Trabeculectomy + MMCTrabeculectomy + MMCAuditAudit

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 mmHg 18.5 mmHg

Mean pre-op IOP

24.1 mmHg 15.7 mmHg

Intraocular pressures(post-operative)

HTG NTG

Mean IOP

(1 year)

12.9 mmHg 11.3 mmHg

% IOP drop

(1 year)

46.5% 28.0%

Mean IOP (latest follow-up)

13.0 mmHg 10.6 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 ≤ 21 97.2%

IOP ≤ 17 87.7% 100%

IOP ≤ 14 70.8% 100%

IOP reduction > 30%

71.7% 57.1%

Success by ethnicity(1 year)

AFC (23) Caucasian (59)

IOP ≤ 21 91.3% (78.3%) 98.3%

IOP ≤ 17 82.6% (78.3%) 94.9%

IOP ≤ 14 60.9% 86.4%

IOP reduction > 30%

65.2% 78.0%

Success by previous surgery (1 year)

None (58) Intraocular (24)

IOP ≤ 21 98.3% (96.6%) 91.7% (90.9%)

IOP ≤ 17 98.3% (96.6%) 75%

IOP ≤ 14 89.7% 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!!BUT!!

It’s only possible withIt’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