Reporting post-operative complications in glaucoma surgical trials

The tables allow for the categorization of complications in terms of their timing after surgery, according to the following, somewhat arbitrary,

defi nitions:

Intraoperative: Occurring during the surgical procedure; Early: Occurring within fi rst postoperative month;

Late: Not present before one month, but occurring afterwards;

Early and Late: Present at some point both within fi rst month and after fi rst month;

Present at final visit: Self-explanatory.

In designing a surgical study, it is important for the investigator to determine what outcomes he/she will want to report. Hopefully these complication tables will help the investigator design the protocol to collect the desired information. For retrospective studies, they can serve as a guide for the clinical chart review.

We felt that mandating the ‘correct’ way to ascertain complications was beyond the scope of this chapter, and risked throwing away ‘good’ data because it was not ‘perfect’ data. For instance, the decision of when to look for a bleb leak, and then how to look for it, is debatable. As another example, the incidence of choroidal detachment is heavily dependent on how one looks. If B-scan ultrasonography were routinely performed one week after trabeculectomy, the incidence of choroidal detachment might be very high, but would all those choroidal detachments really represent complications? On the other hand, if the pupils were only dilated if the patient reported decreased vision, choroidal detachment would certainly be underreported. The critical point is that the investigator explicitly specify in the protocol the techniques that should be employed to ascertain complications and that the complications be defi ned ahead of time.

The cells in the Tables will usually include both a proportion and a percentage.

I. Intraoperative Complications

This table can be altered depending upon the surgical procedures under study. It can be modifi ed to accommodate new surgical procedures that may have their own unique complications.

Anesthetic or systemic complications

Retrobulbar hemorrhage

Subconjunctival hemorrhage

Conjunctival buttonhole

Severing of extraocular muscle tendon

Scleral fl ap problems

Iris prolapse

Wound leak

Anterior chamber bleeding

Serous choroidal detachment

Suprachoroidal hemorrhage

Scleral perforation

Vitreous prolapse

Rupture of trabeculo-Descemet’s membrane

II. General Post-operative Complications

II.1. Loss of visual acuity

Mild

Moderate

Severe

Total

Mild: 1-2 Snellen or ETDRS lines; Moderate: 3-4 lines; Severe: ≥ 5 lines

1Investigators must specify how hard they looked for choroidal detachment, e.g., dilated exam every visit, B scan ultrasonography on every visit, dilated exam only when patient reported reduced vision, etc.

2Blood can be defi ned as a dark appearing choroidal with abrupt onset of pain, and/or blood present on b scan ultrasound.

3Methods of ascertainment must be specifi ed, e.g.all patients underwent OCT on every visit; OCT was performed if there were a clinical suspicion of macular edema, etc.

II.3. Intraocular bleeding

Layered hyphema

Layered hyphema covering the pupil

Blood occluding the internal fi stula (or tube lumen)

Circulating blood in the AC and/or vitreous cavity decreasing vision

II.4. Lens opacity

All studies should have some a priori method for addressing lens opacity.

Pseudophakic eyes at baseline

Increased lens opacity

Cataract extraction

Baseline measure of cataract can include:

–Present or absent;

–Subjective grading as absent, mild, moderate, severe;

–Grading against LOCS photos;

–LOCS photos;

–Objective lens opacity measurement.

II.5. Corneal or graft decompensation

Number of eyes with decompensation at baseline

With decreased acuity of ≥ 2 lines from baseline

New onset painful bullous keratopathy

Requiring corneal surgery

Note: How the status of the cornea was determined at baseline, e.g., CCT, presence of guttata, specular microscopy, etc., must be specifi ed.

II.6. Inflammation

Requiring intraocular aspirate for diagnosis

Requiring chronic topical corticosteroids

Requiring systemic, periocular, or intraocular steroids

Note: How infl ammation was accessed: clinical exam, fl are meter, etc., must be specifi ed.

II.7. Retinal disease

N (%)

Vein occlusion

Artery occlusion

Macular hole

Macular edema

Retinal tear

With detachment requiring surgery

With detachment that could not be repaired

Note: Includes occurrences within three months of surgery (otherwise not attributable to the glaucoma surgery).

III. Complications Specific to Trabeculectomy (Bleb-related)

III.1. Dysesthesia or decreased uncorrected vision

Without obvious cause

With large or exposed bleb

With dellen

Note: Recommend instrument such as the glaucoma symptom scale.

III.2. High bleb (Tenon’s cyst)

Defi ned as taut, opalescent bleb with IOP ≥ 20 mmHg

High bleb

III.3. Bleb leak

The authors should determine a priori how a bleb leak will be detected. For example, ‘We defi ned bleb leak as a positive Seidel test. We performed the test using a fl uorescein strip, whenever the IOP was equal to 6 or less, or when the anterior chamber was shallow, or when there is a suspicion of blebitis. We did not consider diffuse ooze from the entire bleb surface as bleb leaks.’ Or, ‘All eyes underwent Seidel testing on every visit, regardless of bleb appearance or intraocular pressure. Bleb leak was defi ned as a positive Seidel test’.

With discrete hole

Without discrete hole

Requiring slit lamp intervention

Requiring operating room intervention

III.4. Infection

Blebitis (all)

With AC reaction

With hypopyon

Endophthalmitis

Blebitis: defi ned as pus-like material in the bleb with surrounding hyperemia, no vitreous reaction; Endophthalmitis: vitreous reaction in the setting of blebitis. Details of each case of endophthalmitis (culture results, visual outcomes, IOP results) should be documented in a footnote to the table or in the text of the manuscript.

IV. Complications Specific to Drainage Device Surgery

Tube corneal touch (tip of tube in contact with cornea)

Tube lenticular touch (all)

Without laceration of anterior capsule

With laceration of anterior capsule

Tube occlusion (all)

By iris

By vitreous

By other

Tube retraction (lumen of tip is no longer visible in the anterior chamber gonioscopally)

Tube exposure (transconjunctival)

Plate exposure

Plate displacement (symptomatic)