Laser suture lysis after mitomycin C trabeculectomy

The Japan Glaucoma Society guidelines for glaucoma 5th edition

We are pleased to bring you the 5th edition of the Glaucoma Clinical Practice Guidelines. Clinical practice guidelines are based on evidence (scientific grounds). It is a document that presents the treatment that is the most appropriate for the patient. "Glaucoma Clinical Guidelines" was first published in 2003. This was the first guideline for glaucoma treatment in Japan. The principle of glaucoma treatment is to lower intraocular pressure. Means for lowering intraocular pressure includes drugs, lasers, and surgery; Glaucoma is a disease that should be considered as a complex syndrome rather than a single condition. Therefore, the actual medical treatment is not as simple as one word. This time we set the Clinical Questionnaire with a focus on glaucoma treatment. We hope that you will take advantage of the 5th edition.

Parallel Suture: A Simple Approach to Enable Early Laser Suture Lysis and Prevent Hypotony after Trabeculectomy

PURPOSE

To define a modified flap suture approach and evaluate its effectiveness.

METHODS

Clinical data of patients undergoing trabeculectomy with modified parallel suture technique (Group 1, N = 38 eyes) were compared to patients operated with classical flap suture technique (Group 2, N = 42 eyes). In the modified technique, two parallel sutures (one tight and one loose) are placed simultaneously in one of the flap corners with the aim of obtaining a safety stitch when the tight one needs to be cut. Data from preoperative and postoperative visits at day 1, week 1, months 1, 3, 6 and year 1 were recorded from patient charts and compared between the groups.

RESULTS

In Group 1, seven eyes underwent laser suture lysis (LSL) between postoperative days 2 to 8 and in Group 2 two eyes at days 29 and 37. No complication related to LSL was observed. Rate of postoperative hypotony decreased with the parallel suture approach (P= .002). Number of eyes experiencing any of the complications related to hypotony was lower in Group 1 (P= .004). No significant difference was noted in the mean IOP between the groups (P> .05 for all).

CONCLUSION

The modified approach with parallel suture technique was found to be effective and safe. By enabling early LSL, it provided more precise IOP modulation in the early postoperative period. Thus, in our series, the rate of hypotony and hypotony-related complications decreased, while the success of the surgery was preserved.

Combined Visco-Trab operation: A dual filtration pathway for management of advanced glaucoma-midterm results

PURPOSE

To study midterm efficacy and safety of combined Visco-Trab operation for management of advanced glaucoma.

METHODS

168 eyes of 148 patients with advanced glaucoma had Visco-Trab operation (a merge of both viscocanalostomy and trabeculectomy operations). Mean follow-up was 29.1 ± 22.2 months. Criteria of success were intraocular pressure (IOP) of 14 mmHg or less with or without glaucoma medications, with no devastating complications, loss of light perception, or additional glaucoma surgery.

RESULTS

IOP, number of glaucoma drops, and visual field mean deviation were significantly reduced (11.9 ± 5.6 mmHg, 0.7 ± 1.2, and 14.2 ± 6.3 dB, compared to preoperative values of 24.4 ± 9.9 mmHg, 2.8 ± 1.4, and 17.3 ± 6.3 dB, respectively). Success was reported in 136 of 168 eyes (81%) without (100 eyes, 59.5%) or with (36 eyes, 21.5%) glaucoma medications. A functioning bleb was seen in 2/3rd of eyes; diffuse (59 eyes, 35%) and thin ischemic (54 eyes, 32%). Predictors for failure to achieve the target IOP included previous ocular (p = 0.01) or glaucoma (p = 0.04) surgery, number of preoperative glaucoma medications (p = 0.029), and severity of glaucoma (p = 0.058).

CONCLUSION

Combined Visco-Trab operation proved safe and effective, on midterm follow-up, in reducing IOP to the proposed target level in eyes with severe glaucoma via enhancing internal and external filtration.

Postoperative management of trabeculectomy and glaucoma drainage implant surgery

PURPOSE OF REVIEW

This article describes important aspects of postoperative management after trabeculectomy and glaucoma drainage implant surgery.

RECENT FINDINGS

Postoperative management of glaucoma drainage implant surgery includes stabilization of intraocular pressure, possible ligature release, and management of complications such as corneal edema, and tube/plate exposure. Postoperative management of trabeculectomy includes evaluation of bleb encapsulation, management of hypotony, and assessment of need for adjuvant therapy. Recent advances in surgical techniques, device/tissue availability, and imaging continue to shape the postoperative course.

SUMMARY

Careful preoperative planning and postoperative care may decrease the likelihood of complications in tube surgery or trabeculectomy.

Scleral Flap-Everting Suture for Glaucoma-filtering Surgery

PURPOSE

Most filtering surgery failures develop in the early postoperative period. The possibility to apply an everting suture to lift the flap in the postoperative period and reduce the possibility of an early failure is reported.

METHODS

Surgical technique description.

RESULTS

An everting suture may be applied to the scleral flap in all types of ab externo anterior filtering surgeries. It could allow the surgeon to lift the scleral flap after the removal of the releasable sutures.

CONCLUSIONS

The use of an everting suture would eliminate the need to use procedures for lifting the flap that involve puncturing the conjunctiva and may cause hemorrhages and leakage and promote scarring.

Study of efficacy and timing of laser suture lysis in reducing intraocular pressure after trabeculectomy with mitomycin-C

Context:

Laser suture lysis is used to enhance filtration after trabeculectomy.

Aims:

The aim of this is to evaluate the change in intraocular pressure (IOP) after laser suture lysis after trabeculectomy with mitomycin-C and to correlate the efficacy of suture lysis in relation to the time of lysis.

Settings and Design:

Prospective interventional study of seventy eyes of seventy patients.

Subjects and Methods:

Trabeculectomy with mitomycin-C was performed for 352 patients with glaucoma. Laser suture lysis was carried out when indicated for seventy patients during 2^nd–8^th week posttrabeculectomy. Primary outcome measures were IOP at immediate postsuture lysis, 1, 2, 4, 6, and 8 weeks, 3 and 6 months following laser suture lysis. For the purpose of statistical analysis, patients were divided into three groups depending on the week of suture lysis as <3 weeks, 3^rd–5^th week, and >5 weeks posttrabeculectomy and 21 mmHg was used as the cutoff for the achievement of target IOP.

Statistical Analysis Used:

Descriptive statistical analysis has been carried out. Significance is assessed at 5% level of significance. Student's t-test (two-tailed, independent) has been used to find the significance of study parameters on continuous scale between two groups. Chi-square/Fisher exact test has been used to find the significance of study parameters on categorical scale between two or more groups.

Results:

On immediate postsuture lysis, 62 patients (88.6%) had IOP of <21 mmHg which increased to 68 patients (98.6%) at the end of 6 months postsuture lysis. When laser suture lysis was performed during 3^rd–5^th week posttrabeculectomy, 34 patients (73.9%) achieved the target IOP.

Conclusions:

Laser suture lysis during 3^rd–5^th week posttrabeculectomy with mitomycin-C is an effective and safe technique for reducing IOP.

Comparison of 3 different releasable suture techniques in trabeculectomy

PURPOSE

The use of releasable sutures provides an effective and simple way of titrating intraocular pressure (IOP) postoperatively. The purpose of this study was to compare the surgical outcome of 3 releasable suture techniques for closing scleral flaps in patients undergoing primary trabeculectomy.

METHODS

The Wills Eye Glaucoma Research Center retrospectively reviewed the charts of patients who underwent primary trabeculectomy by 3 surgeons using 3 different releasable suture techniques. Ninety eyes of 90 glaucoma patients were divided into 3 groups by releasable suture technique (n = 30 eyes for each group). Main outcome measures included best-corrected visual acuity (BCVA), intraocular pressure (IOP), rate of surgical success, use of supplemental medical therapy, need for additional glaucoma surgery, and complications during suture removal.

RESULTS

The BCVA and IOP were similar among the groups for all follow-up visits. As a determinant of success rate of trabeculectomy, mean decrease of IOP after surgery was over 30% in all groups (p = 0.43). The number of postoperative antiglaucomatous medications, number of complications, and need for an additional glaucoma surgery were similar in all groups (p = 0.40, p = 0.87, and p = 0.47, respectively). The differences in suture-related complications, defined as suture break or need for laser suture lysis, were not significant among the groups (p = 0.09).

CONCLUSIONS

We found that the 3 most common surgical techniques had similar mechanisms of action. All techniques were safe and effective, yielding similar outcomes. All 3 techniques can be used for closing scleral flaps in patients undergoing primary trabeculectomy.

Laser suture lysis after trabeculectomy with mitomycin C: analysis of suture selection

OBJECTIVE

This paper analyses to what extent positioning and timing influences the degree of intraocular pressure (IOP) reduction by laser suture lysis (LSL) after trabeculectomy with mitomycin C.

METHODS

The IOP reduction following LSL was assessed in a consecutive case series of 168 eyes (120 patients) after trabeculectomy with mitomycin C. Scleral flap sutures of 3.3±0.6 were placed on average. The IOP reduction was assessed in terms of suture positioning and the time of LSL.

RESULTS

LSL was performed early (<7 d) on 48 of 168 eyes (29%). The mean IOP before trabeculectomy was 22.1±5.9 and 20.3±6.2 mm Hg on the first postoperative day. LSL additionally reduced the IOP by 6.3±6.9 mm Hg. LSL was performed late (>7 d) on 27 of 168 eyes (16%). The mean preoperative IOP was 20.7±6.0 mm Hg, 12.1±7.8 mm Hg on the first postoperative day, and increased again to 21.7±4.5 mm Hg by the time of LSL. The IOP reduction achieved by LSL was 7.0±5.1 mm Hg. In a subgroup of 54 eyes with 3 scleral flap sutures, there was no significant difference in IOP reduction in a comparison of corner and central sutures (P=0.4). The reduction of IOP after LSL was not significantly correlated with the number of respectively remaining scleral flap sutures (P=0.17). There was no correlation between the time of LSL and IOP reduction (P=0.96).

CONCLUSION

The reduction of IOP after LSL is not related to suture selection or the number of remaining scleral flap sutures.

Breakdown of the blood-ocular barrier as a strategy for the systemic use of nanosystems

Several drug delivery systems have been proposed to overcome physiological barriers, improving ocular bioavailability. Systemic routes are seldom used due to the blood-ocular barrier. Novel drug delivery systems based on nanotechnology techniques have been developed to overcome ocular physiological barriers. This non-systematic review suggests the utilization of a transitory blood-ocular breakdown to allow the access of drugs by nanotechnology drug delivery systems via the systemic route. We discuss the possible ways to cause the breakdown of the blood-ocular barrier: acute inflammation caused by intraocular surgery, induced ocular hypotony, and the use of inflammatory mediators. The suitability of use of the systemic route and its toxic effects are also discussed in this article.

Combined Viscocanalostomy-Trabeculectomy for management of Advanced Glaucoma - A Comparative Study of the Contralateral Eye: A Pilot Study

PURPOSE

To compare combined viscocanalostomy-trabeculectomy (VISCO-TRAB) to trabeculectomy (TRAB) for the management of advanced glaucoma.

MATERIALS AND METHODS

The study cohort comprised of 18 subjects with bilateral advanced glaucoma who underwent VISCO-TRAB surgery (VISCO-TRAB group) in the right eye and TRAB (TRAB group) in the left eye. VISCO-TRAB constituted lamellar scleral flap, deep scleral flap dissection with deroofing of Schlemm's canal (SC), viscodilation of SC, penetrating trabeculectomy, peripheral iridectomy, and tight flap closure. All eyes received subconjunctival mitomycin. Success criteria included intraocular pressure (IOP) < 14 mmHg or > 30% lowering of IOP with no devastating complications. A P value less than 0.05 was considered statistically significant.

RESULTS

Mean IOP was significantly lower after VISCO-TRAB compared to TRAB at 1 week and 3 months postoperatively (P<0.05). No eyes lost more than two lines of Snellen acuity. There were more hypotony-related complications after TRAB than VISCO-TRAB surgery. Target IOP was achieved in 83.3% in the VISCO-TRAB group compared to 55.6% in the TRAB group.

CONCLUSION

Combined VISCO-TRAB is effective in reducing IOP to the target level for advanced glaucoma with lower postoperative complications.

Corneal lamellar grafting to repair late complications of mitomycin C trabeculectomy

Purpose

To report corneal lamellar grafting to repair the late-onset complications after MMC trabeculectomy.

Methods

Multiple case reports.

Results

A 76-year-old male with primary open-angle glaucoma (POAG) and a 55-year-old male with late developmental glaucoma complicated by bleb leaks from a microhole 10 and eight years after surgery, respectively. Severe ciliochoroidal detachment and a shallow anterior chamber were persistent in one case and bleb-related infection recurred in another. Additionally, a 46-year-old male with POAG had hypotony maculopathy with a giant ischemic bleb 18 months after surgery. Although these patients were quite resistant to medical and surgical treatments, they were successfully treated by corneal lamellar grafting without complications.

Conclusions

Tectonic corneal lamellar grafting is a reliable and final surgical method to improve severe cases of hypotony maculopathy or bleb leak after mitomycin C trabeculectomy.

Combined viscocanalostomy-trabeculectomy for management of far-advanced glaucoma: evaluation of the early postoperative course

BACKGROUND AND OBJECTIVE

To study the early postoperative efficacy and safety of combined viscocanalostomy with trabeculectomy (VISCO-TRAB) for treating far-advanced glaucoma.

PATIENTS AND METHODS

Patients with far-advanced glaucoma scheduled for glaucoma surgery were enrolled in the study. Surgery included viscocanalostomy until Schlemm's canal was deroofed and dilated with viscoelastic, followed by penetrating corneotrabeculectomy, peripheral iridectomy, and tight closure of lamellar flap. Patients with severe glaucoma who were treated with trabeculectomy only (TRAB) in the preceding year were used for comparison.

RESULTS

The study included 39 eyes in the VISCO-TRAB group and 40 eyes in the TRAB group. Mean intraocular pressure was significantly lower in the VISCO-TRAB group during the early postoperative period (P < .05). The postoperative course was less eventful in the VISCO-TRAB group with minimal hypotony or suture lysis-related complications.

CONCLUSION

During the early postoperative period, VISCO-TRAB proved efficacious and safe in reducing intraocular pressure to target levels in patients with far-advanced glaucoma.

Laser suture lysis or releasable sutures after trabeculectomy

PURPOSE

To compare the efficacy and complication rates of laser suture lysis (LSL) or releasable sutures techniques after trabeculectomy.

MATERIALS AND METHODS

Forty-eight eyes of 43 consecutive patients with uncomplicated glaucoma who were recruited for primary trabeculectomy with mitomycin-C were divided into 2 groups. Group 1 and group 2 comprised 27 and 21 eyes that were randomly assigned to a standard surgery and releasable suture groups, respectively. A target intraocular pressure (IOP) had been determined on the basis of the severity of the glaucoma and was called a complete success, qualified success, or failure.

RESULTS

In group 1, the mean change in IOP after LSL was 7.31+/-1.98 mm Hg, 6.1+/-1.1 mm Hg, and 3.9+/-1.5 mm Hg when sutures were lysed on the first, second, and third months. In group 2, the mean change in IOP after releasable suture removed was 8.20+/-2.74 mm Hg, 5.12+/-1.65 mm Hg, and 4.4+/-1.0 mm Hg when sutures were released at the first, second, and third months. At the end of 6 months, the success (complete and qualified success) rates were 92% and 90% for LSL and releasable suture groups, respectively. There was no statistically significant differences in success (P>0.05) and complication (P>0.05) rates between groups.

CONCLUSIONS

We observed an effective IOP reduction in eyes that had suture release both in the early and late postoperative periods after LSL and suture release. We believe that both the laserable and releasable suture techniques can be preferred to permanent sutures for closing scleral flaps in primary trabeculectomy with mitomycin-C in uncomplicated glaucoma.

Comparison of fornix- and limbus-based conjunctival flaps in mitomycin C trabeculectomy with laser suture lysis in Japanese glaucoma patients

PURPOSE

To analyze the results of mitomycin C (MMC) trabeculectomy and laser suture lysis using either fornix-based (FB) or limbus-based (LB) conjunctival flaps.

METHODS

Eighty-two Japanese glaucoma patients were treated by MMC trabeculectomy, with 38 eyes receiving an FB conjunctival flap and 44 eyes receiving an LB conjunctival flap. Postoperative intraocular pressure (IOP), the probability of success, and complications were compared between the FB and LB groups.

RESULTS

The IOP of the FB group decreased from 21.6+/-7.90 mmHg to 9.75+/-3.23 mmHg at 12 months postoperation, and the IOP of the LB group decreased from 21.3+/-6.77 mmHg to 9.30+/-3.16 mmHg. The postoperative IOPs were similar in the two groups at all postoperative time points. A life-table analysis (Kaplan-Meier method) showed that the survival rate was similar in the two groups but tended to be lower in the early postoperative period in the FB group. Complications were similar also, with the exception of increased leakage in the FB group.

CONCLUSIONS

MMC trabeculectomy results were similar between FB and LB conjunctival flaps, in agreement with previous reports. However, increased care may be warranted when an FB flap is used in MMC trabeculectomy.

The Outcome of Mitomycin C Trabeculectomy and Laser Suture Lysis Depends on Postoperative Management

PURPOSE

To verify that postoperative management affects the outcome of mitomycin C (MMC) trabeculectomy and suture lysis.

METHODS

A total of 108 eyes in 108 Japanese patients were treated with MMC trabeculectomy. They were divided into two groups based on when the operation was performed: group A, 57 eyes in 1998, and group B, 51 eyes in 2001. The results, including postoperative intraocular pressure (IOP), complications, and postoperative management, were compared between groups. In addition, they were evaluated by a Kaplan-Meier life-table analysis.

RESULTS

Postoperative IOP was lower and the probability of success by life-table analysis was higher in group B than in group A. Postoperative management, including laser suture lysis and subconjunctival injection of 5-fluorouracil, was started significantly earlier in group B than in group A patients. Although more postoperative complications occurred in group B, none were severe and all were adequately managed.

CONCLUSIONS

Starting postoperative management earlier, particularly laser suture lysis, may be necessary to achieve lower and longer IOP control in MMC trabeculectomy.

The effect of the timing of scleral flap suture release on the safety and long-term success of phacotrabeculectomy

PURPOSE

To investigate the effect of the timing of the scleral flap suture release on the safety and long-term success of phacotrabeculectomy.

DESIGN

Retrospective, nonrandomized chart review.

METHODS

We studied 173 eyes of 173 consecutive patients who underwent primary phacotrabeculectomy, with or without intraoperative mitomycin-C, and subsequent scleral flap suture release.

RESULTS

Early suture release (<3 weeks) had a lower long-term success rate than late suture release (>3 weeks), with an average follow-up period of 44.8 months. Patients who used mitomycin-C had statistically later suture release than did patients without mitomycin-C. There were nine cases of hypotony, for which independent risk factors were early suture release and the use of mitomycin-C.

CONCLUSIONS

Greater long-term success with minimal complications was achieved when scleral flap suture release was performed three weeks after phacotrabeculectomy. Suture release within three weeks after surgery was associated with an increased risk of filtration failure and a higher risk of postoperative complications.

Outcomes of Laser Suture Lysis After Initial Trabeculectomy With Adjunctive Mitomycin C

PURPOSE

To evaluate and compare outcomes of eyes that underwent laser suture lysis (LSL) after initial trabeculectomy with mitomycin C (MMC) to those that did not require such an intervention.

METHODS

We reviewed the charts of consecutive patients with open-angle glaucoma who underwent initial trabeculectomy with mitomycin C at the Jules Stein Eye Institute between 1998 and 2003. Primary outcome measures were intraocular pressure (IOP) control at 1 year and success rate of trabeculectomy according to following criteria: criteria A, IOP < 21 mm Hg with >or=20% IOP reduction and criteria B, IOP < 15 mm Hg with >or=30% IOP reduction. Kaplan-Meier survival analysis and Cox's proportional hazards regression analysis were used to estimate and determine influence of laser suture lysis on success rates after trabeculectomy.

RESULTS

Laser suture lysis was performed in 95 eyes (84 patients) whereas 146 eyes (121 patients) did not require it. IOP was significantly higher at 12 months in laser suture lysis eyes compared with non-laser suture lysis eyes (12.9 +/- 5.2 mm Hg versus 11.0 +/- 4.1 mm Hg; P = 0.04). Laser suture lysis eyes also had decreased success rates with criteria B (57% compared with 73% at 1 year for non-LSL eyes; P = 0.005). However, only late laser suture lysis (last LSL session >10 days after trabeculectomy) was associated with worse outcome in Cox's proportional hazards model using criteria B (HR = 2.26; P = 0.004). Late hypotony occurred in 4% and 1% of non-LSL and LSL eyes, respectively.

CONCLUSIONS

Eyes that undergo laser suture lysis >10 days after initial trabeculectomy with mitomycin C are more likely to have poorer long-term IOP control than eyes not requiring laser suture lysis or eyes undergoing laser suture lysis <or=10 days after surgery.

Operative revision of non-functioning filtering blebs with 5-fluorouracil to regain intraocular pressure control

PURPOSE

To determine the efficacy of extensive microsurgical needling revision of failed filtering blebs followed by serial 5-fluorouracil subconjunctival injections.

METHODS

Thirty-six eyes of 34 consecutive patients with progressive open-angle glaucoma refractory to topical therapy submitted to needling revision as a major procedure. All patients required multiple antiglaucoma medications preoperatively, and had completely flat or densely encapsulated filtering blebs. All patients underwent elaborate needling revision (limbus to superior rectus >8 mm diameter, >3 mm elevation, entry-site sutured with 8-0 vicryl and bleb reformed via paracentesis with viscoelastic) in the operating room, followed by serial 5-fluorouracil. The patients were followed for up to 6 months postoperatively. The main outcome measures were intraocular pressure (IOP) and the number of antiglaucoma medications used.

RESULTS

Thirty-one eyes (86%) maintained mean IOP below 15 mmHg postneedling without medication. Overall the mean IOP postneedling was >9 mmHg lower than medicated preoperative levels (P < 0.0001). IOP reduction in encapsulated blebs was marginally superior to that in flat blebs.

CONCLUSIONS

Extensive needling revision in the operating room is safe, straightforward, and produces reproducible restoration of filtering function.

Flap and Suture Manipulation after Trabeculectomy with Adjustable Sutures: Titration of Flow and Intraocular Pressure in Guarded Filtration Surgery

PURPOSE

To describe the intraocular pressure (IOP) changes resulting from scleral flap suture and scleral flap manipulation in an experimental model of conventional guarded filtration surgery.

DESIGN

Experimental study.

METHODS

Trabeculectomy operations were performed with adjustable sutures on 5 donor human eyes connected to a constant flow infusion and a real-time IOP monitoring system. Three different manipulations: posterior lip massage, suture adjustment using special forceps, and suture release, were tested on the completed operation site.

MAIN OUTCOME MEASURES

The success in lowering IOP to the target range of 7 to 15 mm Hg within 5 interventions, the time to reach equilibrium IOP, and the frequency of undesired outcomes.

RESULTS

Posterior lip massage, suture release, and suture adjustment lowered the IOP after stabilization to the target range in less than 5 interventions in 9%, 14%, and 100% respectively (P < 0.001). The median time for IOP to stabilize at the new level after each intervention after correction for the flow rates used was 36.3 minutes for massage, 8.5 minutes for releasable sutures, and 3.7 minutes for adjustment of sutures (P < 0.001).

CONCLUSIONS

These results suggest that suture adjustment may be superior to both posterior lip massage and releasable sutures for managing IOP in the early phase following glaucoma surgery. Following clinical interventions that result in loss of anterior chamber volume, IOP checks should be made at least 40 minutes post-intervention or at a later time afterwards if there is a clinical risk of low aqueous production. Manipulation of the scleral flap and associated sutures may only lower the IOP for minutes to hours if the suture tension is not decreased.

Laser suture lysis after trabeculectomy

PURPOSE

The author attempted to avoid ocular hypotony following a mitomycin-C trabeculectomy by controlling the interval between surgery and laser suture lysis.

METHODS

When 10 seconds of digital pressure on the eye following a mitomycin-C trabeculectomy produced a 20% drop of the intraocular pressure, the decision of whether or not to perform laser suture lysis was delayed until the following examination.

RESULTS

Twenty-nine consecutive eyes (27 patients) with primary open-angle glaucoma underwent mitomycin-C trabeculectomy in which laser suture lysis was required during the postoperative period to reach the target intraocular pressure. The eyes were classified by the severity of the glaucoma: mild, moderate, and severe. For moderate and severe glaucoma, an unqualified success was defined as an intraocular pressure of 10 +/- 2 mm Hg. A qualified success had an intraocular pressure of 5 to 7 mm Hg or 13 to 15 mm Hg. Failure was defined as an intraocular pressure less than 5 mm Hg or greater than 15 mm Hg. Fifteen eyes were called success, 7 eyes qualified success, and 7 eyes failure. When the final laser suture lysis was carried out within the first two postoperative months, two of the failure eyes sustained hypotony. If the final laser suture lysis had been carried out after the first two postoperative months, there were no eyes with hypotony. There was no statistical difference in the final intraocular pressure between the early laser suture lysis and late laser suture lysis groups.

CONCLUSIONS

From this pilot study it would appear that delaying the final laser suture lysis following trabeculectomy (MMC) until after the second postoperative month may reduce the risk of hypotony without adversely affecting the final intraocular pressure.

Ocular hypotony after laser suture lysis following trabeculectomy with mitomycin C

BACKGROUND

To report our experience with laser suture lysis (LSL) following trabeculectomy with mitomycin C, its timing, effectiveness and related complications.

METHODS

We retrospectively examined 38 consecutive eyes of 36 patients that underwent LSL following trabeculectomy with mitomycin C.

RESULTS

The mean preLSL intraocular pressure (IOP) was 27.0 mm Hg (SD 6.3, range 16-39 mm Hg) and the postLSL IOP (IOP 1 h after the last session of LSL) was 16.0 mm Hg (SD 7.2, range 3-31 mm Hg). Following the LSL in 7 eyes (7 of 38) hypotony (IOP<6 mm Hg, lasting more than 24 h) developed. Two groups were defined. In group I no hypotony was found after LSL and group II went through a period of hypotony. The time interval between surgery and LSL was significantly shorter in group II (mean 5.7, SD 7.5, range 1-19 days), compared to group I ( mean 14.7, SD 13.0, range 1-44 days) (p=0.041). The mean final IOP (IOP measured at the last visit) was 13.3 mm Hg (SD 3.4, range 6-20 mm Hg) and mean follow-up was 6.1 months (SD 3.9, range 2.0-15.2 months). No hypotony was found at final examination. PostLSL IOP and final IOP were significantly lower in group II (p=0.002 and p=0.024 respectively). IOP reduction by LSL was significantly greater in group II (p=0.046).

CONCLUSION

LSL is an effective and safe procedure to lower the IOP following trabeculectomy with mitomycin C. Early application of LSL results in lower final IOPs, but has a higher risk of hypotony.

Dysfunctional filtering blebs

Guarded filtration surgery, is commonly used to control the intraocular pressure (IOP) in glaucomatous patients. Filtration surgery lowers the IOP by creating a fistula between the inner compartments of the eye and the subconjunctival space (i.e., filtering bleb). There are several options to improve the function of filtering blebs and to prevent their failure. However, improvement of IOP control after guarded filtration procedures is associated with a higher frequency of bleb-related complications. Early (e.g., bleb leak, excessive filtration, flat anterior chamber, filtration failure) and late (e.g., bleb leak, excessive filtration and hypotony, symptomatic blebs, bleb encapsulation, filtration failure, bleb infection) complications associated with filtering procedures should be managed adequately to prevent further problems. Techniques to improve the function of filtering blebs and to treat postoperative complications have progressed over the past decade.

The effect of adjunctive mitomycin C in Molteno implant surgery

PURPOSE

The purpose of the study is to assess the effect of adjunctive intraoperative mitomycin C (MMC) in Molteno drainage device implantation for patients with recalcitrant glaucomas.

METHOD

Forty-nine eyes of 49 patients who underwent one-stage, single-plate Molteno device implantation with adjunctive intraoperative MMC (0.5 mg/ml) for 3 to 5 minutes (MMC group) were compared to a historic control group of 51 eyes of 51 patients (control group) who received one-stage, single-plate Molteno device implantation without MMC. Success (survival) was defined as an intraocular pressure (IOP) between 6 and 21 mmHg, inclusive, with (qualified success) or without (complete success) glaucoma medications and with no additional glaucoma surgery, phthisis, implant removal, or loss of light perception.

RESULTS

Preoperative conditions were similar between the two groups. There was no significant difference in surgical survival rate between the two groups (P = 0.13, log-rank test). There also were no significant differences in the postoperative IOP levels and numbers of antiglaucoma medications between the two groups at all times (P > 0.05). Visual acuity was improved or remained within one line of preoperative visual acuity in 76.1% of the MMC group and 78.7% of the control group at 1 year after surgery (P = 0.76, chi-square test). Complications and reoperation for complications were similar in both groups (P > 0.05, chi-square test) except for the incidence of early postoperative hypotony and the total number of eyes with complications not requiring reoperation, which were more common in the MMC group (P = 0.027, 0.005, respectively, chi-square test). The most common complications included hypotony with or without a flat anterior chamber or choroidal detachment, followed by hyphema and tube plugging.

CONCLUSION

Molteno device implantation with adjunctive intraoperative MMC in patients with complicated glaucoma may not offer a better chance of surgical success compared with Molteno implantation without MMC.

Postsurgical hypotony: relationship to fistulization, inflammation, chorioretinal lesions, and the vitreous

Hypotony is a natural occurrence, symptom, and complication of surgical treatment. With more sophisticated and aggressive techniques, postsurgical hypotony recently has been given increased attention as an obstacle to success of surgery for glaucoma and retinal detachment. Whereas two standard deviations below normal pressure (15.9-5.8 = 10.1 mm Hg) can be called hypotonous, most eyes, depending on scleral rigidity, lid pressure, eye rubbing, or corneal or retinal edema, will be symptomatic at < 5 mm Hg. Hypotony can be defined as the low pressure (whether acute, transient, chronic or permanent) which, in an individual eye, leads to functional changes (whether asymptomatic or symptomatic) and structural changes (whether reversible or irreversible). Depending on its duration and degree, postsurgical hypotony produces characteristic tissue changes that often are modified by, but separate from, the tissue changes caused by an underlying disease or its surgical treatment. This review summarizes the situations, variably associated with hypotony, that occur after such interventions as cataract extraction, filtering surgery, cyclodialysis, cyclodestruction, and vitreoretinal surgery, in addition to the reported pathomechanisms of hypotony and its proposed treatments.