Risks and sequelae of scleral perforation during peribulbar or retrobulbar anesthesia

Causes and management of sight threatening complications of dermal filler injections: A review

Injectable dermal fillers continue to increase in popularity in aesthetic medicine. Although rare, vision loss secondary to filler injections is a devastating complication associated with a poor visual prognosis. The mechanism for vision loss is thought to be related to retrograde embolization of the dermal filler from peripheral vessels in the face into the ophthalmic arterial system. Early recognition and prompt management are essential if vision is to be salvaged. The use of retrobulbar hyaluronidase is still contentious, however when administered by a specialist, this treatment gives the best chance at visual recovery and should be considered for all cases.

Inverted ILM Flap for a Needle Injury to the Macula after Peribulbar Anaesthesia: A Case Report and Literature Review

Globe perforation following peribulbar anesthetic injection is a rare but dreaded complication that often results in poor visual outcomes. This case report is on a female patient who sustained vitreous hemorrhage, retinal detachment, and macular breaks due to a peribulbar block administered in the setting of cataract extraction. The retina was repaired with pars plana vitrectomy, endolaser of the peripheral retinal break only, and an internal limiting membrane inverted flap for the macular breaks to avoid the endolaser on the macular area, achieving stable visual outcomes. The authors discussed various modes of local anesthesia for vitreoretinal surgery, risks for globe perforations, and how to approach retinal detachment secondary to needle perforations, which are complex cases at high risk for proliferative vitreoretinopathy. Early recognition and intervention in eyes with an inadvertent perforation can lead to a good outcome. Eyes with a longer axial length, superior, and multiple perforations are at higher risk of developing complications such as retinal detachment and vitreous hemorrhage. Complications such as retinal detachment, macular injury, and vascular occlusion are risk factors for poor prognosis.

Preoperative and Intraoperative Spontaneous Scleral Rupture: A Case Report and Review of Literature

Scleral rupture is a rare but significant complication that can occur due to multiple risk factors. In this report, we discuss two instances of scleral perforation that happened during a silicone oil injection and after a peribulbar injection. Our study suggests that prior ocular surgery is a further risk factor for intraoperative scleral rupture, and more investigation is required to identify additional relevant risk factors that weaken the sclera.

Clinical presentation and management of eyes with globe perforation during peribulbar and retrobulbar anesthesia: A retrospective case series

Aim

To evaluate the clinical presentation, management, and outcome of eyes with an inadvertent globe perforation during peribulbar or retrobulbar block.

Methods

This retrospective study evaluated the eyes which had an accidental globe perforation during local ocular anesthesia from 2012 to 2020. The patients were divided into three groups; Group 1: Clear media with no rhegmatogenous retinal detachment (RRD); Group 2: significant vitreous hemorrhage (VH) precluding the retinal view without RRD; and Group 3: RRD with/without VH.

Results

Twenty-five patients (25 eyes) were included in the study. The mean axial length (AL) was 24.7±2.7mm (Range, 20.9-31.2mm). Eleven eyes (45.8%) had an AL≥24mm. The most common presenting features were VH (n=14), hypotony (n=7), and RRD (n=7). The treatment included retinal laser barrage (n=7) and vitrectomy (n=17). Retinal breaks were identified in all the eyes (total breaks=37). Other complications included full-thickness macular hole (n=5), subretinal hemorrhage (n=4), and retinal vascular occlusion (n=4). The mean presenting best-corrected visual acuity (BCVA) in groups 1,2 and 3 were logMAR 0.79±0.73, 1.82±0.78, and 2.13±0.59 respectively. All the patients, except the one who did not undergo surgery, had an attached retina at the time of the last follow-up. The mean final BCVA for each group was logMAR 0.59±0.79, 0.48±0.26, and 1.25±0.64 respectively (p=0.006). The development of RRD was associated with a larger AL (p=0.015); while the development of significant VH precluding the retinal view was associated with the superior location of the perforation (p=0.015), late recognition of the perforation (p=0.004), and multiple perforations (p=0.015).

Conclusion

Early recognition and intervention in eyes with an inadvertent perforation can lead to a good outcome. Eyes with a longer AL, superior, and multiple perforations are at higher risk of developing complications like RRD and VH. Complications like RRD, macular injury, and vascular occlusion are risk factors for poor prognosis.

Endophthalmitis and Retinal Detachment after Ocular Injury by Animal Inoculation Needle

Purpose: To report a case of endophthalmitis and retinal detachment after injury caused by an animal inoculation needle. Case summary: A 39-year-old man received an injury to his left eye with an animal inoculation needle while vaccinating a pig came to the hospital due to decreased visual acuity. At initial presentation, the best-corrected visual acuity in the left eye was “counting fingers,” and slit lamp examination revealed corneal lacerations, anterior capsule rupture, and traumatic cataract. Ultrasonography showed no specific findings in the vitreous and retina. Primary corneal suture, phacoemulsification, anterior vitrectomy due to rupture of the posterior capsule and vitreous prolapse, intraocular lens implantation, and intravitreal antibiotic injection were performed. On day 1 postoperatively, vitrectomy, anterior chamber irrigation, intravitreal antibiotic injection, and silicone oil injection were performed as signs of endophthalmitis, such as hypopyon and retinal tear, and focal retinal detachment were observed during surgery. Silicone oil removal was performed 7 months after the operation and the best-corrected visual acuity was 0.6. There has been no recurrence during follow-up. Conclusions: This is the first report in Korea of ocular injury caused by an animal inoculation needle. If the fundus is not observed in such injuries, there is a possibility of endophthalmitis and retinal detachment and early vitrectomy should be considered.

Imaging Features of a Retinal Detachment and Secondary Epiretinal Membrane Following Inadvertent Globe Penetration From Peribulbar Anesthesia

Purpose:

We present imaging features of retinal detachment (RD) and secondary epiretinal membrane in a case of an inadvertent globe penetration following preoperative peribulbar anesthesia.

Methods:

A 60-year-old woman was referred for a localized RD and epiretinal membrane following uneventful cataract surgery. Widefield fundus photography and optical coherence tomography were used to assess and record the pathology. The current literature was reviewed.

Results:

Full-thickness breaks were noted in the neurosensory retina extending into the scleral wall. Vertical tracks were noted in the inferotemporal quadrant of the eye. The patient underwent trans pars plana vitrectomy, membrane peel, and gas. Her 1-month postoperative visual acuity was 20/30.

Conclusions:

Globe penetration with RD is a rare but potentially sight-threatening complication of peribulbar anesthesia. Diagnosis can be challenging because of the infrequency of occurrence and delays in presentation. A high index of suspicion is key alongside consideration of other likely differentials.

Examining the Role of Retrobulbar Hyaluronidase in Reversing Filler-Induced Blindness: A Systematic Review

PURPOSE

To provide a systematic review of the literature concerning retrobulbar hyaluronidase injections as a treatment for hyaluronic acid gel filler-induced blindness and evaluate the level of evidence for this proposed therapy.

METHODS

The authors performed a search of English language articles published on the use of retrobulbar hyaluronidase to reverse vision loss precipitated by hyaluronic acid gel fillers. Articles reviewed included case reports/series, experimental investigations, expert opinion commentaries, and major reviews. To date, there have been no case-control, cohort, or randomized control studies to evaluate this treatment. Five anecdotal descriptions of hyaluronic acid gel filler blindness treated specifically with retrobulbar hyaluronidase were identified, for a total of 9 patients. One hundred twelve articles in total on this treatment and related topics, including filler-induced blindness and alternative treatments, were identified and reviewed.

RESULTS

Of the 9 documented cases of patients treated with retrobulbar hyaluronidase for hyaluronic acid-induced blindness, visual improvement was demonstrated in 2 cases. The successes, however, are undermined by inconsistent pretreatment ophthalmic assessment and documentation. Animal studies demonstrate mixed results. Laboratory studies document the inability of hyaluronidase to cross the optic nerve sheath.

CONCLUSIONS

There is not currently enough evidence to support retrobulbar hyaluronidase as a treatment for filler-induced blindness. Additional studies are needed to further evaluate its efficacy and explore alternative treatments.

Inadvertent globe penetration during retrobulbar anesthesia: A case report

BACKGROUND

To report the possible reasons for needle perforation and complications related to perforation, as well as the clinical management of subretinal hemorrhage (SRH) during retrobulbar injection.

CASE SUMMARY

A 65-year-old female was scheduled to undergo pars plana vitrectomy (PPV) in her left eye for rhegmatogenous retinal detachment (RRD). During retrobulbar anesthesia, needle perforation of the globe occurred. Massive SRH in the inferotemporal quadrant together with vitreous hemorrhage were observed. The patient underwent PPV combined with retinotomy for removal of the massive SRH. After earlier surgical intervention, successful reattachment of the retina was achieved.

CONCLUSION

Inadvertent globe penetration during retrobulbar anesthesia is associated with a poor prognosis and may result in blindness. Timely detection and earlier intervention may be beneficial.

Ocular complications of perioperative anesthesia: a review

Ocular complications associated with anesthesia in ocular and non-ocular surgeries are rare adverse events which may present with clinical presentations vacillating between easily treatable corneal abrasions to more serious complication such as irreversible bilateral vision loss. In this review, we outline the different techniques of anesthetic delivery in ocular surgeries and highlight the incidence and etiologies of associated injuries. The changes in vision in non-ocular surgeries are mistaken for residual sedation or anesthetics, therefore require high clinical suspicion on part of the treating ophthalmologists, to ensure early diagnosis, adequate and swift management especially in surgeries such as cardiac, spine, head and neck, and some orthopedic procedures, that have a comparatively higher incidence of ocular complications. In this article, we review the literature for reports on the clinical incidence of different ocular complications associated with anesthesia in non-ocular surgeries and outline the current understanding of pathophysiological processes associated with these adverse events.

Management of iatrogenic globe perforation during peribulbar anesthesia with submacular hemorrhage

A patient with an amblyopia and poor vision in the fellow eye experienced iatrogenic globe perforation during peribulbar anesthesia for cataract surgery. The injection and surgery were immediately aborted. Visual acuity was hand motion, and retinal examination revealed retinal detachment, hemorrhagic choroidal detachment, and submacular hemorrhage. These were initially managed medically until the hemorrhagic choroidal detachment resolved and afterward by combined phacoemulsification with pars plana vitrectomy, subretinal recombinant tissue plasminogen activator, and gas tamponade. Two weeks post operative, the patient achieved the best-corrected visual acuity of around 20/200, which after 1 year of follow-up improved to 20/70.

A New Two-Step Anesthesia for 23- or 25-Gauge Vitrectomy Surgery: A Prospective, Randomized Clinical Trial

OBJECTIVE

To investigate the safety and efficacy of topical anesthesia combined with subconjunctival anesthesia (termed two-step anesthesia) for 23- or 25-gauge pars plana vitrectomy or other posterior segment surgery.

METHODS

Patients (n = 90) requiring 23-/25-gauge vitrectomy or other posterior segment surgery were randomized into 3 groups. Group 1 received peribulbar anesthesia, group 2 received retrobulbar anesthesia and group 3 received two-step anesthesia. A 5-point visual analog pain scale (VAPS) was used to measure self-report of patient pain. Complications were recorded for subsequent analysis.

RESULTS

VAPS scores for overall intraoperative pain ranged from 0 to 3 (1.07 ± 1.07) in group 1, from 0 to 2 (0.69 ± 0.93) in group 2 and from 0 to 3 (1.06 ± 0.98) in group 3. Assessment of surgeon discomfort score ranged from 0 to 2 (0.31 ± 0.66) in group 1, from 0 to 3 (0.38 ± 0.82) in group 2 and from 0 to 2 (0.47 ± 0.62) in group 3. Both scores reveal no significant difference among the 3 groups. While there were no complications noted in group 1, there was an ocular perforation in group 2. Additionally, there were no complications in group 3 related to the anesthetic technique.

CONCLUSIONS

Results suggest that two-step anesthesia is a safe and effective anesthetic approach for selected patients undergoing 23- or 25-gauge pars plana vitrectomy or other posterior segment surgeries. It may offer a viable alternative to peribulbar anesthesia and retrobulbar anesthesia for carefully selected 23- or 25-gauge cannular-access ocular surgeries.

Retrospective analysis of complications associated with retrobulbar bupivacaine in dogs undergoing enucleation surgery

OBJECTIVE

To investigate complications associated with, and without, bupivacaine retrobulbar local anesthesia in dogs undergoing unilateral enucleation surgery.

STUDY DESIGN

Retrospective, observational study.

ANIMALS

A total of 167 dogs underwent unilateral enucleation surgery via a transpalpebral approach.

METHODS

Records from 167 dogs that underwent unilateral enucleation surgery that did (RB) or did not (NB) include retrobulbar bupivacaine anesthesia were reviewed, including anesthetic record, daily physical examination records, surgery report, patient discharge report and patient notes within 14 days of the surgery. Specific complications and severity were compared between RB and NB using the Wilcoxon rank-sum test. A 'complication burden' (0-5) comprising five prespecified complications was assigned and tested using rank-sum procedures. Statistical significance was set to 0.05.

RESULTS

Group RB included 97 dogs and group NB 70 dogs. Dogs in NB had a 17.0 percentage points (points) greater risk for a postoperative recovery complication (38.6% versus 21.6%; 95% confidence interval: 3.0-30.6 points; p = 0.017). There was inconclusive evidence that dogs in group RB had a lower risk of requiring perioperative anticholinergic administration (12.4% versus 22.9%; 10.5 points; p = 0.073). Other complications were similar between groups RB and NB with risks that differed by <10 points. The risk of hemorrhage was similar between groups RB (22.7%) and NB (20.0%) with no significant difference in the level of severity (p = 0.664).

CONCLUSIONS AND CLINICAL RELEVANCE

In this retrospective study, the use of retrobulbar bupivacaine for enucleation surgery in dogs was not associated with an increased risk of major or minor complications.

Repair of Rhegmatogenous Retinal Detachment Following Globe Perforation by Retrobulbar Anesthesia

Globe perforation following retrobulbar or peribulbar anesthetic injection is a rare but dreaded complication that often results in suboptimal visual outcomes. This video describes a 72-year-old woman who sustained a globe perforation during retrobulbar block in the setting of cataract extraction and later developed a retinal detachment. The retina was repaired with pars plana vitrectomy and silicone oil, resulting in a favorable visual outcome. The authors discuss various modes of local anesthesia for vitreoretinal surgery, risks for globe perforations, and how to approach retinal detachment secondary to needle perforations, which are complex cases at high risk for proliferative vitreoretinopathy.

Acupuncture resulting in eye penetration and proliferative vitreoretinopathy - Surgical and medical management with intraocular methotrexate

Purpose

To highlight the surgical and medical management used in an extensive globe penetrating injury caused by an acupuncture needle.

Observations

We report on a case of acupuncture treatment error resulting in needle penetration of the eye, retinal detachment, and progressive post-traumatic proliferative vitreoretinopathy (PVR). This patient required aggressive surgical management with multiple vitrectomies along with adjunctive intravitreal methotrexate to control ongoing PVR. At last follow-up, 15 months after presentation, the patient's BCVA was 20/40 and the periphery was flat with fibrosis stable.

Conclusions and Importance

Open globe injuries are a subtype of ocular trauma which can cause irreparable vision loss. This case highlights the extensive potential complications which can occur following traumatic injury to the retina and choroid, as well as the role of both surgical and medical management of retinal detachment and PVR. In addition, this is the first report of the use of off-label adjunctive intravitreal methotrexate to control post-traumatic PVR. Further research into this treatment approach could reveal a role of adjunctive methotrexate in the management of such injuries.

Management of inadvertent needle penetration resulting in subretinal triamcinolone acetonide and retinal detachment

Purpose

To report management of inadvertent needle penetration during subtenons triamcinolone acetonide administration resulting in retinal detachment.

Observations

A 71-year-old female with history of diabetes, hypothyroidism, and mild myopia underwent subtenons triamcinolone acetonide (TA) injection in the right eye for nodular scleritis. There was unexpected patient movement concurrent with the injection resulting in needle penetration, subretinal and intravitreal injection of TA, superotemporal retinal break, and macula-involving retinal detachment. The patient underwent partial subretinal TA removal, successful retinal detachment repair, and recovered 20/25 visual acuity.

Conclusions and importance

In spite of prominent subretinal TA and retinal detachment, successful repair of retinal detachment and recovery of good visual acuity is possible.

Vitreous hemorrhage and Rhegmatogenous retinal detachment that developed after botulinum toxin injection to the extraocular muscle: case report

Background

The authors report a case of a rare complication that occurred after botulinum toxin injection to the extraocular muscle, which was easily overlooked and successfully corrected by surgery.

Case presentation

A 34-year-old female patient visited our clinic for diplopia and ocular motility disorder after removal of an epidermoid tumor of the brain. At her initial visit, her best-corrected visual acuity (BCVA) was 20/20 for both eyes. An alternate cover test showed 45 prism-diopter esotropia and 3 prism-diopter hypertropia in the right eye. Following 6 months of observation, the deviation of the strabismus did not improve, and botulinum toxin was injected into the right medial rectus (RMR). After 6 days, she visited our clinic with decreased visual acuity of her right eye. The BCVA was found to be 20/50 for her right eye. Funduscopic examination presented a retinal tear inferonasal to the optic disc with preretinal hemorrhage. Subretinal fluid nasal to the fovea was seen on optical coherence tomography (OCT). Barrier laser photocoagulation was done around the retinal tear; however, her visual acuity continued to decrease, and vitreous hemorrhage and subretinal fluid at the lesion did not improve. In addition, a newly developed epiretinal membrane was seen on OCT. An alternate cover test presented 30 prism-diopter right esotropia. 19 weeks after RMR botulinum toxin injection, she received pars plana vitrectomy, membranectomy, endolaser barrier photocoagulation, and intravitreal bevacizumab (Avastin®) injection. After 4 months, her visual acuity improved to 20/20, and only 4 prism-diopter of right hypertropia and 3 prism-diopter of exotropia were noted. Vitreous opacity and the epiretinal membrane were completely removed, as confirmed by funduscopic and examination.

Conclusions

Sudden loss of vision after injection of botulinum toxin into the extraocular muscle may suggest a serious complication, and a prompt, thorough ophthalmic examination should be performed. If improvements are not observed, rapid surgical intervention is recommended to prevent additional complications.

Electronic supplementary material

The online version of this article (10.1186/s12886-017-0649-2) contains supplementary material, which is available to authorized users.

Choroidal neovascularization secondary to ocular penetration during retrobulbar anesthesia and its treatment

Retrobulbar anesthesia is still used before ocular surgery; however, it has various complications including ocular penetration. The penetration/perforation of the globe can cause complications such as endophthalmitis, retinal detachment, and scotoma. Choroidal neovascularization (CNV) is rarely seen, following choroidal rupture in penetrating eye injuries. Here, we present a patient who underwent a pars plana vitrectomy for vitreous hemorrhage secondary to ocular penetration during a retrobulbar injection for cataract surgery. This patient later developed CNV at the penetration site during follow-up. Physicians should remember that CNV can occur as an unusual late complication of ocular penetration during retrobulbar anesthesia.

Comparison of Olive Tipped and Conventional Steven's Cannula for Sub-Tenon Ophthalmic Anesthesia

PURPOSE:

To compare the efficacy of the olive tipped (OT) cannula to the conventional Steven's cannula for sub-Tenon block (STB) before cataract surgery.

METHODS:

This prospective, randomized, double-masked compared STB delivered in cataract surgery patients with an OT cannula or a conventional Steven's cannula (ST). Outcome variables included the akinesia score and lid movement scores at 5 and 10 min. The patient perception of pain during delivery of the STB and surgery were also compared between groups. Surgeon satisfaction with anesthesia was compared between groups. P <0.05 was statistically significant.

RESULTS:

There were sixty patients in each group. The age between groups was not statistically different (P = 0.4). The body mass index was higher in the ST group compared to the OT group (P < 0.001). The akinesia score at 5 and 10 min did not differ between groups (P = 0.07 and P = 0.6, respectively). The patient perception of pain during STB and surgery were similar between groups (P = 0.1 and P = 0.06, respectively). There were six patients with mild chemosis and redness in the OT group and 15 patients in the ST group.

CONCLUSION:

An OT cannula is equally effective as the conventional Steven's cannula for delivering STB anesthesia before cataract surgery.

Peribulbar anesthesia causing bilateral orbital hemorrhage

We report a case of bilateral orbital hemorrhage as a complication of peribulbar anesthesia in a 78 year old man. Initially, unilateral orbital hemorrhage occurred but quickly spread to the contralateral side. Neuroophthalmological assessment revealed a proptosed tense globe with normal retinovascular findings. Visual acuity was adversely affected and this was conservatively managed with no lasting ophthalmic sequela. This patient’s case was reported as it illustrates an unusual complication of bilateral spread of orbital hemorrhage secondary to peribulbar anesthesia. It highlights how early ophthalmic assessment can ensure a good visual outcome in the setting of appropriate ophthalmic monitoring. The mechanisms of orbital hemorrhage spread and appropriate management options are discussed.

Local Anesthesia With Blunt Sub-Tenon's Cannula Versus Sharp Retrobulbar Needle for Vitreoretinal Surgery: A Retrospective, Comparative Study

BACKGROUND AND OBJECTIVE

To evaluate the safety and efficacy of a blunt sub-Tenon's cannula for local anesthesia before vitreoretinal surgery compared to a sharp retrobulbar needle.

PATIENTS AND METHODS

Retrospective, comparative study of all patients undergoing vitreoretinal surgery at the Medical College of Wisconsin between August 2009 and November 2013. Institutional review board approval was obtained.

RESULTS

Of 940 surgeries performed with a sub-Tenon's cannula, 99% (938 of 940) were completed. Of the 771 surgeries performed with a sharp retrobulbar needle, 99% (770 of 771) were completed. Factors associated with use of a sharp retrobulbar needle over sub-Tenon's cannula were presence of prior scleral buckle (P < .01) and inclusion of scleral buckle placement in the procedure (P < .01). No case of globe perforation, severe retrobulbar hemorrhage, or severe conjunctival chemosis was observed in either group.

CONCLUSION

Blunt sub-Tenon's cannula appears as effective and safe as a sharp retrobulbar needle for local anesthesia during vitreoretinal surgery. Vitreoretinal surgeons may wish to consider a blunt sub-Tenon's cannula for local surgical anesthesia.

An efficient capacitive sensing scheme for an ophthalmic regional anesthesia training system

Ophthalmic regional blocks are critical preoperative procedures involving the insertion of a syringe needle into the orbital cavity at such a position and angle that akinesia and analgesia is achieved without damage or harm to the eye and its associated musculature. A training system that accurately represents the orbital anatomical features and provides qualitative feedback on the performed anesthetic technique, can be of immense help in reducing risks involved in regional block administration. In this paper, a training system that employs a special but simple capacitive sensing scheme has been developed. A rapid prototyped eye-model has been used to ensure anatomical accuracy. Capacitive transmitter electrodes placed on the orbital wall along the length of the extraocular muscles are excited with a special excitation sequence and the displacement current at the needle of the syringe is measured using simple electronic unit and a Data Acquisition System, enabling the developed Virtual Instrument to detect the depth of penetration and proximity of the syringe needle to the ocular muscles. Additionally, the system detects needle touch of the muscles accurately. The proposed electrode array system and excitation schemes have been validated on a prototype system thus demonstrating its usefulness for practical training purposes.

Evaluation of limbal and pars plana silicone oil removal in aphakic eyes

PURPOSE

To compare limbal and pars plana silicone oil removal (SOR) in aphakic eyes and to evaluate the acute effect of silicone oil flow to the corneal endothelium.

METHODS

Sixteen aphakic patients with silicone oil endotamponade requiring SOR were recruited for this prospective study and randomly scheduled for limbal or pars plana SOR. The central corneal thickness (CCT), visual acuity (VA) and intraocular pressure were measured preoperatively, on the first postoperative day and 4 months after surgery. Endothelial cell density (ECD) was measured preoperatively and at the end of follow-up. The in vitro study was performed on ten enucleated porcine eyes. Corneoscleral discs were prepared and fixed on artificial anterior chamber followed by 2.5-mm limbal incision and 5-ml silicone oil injection in six cases and 5 ml balanced salt solution (BSS) in four cases.

RESULTS

The ECD decreased by 239.2 ± 86.7 (13.9%) and 86.7 ± 22.4 cells/mm(2) (5%) after limbal (n = 8) and pars plana SOR (n = 8), respectively (p < 0.001 for both). The difference between the groups was significant (p < 0.001). A significant increase in CCT and corresponding decrease in VA was noted on the first postoperative day using both procedures. At the end of follow-up, the CCT and VA were comparable to initial values. Postoperative hypotony (≤6 mmHg) was observed more frequently after limbal SOR. In the experiment, lamellar abrasions of corneal endothelium were observed after silicone oil injection, whereas no changes were observed after BSS injection.

CONCLUSION

Limbal SOR causes more considerable damage to the corneal endothelium than the pars plana approach because of mechanical abrasion.