Trabeculectomy + MMC Audit Mark Chiang, Clinical Research Fellow Mr. Peter Shah, Consultant Ophthalmic Surgeon Good Hope Hospital

Aim To assess success and complication rates of trabeculectomies augmented with mitomycin C To compare results to the National Trabeculectomy Survey To define the characteristics of patients undergoing trabeculectomy with MMC

Methods Prospective database of consecutive patients undergoing trabeculectomy + MMC under care of Mr. Peter Shah Data collected Demographics Pre-operative, operative and follow-up data

Results Total number of eyes = 123Total number of eyes = 123 Note retrieval 100%Note retrieval 100% 2004 Data update 99%2004 Data update 99%

Gender

Age at surgery Mean age = 55.6 years

Ethnicity

Glaucoma type

Pre-op medications Average no. of drops = 2.65 (36.6% on Diamox)

Surgeons

Intraocular pressures (pre-operative) HTG (108 eyes)NTG (15 eyes) Mean pre-op highest IOP 38.0 mmHg18.5 mmHg Mean pre-op IOP 24.1 mmHg15.7 mmHg

Intraocular pressures (post-operative) HTGNTG Mean IOP (1 year) 12.9 mmHg11.3 mmHg % IOP drop (1 year) 46.5%28.0% Mean IOP (latest follow-up) 13.0 mmHg10.6 mmHg % IOP drop (latest follow-up) 46.1%32.5%

IOP distribution (1 year)

Overall success (latest follow-up – mean 613 days) HTG (106 eyes)NTG (14 eyes) IOP ≤ % IOP ≤ %100% IOP ≤ %100% IOP reduction > 30% 71.7%57.1%

Success by ethnicity (1 year) AFC (23)Caucasian (59) IOP ≤ % (78.3%)98.3% IOP ≤ % (78.3%)94.9% IOP ≤ %86.4% IOP reduction > 30% 65.2%78.0%

Success by previous surgery (1 year) None (58)Intraocular (24) IOP ≤ % (96.6%)91.7% (90.9%) IOP ≤ % (96.6%)75% IOP ≤ %54.2% IOP reduction > 30% 75.9%70.8%

Bleb morphology (1 year) Excellent bleb morphology 75.0%

Bleb morphology (1 year) Satisfactory morphology 21.4%

Bleb morphology (1 year) Poor morphology 3.6%

Bleb Needling Revision 13.8% of patients (17/123) 64.7% males Mean pre-op highest IOP 40.7 mmHg 47.1% on Diamox pre-operatively 47.1% had previous intraocular surgery 41.2% required topical drops at latest follow-up 35.3% African-Caribbean

Post-op management

Complications

Clinically Significant Early Hypotony (CSEH) 4.9% of patients Required intervention Viscoelastic to AC Conjunctival / scleral flap suturing Analysis of CSEH reveals: 33.3% AFC 66.7% < 45 years of age

Follow-up failures (DNA) DNA in 6 patients during follow-up 4 African-Caribbean 2 Caucasian – 1 alcoholic / 1 psychiatric 5 males Mean age 45.7 years old Age < 45 Male African-Caribbean ethnicity

Surgery technique Fornix based conjunctival flap Wide sub-Tenons treatment with MMC (0.1 – 0.2 mg/ml for 1 – 3 mins) Pre-placed, buried, releasable ± adjustable scleral flap sutures Intra-op IOP titration Buried purse-string & mattress closure of conjunctiva and Tenons

Conclusion High success rates for this series Low complication rates for this series Results exceed National Trabeculectomy Survey Complications are more common in African-Caribbean patients and in young patients

Summary Success 97.2% Sight threatening complications 0.8% 0 Wipe-out 0 Endophthalmitis 0 Suprachoroidal haemorrhage 1 Late hypotony Clinically Significant Early Hypotony (requiring intervention) 4.9%

National Trabeculectomy Survey Success, IOP < 21 – 92% Complications Hypotony – 24.3% Hypotony maculopathy – 0.2% Endophthalmitis – 0.3% Wipe-out – 0.4% of total cohort, 5% in advanced glaucoma Cataract needing extraction – 2.5%

Other series Success – 80 – 90% Complications Hypotony – 4.8 – 47% Hypotony maculopathy – 4 – 12% Blebitis – 2 – 5.7% Endophthalmitis – 0.8 – 8% Wipe-out – 25% in one series Cataract needing operation during follow-up – 12 – 55%

BUT!!

It’s only possible with Good pre-operative, peri-operative and intensive post-operative care Good success with lower doses of MMC but 34% post-op 5-FU and 14% bleb needling revision

Trabeculectomy with MMC is a complex operation requiring high degree of manual dexterity and extensive glaucoma experience Suggest Fellowship training for all surgeons performing this operation With close Consultant supervision, high success rates for Fellows in training Discussion points

Actions Continue long-term analysis of series Target African-Caribbean and JOAG patients for intensive intervention Improve patient information Consider glaucoma support nurse help These results only possible with continued Fellow support

Pearls Identify thin tissues pre-op Small peritomy Stromal hydration Careful closure ? No MMC Thin Tissues + Leak = Early Failure

In AFC / thick tissues need early (<10 days) high flow into sub-Tenon space May need to remove both releasables Pearls

Thin conj and Tenons – need thick scleral flap to control aqueous outflow Pearls

JOAGs get hypotony Need early surgical intervention Beware of the young! Pearls