Topical anesthesia effective with 25-gauge vitrectomy

Pain during epiretinal membrane surgery is comparable to pain during surgery with peribulbar anesthesia, one study shows.

PARIS – When 25-gauge vitrectomy is used, topical anesthesia permits the successful management of some vitreoretinal disorders with significant advantages and no more pain than peribulbar anesthesia, according to two surgeons.

“In a prospective study … we have compared the subjective response in terms of pain of two groups of patients operated with respectively peribulbar and topical anesthesia for a number of conditions requiring vitrectomy, mainly macular hole and epiretinal membranes,” Raphael Adam, MD, said at the annual meeting of the French Society of Ophthalmology.

While a significant difference was found between the two types of anesthesia in the patients undergoing macular hole surgery, Dr. Adam and Dr. T. Rodallec found topical anesthesia to be as effective as peribulbar in the patients who were operated with 25-gauge vitrectomy for epiretinal membranes and other minor vitreoretinal disorders.

Topical anesthesia

Ninety patients between the ages of 25 and 88 years were included in the study. Vitrectomy was performed in all cases using the 25-gauge system. Topical anesthesia with lidocaine 2% gel was used in 32 of the patients (35%).

The protocol for topical anesthesia included the administration of Atarax (hydroxyzine, Pfizer) 25 mg to 100 mg 2 hours before surgery, sedation with sufentanil and, in some cases, midazolam immediately before surgery, followed by a first application of Betadine (povidone-iodine, Purdue Pharma). In the operating theater, after a second application of povidone-iodine, Betadine, eyelid draping and application of the blepharostat, patients were administered topical lidocaine 2% gel. Diprivan (propofol, AstraZeneca), in a variable dosage of 10 mg to 14 mg according to body weight and age, was injected before the insertion of the 25-gauge plugs.

“No sub-Tenon injection was needed. Additional doses of topical anesthetic were used intraoperatively in three of the macular hole patients, one of which with a post-traumatic macular hole necessitating a 360° endolaser therapy and the second one with a peripheral temporal lesion needing cryotherapy. None of the patients operated for epiretinal membranes required anesthetic supplementation during surgery,” Dr. Adam said.

Pain score

In this 25-gauge vitrectomy technique no sub-Tenon injection is used. Image: Adam R

Intraoperative pain was quantified at the end of the procedure using a visual analog scale from 0 (no pain) to 10 (unbearable pain).

“Approximately 70% of the patients in both the peribulbar and the topical anesthetic group reported an intraoperative pain score between 0 and 2. In the topical anesthetic group, one patient reported a pain score of 7. It was a patient operated for macular hole who did not express any sign of pain during surgery but obviously suffered in silence,” Dr. Adam said.

The analysis of this data in terms of relationship between pain score, type of anesthetic and type of surgery showed no significant difference between the methods of anesthesia in the patients operated for epiretinal membranes or intravitreal hemorrhage. However, the patients operated for macular hole under topical anesthesia reported a significantly higher pain score compared with those who underwent surgery under peribulbar anesthesia.

“Our results suggest that peribulbar anesthesia is a better modality for macular hole surgery, which is a longer and often more complicated procedure. Other types of vitreoretinal surgery, like epiretinal membranes removal, can benefit from the friendlier and less invasive approach of topical anesthesia,” Dr. Adam said.

Publications

Other researchers have investigated the use of topical anesthesia during vitreoretinal procedures. Dr. Adam talked about a study on three-port, 20-gauge vitrectomy presented by N. Yepes at the 1998 Association for Research in Vision and Ophthalmology meeting.

“At the time, this study sparked quite a lot of controversy because surgery had been performed under topical anesthesia,” Dr. Adam said.

A total of 134 patients, 69 with proliferative diabetic retinopathy, underwent posterior vitrectomy under topical anesthesia with lidocaine 4% drops and mild sedation. In the course of surgery, 84 endolaser and 26 indentation procedures were performed. Pain was classified on a scale between 1 (no pain) and 4 (unbearable pain).

The author emphasized that all the patients remained conscious throughout the procedure, Dr. Adam said.

On the whole, surgery was perceived as painless, with brief moments of fairly mild pain (grade 2) at the stages of sclerectomy, cauterization and closure of the conjunctiva.

In Ophthalmologica, Tang and colleagues published the results of 25-gauge vitrectomy for macular-based disorders under topical anesthesia with Alcaine 2% (proparacaine, Alcon) drops in 46 eyes. The levels of intraoperative analgesia were graded from 1 (adequate) to 3 (inadequate). Good tolerance of the procedure was reported in 67% of the cases, 28% needed an additional dose of anesthetic during surgery and only 4.3% needed intraoperative sedation.

A recent 2-year prospective study published by Theocharis and colleagues compared lidocaine 2% gel vs. peribulbar anesthesia for 25-gauge and 23-gauge vitrectomy in 69 patients.

“The pain score was comparable with the two types of anesthesia, while a significant difference was found between the technical difficulty of performing 23 gauge vs. 25 gauge under topical anesthesia,” Dr. Adam said.

Another study

Another experience with 25-gauge vitrectomy with topical anesthesia was presented at the meeting by Olivier Rebollo, MD.

The study included data of 55 patients operated on for epiretinal membrane, macular hole and vitreomacular traction syndrome.

“All patients tolerated surgery extremely well,” Dr. Rebollo said. “A slight and transient pain sensation was experienced at the moment sclerotomies were performed.”

There was no delay or limitation at any stage of surgery related to this method of anesthesia, he said. Ocular saccades that occurred during membrane peeling were due to the natural tendency of the patients’ eyes to follow the movement of the surgical instruments, but this did not interfere with the success of surgical maneuvers.

A reduction in rates of postoperative problems such as hemorrhages, chemosis and conjunctival hyperemia was observed, and this “improved greatly the satisfaction and comfort of both patient and surgeon,” Dr. Rebollo noted.

Both surgeons said that topical anesthesia avoids the characteristic complications of peribulbar injection, such as ocular hypertension, muscular paralysis, orbital hematoma and globe perforation, as well as the potential adverse effects on the optic nerve and optic nerve vascularization.

In addition, it allows the surgeon to gain time and could be a safer alternative in patients with severe cardiovascular problems, patients under anticoagulant therapy and highly myopic patients.

“The main problem is that it does not blockade eye movements and therefore necessitates special, more rigid surgical instruments,” Dr. Adam said.

For the same reason, the learning curve is longer, and a good experience with more traditional techniques of vitreoretinal surgery is necessary before starting with this more demanding approach, Dr. Rebollo recommended.

According to both surgeons, accurate patient selection, especially at the beginning of the learning process, is mandatory and greatly improves the success of surgery.

For more information:

• Raphael Adam, MD, can be reached at Department of Prof. Nordmann, Hopital des Quinze-Vingts, 28 rue de Charenton, 75012 Paris, France; +33-680389285; fax: +33-140021299; e-mail: raphadam@yahoo.fr. Dr. Adam has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
• Olivier Rebollo, MD, can be reached at +33-467558840; fax: +33-467558841; e-mail: olivier.rebollo@wanadoo.fr. Dr. Rebollo has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

References:

• Tang S, Lai P, et al. Topical anesthesia in transconjunctival sutureless 25-gauge vitrectomy for macular-based disorders. Ophthalmologica. 2007;221(1):65-68.
• Theocharis IP, Alexandridou A, Tomic Z. A two-year prospective study comparing lidocaine 2% jelly versus peribulbar anaesthesia for 25G and 23G sutureless vitrectomy. Graefes Arch Clin Exp Ophthalmol. 2007;245(9):1253-1258.

• Michela Cimberle is an OSN Correspondent based in Treviso, Italy, who covers all aspects of ophthalmology. She focuses geographically on Europe.