Table 1

Patient characteristics and preoperative state and risk factors*

Molteno implant n = 45 eyes (43 patients)Trabeculectomy n = 94 eyes (79 patients)
*More than one risk factor present in some cases.
Sex29 male; 14 female30 male; 49 female
Age at operation (years)78.7 (range 65–95)78.5 (56–92)
Diagnosis
    Primary open angle glaucoma23 (51%)72 (77%)
    Primary open angle glaucoma with pseudoexfoliation22 (49%)22 (23%)
Preoperative visual acuity
    ⩾20/302 (4%)15 (16%)
    <20/30–20/400>32 (71%)63 (67%)
    ⩽20/40011 (24%)16 (17%)
Preoperative area of field remaining
    80–100%14 (31%)25 (27%)
    60–79%6 (13%)23 (25%)
    40–59%7 (16%)19 (20%)
    20–39%11 (24%)10 (11%)
    0–19%7 (16%)10 (11%)
    Not known06 (6%)
Advanced field loss threatening fixation7 (16%)6 (6%)
Very advanced field loss involving fixation7 (16%)11(12%)
Cornea guttata9 (20%)0
Previous ocular surgery
    Trabeculectomy9 (20%)2 (2%)
    Sinusotomy01 (1%)
    Laser peripheral iridotomy1 (2%)0
    Argon laser trabeculoplasty1 (2%)1 (1%)
General risk factors
    Dementia7 (16%)3 (3%)
    Ischaemic heart disease, cerebrovascular accident/renal failure6 (13%)13 (14%)
    Chronic respiratory failure1 (2%)8 (9%)