Contact Transscleral Cyclophotocoagulation with Diode Laser in Refractory Glaucoma

Efficacy and safety of transscleral cyclophotocoagulation versus cyclocryotherapy in the treatment of intractable glaucoma: A systematic review and meta-analysis

To perform a meta-analysis to compare the efficacy and safety of diode laser transscleral cyclophotocoagulation (TSCPC) and cyclocryotherapy (CCT) in the treatment of intractable glaucoma. Systemic searches of the Ovid MEDLINE, EMBASE, and Cochrane Library databases yielded experimental and observational comparative studies. TSCPC and CCT efficacy and safety outcomes were compared. Subgroup analyses of participant ethnicity, preoperative intraocular pressure (IOP) level, and underlying causes of glaucoma were conducted. The pooled effects were computed using the random-effects model. The meta-analysis included nine studies totalling 668 eyes. There was no statistically significant difference between the TSCPC and CCT groups in the IOP reduction (IOPR%), decrease in antiglaucoma medications, the operative success rate with or without medications, or retreatment rate in the efficacy analysis. In the subgroup analysis, CCT had a better IOP-lowering effect among non-Asian participants and a non-inferior IOPR% to TSCPC among Asian participants. TSCPC and CCT were associated with similar rates of deterioration in visual acuity, postoperative visual analog scale, and other analysed postoperative complications in the safety analysis. In both groups, severe complications were uncommon. Diode laser TSCPC and CCT had nearly equivalent clinical efficacy in treating intractable glaucoma, while CCT demonstrated a better IOP-lowering effect in non-Asian. Both cyclodestructive procedures have a comparable safety profile.

Micropulse transscleral cyclophotocoagulation (MP-CPC): efficacy endpoints for the treatment of refractory paediatric glaucoma - a retrospective case-series

BACKGROUND

This study evaluates the efficacy and safety of micropulse transscleral cyclophotocoagulation (MP-CPC) in paediatric patients.

METHODS

This retrospective case-series recruited 44 eyes for glaucoma patients who were younger than 17 years and were treated with MP-CPC and followed for at least one year. Pre- and post-intervention intraocular pressure (IOP) was compared out to at least one year postoperatively. Success rates at 6 months and 1 year postoperatively were assessed. P < 0.05 was considered statistically significant.

RESULTS

There were 35 (79.5%) eyes with a history of glaucoma surgery. IOP decreased statistically significantly from a baseline of 32.7 (standard deviation:8.7 mmHg) to 23.2 (8.6) and 21.7 (7.9) mmHg at the 6 months and 1-year follow-up, respectively (P < 0.0001, all comparisons). Overall success was noted in 19 (47.5%) eyes at the 6 months follow-up, and 23 (53.5%) eyes at 1 year.

CONCLUSIONS

MP-CPC reduces IOP and the burden of medications in paediatric patients with glaucoma. Additionally, its safety profile favours the use of MP-CPC as an adjunctive modality for refractory glaucoma.

Management of Anticoagulation and Antiplatelet Therapy in Glaucoma Surgery

The use of antithrombotic therapy is rising as the population of older adults grows and novel agents with wider indications emerge. Likewise, surgical treatment of glaucoma may become increasingly common as the prevalence of glaucoma increases and innovative treatment options are developed. These trends highlight the need to understand how best to manage antithrombotic therapy in the context of glaucoma surgery. This review article describes current literature on antithrombotic therapy and perioperative thromboembolic risk evaluation based on individual factors. In addition, guidance is offered on the management of antithrombotic therapy in the setting of each type of glaucoma surgery, with an emphasis on a multidisciplinary approach involving the patients' treating physicians.

Micropulsed diode laser cyclophotocoagulation in recurrent pediatric glaucoma

PURPOSE

To evaluate the intermediate-term efficacy and safety of micropulsed diode laser cyclophotocoagulation in recurrent pediatric glaucoma.

PATIENTS AND METHODS

A prospective interventional study included children <16 years old diagnosed with recurrent glaucoma, attending Mansoura University, during the period from July 2017 to November 2017. Micropulsed diode laser sessions were performed in all the cases. The main outcome was the intraocular pressure reduction with monitoring of complications as secondary outcome. The mean follow-up period was 15.08 ± 1.1 (mean: 12-16) months.

RESULTS

A total of 36 eyes of 29 patients were included (62% males) with median age of 24 months. Primary congenital glaucoma represented 47.2% of the initial diagnoses. At the 15th month, the mean intraocular pressure dropped significantly from 37.5 ± 11.3 mmHg at baseline to 20.03 ± 2.7 mmHg (p < 0.001) with 37.15% reduction. The mean number of glaucoma medications decreased significantly from 2.6 ± 0.5 pretreatment to 1.7 ± 0.6 at the 15th month (p < 0.001). A total of 24 eyes (66.7%) required second session of treatment with mean number of 1.7 ± 0.5 sessions per eye. The cumulative probability of qualified success was 69.4%, 58.3%, 52.8%, 47.2%, and 41.7% at 1, 3, 6, 12, and 15 months after treatment. Qualified success was achieved in 61% at 15 months without statistically significant difference between the initial diagnoses (p = 0.61). None of the eyes developed any major ocular complications throughout the follow-up period.

CONCLUSION

Micropulsed diode laser was proved to be a safe approach with relative effectiveness in controlling intraocular pressure in children with recurrent glaucoma.

Advanced glaucoma following Nd:YAG capsulotomy: a case report

Background

We present a case of aphakic pupil block caused by vitreous prolapse into the anterior chamber following Nd:YAG capsulotomy.

Case presentation

This resulted in advanced glaucoma in a young patient, which presented a significant clinical management challenge.

Conclusions

Ultimately, at the time of writing, her intraocular pressure and uveitis were well controlled, however the long-term outcome remains uncertain, given the uncompromising natural history of her complicated ocular condition.

Multicenter clinical trial of high-intensity focused ultrasound treatment in glaucoma patients without previous filtering surgery

PURPOSE

To evaluate the efficacy and safety of the ultrasonic circular cyclocoagulation procedure in patients with open-angle glaucoma naïve of previous filtering surgery.

METHODS

Prospective non-comparative interventional clinical study conducted in five French University Hospitals. Thirty eyes of 30 patients with open-angle glaucoma, intra-ocular pressure (IOP) > 21 mmHg and with no previous filtering glaucoma surgeries were sonicated with a probe comprising six piezoelectric transducers. The six transducers were activated with a 6-s exposure time. Complete ophthalmic examinations were performed before the procedure and at 1 day, 1 week, 1, 2, 3, 6 and 12 months after the procedure. Primary outcomes were qualified surgical success (defined as IOP reduction from baseline ≥20% and IOP > 5 mmHg with possible re-intervention and without hypotensive medication adjunction) and complete surgical success (defined as IOP reduction from baseline ≥20%, IOP > 5 mmHg and IOP < 21 mmHg with possible re-intervention and without hypotensive medication adjunction) at the last follow-up visit and vision-threatening complications. Secondary outcomes were mean IOP at each follow-up visit compared with baseline, medication use, complications and re-interventions.

RESULTS

Intra-ocular pressure was significantly reduced (p < 0.05) from a mean pre-operative value of 28.2 ± 7.2 mmHg (n = 3.6 hypotensive medications) to 19.6 ± 7.9 mmHg at 12 months (n = 3.1 hypotensive medications and n = 1.1 procedures) (mean IOP reduction of 30%). Qualified success was achieved in 63% of eyes (19/30) (mean IOP reduction of 37% in these eyes) and complete success in 46.7% of eyes (14/30) (mean IOP reduction of 37% in these eyes) at the last follow-up. No major intra- or post-operative complications occurred.

CONCLUSIONS

The UC(3) procedure seems to be an effective and well-tolerated method to reduce IOP in patients with open-angle glaucoma without previous filtering surgery.

Diode laser cyclophotocoagulation paves way to a safer trabeculectomy in eyes with medically uncontrollable intraocular pressure

High intraocular pressure (IOP) not responding to systemic and topical anti-glaucoma medications renders the eye at risk for both intra- and post-operative complications of glaucoma filtration surgery. Laser cyclophotocoagulation is able to lower IOP in such refractory glaucoma eyes and may make the surgical event safer. This study assessed diode laser cyclophotocoagulation (DLCP) when used as a temporary measure for lowering IOP prior to performing trabeculectomy. This study is a  retrospective analysis of cases planned for trabeculectomy surgery, uncontrolled on maximally tolerable systemic anti-glaucoma medications. They were analysed for response to DLCP in terms of IOP control, vision-related complications, increased inflammation, post-trabeculectomy hypotony and chances of phthisis and ciliary shutdown. Twelve eyes of ten patients aged 35-65 years were identified and all followed up for at least 2 years. One week following DLCP, the IOP (mean ± SD) declined by 51 % from 46.8 ± 5.4 to 22.8 ± 3.3 mmHg. The IOP was further reduced to 15.4 ± 2.7 mmHg at 4 weeks after trabeculectomy; it remained in the mid-teens for a minimum of 2 years in all cases. The mean (±SD) visual acuity improved from 1.4 ± 0.4 to 0.8 ± 0.4 LogMAR equivalents following trabeculectomy. In four eyes, phacoemulsification was performed 5-7 months after trabeculectomy with improvement in best-corrected visual acuity. One patient developed transient hypotony, post-trabeculectomy, which resolved by 6 days. There were no other complications like increased inflammation, prolonged hypotony or suprachoroidal haemorrhage. DLCP is, thus, effective and safe for temporarily controlling IOP; thereby trabeculectomy can be performed in a quieter ocular milieu.

Long-term results from cyclocryotherapy applied to the 3o'clock and 9o'clock positions in blind refractory glaucoma patients

PURPOSE

To report the long-term follow-up results after cyclocryotherapy, applied to the 3-o'clock and 9-o'clock positions in blind refractory glaucoma patients.

METHODS

We retrospectively reviewed the charts of 19 blind patients, and a total of 20 eyes with refractory glaucoma who were treated with cyclocryotherapy. Cyclocryotherapy treatments were performed using a retinal cryoprobe. The temperature of each cyclocryotherapy spot was -80°C and each spot was maintained in place for 60 seconds. Six cyclocryotherapy spots were placed in each quadrant, including the 3-o'clock and 9-o'clock positions.

RESULTS

The mean baseline pretreatment intraocular pressure (IOP) in all eyes was 50.9 ± 12.5 mmHg, which significantly decreased to a mean IOP at last follow-up of 14.1 ± 7.1 mmHg (p < 0.001). The mean number of antiglaucoma medications that patients were still taking at last follow-up was 0.3 ± 0.6. Devastating post-procedure phthisis occurred in only one eye.

CONCLUSIONS

Cyclocryotherapy, performed at each quadrant and at the 3-o'clock and 9-o'clock position, is an effective way to lower IOP and, thus, is a reasonable treatment option for refractory glaucoma patients who experience with ocular pain and headaches.

Diode laser transscleral cyclophotocoagulation followed by phacotrabeculectomy on medically unresponsive acute primary angle closure eyes: the long-term result

Background

To explore the intraocular pressure-lowering effect and complications of diode laser transscleral cyclophotocoagulation (DLTSC) followed by phacotrabeculectomy on medically unresponsive acute primary angle closure eyes.

Methods

Nine eyes of nine medically unresponsive acute primary angle closure patients were enrolled. All the patients underwent cyclophotocoagulation followed by phacotrabeculectomy to control the prolonged acute attack. Data were recorded prospectively and then analyzed retrospectively. The reduction in intraocular pressure, improvement of vision and the complications were evaluated.

Results

After DLTSC, the IOP of all the patients were reduced, but all were above 21 mmHg under topical anti-glaucoma medications. After phacotrabeculectomy, the IOP of all the patients was decreased. At the final visit, the vision of all the patients was improved and the IOP of all the patients was below 21 mmHg without anti-glaucoma medications. There were no complications during the DLTSC and phacotrabeculectomy. Uveitis was the common complications after the both procedures, which were resolved by medication treatment.

Conclusion

Diode laser transscleral cyclophotocoagulation followed by phacotrabeculectomy is an alternative procedure to control the intraocular pressure of medically unresponsive acute primary angle closure eyes with few complications.

Current surgical options for the management of pediatric glaucoma

Currently, there are numerous choices for the treatment of pediatric glaucoma depending on the type of glaucoma, the age of the patient, and other particularities of the condition discussed in this review. Traditionally, goniotomy and trabeculotomy ab externo have been the preferred choices of treatment for congenital glaucoma, and a variety of adult procedures adapted to children have been utilized for other types of pediatric glaucoma with variable results and complications. More recently, seton implantations of different types have become more popular to use in children, and newer techniques have become available including visualized cannulation and opening of Schlemm's canal, deep sclerectomy, trabectome, and milder more directed cyclodestructive procedures such as endolaser and transcleral diode laser cyclophotocoagulation. This paper reviews the different surgical techniques currently available, their indications, results, and most common complications to allow the surgeon treating these conditions to make a more informed choice in each particular case. Although the outcome of surgical treatment in pediatric glaucoma has improved significantly, its treatment remains challenging.

Risk factors for hypotony after transscleral diode cyclophotocoagulation

PURPOSE

To evaluate risk factors associated with hypotony after transscleral diode cyclophotocoagulation (TCP) in East Asian patients with intractable glaucoma.

METHODS

Clinical data from 90 eyes of 90 patients who underwent TCP for various indications at Singapore National Eye Centre between 2005 and 2007 were retrospectively reviewed. Baseline intraocular pressure (IOP) was compared with postoperative IOP at 1 month, 3 to 6 months, and 1 year. Mean total energy per session was calculated in Joules and retreatment rates were recorded. Change in visual acuity and number of medications were recorded at 1-year follow-up. Success was defined as percentage of patients achieving an IOP of 5 to 21 mm Hg with or without medications. Hypotony was defined as IOP <5 at the end of 1-year follow-up period. Factors, such as underlying diagnosis, total energy used, age, earlier operations, and retreatment rates, which may influence the development of hypotony were analyzed using univariate analysis.

RESULTS

Success was achieved in 54.0% of patients. Mean total energy used was 83.3±31.7 J. Mean pretreatment IOP was 41.8±12.9 mm Hg, which reduced to 20.7±12.1 mm Hg (P<0.001) at 1 month and 17.8±12.9 mm Hg (P<0.001) at 1 year. Sixteen (39.0%) patients developed hypotony. Univariate analysis showed that neovascular glaucoma patients have a significantly increased risk for developing hypotony post TCP (odds ratio=9.17, 95%; confidence interval=1.85-45.36).

CONCLUSION

Underlying diagnosis of neovascular glaucoma is a significant risk factor for hypotony post TCP.

Longterm follow-up of diode laser transscleral cyclophotocoagulation in the treatment of refractory glaucoma

PURPOSE

This prospective study was conducted to evaluate the efficacy and safety of transscleral diode laser cyclophotocoagulation (TDLCP) in advanced refractory glaucoma.

METHODS

A total of 124 eyes in 121 patients with advanced glaucoma refractory to medical treatment were treated consecutively with TDLCP. Success was defined as final intraocular pressure (IOP) of 5-21 mmHg in eyes with visual acuity (VA) of more than hand movements (HM) and relief of pain in eyes with VA of HM or less, including blind eyes.

RESULTS

Mean patient age was 65.6 +/- 17.1 years (range 14-91 years). Mean follow-up was 17 +/- 14.6 months (range 3-42 months). Mean pretreatment IOP was 29.9 +/- 8.4 mmHg (range 17-58 mmHg) and IOP at last follow-up was 20.8 +/- 8 mmHg (range 6-45 mmHg) (p < 0.001). The number of laser applications (mean 9.2 +/- 2.8, range 4-15) and maximal laser power (mean 2.01 +/- 0.22 mW, range 1.3-3.0 mW) were not associated with lower postoperative IOP. Intraocular pressure of < or = 21 mmHg was recorded in 63.0% of eyes at the last follow-up visit. Overall, 28 (21.7%) eyes required at least one retreatment. No phthisis bulbi or persistent hypotonia developed.

CONCLUSIONS

TDLCP is an effective and safe method for the treatment of advanced refractory glaucoma, although repeated treatments are often necessary.

Controlled Cyclophotocoagulation with diode laser in refractory glaucoma and long term follow up at King Abdulaziz University Hospital, Riyadh

PURPOSE

To evaluate the clinical efficacy and safety of controlled contact transscleral diode laser Cyclophotocoagulation (COCO) procedure in reducing the Intraocular Pressure (IOP) among patients with refractory glaucoma.

METHODS

Thirty two patients (35 eyes) with refractory glaucoma in prospective clinical studies were treated with trans-sclera diode laser in a controlled manner. The energy power used was 5 W in adults and 3 W in children, exposure time was 0.5 s, a total of 16 shots were applied over ciliary body and four shots in each quadrant. Pre and postoperative IOP were measured at different postoperative visits. Snellen visual acuity, the number of anti-glaucoma medications and associated complications were also recorded. Student T test was used to compare the pre and post intervention IOPs, while Wilcoxon Signed Ranks test was used, to detect significance change in medication dependency.

RESULTS

The mean (SD) follow up time was 80.2(±9.6) months, range (36-84) m, where the mean IOP was significantly reduced from 35.1 mm Hg (±10.7) before intervention to 18.8 mm Hg (±7.3) after intervention, in the final visit (P < 0.0001). Complete success was achieved in seven eyes (20%), 22 eyes (62.8%) showed qualified successes and complete failure was reported in six eyes (17.1%). The overall success rate was 82.8% (95% CI: 70.4-95.3). Visual acuity improved in three eyes (8.5%), no change took place in 27 eyes (77.1%) and decreased in five eyes (14.2%). The number of anti-glaucoma medications has significantly changed between pre and post intervention (P < 0.0001). No cases of hypotony, phthisis bulbi or sympathetic ophthalmia were reported.

CONCLUSION

Controlled COCO is a simple procedure, safe with minimal complications and fewer side effects.

Diode Laser Transscleral Cyclophotocoagulation for the Treatment of Refractory Glaucoma After Penetrating Keratoplasty

PURPOSE

To evaluate the effect and safety of diode laser transscleral cyclophotocoagulation (TSCPC) in eyes with refractory glaucoma after penetrating keratoplasty (PK).

METHODS

Diode laser TSCPC was performed on 32 eyes of 32 patients with secondary glaucoma after penetrating keratoplasty. The mean follow-up period was 11.4 +/- 3.8 months (range, 6-20 months). The intraocular pressure (IOP), number of glaucoma medications, graft status, side effects, and complications of the procedure were all recorded during the follow-up period. The treatment was considered successful if after one cyclodiode treatment the IOP could be reduced to or below 22 mmHg with or without medication. The success rate of the diode laser treatment was analyzed by the Kaplan-Meier survival analysis method during the 6th and 12th months of the follow-up period and the end of the study. The decrease in drug requirement after laser treatment was analyzed by the Wilcoxon nonparametric test. Statistical significance was set at p < 0.05.

RESULTS

During the follow-up period, diode laser TSCPC reduced the IOP significantly. Our cumulative success rate was 56% at the end of the study. Cyclodiode treatment resulted in an IOP less than 22 mmHg in 97% of the eyes on the 6th month and 72% of the eyes on the 12th month with or without medication. The total retreatment rate of the study was 44%. More than one treatment was necessary, 8 times in the 1st month, 9 times in the 3rd month, 5 times in the 6th month and 3 times in the 12th month. The average number of antiglaucomatous drugs used was 2.8 before surgery and 1.2 after the 12th month follow-up period (p < 0.05). No eyes with graft failure after treatment were present. Visual acuity improved (> 2 Snellen lines of acuity) in two eyes and remained the same in the others. No serious side effects such as phthisis bulbi or hypotonia were observed.

CONCLUSIONS

Diode laser TSCPC appears to be a safe and effective procedure for the treatment of uncontrolled glaucoma secondary to penetrating keratoplasty.

Incisional surgery for angle closure glaucoma

Angle closure glaucoma remains a major challenge for ophthalmologists. The three main challenges in the treatment of angle closure glaucoma are, firstly, to achieve rapid reduction of intraocular pressure in acute angle closure glaucoma, secondly, to prevent progression to chronic angle closure glaucoma, and thirdly, to manage established chronic angle closure glaucoma. Incisional surgery for angle closure glaucoma is typically required when laser surgery and/or medical therapy fail to control the intraocular pressure or control progressive synechial closure. The role for surgical iridectomy and emergency trabeculectomy in the modern management of acute angle closure glaucoma is diminishing. Trabeculectomy, goniosynechialysis, cyclodestructive procedures, and glaucoma implant are effective surgical options for chronic angle closure glaucoma, but none of them have been shown to be more effective than the others with proper comparative clinical trials. Trabeculectomy and goniosynechialysis are often combined with cataract extraction, which appears to offer additional pressure-control benefits to patients with chronic angle closure glaucoma.

Visual loss after transscleral diode laser cyclophotocoagulation for primary open-angle and neovascular glaucoma

BACKGROUND AND OBJECTIVE

Varying incidences of visual loss after transscleral diode laser cyclophotocoagulation for uncontrolled intraocular pressure (IOP) have been reported. This study compared the treatment response in primary open-angle (POAG) and neovascular (NVG) glaucoma, particularly regarding vision loss.

PATIENTS AND METHODS

Case notes of consecutive patients who underwent transscleral diode laser cyclophotocoagulation between March 2001 and September 2005 were retrospectively reviewed. A diagnosis of POAG or NVG and at least 6 months of follow-up were required for inclusion. Conservative laser parameters were used. The treatment response of the POAG and NVG groups was compared.

RESULTS

Twenty-five eyes of23 patients with POAG and 14 eyes of 14 patients with NVG were studied. Mean follow-up was 22.4 and 12.9 months in the POAG and NVG groups, respectively. Post-treatment, both groups had significant reduction in mean IOP of 7.3 (29.2%) and 13.2 (36.6%) mm Hg, respectively (between group P = .18). One eye in each group had mild hypotony of 4 mm Hg, and no eyes became phthisical. Oral acetazolamide treatment was significantly reduced in both groups. Visual acuity post-treatment decreased in both groups; the POAG eyes had better initial visual acuity and lost more visual acuity. Nine of 25 (36%) POAG and 4 of 8 (50%) NVG eyes lost 2 or more LogMAR lines.

CONCLUSIONS

Transscleral diode laser cyclophotocoagulation reduced IOP and medication requirements in POAG and NVG. Patients should be warned that visual loss may occur, especially in endstage glaucoma.

Scleral thinning after transcleral diode laser cycloablation

BACKGROUND AND OBJECTIVE

To highlight the occurrence of scleral thinning after transcleral diode laser cycloablation therapy.

PATIENTS AND METHODS

A retrospective chart review was done of consecutive patients from the glaucoma and pediatric ophthalmology clinics of a tertiary eye care center in whom the presence of scleral thinning was noted after transcleral diode laser cycloablation therapy.

RESULTS

Eleven eyes of 9 patients with various types of glaucoma (traumatic, congenital, juvenile, steroid induced, uveitic, and secondary angle closure) were found to have scleral thinning after undergoing transcleral diode laser cycloablation therapy for refractory glaucoma. Seven patients had undergone only 1 session before new scleral thinning was noted. Two patients had bilateral transcleral diode laser cycloablation therapy and subsequent bilateral thinning.

CONCLUSIONS

Scleral thinning may occur after diode laser cycloablation therapy even with only 1 treatment session and intact sclera, and young patients may be more susceptible to thinning.

Refractory glaucoma ? tube or diode?

BACKGROUND

The aim of the present study was to assess the relative effectiveness of tube surgery and cyclodiode laser in terms of achieving intraocular pressure control.

METHODS

A retrospective study was undertaken to compare patients undergoing double plate Molteno tube implantation with patients undergoing diode cyclophotocoagulation. Intraocular pressure (IOP) was documented at 7 days prior to surgery and postoperatively at various time points. Surgical success was defined as a final IOP between 6 (inclusive) and 21 mmHg (inclusive), without the use of topical medication, while 'qualified' success was defined as IOP within the same range with the use of topical medication.

RESULTS

Twenty-eight diode patients and 26 tube patients were included for the study. An average follow up of 150 weeks (range = 21-322 weeks) was available. Mean preoperative IOP was 37 +/- 12 mmHg for the tube group and 39 +/- 16 mmHg for the diode group (t = 0.51, P = 0.61). The final IOP was 17 +/- 12 mmHg for the tube group and 21 +/- 13 mmHg for the diode group (t = 0.35, P = 0.73). Surgical success was achieved in 46% of tube eyes and 11% of diode eyes, while qualified success was achieved in 81% of tube eyes compared with 64% of eyes in the diode group. Two eyes which underwent diode became phthisical.

CONCLUSIONS

IOP control may be achieved in a greater number of patients with tube surgery. The possible benefits of IOP control in diode patients need to be weighed against the risks of long-term visual loss and the need for multiple re-treatments in this group.

Real-time imaging of transscleral diode laser cyclophotocoagulation by optical coherence tomography

PURPOSE

To present optical coherence tomography (OCT) for real-time imaging of cyclophotocoagulation effects.

METHODS

In a pilot study, real-time transscleral OCT images were generated during diode laser cyclophotocoagulation in four eyes of four patients suffering from uncontrolled glaucoma using a specially designed contact applicator containing the OCT fiber, a focussing fiber optic and the fiber of the diode laser.

RESULTS

When the contact system was used, two layers could be differentiated: a superficial thick hyperreflective complex representing conjunctiva, Tenon's capsule, episclera and sclera, and a thinner hyporeflective layer representing the ciliary body. During cyclophotocoagulation, real-time OCT showed a clear and sudden thickening of the ciliary body in the treated area.

CONCLUSION

This new OCT device represents a first step towards visual, real-time imaging of cyclophotocoagulation. After further adaptation of the delivery system, further trials are needed to correlate OCT findings with aqueous production and intraocular pressure.

Diode laser cycloablation in adult glaucoma: long-term results of a standard protocol and review of current literature

BACKGROUND

To study the long-term efficacy and safety of diode laser cycloablation under a standard protocol in refractory glaucoma.

METHODS

A retrospective study involving 42 eyes (39 patients), observed for 36-84 (mean 65.7) months after cycloablation involving 14 burns of 2-W power and 2-s duration, over 270 degrees of the ciliary body.

RESULTS

By final review, mean intraocular pressure (IOP) had dropped by 50.3% from 31.4 +/- 8.8 mmHg before treatment to 15.6 +/- 6.3 mmHg (P < 0.0001). Thirty-seven of the 42 eyes (88.1%) achieved IOP < 22 mmHg. Thirty-five of the 42 eyes (83.3%) eyes achieved IOP reduction > or = 30% from baseline levels. The mean number of antiglaucoma medications per eye dropped from 2.55 +/- 0.83 to 1.71 +/- 1.44 (P = 0.0004). The percentage of eyes requiring oral acetazolamide dropped from 92.9% to 11.9% (P < 0.0001). About 59.6% of eyes required multiple treatment sessions (mean 2.17). Twenty-seven (64.3%) eyes suffered deterioration, 11 (26.2%) maintained stability and 4 (9.5%) exhibited improvement of visual acuity. No relationship between the number of treatment sessions and visual outcome was evident.

CONCLUSIONS

This conservative repeatable protocol affords delivery of the minimum dose of photocoagulation necessary to achieve a safe, long-term ocular hypotensive response, while minimizing the risk of serious adverse effects, and is valuable in the difficult treatment of refractory glaucoma.

Long-term efficacy and visual acuity following transscleral diode laser photocoagulation in cases of refractory and non-refractory glaucoma

AIMS

Transscleral diode laser cyclophotocoagulation (TSCP) is widely accepted in the treatment of refractory glaucoma especially in eyes with poor vision. However, until recently, there has been a reluctance to extend its use to eyes with good visual acuity (VA). The aims of this study were to evaluate the long-term efficacy and safety of TSCP for a range of glaucoma conditions, with particular emphasis on post-treatment VA in seeing eyes.

METHODS

A retrospective analysis of case notes of 74 treated eyes was conducted over a period of 4-30 months (mean 12.5 months).

RESULTS

Mean (SD) intraocular pressure (IOP) was reduced by 43% from 40.3 (6.7) to 21.1 mmHg (5.4) at the final index visit. Of all patients, 58% had a reduction in glaucoma drops and all discontinued oral Acetazolamide; 9% experienced complications. Mean VA was preserved in the subgroups with good vision, although 3/23 (13%) patients with primary open-angle glaucoma (POAG) lost vision due to cataract and glaucoma progression. There were no cases of hypotony (IOP<or=5 mmHg) or phthisis and only one eye required re-treatment.

CONCLUSIONS

TSCP is highly effective and safe for various types of glaucoma, and its use can be extended to eyes with good vision.

Macromorphometric study on ciliary body location in canine eyes

This macroscopic study firstly examined the precise locational information of the canine ciliary body, i.e., the ciliary crown and the ciliary ring in the beagle. The safe and effective transscleral laser photocoagulation technique requires the accurate location of the ciliary body. In both sides of the eyeball in 10 beagle dogs, the width of the ciliary ring and the distance from the limbus to the ciliary ring were measured with calipers using a stereomicroscope at the 8 points. The widest portion of ciliary body was found at the dorsal to ventro-temporal area of the lateral canthus (lateral portion of the eyelid; ear side). In contrast, the narrowest portion was seen at the ventro-nasal to nasal area of the medial canthus (medial portion of the eyelid; nasal quadrants). Use of transscleral photocoagulation at the present narrowest area of ciliary body may carry a high risk of destruction of the optic portion of retina.

Transscleral diode laser cyclophotocoagulation as primary and secondary surgical treatment in primary open-angle and pseudoexfoliatve glaucoma

BACKGROUND

Transscleral diode laser cyclophotocoagulation (TDLC) has been used successfully in the treatment of refractive glaucoma. However, little is known about TDLC as a primary or secondary surgical procedure in primary open-angle and pseudoexfoliative glaucoma.

METHODS

In a retrospective chart review we analyzed 90 eyes (48 OD/42 OS) in 90 patients (mean age 75 years, range 60-92 years; 51 men/39 woman) with primary open-angle glaucoma (n=66) and pseudoexfoliative glaucoma (n=24) who consecutively underwent TDLC with a minimum follow-up of 24 months. In 24 eyes (26.7%) TDLC was the primary surgical treatment. Mean energy was 80 J (60-92 J). Success was defined as a final intraocular pressure (IOP) between 4 and 18 mmHg, a minimum IOP reduction of 20% and the absence of major complications.

RESULTS

The overall success rate was 36.7% after 24 months. A mean of 1.3 procedures was performed per patient. No correlation between age and success rate (p=0.887) or gender and success rate (p=0.895) was seen. There was no significant reduction in antiglaucomatous medication (p=0.208), no significant loss of visual acuity (p=0.324) nor a significant relationship between loss of visual acuity and failure of treatment (p=0.201). In patients with primary open-angle glaucoma the success rate was 40.9% after 24 months; in patients with pseudoexfoliative glaucoma it was 25.0% after 24 months. There was no significant difference between primary open-angle glaucoma and pseudoexfoliative glaucoma (p=0.684). Previous ocular surgery decreased the success probability from 45.8 to 33.3% (p=0.001). Prolonged hypotonia occurred in 1 patient. No phthisis bulbi developed.

CONCLUSIONS

Transscleral diode laser cyclophotocoagulation is an effective and safe method not only in the treatment of refractive glaucoma, but also as a primary surgical procedure in primary open-angle and pseudoexfoliative glaucoma. TDLC may be used more widely in glaucoma therapy, although further long-term studies have to confirm these findings.

Sympathetic ophthalmia in Singapore: new trends in an old disease

BACKGROUND

Sympathetic ophthalmia (SO) is an uncommon uveitic condition that occurs after injury to the uvea of one eye and may occur after accidental ocular trauma or ocular surgery. We sought to investigate the common causes of SO in Singapore and the demographic profile as well as the final visual acuity after treatment in these patients.

METHODS

This was a retrospective, non-comparative case series in which patients with SO were identified from the Singapore National Eye Centre uveitis database in the period between 1993 and 2003. The patients' case records were examined for a history of ocular trauma or surgery and subsequent development of bilateral or contralateral uveitis consistent with SO or histopathological evidence of SO in enucleated eyes. The medical records of these patients were reviewed for details of the inciting event, presentation, treatment, and visual acuity.

RESULTS

A total of ten patients (six men and four women) were diagnosed with SO in the period of study. SO occurred after accidental trauma in three patients and following ocular surgery in seven. Vitreoretinal surgery was responsible for four of these cases, and diode laser cyclophotoablation for another two, whereas neodymium:yttrium-aluminium-garnet (Nd:YAG) laser cyclotherapy was the cause in the last patient. Overall, six of ten patients underwent at least one vitreoretinal procedure. Four of the patients had a final visual acuity of 6/15 or better, whereas five had a visual acuity of 6/30 or worse. Good final visual acuity appeared to be associated with early initiation of immunosuppressive therapy.

CONCLUSION

In this series, ocular surgery, especially vitreoretinal surgery, had overtaken non-surgical trauma as the major cause of SO. A good outcome was possible in most cases if an early diagnosis was made and immunosuppressive treatment started promptly.

Diode laser transcleral cyclophotocoagulation for refractory glaucoma: a 1 year follow-up of patients treated using an aggressive protocol

PURPOSE

To prospectively evaluate the intraocular pressure (IOP) lowering ability, retreatment rate, and complications of transcleral Diode laser cyclophotocoagulation using a higher power setting than what is generally recommended.

PATIENTS AND METHODS

A total of 36 eyes of thirty six patients with refractory glaucoma, and who fitted our inclusion criteria underwent Diode cyclophotocoagulation. The laser power was set at 2250 mW, with a duration of 2000 ms, and a total number of 28 shots for the first treatment and 20 shots for any consequent one. The patients were followed up for 1 year with the following outcomes being analysed: IOP, visual acuity, change in the number of medications, and complications.

RESULTS

The mean IOP decrease was 53% (P < 0.05), and 72.2% of the patients maintained an IOP < or =21 mmHg for the whole duration of the study The number of medications necessary to control the pressure, significantly dropped from 2.8 to 0.89 (P < 0.05), and 25% of the patients needed the treatment to be repeated only once. In all, 33% of the patients improved their visual acuity after the treatment, while 22% worsened, and the rest stayed the same. The most common treatment complications were conjunctival injection and corneal oedema, and these were both transient and reversible.

CONCLUSION

The use of the higher power setting of 2250 mW, resulted in a sustained lower IOP, less use of medications, less need for retreatment, relative preservation of visual acuity, and only reversible complications.

Contact diode laser transscleral cyclophotocoagulation for refractory glaucoma: comparison of two treatment protocols

BACKGROUND

Diode laser transscleral cyclophotocoagulation has shown promising results in the treatment of refractory glaucoma. Treatment with a lower energy level per pulse and lower total energy is safer but may be less effective. We performed a study to evaluate the clinical effectiveness and safety of contact transscleral cyclophotocoagulation using two different protocols in the treatment of Chinese patients with refractory glaucoma.

METHODS

Review of the records of 129 patients with refractory glaucoma who underwent contact transscleral cyclophotocoagulation for the first time performed by two different surgeons. In group 1 (73 eyes) the output was 2.5 W and the exposure time 2 seconds; in group 2 (56 eyes) the corresponding values were 2.0 W and 1.5 seconds. We recorded the number of antiglaucoma medications used, Snellen visual acuity, slit-lamp biomicroscopic findings, intraocular pressure (IOP) and findings on ophthalmoscopy with pupil dilation before and 1 day, 1 week, 1 month, 3 months and 6 months after treatment.

RESULTS

The mean age of the patients was 56.4 years (standard deviation [SD] 18.3 years) in group 1 and 53.5 (SD 18.0) years in group 2. The most frequent diagnoses were neovascular glaucoma secondary to proliferative diabetic retinopathy or central retinal vein occlusion, and glaucoma associated with penetrating keratoplasty. The mean number of laser pulse applications per patient was 27 (SD 5.1) (range 10-36) in group 1 and 55 (SD 6.1) (range 40-60) in group 2. One month after treatment, the mean reduction in IOP was 20.2 mm Hg (SD 14.2 mm Hg) in group 1 and 13.7 mm Hg (SD 15.8 mm Hg) in group 2, a significant difference (p = 0.035). There was no difference between the two groups in the mean reduction in IOP at 6 months (19.1 mm Hg [SD 15.1 mm Hg] vs. 14.2 mm Hg [SD 16.3 mm Hg]). The mean reduction in the number of antiglaucoma medications was 1.2 (SD 1.1) in group 1 and 0.6 (SD 1.0) in group 2 (p = 0.003). The incidence rates of transient hyphema in the anterior chamber (23.3% vs. 7.1%) and of transient exudate in the anterior chamber (8.2% vs. 0.0%) were significantly higher in group 1 than in group 2 (p < 0.005).

INTERPRETATION

To achieve greater IOP reduction with diode laser transscleral cyclophotocoagulation, an increase in energy per pulse may be more effective than an increase in total applications.

Trans-scleral diode laser cyclophoto-coagulation in the treatment of diabetic neovascular glaucoma

AIMS

To assess efficacy of trans-scleral diode laser cyclophotocoagulation in the treatment of diabetic neovascular glaucoma refractory to medical therapy.

METHODS

Case notes of 20 eyes of 20 patients who had the treatment were analysed. The mean follow-up after initial treatment was 22.5 months (range of 18-24).

RESULTS

Mean (SD) pretreatment intraocular pressure (IOP) for the 20 eyes was 34.4 mmHg (9.5) reducing to 18.2 mmHg (12.4) at the final index visit (P = 0.0001). The mean (SD) number of topical antiglaucoma medication was significantly lowered from 3.9 (0.3) to 1.2 (1.3). Four patients had visual acuity of 6/60 or better before the treatment. Two of them maintained the same level of vision and the other two had their vision reduced over the course of study; however, none of them deteriorated beyond 6/60. Six out of the remaining 16 patients who had vision of counting fingers or worse before treatment progressed to no perception of light at the final index visit. The mean (SD) number of treatment sessions was 1.45 (0.68). A total of 10 patients had previous pars plana vitrectomy (PPV). Patients with two or more PPVs developed hypotony (IOP </=5). There were five eyes with hypotony, one of which became phthisical.

CONCLUSION

Trans-scleral diode laser cyclophotocoagulation is a useful tool in the management of diabetic neovascular glaucoma. The current treatment regime needs to be adjusted to reflect higher risk of hypotony and phthisis in diabetic neovascular glaucoma in eyes that have had multiple pars plana vitrectomies.

Sympathetic ophthalmia following ciliary body laser cyclophotocoagulation for rubeotic glaucoma

A 60-year-old Asian man presented with left rubeotic glaucoma secondary to a central retinal vein occlusion. He was successfully treated with laser diode cyclophotocoagulation of the ciliary body. Nine months later he developed right progressive visual loss, headache, corneal oedema, anterior chamber cells, flare, mutton fat keratic precipitates, a swollen disc, and a minimal inferior visual field defect. A diagnosis of sympathetic ophthalmia was made, which was confirmed by characteristic findings seen on fluorescein and indocyanine green angiography.

Assessing the 'cyclodiode G-probe' using a grey scale test: reproducibility and differences between probes

AIMS

1. To determine the number of clinicians performing cyclodiode therapy who reuse the 'G-probe' used for the delivery of cyclodiode therapy. 2. To show a simple method to assess the output of the 'G-probe' that can be used in the clinical setting.

METHODS

A total of 71 questionnaires were sent to ophthalmologists who have an Oculight SLx Iris Medical Diode Laser. Ophthalmologists were asked as to whether they performed cycloablative therapy using the 'G-probe' and whether they reused the G-probe. They were also asked as to the frequency of any reuse of probes. To determine the output of the 'G-probe', paper copies of a custom-made grey scale chart containing graded blocks of increasing shades of grey densities were produced. A special probe holder was made so that the G-probe tip could be held at a fixed distance from the grey scale chart. Laser burns were made on the grey scale using this arrangement and measurements of the burn size were made. After using 'standard settings' of 2000 ms and 2000 mW, 'threshold' burns were defined. Five new probes (with two different operators) were tested to assess the interprobe, interoperator, and intersheet variability of test. Probes were then tested for the burn size produced between 1000 and 3000 mW, and 1000 and 3000 ms.

RESULTS

Results from the questionnaire showed that of the 44 respondents (62.0% response), 93.2% performed cyclodiode therapy with 58.5% reusing the G-probe. Among them, 56.1% reused probes on more than one occasion. Results from testing a new G-probe on the grey scale chart showed that with 'standard settings', highly reproducible burns at grey density 8 could be produced. No significant interprobe, interoperator, and intersheet variations were noted. Above 3 J of laser energy, the test could detect a 20% increase in energy settings and it was found that at levels of 4 J or above, alterations to the power setting had a greater influence on burn production than alterations to the time setting.

CONCLUSIONS

This study demonstrates 1. that many clinicians in the UK reuse G-probes, 2. a simple, quick, and highly reproducible method to assess the laser output from the G-probe used for cyclodiode therapy. The method can help the ophthalmic surgeon to test the G-probe prior to commencement of therapy and with a standard treatment protocol, may produce a more predictable intraocular pressure reduction.

Effect of diode laser contact transscleral pars plana photocoagulation on intraocular pressure in glaucoma

PURPOSE

To evaluate the efficacy of diode laser contact transscleral pars plana photocoagulation (CTPPP) for intraocular pressure (IOP) control in glaucoma and its clinical application.

METHOD

A prospective, non-randomized hospital-based pilot study was conducted. Fourteen patients with poor visual acuity (VA worse than 6/60) and medically uncontrolled, refractory glaucoma were recruited, and CTPPP was performed after informed consent.

RESULTS

Mean preoperative IOP was 41.0 mmHg (SD 12.6, range 27-70, n = 14). At 1 week postoperatively, IOP was reduced in 12 of 14 (86%) patients to a mean of 28.6 mmHg (SD 15.8, range 3-55, n = 14). This represented a mean decrease of 12.4 mmHg. Mean IOP was 34.0 mmHg (SD 17.4, range 5-71, n = 14) and 31.6 mmHg (SD 13.4, range 5-22, n = 12) at 4 and 12 weeks, respectively. The IOP reduction was significant at 1 week (P = 0.001, paired t-test) and at 12 weeks (P = 0.04, paired t-test). The two patients with preoperative pain reported abolition of pain after the procedure. Seven of 13 patients on preoperative antiglaucoma eye drops did not require eye drops postoperatively.

CONCLUSION

Diode laser CTPPP was found to significantly reduce IOP in the majority of patients at 1 week postoperatively, with less but still significant effect at 12 weeks. Its potential application as a procedure for short-term IOP reduction in medically uncontrolled glaucoma requiring filtering surgery needs to be further investigated.

Efficacy and safety of contact transscleral diode laser cyclophotocoagulation for advanced glaucoma

BACKGROUND

This prospective study was conducted to evaluate the efficacy and safety of transscleral diode laser cyclophotocoagulation in refractory, advanced glaucoma.

PATIENTS AND METHODS

One hundred eyes of 100 patients with advanced glaucoma refractory to medical treatment were consecutively treated by transscleral diode laser cyclophotocoagulation. Success was defined as a final intraocular pressure between 5 and 21 mm Hg in eyes with a visual acuity of more than hard movements, relief of pain in eyes with a visual acuity of hand movements or less including blind eyes, and reduction of carbonic anhydrase inhibitor use in all eyes.

RESULTS

Ninety-three patients were followed up for 1 year after initial treatment. The overall success rate was 74.2%. Of 60 eyes with a visual acuity of more than hand movements, intraocular pressure between 5 and 21 mm Hg was achieved in 41 (68.3%) eyes. Relief of pain was achieved in 28 (84.8%) of 33 eyes. Reduction of systemic carbonic anhydrase inhibitor use was highly significant (P < 0.0001). Within 1 year, 173 laser procedures (mean, 1.9 per patient) were performed. The probability of success increased significantly (P = 0.004) with the age of the patients, from 55% for patients younger than the age of 50 years to 83% for patients older than the age of 50 years. Previous ocular surgery decreased the success probability from 95% to 68% (P = 0.02). A high success rate was achieved in inflammatory glaucoma (75%), primary open-angle glaucoma (89.5%), and neovascular glaucoma (86.7%). The results were relatively poor in traumatic glaucoma (57.1%), aphakic glaucoma (57.1%), and congenital or juvenile glaucoma (62.5%). No significant relationship between loss of visual acuity and failure of treatment (P = 0.3) could be detected. No phthisis bulbi or persistent hypotonia developed.

CONCLUSIONS

Transscleral diode laser cyclophotocoagulation is an effective and safe method for the treatment of advanced, refractory glaucoma. However, repeated treatments are often necessary. Success of treatment depends on the age of patients, previous surgery, and the type of glaucoma.

Pupillary distortion and staphyloma following trans-scleral contact diode laser cyclophotocoagulation: a clinicopathological study of three patients

PURPOSE

To search for the cause of scleral thinning and pupillary distortion following trans-scleral contact diode laser cyclophotocoagulation (TCDLC).

METHODS

We reviewed the records of 3 patients in whom there were complications of scleral thinning and pupillary distortion following TCDLC. One of the eyes was later enucleated, and we present the histopathological findings. Using the histopathological features in this patient, we discuss the possible pathogenesis of the scleral thinning and pupillary distortion.

RESULTS

Case 1 is a 46-year-old white woman who following TCDLC in an area of clinically normal sclera developed a staphyloma. Case 2 is a 52-year-old white woman who following TCDLC in an area of scarred sclera developed mild thinning. Case 3 is an 85-year-old white man who following TCDLC developed pupillary distortion, and gonioscopy revealed damage to the peripheral iris. Histological examination of case 1 revealed the staphyloma covered by a thin layer of conjunctival epithelium, collagen and vitreous condensation. We also observed cicatricial cilary body contraction causing distortion of the pupil and lens.

CONCLUSIONS

Therapeutic TCDLC can produce scarring of the iris root, anterior chamber angle, draining structures and ciliary body, and may result in pupillary distortion. Pre-existing scleral scars may predispose to scleral damage following TCDLC. We discuss a simple strategy to avoid this complication of TCDLC.

Transscleral contact krypton laser cyclophotocoagulation for treatment of posttraumatic glaucoma

PURPOSE

To evaluate the usefulness of the krypton laser for transscleral contact cyclophotocoagulation in the treatment of posttraumatic glaucoma.

PATIENTS AND METHODS

A total of 18 eyes of 18 patients with therapy-resistant posttraumatic glaucoma treated with krypton laser cyclophotocoagulation from 1991 to 1996 were included in this review. The krypton laser was delivered by a fiberoptic probe with simultaneous compression of the sclera. The energy used was 3 to 5 J per application at the tip of the probe, with an exposure time of 10 seconds. The treatment covered 90 to 360 degrees of the ciliary body with approximately 10 applications per quadrant.

RESULTS

With one or more cyclophotocoagulation treatments, the intraocular pressure decreased from the baseline mean (+/- standard deviation) of 32.6 +/- 12.8 mm Hg to 23.6 +/- 10.3 mm Hg (n = 17) at 1 month, to 21.8 +/- 7.5 mm Hg (n = 13) at 3 months, to 22.5 +/- 7.6 mm Hg (n = 13) at 6 months, and to 19.6 +/- 10.5 mm Hg (n = 18) at the last control visit (mean, 19.4 months; range, 3 weeks to 73 months) after cyclophotocoagulation but no other glaucoma procedure. At baseline, 17 (94%) of 18 patients were taking glaucoma medication, as were 15 (83%) of 18 patients at the last control visit. One (6%) case of phthisis occurred.

CONCLUSIONS

Krypton laser cyclophotocoagulation is an effective and reasonably well tolerated means of lowering intraocular pressure in posttraumatic glaucoma. Because of the refractory nature of the disease, repeated treatments may be needed.

Long-term outcome of cyclocryotherapy for refractory pediatric glaucoma

OBJECTIVE

To evaluate the success rate and long-term outcome of cyclocryotherapy for refractory pediatric glaucoma.

DESIGN

Retrospective interventional case series.

PARTICIPANTS

A total of 64 eyes of 49 patients from 2 institutions with pediatric glaucomas resistant to conventional medical and surgical therapies treated with cyclocryotherapy from 1975 to 1996 were included in this review.

INTERVENTION

Cyclocryotherapy was performed on eyes with pediatric glaucoma resistant to maximal medical and surgical interventions. Each cyclocryotherapy session was evaluated in terms of area treated, temperature, and number of applications placed.

MAIN OUTCOME MEASURES

Criteria for success included intraocular pressure (IOP) of 21 mmHg or less without devastating complications or need for further glaucoma surgery.

RESULTS

The mean baseline pretreatment IOP of all eyes was 30.0 +/- 8.1 mmHg. Six months after their last treatment, 42 eyes (66%) were successes. Longer term follow-up (mean, 4.8 +/- 3.3 years) yielded a lower final success rate in 28 eyes (44%). For these 28 eyes, mean IOP was reduced from 30.3 +/- 7.8 mmHg pretreatment to 16.8 +/- 4.0 mmHg after their last cyclocryotherapy treatment session (P < 0.001). The average number of cyclocryotherapy sessions for successful eyes was 4.1 +/- 4.0 (range, 1-17). The mean follow-up time for these successful eyes was 4.9 +/- 3.4 years. Devastating complications attributable to cyclocryotherapy included phthisis (5 eyes) and retinal detachment (5 eyes). Devastating complications occurred more frequently among eyes with aniridia than among all other eyes (nonaniridics) (50% vs. 11%, respectively; P < 0.05).

CONCLUSION

Cyclocryotherapy is an effective means of lowering IOP and is a reasonable treatment option in selected pediatric patients with refractory glaucoma. Eyes with aniridia experienced a very high rate of phthisis after cyclocryotherapy and may be poor candidates for this treatment.

Diode laser cyclophotocoagulation: dose-standardized therapy in end-stage glaucoma

BACKGROUND

Ciliary body ablation in end-stage glaucoma has been widely performed with cryotherapy and neodymium:yttrium aluminium garnet (Nd:YAG) laser, both techniques frequently involving considerable pain and postoperative inflammation, with an unpredictable final intraocular pressure (IOP) and a significant risk of phthisis. Diode laser cyclophotocoagulation (cyclodiode laser) has recently been introduced in an attempt to avoid some of these problems.

METHODS

Thirty patients with uncontrolled IOP and advanced glaucoma were divided on clinical grounds into two groups and were treated with either a half or a full standardized dose of laser (40 x 1500 mW for 1500 ms) and monitored for IOP control, visual acuity, postoperative inflammation and phthisis. Success of IOP control was defined as IOP < 22 mmHg or a decrease in IOP of > 30%; preservation of visual acuity or control of pain in blind eyes was also assessed.

RESULTS

A sustained lowering of IOP was achieved in 90% of patients, with a mean follow up of 10.4 months. For the full treatment cases (group A), mean (+/-SD) pre-operative and postoperative IOP was 49.4 +/- 11.2 and 25.8 +/- 17.7 mmHg, respectively (a 48% reduction); 55% of patients achieved IOP < 22 mmHg and 68% gained an IOP reduction of > 30%. For the half-treatment cases (group B). the mean pre-operative and postoperative IOP was 29.4 +/- 4.3 and 18.9 +/- 5.7 mmHg, respectively (a 36% reduction); 63% of patients achieved IOP < 22 mmHg and 50% gained an IOP reduction of > 30%. Neovascular glaucoma was present in 60% of patients; the full-treatment subgroup of these patients achieved a mean lowering of IOP of 58%. Of 22 sighted eyes, 11 (50%) recorded no change in vision; seven (32%) eyes lost and four (18%) eyes gained vision; pain control was achieved in six of eight blind eyes (75%). There was no significant postoperative inflammation, one case of hypotony and no suggestion to date of sympathetic ophthalmia.

CONCLUSION

Diode laser cyclophotocoagulation appears to be simple, safe and is frequently successful in the control of IOP in end-stage glaucoma. Optimum dosage parameters remain to be determined.

Diode laser contact transscleral cyclophotocoagulation for refractory glaucoma in Asian patients

PURPOSE

To evaluate the effectiveness and safety of diode laser contact transscleral cyclophotocoagulation in Asian patients with refractory glaucoma by lower energy settings with an innovative probe featuring a glass ball tip that focused the laser beam onto the ciliary body.

METHODS

This prospective clinical study included consecutive Asian patients with dark irides and confirmed for glaucoma. Only one eye of each patient was treated. Diode laser contact transscleral cyclophotocoagulation treatment was performed with the center of the probe placed 1.5 mm behind the limbus. About 30 pulses of 810-mm laser radiation (power, 1.8 to 2.0 W; duration, 0.3 to 0.5 second) were applied around the eye. Patients were examined at fixed postoperative intervals. Intraocular pressure levels and postoperative complications were recorded. The relation between patient and disease characteristics, total laser energy delivered, and intraocular pressure effects were analyzed.

RESULTS

Thirty-three patients were studied, with a mean follow-up period of 9.4 months. An average 56% of patients showed a 30% or greater drop in intraocular pressure. About 38% of patients achieved sustained intraocular pressure lowering to below 22 mm Hg at 18 months. Complications were few and included transient hypotony and iritis.

CONCLUSIONS

In Asian patients with refractory glaucoma or painful glaucomatous eyes with poor visual acuity (defined for this study as worse than 20/200), low-energy-setting diode laser contact transscleral cyclophotocoagulation by means of the glass ball probe is relatively effective and safe.

Real-time control for transscleral cyclophotocoagulation

BACKGROUND

In transscleral cyclophotocoagulation, the surgeon cannot directly observe the applied laser effects. Overdosage, possibly resulting in unwanted pop effects, or underdosage with no therapeutic effect therefore often occur.

METHOD AND MATERIALS

Laser radiation passing through the sclera and ciliary body is partly reflected from the fundus and can be monitored from outside the eye by a detector system. Since all other parameters influencing the intensity of the recorded radiation are constant in time during one laser exposure, the time dependence of this radiation directly reflects the change of transmission of the treated tissue. The laser exposure therefore can be stopped by a computer when certain criteria of the recorded curves are fulfilled. In addition, the transmission curves are displayed on a monitor in real time, permitting the surgeon to interrupt the exposure. A Nd:YAG laser and a diode laser are connected to the device. After successful tests in enucleated porcine eyes which were evaluated histologically and in human cadaver eyes this method is applied to patients suffering from refractory glaucoma.

RESULTS

The transmission curves from enucleated porcine eyes show that the 810-nm diode laser is more appropriate for this method than the 1064-nm. Nd:YAG laser, because the radiation output of the diode is more stable in time and the tissue absorption is higher, both resulting in a larger dynamical range of useful signal. The curves from the porcine eyes, the human cadaver eyes and the curves from patients show a typical shape which allows interruption of exposure either by the surgeon or by the computer program before a pop effect occurs.

CONCLUSIONS

This new method increases the precision and safety of transscleral cyclophotocoagulation.

"Cyclodiode". Trans-scleral diode laser cyclophotocoagulation in the treatment of advanced refractory glaucoma

PURPOSE

To analyze the results of intraocular pressure (IOP) reduction by diode laser contact cyclophotocoagulation ("cyclodiode") in cases of advanced glaucoma refractory to alternative treatments.

METHODS

Two hundred and ten eyes of 195 patients, ages 1 to 89 years (mean, 51 years) were followed for 3 to 30 months (mean, 10 months) after cyclodiode treatment.

RESULTS

More than one treatment was given in 102 eyes (49%), and the overall mean number of treatments given per eye was 1.75 (range, 2-5). Mean pretreatment IOP was 34.1 mmHg (+/-10.6 mmHg). At last follow-up, mean IOP was 20.1 mmHg (+/-9.3 mmHg), and mean total medications was reduced from 2.3 to 1.7. Mean final IOP was lowest in patients with silicone oil glaucoma (17.3 mmHg), and the mean reduction in IOP was greatest in patients with neovascular glaucoma (23.9 mmHg). At last follow-up, visual acuity was worse than before treatment in 29% of eyes, unchanged in 60%, and better in 11%. Overall success rate (IOP < 22 mmHg) was 66% at a mean follow-up of 10 months. Phthisis occurred in one eye (0.5%), and chronic hypotony (0 mmHg < IOP < 5 mmHg for > 3 months) in a further two eyes (1%). Corneal graft decompensation followed treatment in two eyes, macular pucker occurred in one eye, and combined hyphema/vitreous hemorrhage in one patient.

CONCLUSIONS

Diode laser cycloablation is relatively safe and effective at controlling IOP in eyes with advanced refractory glaucoma in the short and medium term. With the treatment parameters used, multiple applications may be needed.

Transscleral diode laser cyclophotocoagulation for refractory pediatric glaucomas

PURPOSE

To evaluate the success of contact transscleral cyclophotocoagulation (TDC) in patients with refractory pediatric glaucomas.

METHODS

Twenty-six eyes of 20 patients with therapy-resistant pediatric glaucomas were included in this retrospective study. Subgroup analysis was performed for patients 10 or younger and patients older than 10 at time of first TDC procedure. Diode laser cyclophotocoagulation was applied using a fiber optic G-probe. Follow up until time of failure or for a minimum of 6 months was obtained for all procedures in all eyes. Failure was defined as intraocular pressure (IOP) greater than 21 mm Hg, repeat of TDC due to clinically inadequate IOP control, progression to another procedure, or serious complication.

RESULTS

Baseline mean pretreatment IOP was 34.2 +/- 10.4 mm Hg (range, 15 to 62 mm Hg). Ten of 26 eyes (38%) were successful 6 months after initial TDC. A mean decrease in IOP of 10.3 +/- 14.7 mm Hg was noted after the first procedure (P < 0.05). Eighteen eyes (70%) were retreated at least once. The mean decrease in IOP for all patients after all procedures was 12.9 +/- 13.4 mm Hg (P < 0.001). This represents a mean percent decrease in IOP of 33.2 +/- 6.9%. The overall success rate was 50%, including retreated patients. The younger and older subgroups did not differ with regard to overall success, time to failure, or retreatment rats. One patient suffered a retinal detachment. Visual loss was noted in 4 of 22 eyes with reliable visual acuity measurements.

CONCLUSION

TDC is an effective means of decreasing IOP in some patients with refractory pediatric glaucomas. Although the retreatment rate is high, the procedure generally is well tolerated with few complications.

Ciliary body ablation: where are we and how did we get here?

Management of intraocular pressure remains the cornerstone of glaucoma treatment. Related medical and surgical practices involve increasing aqueous outflow or decreasing aqueous production. Filtration procedures that increase aqueous outflow are the first-line surgical defense in glaucoma. However, some cases of glaucoma are resistant to such treatment. In these cases, ciliary body ablation by various methods has had substantial success. Surgical manipulation of aqueous production has been used in glaucoma management since the turn of the century. Techniques have progressed markedly as technology has produced more discrete therapies designed to decrease aqueous production by destroying ciliary body epithelium. Over the past 90 years success has been achieved with a wide range of techniques, from surgical disinsertion of the ciliary body to recent laser and ultrasound techniques. With the development of more precise contact lasers and endoscopic visualization, side effects have been reduced and clinical success rates increased.