| Parameter |
Effectiveness of various Modalities |
|
Akinesia |
i) RB and PB anaesthesia produce equally good akinesia [27,86]
ii) Adding hyaluronidase appears to increase the effectiveness of these blocks in producing akinesia. However the use of hyaluronidase in procedures other than RB is controversial.
iii) There is insufficient evidence to determine whether RB or PB blocks produce better akinesia than sub-Tenon’s block. Comparing between RB and ST procedures, akinesia is slightly less effective in ST procedure, but there is insufficient evidence to support this conclusion.
(In summarising above conclusions, the survey [27] combined the qualitative statements and the actual muscle movement measurements). |
|
Patient-reported pain during Anaesthetic administration |
i) Application of anaesthesia by injection is more painful than that by topical means for patients not receiving sedation.
ii) Amidst the injection type procedures, ST approach is least painful.
iii) There is weak evidence that PB blocks are slightly less painful than RB blocks [27]. |
|
Patient reported
intra-operative pain |
i) Intra-operative pain is greater with topical anaesthesia compared with injection blocks.
ii) Addition of IC non-preserved lidocaine to topical anaesthesia improves the pain control of this modality.
iii) Amidst injection type procedures, pain during intra-operative surgery is less with ST procedure compared to RB or PB procedures.
(Time-duration of surgery is an important factor in assessing the intra-operative pain, but the effect of this on the above observations is not known [27]). |
|
Visual Recovery (VR) |
RB, PB and ST cause optic nerve conduction delay. VR is normally up to 6 hrs post-operative, whereas instant recovery is attained under topical anaesthetic. |
RB: Retrobulbar; PB: Peribulbar; ST: Sub-Tenon’s; IC: Intracameral