Compliance to recommendations in SIGN 144 pre-SIGN and post-SIGN
| Parameters from SIGN 144 | Pre-SIGN | Post-SIGN | P values |
| A minimum of two intraocular pressure readings on a single occasion using the same tonometer is recommended with type of tonometer specified | |||
| Number of readings | n= 104 | n= 152 | P= 0.02 |
| Reading taken on one occasion only | 64 (61.5%) | 69 (45.3%) | |
| Repeated readings on same occasion or >2 separate occasions | 38 (36.5%) | 82 (53.9%) | |
| Intraocular pressure not recorded | 2 (1.92%) | 1 (0.7%) | |
| To promote consistency between primary and secondary care, tonometry should be performed with Goldmann-type or Perkins-type tonometers | |||
| Type of tonometry | n= 102 | n= 151 | P=0.01* |
| Contact tonometry (CT) | 60 (58.8%) | 121 (79.6%) | |
| Non-contact tonometry (NCT) | 29 (28.4%) | 25 (16.4%) | |
| Both | 4 (3.9%) | 0 | |
| Not specified | 9 (8.8%) | 5 (3.3%) | |
| Van Herick's method or gonioscopy may be used to detect narrow anterior chamber angles in patients with ocular hypertension or suspected angle closure | |||
| Angle assessment | n= 104 | n= 152 | P< 0.001 |
| Yes | 15 (14.4%) | 50 (32.9%) | |
| No | 89 (85.6%) | 102 (67.1%) | |
| Central corneal thickness should be measured in patients with ocular hypertension or suspected glaucoma | |||
| Central corneal thickness | n= 104 | n= 152 | P< 0.001 |
| Yes | 3 (2.9%) | 76 (50.0%) | |
| No | 101 (97.1%) | 76 (50.0%) | |
| The narrowest rim:disc ratio and disc size should be recorded and considered alongside additional indicators of glaucoma, such as optic disc nerve fibre layer haemorrhage and cup:disc ratio asymmetry | |||
| Disc diameter | n= 104 | n= 152 | P< 0.001 |
| Yes | 4 (3.8%) | 30 (19.4%) | |
| No | 100 (96.2%) | 123 (80.6%) | |
| Rim:disc ratio | n= 104 | n= 152 | P= 0.64 |
| Yes | 3 (2.9%) | 3 (2.0%) | |
| No | 101 (97.1%) | 149 (98.0%) | |
| Cup:disc ratio | n= 104 | n= 152 | P< 0.001 |
| Yes | 61 (58.7%) | 127 (83.6%) | |
| No | 43 (41.3%) | 25 (16.4%) | |
| Recording of optic disc appearance† | n= 104 | n= 152 | P= 0.83 |
| Yes | 50 (48.1%) | 71(46.7%) | |
| No | 54 (51.9%) | 81(53.3%) | |
| Image attached | n= 104 | n= 152 | P< 0.001 |
| Yes | 8 (7.7%) | 56 (36.8%) | |
| No§ | 96 (92.3%) | 96 (63.2%) | |
| Standard automated perimetry is recommended for visual field testing—a minimum of two visual field tests with consistent findings | |||
| Number of visual fields done | n= 104 | n= 152 | P=0.07‡ |
| One visual field test | 65 (62.5%) | 67 (44.1%) | |
| Two or more/repeatable visual field tests | 33 (31.7%) | 65 (42.8%) | |
| No information on visual fields | 6 (5.8%) | 20 (13.2%) | |
| The optic discs should be photographed and the images transmitted with the electronic referral letter | |||
| Disc photograph taken | n= 104 | n= 152 | P< 0.001 |
| Yes | 15 (14.4%) | 59 (38.8%) | |
| No | 89 (85.6%) | 93 (61.2%) | |
*P values for comparison of CT and NCT only.
†Includes indicators like haemorrhage, neuroretinal rim thinning and so on.
‡P value for comparison of two fields versus one or no field.
§Perimetry not attached, however mentioned as 'abnormal visual fields', and so on, in referrals.
SIGN, Scottish Intercollegiate Guidelines Network.