|
| Study | Type of the study | Year | Number of eyes | Treatment protocol | Study result |
|
| Spoor et al. [56] | Comparative observational study | 1990 | 22 eyes from 21 patients | 13 patients were treated with intravenous megadose methylprednisolone, 8 patients were treated with high-dose dexamethasone | 12 of 13 patients from methylprednisolone group and 7 of 9 eyes from dexamethasone group experienced improved visual function |
| The difference between two group was not significant |
| Seiff [47] | Comparative observational study | 1990 | 36 | 21 patients were acutely treated with high-dose intravenous dexamethasone and 15 were not | 62% of the treated patients and 33% of the untreated patients showed visual improvement |
| The difference was not statistically significant |
| Maureillo et al. [57] | Non-comparative observational study | 1992 | 23 | High-dose intravenous steroids were initiated in all patients | Nine of 16 patients who received steroids only showed significant improvement |
| If vision did not improve significantly after 24 to 48 hours, decompression of the optic nerve was considered |
| Chou et al. [45] | Comparative observational study | 1996 | 58 | 23 patients were treated with intravenous dexamethasone or oral prednisolone; 25 patients underwent optic canal decompression in addition to medical treatment | 13 of the 23 cases (57%) in the medical group had visual improvement |
| 10 cases were monitored without treatment | 15 of 25 cases (60%) in the surgical group had visual improvement; |
| none of the control patients showed any improvement in visual acuity |
| Levin et al. [22] | Comparative observational study | 1999 | 133 | 9 patients received no treatment, 85 patients were treated with corticosteroids, and 33 patients underwent optic canal decompression | 32% of the surgery group, 57% of the untreated group, and 52% of the steroid group showed visual improvement; there were no significant differences between any of the treatment groups |
| Wang et al. [23] | Comparative observational study | 2001 | 61 | 25 patients treated with high-dose steroids, 7 patients underwent optic nerve decompression, 13 received no treatment, and others underwent facial surgery | There was no significant difference in the improvement of visual acuity in patients treated with surgical versus nonsurgical methods |
| Kitthaweesin [58] | Comparative observational study | 2001 | 21 | 10 patients received dexamethasone intravenously, and 11 received intravenous methylprednisolone | 70% of patients treated with dexamethasone, and 45% of patients treated with methylprednisolone experienced visual improvement |
| There were no significant differences in the visual improvement between the two groups |
| Chuenkongkaew and Chirapapaisan [59] | Comparative observational study | 2002 | 44 | 22 patients selected to receive intravenous high-dose dexamethasone, and 20 cases received megadose methylprednisolone | Visual improvement was shown in 37.5% of the dexamethasone group and 50% of the methylprednisolone group. There was no significant difference between the two groups |
| Yip et al. [60] | Comparative observational study | 2002 | 21 | 9 patients were treated with intravenous methylprednisolone, and 12 patients were treated conservatively | Visual recovery was observed in 44.4% of eyes treated with methylprednisolone and in 33.3% treated conservatively, there were no differences in visual improvement between the two groups |
| Yang et al. [61] | Comparative observational study | 2004 | 42 | 24 patients received treatment with megadose steroids combined with optic nerve decompression, and 18 with megadose methylprednisolone alone | Patients in a surgical group with an initial VA of NLP had a better visual improvement than those in nonsurgical group |
| Entezari et al. [62] | Randomized placebo-controlled clinical trial | 2007 | 31 | 16 eyes received intravenous and oral corticosteroid, 15 eyes received normal saline as the placebo group | There was no difference in visual acuity improvement between intravenous high-dose corticosteroids and placebo |
| Lee et al. [15] | Comparative observational study | 2010 | 116 | 75 patients received no acute treatment, and 41received steroids and/or surgery | Of the treated group, 24% and of the untreated group 20% showed improvement of VA |
| There was no difference between the two groups in improvement of VA |
| Pokharel et al. [63] | Comparative observational study | 2016 | 10 | 4 cases received intravenous methylprednisolone, and 6 cases were observed without steroid treatment | The visual recovery after intravenous steroid treatment was rapid and beneficial in cases with vision better than NPL |
| Sosin et al. [64] | Comparative observational study | 2016 | 109 | 9 patients received intravenous corticosteroid, 62 patients underwent observation, 31 patients received surgical intervention, and the others underwent surgery and corticosteroid administration | Outcomes following corticosteroid administration and observation were comparable |
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