Scleral perforation is a rare but one of the most devastating complications of local ocular anesthesia.1–31 Studies have suggested an incidence of 0.007–0.13%, with the rate being higher for retrobulbar blocks than peribulbar.1,2,6,9,12,14,21 The incidence of globe perforation at our center was similar to that reported in literature. The risk factors for this unfortunate incident include posterior staphyloma, long axial length, uncooperative patient, multiple attempts and inexperienced personnel.4–6, 8,12–15, 18,19 A combination of these factors was responsible for globe perforation in our series.
The early indicators of globe perforation include movement of eyeball while moving the anesthetic needle, unusual difficulty while injecting, severe pain response, sudden increase in the intraocular pressure or severe hypotony, corneal clouding, change in the ocular red reflex, sudden loss of vision, visible enlargement of the eyeball, and popping sound.9–11, 14,21 However, it is not always easy to identify the perforation at the time of injecting. In our case series, only half patients were identified to have perforations. Other authors have also reported that most perforations are recognized in the post-operative period.3,4,7,10,15,17,18
The early management remains controversial. While some authors advocate postponing the planned surgery, others recommend proceeding with the same. In case the cataract is dense, it is better to proceed with the surgery. No contraindication for the placement of an intraocular lens has yet been reported.6,10, 15–17,19 In our case series, all but one patient underwent the surgery immediately without any intra-operative complications. A vitreoretinal opinion should be sought as early as perforation is suspected. In case of a clear media, treatment of the site of perforation leads to a good outcome. None of such patients in our case series progressed to RD. This may be due to a pre-existing posterior vitreous detachment or scar formation subsequent to the local inflammatory reaction produced around the site of the tear.6,9,10,15 It is imperative to mention that these patients need to be followed-up closely as subretinal fluid can accumulate rapidly.
The presence of VH with or without RD warrants an immediate vitrectomy due to aggressive development of PVR changes.4, 6–10,14, 15–17,19,21 One patient in our series, who presented 4 months after the perforation had such advanced PVR that surgery could not be performed. An early surgery in the other patients helped achieve cent percent anatomical success. The retina remained attached even after tamponade was removed. The outcome of patients in our case series were better than reported earlier.6,10,14,16−19 This may be due to early recognition and timely management as well as improvement in the technique of vitreoretinal surgery over the years. Table 4 summarises the results of the previous studies reporting the management outcomes of ocular perforation during local ocular anaesthesia.
More than half the patients achieved BCVA ≥ 20/80. As reported in the literature, the patients with RD in our series also had a worse visual outcome than those without RD.6,18,19 One-fourth patients achieved a final BCVA < 20/200. The causes for poor visual outcome in these cases included vascular occlusion (n = 3), retinal necrosis inside the macula (n = 1), RD with advanced PVR changes (n = 1) and failed PKP graft (n = 1). Retinal vascular occlusions may be caused by inadvertent injection of the medication into the globe leading to a sudden rise of intraocular pressure, popularly called as ocular explosion.11,17 Even in case of scleral perforation, utmost care should be taken to prevent injecting the anaesthetic agent intraocularly as it can lead to mechanical as well as chemical damage. One-fourth patients achieved a final BCVA 20/120 − 20/200. The causes for sub-optimal gain in vision in these patients included macular pathologies like FTMH, SRH and macular pucker. Other authors have also reported poor visual outcome due to macular injury during the anaesthesia.4,9,18,21,28−30
To the best of our knowledge, this is the largest case series till date evaluating the management of inadvertent scleral perforation during peribulbar anesthesia. The limitations of the study include its retrospective nature and small sample size.
In conclusion, it is important to be extremely cautious while giving peribulbar anesthesia in high-risk cases or shift to safer techniques like subtenon anesthesia. Ocular perforation should be suspected when fresh VH is noted on the first POD. Early appropriate intervention for associated complications can help achieve a good outcome to the patients with inadvertent perforation. Risk factors for poor outcome include intraocular injection of the anesthetic drugs, macular injury and RD.