|LETTER TO EDITOR
|Year : 2006 | Volume
| Issue : 3 | Page : 210-211
Comparing Subtenon's anesthesia with peribulbar technique for cataract surgery
Consultant Ophthalmologist, Ajay Nagar, Ajmer - 305 001, India
Consultant Ophthalmologist, Ajay Nagar, Ajmer - 305 001
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Barikh L. Comparing Subtenon's anesthesia with peribulbar technique for cataract surgery. Indian J Ophthalmol 2006;54:210-1
I read with interest, the article by Gogate et al . The authors have pointed out that Subtenon's anesthesia is quite safe for cataract surgery. This fact has been proved by multiple authors., The authors claim that this was the first study where Subtenon's anesthesia was used for manual small incision cataract surgery (MSICS). However, the authors did not explain why the effect of Subtenon's anesthesia would be different for such a surgery (MISCS). There were few other doubts I had over methodology
1. Since the patients who have been given peribulbar anesthesia have to wait for surgery, it makes them anxious. An anxious patient would have added to bias, since the grading was subjective.
2. Once randomization was done for 200 patients, why was it used only for 168 and then stopped? Which software was used?
3. Pain and the analog scale is a subjective feeling. The concept of average pain is difficult to understand. What would be a mild pain and severe pain? What was the methodology to describe the patient, what would or should be reported as mild pain and when to call it moderate or severe pain?
4. Almost all the markers recorded seem subjective; even the chemosis and subconjuctival hemorrhage which could have been graded using some objective classification, were left to the surgeon's choice. Having four different surgeons adds to higher bias, since they graded their own surgery. If the surgeon who operated had graded others' surgery, I am sure it would have made a difference.
5. Scoring of akinesia is biased, since the surgeons have graded the movement from 0-3 and then repeated it in all 4 quadrants. How did the authors grade all this? Were all the patients told to roll the eyes in the operation theatre before surgery and measured on Kestenbaum's rule?
6. Was the injection repeated in peribulbar or in Subtenon's (since almost 90% did not achieve good akinesia (a score of 6 or more)? Shouldn't they have put another grade for the patients, where the injection had to be repeated for the surgery?
7. There are three aims of anesthetic block in ophthalmic surgery: anesthesia, analgesia and akinesia. 96.6% patients in the peribulbar group had a score of 4 or less; 90% patients in the Subtenon's group had a score of more than 6 or more. This suggests that the movement was almost present in 9 out of every 10 patients in the Subtenon's group. I agree that the patient's comfort is our top priority; however, the surgeon's comfort is the top priority for any successful surgery. Though Subtenon's anesthesia may be a safe alternative for anesthesia, akinesia is not achieved and the difference is significant.
| References|| |
Parkar T, Gogate P, Deshpande M, Adenwala A, Maske A, Verappa K. Comparison of subtenon anaesthesia with peribulbar anaesthesia for manual small incision cataract surgery. Indian J Ophthalmol
Briggs MC, Back SA, Esakowitz L. Subtenons versus peribulbar anesthesia for cataract. Eye
Davis DB, Mandel MR, Nileson PJ, Alerod CW. Evaluation of local anesthesia technique for small incision cataract surgery. J Cataract Refract Surg