculectomy with mitomycin C was performed on both eyes: the eye first operated received a fornix-based conjunctival flap, whereas the fellow eye was assigned to the limbus-based group. We compared preoperative and postoperative visual acuity, intraocular pressure, number of antiglaucoma medications, and postoperative complications between flap-based and limbus-based groups.

RESULTS

There was no difference in the decrease in the mean intraocular pressure between the fornix-based and limbus-based groups after phacotrabeculectomy: from 22.1+/-4.4 mm Hg to 16.2+/-3.4 mm Hg in the fornix-based group, and from 22.4+/-4.5 mm Hg to 15.9+/-3.2 mm Hg in the limbus-based group. The two groups also did not differ in the number of medications received either before or after the surgery. Early bleb leak was observed only in the fornix-based group (2 eyes).

CONCLUSIONS

Phacotrabeculectomy with intraoperative mitomycin C was successful in regard to both reduction of intraocular pressure and glaucoma medications. There was no difference in the safety or efficacy of the procedure between groups receiving either fornix- or limbus-based flap, except for the early bleb leak, which was observed only in the fornix flap group.

Comparison between Results of Trabeculectomy in Primary Congenital Glaucoma with and without the Use of Mitomycin C

PURPOSE

To evaluate the results of trabeculectomy with and without the use of mitomycin C in children with primary congenital glaucoma.

METHODS

The authors retrospectively studied the data of 91 patients who underwent the first trabeculectomy for primary congenital glaucoma, with 19 years of follow-up. Success criteria were set with two distinct values of intraocular pressure: lower or equal to 15 mm Hg or lower than 21 mm Hg and separately analyzed.

RESULTS

Among the studied patients, 61 had undergone trabeculectomy without mitomycin C and 30 with mitomycin C. The comparison between the groups of patients showed age homogeneity (P = 0.152) and did not demonstrate any difference in preoperative (P = 0.234) and postoperative (P = 0.907) intraocular pressure. Success rates through time, for both pressure limits was not different between the groups. Both age and the presence of previous trabeculotomy did not influence the success of trabeculectomy through time, for the two pressure limits considered. The complication rate was higher among the patients who received mitomycin C (P = 0.010).

CONCLUSIONS

The success of trabeculectomy for primary congenital glaucoma with mitomycin C was not different than that of trabeculectomy with mitomycin C in the studied patients. Mitomycin C was associated with a higher incidence of complications.

Selective vs argon laser trabeculoplasty: hypotensive efficacy, anterior chamber inflammation, and postoperative pain

PURPOSE

To compare selective laser trabeculoplasty (SLT) with conventional argon laser trabeculoplasty (ALT) in terms of hypotensive efficacy, anterior chamber inflammation, and pain reported by the patients treated.

METHODS

A prospective study performed on 40 consecutive patients. Group I (n = 20): SLT 180 degrees. Group II (n = 20): ALT 180 degrees. Intraocular pressure, flare (Laser-Flare-Meter, Kowa FM-500, Japan), and pain (Visual Analogue Scale) were measured before treatment and 1 h, 24 h,1 week, and 1, 3 and 6 months after treatment. Statistically significant differences were determined by an independent-sample Student's t-test.

RESULTS

At 6 months after treatment, pressure reduction was similar in both groups: SLT 22.2% (range 0-36.3%) and ALT 19.5% (range 0-30.2%), P= 0.741. The energy released during treatment was significantly lower in SLT (48.3 SD 7.4 mJ) than in ALT (4321 SD 241.7 mJ), P < 0.001. At 1 h after treatment,anterior chamber flare was also lower in SLT(13.3 SD 6.3 vs 20.7 SD 7.4 photons/ms),P = 0.003. Pain reported by the patients during the treatment was significantly lower in SLT(2.0 SD 0.7 vs 4.3 SD 1.3), P<0.001.

CONCLUSIONS

The hypotensive efficacy of both lasers at the end of follow-up was similar. The energy released during treatment and inflammation produced in the anterior chamber in the immediate postoperative period were significantly lower for SLT. The SLT procedure was better tolerated, producing less discomfort during treatment than conventional trabeculoplasty with argon.

[Clinical observation of the combination of phacoemulsification and trabeculectomy]

OBJECTIVE

To evaluate the therapeutic effects of combined phacoemulsification and trabeculectomy surgery with intraocular lens implantation and compare the results of two different approaches.

METHODS

In a retrospective study, forty eyes of 35 cases cataract patients with primary open-angle or chronic angle-closure glaucoma were assigned to undergo either a single incision (single incision group, 15 eyes) or two-incision (double incision group, 25 eyes). best-corrected visual acuity (BCVA), pre-and post-operation intraocular pressure (IOP), postoperative bleb formation and postoperative complications were analyzed and compared between the two procedures. All cases were followed up for over 12 months.

RESULTS

The mean IOP of 35 cases (40 eyes) in 12 months postoperatively was (14.35 +/- 3.03) mm Hg (1 mm Hg = 0.133 kPa), which was distinctly lower than that of preoperative [(35.76 +/- 4.39) mm Hg (t = 25.39, P < 0.001)]. There was no significant difference between the two groups in the mean IOP preoperation and 1 week, 1 month, 3, 6, 12 months postoperation. The postoperative BCVA was between 0.2 and 1.2, BCVA < 0.3 was found in three eyes (7.5%), and > or = 0.3 in 37 eyes (92.5%), BCVA was significantly improved in 4 eyes after surgery (chi(2) = 31.03, P < 0.001). There was no obviously difference in visual acuity between the two groups at one week, 3 months postoperatively (chi(2) = 0.22, and 0.05, P > 0.05), the type I or II bleb formation was detected in 35 eyes (87.5%). Post operation, among the eyes, 13 eyes were single-incision while 22 eyes with double-incision. No severe postoperative complications were revealed in all of operated cases.

CONCLUSIONS

The procedures of combined phacoemulsification with trabeculectomy is safe, effective surgery for cataract patients combined with glaucoma. There were no differences in IOP, BCVA developing, bleb formation in early stage postoperatively using either single-incision or double-incision.

Pseudoexfoliation syndrome and pseudoexfoliative glaucoma

BACKGROUND

Pseudoexfoliative glaucoma (PXG) is a common secondary glaucoma that occurs when pigment and abnormal basement membrane material from anterior segment anatomical structures deposit in the trabecular meshwork. This anomaly arises from the predisposing condition, pseudoexfoliation syndrome (PXE). Complications are common, making this one of the most difficult glaucomas to manage.

PURPOSE

The literature is reviewed in order to facilitate understanding of this condition.

[Clinical observation of combined surgery for cataract and glaucoma: phacoemulsification and viscocanalostomy]

OBJECTIVE

To evaluate the therapeutic effects and safety of phacoemulsification-intraocular lens (IOL) implantation combined with viscocanalostomy (V-P) and compared the outcomes of phacoemulsification-IOL implantation combined with trabeculectomy (T-P).

METHODS

Combined phacoemulsification with corneal incision, foldable intraocular lens implantation and viscocanalostomy was performed in 30 eyes of 28 cataract patients with primary open-angle glaucoma.

RESULTS

Follow-up was performed up to 6 months after surgery. The mean intraocular pressure (IOP) of V-P group was (14.65 +/- 2.70) mm Hg (1 mm Hg = 0.133 kPa) with a mean pressure reduction of 10.33 mm Hg compared with IOP before the operation (P = 0.000). There were no statistical differences of the IOP within two groups during postoperative 1 week, 1 and 6 month (P = 0.661, 0.381, 0.526). Postoperatively, the best corrected visual acuities of V-P group were > or = 0.5 in 18 eyes (follow-up 29 eyes, 62.1%), 20 eyes (28 eyes, 71.4%), 24 eyes (30 eyes, 80.0%) at 1 week, 1 month and 6 months, but no statistical difference with T-P group, (P = 0.621, 0.702, 0.893). Complications of V-P group included: Descemet's membrane puncture 2 eyes (6.7%), Schlemm's tube puncture 2 eyes (6.7%) and IOP spikes 4 eyes (13.3% at 24 hours postoperatively). The V-P group showed a significantly less inflammation, hyphema and choroidal detachment than that in the T-P group.

CONCLUSIONS

Phacoemulsification-IOL implantation combined with viscocanalostomy is a safe and efficacious surgery with lower complications.

The Advanced Glaucoma Intervention Study (AGIS): 13. Comparison of treatment outcomes within race: 10-year results

OBJECTIVE

To present for black and white patients with medically uncontrolled glaucoma 10-year results of treatment with 1 of 2 randomly assigned surgical intervention sequences.

DESIGN

Randomized clinical trial.

PARTICIPANTS

Three hundred thirty-two black patients (451 eyes) and 249 white patients (325 eyes). Eyes had glaucoma that could not be controlled with medications alone.

METHODS

Eyes were randomly assigned to 1 of 2 sequences: argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy (ATT) or trabeculectomy-ALT-trabeculectomy (TAT). Second and third interventions were offered after failure of the preceding intervention. Minimum required intraocular pressure (IOP) for intervention failure ranged upward from 18 mmHg, the value depending on whether recent optic disc or visual field (VF) deterioration occurred, and on the magnitude of the field defect. Patients were observed every 6 months, with total potential follow-up ranging from 8 years, 4 months to 13 years.

MAIN OUTCOME MEASURES

The averages over follow-up of (1) the percentage of eyes having moderate loss of VF and (2) the percentage of eyes having moderate loss of visual acuity (VA).

RESULTS

Race-treatment interactions in VF and VA loss are significant for the 2 main outcome measures; therefore, results of treatment sequence differences are presented by race. In black patients the average percent of eyes with VF loss was less in the ATT sequence than in the TAT sequence, a difference that is not statistically significant at any visit. In white patients, conversely, after 18 months the average percent of eyes with VF loss was less in the TAT sequence, a difference that increases and is statistically significant in years 8 to 10. In both black and white patients, the average percent of eyes with VA loss was less in the ATT sequence; this difference is statistically significant throughout 10 follow-up years in black patients and is statistically significant only for the first year in white patients. In both black and white patients, average IOP reductions were greater in the TAT sequence, though the TAT-ATT difference was substantially greater in white patients. In both black and white patients, first-intervention failure rates were substantially lower for trabeculectomy than for trabeculoplasty. Ten-year cumulative incidence of unilateral VF impairment comparable to legal blindness was modest in eyes of black (ATT 11.9%, TAT 18.5%) and white (ATT 9.9%, TAT 7.3%) patients.

CONCLUSIONS

Although IOP was lowered in both sequences in black and white patients with medically uncontrolled glaucoma, long-term visual function outcomes were better for the ATT sequence in black patients and better for the TAT sequence in white patients.

Outcome of consecutive trabeculectomy

PURPOSE

To establish a criterion for success of primary phakic trabeculectomy in the second eye of the same patient, using the first operated eye as a predictor for the surgical outcome.

METHODS

The outcome of primary phakic trabeculectomy was retrospectively compared in both eyes of 23 patients. Sixteen patients were treated with antimetabolites and seven were not. Postoperative intraocular pressure and number of glaucoma medications in paired eyes of the same patients were compared. Surgical success was defined as postoperative IOP of <20 mmHg without medication. Bleb morphology and the number of glaucoma medications were also compared in both eyes.

RESULTS

There was a positive correlation between the two eyes of a patient in the IOP values at each postoperative time point in both groups (with and without antimetabolites) (P > 0.05). At the last follow-up visit after trabeculectomy, the number of glaucoma medications used in paired eyes were not significantly different (P > 0.83). Surgical failure occurred more often in paired eyes than in single eyes. Bilateral failure occurred in 60% (3/5) of the failed trabeculectomies with antimetabolites and in 100% (3/3) of the failed trabeculectomies without antimetabolites.

CONCLUSION

Trabeculectomy outcome in paired eyes of patients was similar in both antimetabolites treated and untreated eyes. Thus, trabeculectomy outcome in the first operated eye can predict the surgical result in the second eye of the same patient.

Long-term evaluation of trabeculectomy in primary open angle glaucoma and chronic primary angle closure glaucoma in an Asian population

PURPOSE

A retrospective cohort study was undertaken to evaluate and compare the long-term results of trabeculectomy in primary open angle glaucoma (POAG) and chronic primary angle closure glaucoma (CPACG) in an Asian population.

METHODS

Yearly diurnal measurements of intraocular pressure (IOP), best-corrected visual acuity, optic disc and visual field records of patients having primary adult glaucomas who had undergone trabeculectomy, without anti-mitotic agents, with a minimum of 5 years follow up were evaluated. Only one eye of each patient was studied. The success rates for IOP control in POAG and CPACG were statistically analysed.

RESULTS

Sixty-four eyes of 64 patients were studied. The overall probability of success of trabeculectomy in controlling IOP to < or = 21 mmHg with or without additional topical antiglaucoma medication was 0.94 and 0.88 at 5 and 10 years, respectively. There was no statistically significant difference in the qualified and absolute success rates for IOP control between POAG and CPACG eyes (log rank test P= 0.6, 0.88, respectively). Twelve of 38 CPACG eyes had a two-line decrease in visual acuity as compared to four of 26 POAG eyes (P = 0.17). Progression or development of a cataract was the most common cause of visual decline.

CONCLUSIONS

Trabeculectomy without antimetabolite use appears to be efficacious in lowering IOP and in visual field preservation over a period of 10 years in both POAG and CPACG. Development/progression of cataract especially in eyes with chronic angle closure glaucoma after trabeculectomy must be considered an important issue.

Factors for progression and glaucoma treatment: The Early Manifest Glaucoma Trial

PURPOSE OF REVIEW

This review summarizes factors for progression in the Early Manifest Glaucoma Trial (EMGT), including the effect of treatment. EMGT randomized patients with early glaucoma either to argon laser trabeculoplasty plus betaxolol (n = 129) or to no immediate treatment (n = 126) and followed them every 3 months.

RECENT FINDINGS

Treated patients had delayed progression, as compared with controls. In Cox regression, EMGT treatment halved the risk of progression (hazard ratio = 0.50; 95% confidence interval: 0.35, 0.71). Risk decreased about 10% with each millimeter mercury of intraocular pressure (IOP) reduction from baseline; the higher (or lower) the IOP at follow-up, the higher (or lower) the risk. Baseline factors increasing progression were higher IOP, exfoliation, bilateral disease, worse perimetric mean deviation and older age; frequent disc hemorrhages at follow-up also increased risk.

SUMMARY

EMGT treatment reduced progression risk in half, demonstrating the value of IOP lowering in early glaucoma. Age and indicators of disease severity also predicted progression.

Acute ultrastructural changes of the trabecular meshwork after selective laser trabeculoplasty and low power argon laser trabeculoplasty

BACKGROUND AND OBJECTIVES

To compare the histopathological changes in the human trabecular meshwork after low power argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT) with a Q-switched, frequency-doubled, neodymium:yttrium-aluminium-garnet (Nd:YAG) laser.

STUDY DESIGN/MATERIALS AND METHODS

In gonioscopically normal trabecular meshwork of three patients awaiting enucleation due to malignant melanoma of the choroid, SLT and ALT were performed 1-5 days prior to enucleation. In each eye, the lower half of trabecular meshwork received SLT, one quadrant low power (460 mW) ALT and one quadrant was left untreated. Specimens were evaluated with light and transmission electron microscopy.

RESULTS

A sharp demarcation line was visible between the laser treated and untreated intact trabecular meshwork after ALT and SLT. Both lasers caused disruption of trabecular beams, but the extent of the damage was smaller after SLT. The collagen component of trabecular beams was mostly amorphous, the long-spacing collagen was scanty after ALT, but more abundant after SLT. In the intertrabecular spaces fragmented cells and tissue debris with only a few pigmented cells were observed. Some endothelial cells were desquamated, but appeared slightly better preserved after SLT than ALT.

CONCLUSIONS

Our ultrastructural comparison of the morphological changes after low power ALT and SLT in patients demonstrated that both lasers caused splitting and fragmentation of the trabecular beams of the trabecular meshwork, but the extent of the damage was smaller and the preservation of long-spacing collagen better after SLT than after ALT.

A comparative study of small incision trabeculectomy avoiding Tenon's capsule vis-à-vis trabeculectomy with Mitomycin-C

PURPOSE

To compare the results of small incision trabeculectomy avoiding Tenon's capsule (SIT) vis-à-vis intraoperative use of Mitomycin-C (MMC) in primary chronic angle closure glaucoma.

METHODS

A controlled prospective study was conducted on 60 consecutive primary chronic angle closure glaucoma patients requiring glaucoma filtration surgery. Patients were divided into two groups, Group I (n = 30): those undergoing SIT and Group II (n = 30): those undergoing trabeculectomy with MMC. Patients were followed up serially for 24 months and their intraocular pressure (IOP) was monitored. Success was defined as IOP < or = 22 mm Hg with no additional anti-glaucoma medication or laser/surgical intervention. Success was also defined as a 30% reduction from the initial IOP at which optic disc cupping and/or visual field changes occurred.

RESULTS

The final mean IOP with SIT was 16.80 +/- 4.20 mm Hg as against 17.84 +/- 3.80 mm Hg with trabeculectomy with MMC. Final success rate of 93.3% was obtained with SIT versus 90% with trabeculectomy with MMC. No major complications were seen with either procedure.

CONCLUSION

Small incision trabeculectomy safely and effectively reduces the IOP in over 90% cases. The advantages of this procedure over trabeculectomy with MMC are its low cost, use of a small (2.5 mm) limbal incision which obviates the dissection of Tenon's capsule and absence of any major complication.

Combined trabeculectomy and vitrectomy for pseudophakic malignant glaucoma and extensive peripheral anterior synechia-induced secondary glaucoma

We report combined trabeculectomy and vitrectomy in a 66-year-old woman with combined-mechanism glaucoma. Trabeculectomy supplemented with mitomycin-C was done first. Before the scleral and conjunctival flap were sutured, an anterior vitrectomy was performed via the peripheral iridectomy until a pathway between the anterior chamber and aqueous pool in the vitreous cavity was established. One day postoperatively, the intraocular pressure (IOP) was 10 mm Hg. Six months later, the IOP was 13 mm Hg and the bleb remained formed.