Incidence of inadvertent globe perforation during strabismus surgery

"Pinch and Stretch" technique to overcome ocular hypotony during scleral suturing of recti muscles

During extraocular muscle surgery, an uneventful scleral suture pass is very essential. In presence of normal intraocular tension, the surgery is quite predictable and safe. However, in the presence of significant hypotony, it becomes challenging. Therefore, to mitigate complication rate in these cases, we have adopted a simple technique, that is, the "pinch and stretch" technique. The surgical steps of this technique are as follows: In eyes with significant ocular hypotony, the surgery is initiated with a routine forniceal/limbal peritomy, following which the muscle is sutured and dis-inserted. Using three tissue fixation forceps, the scleral surface is stabilized. Using first forceps, the surgeon rotates the globe toward themself from the muscle stump, and with the remaining two forceps, the assistant pinches and stretches the episcleral tissue in an outward and upward direction just beneath the intended marks. This creates a flat scleral surface with significant firmness. Sutures are passed over this rigid sclera and the surgery is completed without any complications.

Scleral Perforation as a Complication of Strabismus Surgery: A Literature Review

The aim of this review was to report the existing literature on the incidence, risk factors, treatment, and outcomes of scleral perforation as a vision-threatening complication of strabismus surgery. The current literature reported an incidence range of scleral perforation/penetration between 3 in 1,000 and 7.8%. Rectus muscle recession was the most commonly mentioned risk factor among the studies. Other risk factors were myopia, previous extraocular muscle surgery, surgeon experience, S-24 needle use, muscle reattachment posterior to the original insertion site, operating on a horizontal rectus muscle, and young age. Different views existed in the literature regarding scleral perforation management. Some ophthalmologists advocated management by cryopexy or indirect ophthalmoscopic laser uniformly, whereas others reserved it for more complicated cases. Antibiotic therapy for endophthalmitis prophylaxis was recommended by one study and shown to be practiced by some ophthalmologists. [J Pediatr Ophthalmol Strabismus. 2022;59(4):214-223.].

Integrated Intraoperative Optical Coherence Tomography during Scleral Pass in Strabismus Surgery

We describe a novel application of integrated intraoperative OCT (iiOCT) to strabismus surgery during the scleral pass and demonstrate it to be a useful tool. A number of complications can arise from inappropriate scleral pass depth during strabismus surgery, leading to an increased risk of unwanted complications including endophthalmitis, retinal detachment, and a lost or slipped muscle. Our study demonstrated that the use of iiOCT provides easy to interpret, real-time feedback to the strabismus surgeon and may translate to safer, more consistent scleral suturing during strabismus surgery and strabismus surgical training. .

Endophthalmitis after strabismus surgery: incidence and outcome in relation to age, operated eye muscle, surgical technique, scleral perforation and immune state

PURPOSE

Identify risk factors for endophthalmitis after strabismus surgery (EASS) and relate these to incidence and outcome.

METHODS

Ophthalmologists, who had operated, diagnosed or treated EASS, completed a case record form with 71 questions in six domains: Preoperative, Surgery, Perforation, Postoperative, Outcome and Experts' opinion. To estimate the age-specific incidence per number of strabismus operations in the Netherlands during 1994-2013, the age distribution of Dutch cases was compared with the age-specific rates of strabismus surgery in the Dutch Registry of Strabismus Operations and with population data. Exploratory data analysis was performed. The immune state was evaluated in six patients. Five enucleated eyes were studied histopathologically.

RESULTS

None of the 26 patients (27 eyes with EASS) were between 9 and 65 years old, except for one patient with retinal haemorrhage followed by endophthalmitis. In the Netherlands during 1994-2013, the rate of EASS was approximately one per 11 000 strabismus operations, but one per 4300 for children aged 0-3 and one per 1000 for patients 65 and older. Endophthalmitis was diagnosed on postoperative day 1-4 in children aged 0-3. In all 15 children aged 0-5, the 16 affected eyes were phthisical, eviscerated or enucleated. The involved eye muscle had been recessed in 25 of 27 cases. It was a medial rectus in 15 of 16 children aged 0-6. It was a lateral (6), inferior (2) or medial (1) rectus in elderly. Scleral perforation went unnoticed in all children (no record in three) and in two of seven elderly (no record in two). Histopathology showed transscleral scarring compatible with scleral perforation in four patients but, in a two-year-old girl who had EASS together with a transient medial rectus palsy, the sclera underneath the former suture tract was not perforated but did contain the long posterior ciliary artery.

CONCLUSIONS

Endophthalmitis after strabismus surgery (EASS) affects children and elderly, with a grave outcome in young children. It occurs after recession of the medial rectus muscle in children, and it may occur without scleral perforation. Age and perforation are key determinants that interact with other factors that determine the occurrence and fulminance of EASS.

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.

Extraocular and Intraocular Infections Following Strabismus Surgery: A Review

An extensive literature review of various types of infections following strabismus surgery was facilitated by using the search engines PubMed and Google Scholar. In both search engines, the phrases "infection following strabismus surgery," "infection strabismus surgery," "complications of strabismus surgery," "endophthalmitis strabismus surgery," and "strabismus scleral perforation" were used for the review. The type of infection, surface involved, and site of the infection determined the type of therapy. Infections involving deeper tissues, such as periocular infection or orbital cellulitis, required systemic therapy. Sub-Tenon's abscesses required incision and drainage, as well as systemic antibiotics. The development of endophthalmitis following strabismus surgery was rare, but was usually devastating to the visual result. Symptoms of an adverse intraocular condition began by mean postoperative day 3, but the definitive diagnosis and treatment of endophthalmitis was not made until mean postoperative day 6. Despite early detection of this latter type of infection and early surgical intervention with vitreous paracentesis and intraocular injection of antibiotics, the visual result was extremely poor in more than two-thirds of the reported cases. Although there is no known way to truly prevent all infections following strabismus surgery, several techniques may be prudent for the strabismus surgeon to adopt to decrease the bacterial load and minimize the risk of infection. The surgeon should be encouraged to consider preoperative use of povidone-iodine on the operative field and avoid scleral perforation during surgery. [J Pediatr Ophthalmol Strabismus. 2019;56(4):214-221.].

The incidence and clinical outcome of complications in 4,000 consecutive strabismus operations

PURPOSE

To test the validity of the British Ophthalmic Surveillance Unit (BOSU) study's incidence figure of severe complications following strabismus surgery and to determine the incidence, type, risk factors, and outcome of all strabismus surgery complications at a single institution.

METHODS

A prospective audit of consecutive strabismus operations performed by consultants or trainees was carried out between 2011 and 2016 at Moorfields Eye Hospital NHS Foundation Trust. Patient diagnosis, age, sex, surgical details, complications, and outcome were recorded from hospital records. We classified complications as minor, moderate, or severe. The outcome was graded using the Bradbury and Taylor grading system (I to IV), with a poor or very poor outcome meaning loss of corrected visual acuity or unexpected primary position diplopia.

RESULTS

A total of 4,076 consecutive strabismus operations were performed during the study period. There were 46 (1.13%) complications, of which 28 (0.69%) were minor, 7 (0.17%) were moderate, and 9 (0.22%) were severe. Only 1 patient (0.02%) had a poor visual outcome. Two patients had nonocular postoperative complications (0.05%).

CONCLUSIONS

In this large, prospective series, we found the rate of severe complications of strabismus surgery to be 1 in 455 cases. Our results validate the findings of the BOSU study.

Impact of a Strabismus Surgery Suture Course for First- and Second-Year Ophthalmology Residents

PURPOSE

To investigate the effectiveness of an eye muscle surgery course on first- and second-year postgraduate ophthalmology residents.

METHODS

This prospective cohort pilot study invited first- and second-year ophthalmology residents to participate in a 2-hour strabismus surgery course at Wills Eye Hospital. The course consisted of a didactic session followed by a wet laboratory session. The wet laboratory session simulated strabismus surgery using a model constructed of chicken breast followed by partial-thickness scleral suture passes in pig eyes. A structured self-assessment evaluation form and a questionnaire in the validated Ophthalmology Surgical Competency Assessment Rubric approved by the International Council of Ophthalmology (ICO-OSCAR:strabismus) were used to assess the effectiveness of the course.

RESULTS

A total of 12 residents, 8 (67%) first-year and 4 (33%) second-year, were enrolled for this survey. Following the course, most residents felt less anxious (73%). All residents responded that the course was helpful or somewhat helpful in preparation for strabismus surgery. Regarding the distribution of ratings on questions of subjective experience, knowledge of steps, and understanding of potential complications, the residents gave significantly higher ratings after the course (P < .029). The change in the modified ICO-OSCAR:strabismus assessment's mean score was statistically significant before and after training (P = .038).

CONCLUSIONS

A strabismus course can play an important role in preparing residents for strabismus surgery. [J Pediatr Ophthalmol Strabismus. 2017;54(6):339-345.].

Comparison of adjustable sutures versus nonadjustable sutures in intermittent exotropia

PURPOSE

To compare adjustable sutures versus nonadjustable sutures for intermittent exotropia.

METHODS

In this randomized prospective interventional study, 40 adult patients with intermittent exotropia were randomly divided into 2 equal groups. Both groups underwent bilateral lateral rectus recession. In group A, adjustable suture recession was performed, and in group B, nonadjustable suture recession was performed. Patients were followed up for 6 months and outcome measures were residual deviation, binocular status, and need for resurgery.

RESULTS

Success was defined as alignment of 2 eyes <10 prism diopters (PD) of deviation at the end of 12 weeks. Need for resurgery in a 12-week follow-up period was considered to be failure. At the end of the study, 90% of the patients in group A and 85% of the patients were within 10 prism diopters of orthophoria (p = 0.316). At the end of 6 months, mean deviation in group A was 6.20 PD and in group B it was 5.60 PD (p = 0.31). No patient underwent resurgery.

CONCLUSIONS

Adjustable hang-back recession has no definite added advantage over nonadjustable hang-back recession in intermittent exotropia.

Y-Split Recession of the Medial Rectus Muscle as a Secondary and/or Unilateral Procedure in the Treatment of Esotropia with Distance/Near Disparity

Introduction

In esotropia with larger angles > near than at distance, splitting of the medial rectus muscle has been suggested as a treatment option. Previous reports of bilateral medial rectus Y-splitting as a first intervention showed a reduction of the distance/near disparity with fewer side effects compared to posterior fixation surgery. We address whether a medial rectus Y-splitting as a secondary and/or a unilateral procedure also reduce distance/near disparity.

Materials and Methods

We retrospectively reviewed the charts of four patients undergoing Y-split recession as a second and/or unilateral surgery. Main outcomes were distance/near disparity and squint angles.

Results and Discussion

Three of the four patients had undergone unilateral Y-splitting of the medial rectus as a secondary surgery, three as a unilateral procedure. Mean distance/near disparity was reduced from 17 PD preoperatively to zero at the final follow-up (FU). Preoperative angles ranged from 45 PD to 66 PD at near and from 25 PD to 55 PD at distance. At the final FU, these angles ranged from 0 PD to 20 PD at near and at distance. Mean FU was 42 months (range: 12–60 months).

Conclusion

Y-split recession as a secondary and/or unilateral surgery for distance/near esotropia can reduce distance/near disparity with good long-term results. Residual esotropia can be corrected by adding resection of the lateral rectus muscle.

Evaluation of macular thickness change after inferior oblique muscle recession surgery

PURPOSE

This study aimed to evaluate the changes in macular thickness following inferior oblique muscle recession surgery.

MATERIALS AND METHODS

Thirty-eight eyes from 21 patients undergoing ocular muscle surgery were included. Patients were grouped into three groups based on the type of surgical intervention: Group I (n = 12), inferior oblique recession surgery alone; Group II (n = 12), inferior oblique plus horizontal muscle surgery; Group III (n = 14), horizontal muscle surgery alone. Each eye was scanned using the optical coherence tomography (OCT) device preoperatively and on the first postoperative day to measure macular thickness.

RESULTS

Following surgery, a significant increase in foveal thickness occurred in Group I (P < 0.05) and Group II (P < 0.01). In addition, a statistically significant difference was observed between the groups with regard to the increase in foveal thickness (P = 0.016), with significantly lower changes in Group III.

CONCLUSION

Our findings suggested that inferior oblique muscle recession surgery is associated with an increase in macular thickness.

Complications of Strabismus Surgery

All surgeries carry risks of complications, and there is no way to avoid ever having a complication. Strabismus surgery is no different in this regard. There are methods to reduce the risk of a complication during or after surgery, and these steps should always be taken. When a complication occurs, it is important to first recognize it and then manage it appropriately to allow for the best outcome possible. This article will discuss some of the more common and/or most devastating complications that can occur during or after strabismus surgery as well as thoughts on how to avoid them and manage them should they happen.

Post-strabismus surgery aqueous misdirection syndrome

A 24-year-old man was referred to the glaucoma clinic of our tertiary eye care centre in view of uncontrolled intraocular pressure (IOP) in the left eye despite maximal medication. The patient had undergone left eye cosmetic squint surgery 1 month before (medial rectus resection 9 mm and lateral rectus recession 12 mm) for congenital third nerve palsy. Post-squint surgery, the patient developed pain and was being managed symptomatically. However, 1 week later, he developed diffuse corneal oedema and severe pain, and was readmitted for management in the same hospital. He presented to our centre with an IOP of 16 mm Hg in the right eye and 58 mm Hg in the left eye. We made a diagnosis of left eye post-strabismus surgery aqueous misdirection syndrome, and performed left eye core vitrectomy with 360° goniosynechialysis and ultimately a trabeculectomy to reduce IOP.

Complications of strabismus surgery: incidence and risk factors

PURPOSE

To perform a systematic review of the complications of strabismus surgery, focusing on incidence and risk factors.

MATERIAL AND METHODS

A systematic literature search was performed using the Medline and Cochrane databases.

RESULTS

Local complications, such as conjunctival injection and mild scarring, are almost universal but only rarely have long-term clinical significance. There are several important complications that are uncommon but associated with significant long-term sequelae, including slipped muscles, lost muscles, stretched scars, incarcerated muscles, pulled-in-two syndrome, periocular infections, orbital cellulitis, scleral perforations, retinal detachments, endophthalmitis, anterior segment ischemia, and surgical errors.

DISCUSSION

Strabismus surgery is associated with a number of common and serious complications, and it is important for both surgeons and patients to be aware of the risks.

Cyanoacrylate tissue adhesive on a polyglactin scaffold in strabismus surgery: a laboratory study

BACKGROUND

The use of cyanoacrylate tissue adhesives in strabismus surgery has been variously successful, depending primarily on achieving adequate bond strength and minimizing extraocular muscle slippage. We investigate a novel approach to this problem, involving cyanoacrylate tissue adhesive on a polyglactin 910 scaffold as a means to secure extraocular muscle to the sclera for strabismus surgery.

METHODS

In this experimental laboratory study, butyl-cyanoacrylate was used to fix a polyglactin 910 scaffold to the sclera of cadaver eyes. After allowing for polymerization, a force was applied to the mesh until the polyglactin-sclera bond failed. The maximum load (g) required for bond failure was recorded. The effects of surface area of the polyglactin 910 mesh as well as time required for cyanoacrylate tissue adhesive polymerization on bond strength were investigated.

RESULTS

All combination of variables tested, except for experiments involving polyglactin 910 mesh that is 30 mm(2) with a polymerization time of 15 seconds or 30 seconds and polyglactin 910 mesh that is 40 mm(2) with a polymerization time of 15 seconds, achieved a bond strength that was significantly greater than those forces seen in a physiologic setting (P > 0.05). Increasing area or time resulted in increasing bond strength. Area and time were found to be independent variables.

CONCLUSIONS

The cyanoacrylate tissue adhesive-derived polyglactin-sclera bond achieved a maximum load greater than those seen in a physiologic setting. Our novel approach demonstrates a clinically feasible alternative to traditional means for bonding muscle to sclera in strabismus surgery.

Bacterial Species and Surgical Sites Involved in Contamination During Strabismus Surgery

PURPOSE

Residual bacterial colonization of the eye after strabismus surgery is common. This study aimed to identify the bacterial pathogens and contaminated sites involved during strabismus surgery.

DESIGN

A prospective, case-control study of 44 patients aged 1-78 years who underwent strabismus surgery.

METHODS

Before participation, we received clinical research board approval, and informed consent was obtained from each of the patients or the parents. Five percent povidone-iodine was used to sterilize the surgical site in all cases. Intraoperative swabs were taken from conjunctival incision site, plain gut suture, scleral surgery site, Vicryl suture, and lid specula. Bacteria isolates were identified by culture growth and Gram staining. Positive and negative control samples were collected.

RESULTS

Samples from 13 (29.5%) of 44 cases were positive for growth of bacteria. The conjunctival incision site was involved in 9 cases (20.5%), and the lid speculum in 7 cases (15.9%). All 13 colonized plates grew the coagulase-negative Staphylococcus strain. Staphylococcus aureus was cultured in 1 case (2.3%) and was associated with the only case of postoperative infection. The S. aureus cultures came from both the conjunctival incision site and the lid speculum.

CONCLUSIONS

Despite a high contamination rate of 29.5%, incidence of clinically significant infection was low. Our study suggests involvement of the eyelids and conjunctiva in harboring bacteria even after the use of povidone-iodine. Regardless of the mechanism of contamination, we should continue to focus our efforts on reducing intraoperative conjunctival bacterial load. Irregular tear film can contribute to postoperative complications.

Preferences of pediatric ophthalmologists and vitreoretinal surgeons of the treatment of scleral perforations during strabismus surgery

PURPOSE

To evaluate the preferences of pediatric ophthalmologists and vitreoretinal surgeons with regard to the initial management of scleral perforation during strabismus surgery and to determine whether they perceived one mode of treatment conferred a significant advantage over another in terms of the complication rate.

METHODS

Six hundred sixty-five pediatric ophthalmologists and 494 vitreoretinal surgeons registered with their respective national organizations were invited by an e-mail to respond to an anonymous, web-based survey. The responses to the survey were compared between groups.

RESULTS

A total of 169 ophthalmologists participated, 133 of whom were pediatric ophthalmologists and 36 vitreoretinal surgeons. Significantly more pediatric ophthalmologists than vitreoretinal surgeons recommend initially managing scleral perforation by observation (P = .001). Among pediatric ophthalmologists, method of treatment was not perceived to affect outcome (P = .75). However, laser photocoagulation was perceived to result in the best outcome among vitreoretinal surgeons (P = .03).

CONCLUSION

Significant differences exist among pediatric ophthalmologist and vitreoretinal surgeon management preferences and perceived treatment outcomes for scleral perforation.

Globe perforation during strabismus surgery in an animal model: Treatment versus observation

PURPOSE

To evaluate the role of cryopexy or laser therapy versus observation for management of accidental globe perforation during strabismus surgery in an experimental animal model.

METHODS

An S-24 needle was passed through the sclera and into the vitreous cavity in both eyes of 42 rabbits. Cryopexy was performed in 22 eyes, and laser therapy was applied in 20 other eyes; the 42 untreated fellow eyes served as controls. The incidence of complications was compared between treated and untreated eyes.

RESULTS

Cataracts were observed in 7 eyes (8.3%) and corneal opacity in 1 eye (1.2%) vitreous hemorrhage occurred in 28 eyes (33.3%), leading to vitreous opacity in 1 eye (1.2%). Transient localized subretinal fluid accumulation around the retinal break developed in 1 eye (1.2%). There were no cases of endophthalmitis or retinal detachment. There was no significant difference in the rate of complications among the 3 groups.

CONCLUSIONS

Vision-threatening consequences of globe perforation during strabismus surgery were uncommon in this rabbit model. Simple observation without intervention may have similar results as prophylactic cryopexy or laser therapy.

Inadvertent scleral perforation in eye muscle versus retinal detachment buckle surgery

PURPOSE

Inadvertent scleral perforation is a recognized complication of eye muscle and retinal detachment buckle surgery. If these operations are performed by the same surgeon, it is unknown which of these procedures has a higher risk of scleral perforation.

METHODS

In the period from 1999 until 2004, 427 eyes of 317 patients were operated using eye muscle surgery and 81 eyes of 80 patients with retinal detachment buckle surgery. All operations were performed by the same surgeon (JK). In a retrospective, single-center, comparative, observational study, the records of these patients were assessed to determine the number of scleral perforations with retinal damage or drainage of subretinal fluid.

RESULTS

In the group receiving retinal detachment buckle surgery there were two cases of scleral perforation. In one case, scleral perforation occurred during buckle installation and in the other case during placement of a cerclage. The rate of scleral perforation was 2.5 % per patient and per eye in this group. In the group receiving eye muscle surgery no scleral perforations occurred.

CONCLUSION

The number of scleral perforations was higher in retinal detachment buckle surgery than in eye muscle surgery, with all procedures having been performed by the same surgeon.

Effect of full tendon transposition augmented with posterior intermuscular suture for paralytic strabismus

PURPOSE

To evaluate the results of the full rectus muscle transposition augmented with a posterior intermuscular suture for paralytic strabismus.

DESIGN

Single-center, retrospective, interventional case series.

METHODS

This study retrospectively reviewed the medical records from November 1994 to September 2004 of 16 patients who underwent the full tendon transposition that was augmented with posterior intermuscular suture for paralytic strabismus. This series evaluated the results of a single transposition surgery; five patients had previous nontransposition strabismus surgery. The following data were analyzed before and after the operation: (1) the angle of deviation in the primary position, (2) the presence of diplopia in the primary position, (3) the binocular single visual fields, (4) the presence of an abnormal head posture, (5) the motility of the affected eye, and (6) the procedure that was performed.

RESULTS

The preoperative angle of deviation in the primary position was 59 +/- 22 prism diopter (prism diopter; range, 30 to 115 prism diopter) compared with 17 +/- 12 prism diopter (range, -10 to 40 prism diopter) after the operation. The preoperative binocular single visual fields improved from 0 degrees to 60 +/- 25 degrees (range, 0 to 90 degrees) after the operation. Diplopia in the primary position was resolved in 11 patients (69%) after the operation. There were no complications such as scleral perforation, unwanted vertical deviations, or anterior segment ischemia in any of the cases during the procedure and postoperative follow-up.

CONCLUSION

Full tendon transposition that is augmented with a posterior intermuscular suture is an effective procedure that results in improved ocular alignment in patients with paralytic strabismus and has a favorable complication profile.

Scleral penetrations and perforations in strabismus surgery and associated risk factors

OBJECTIVE

To evaluate the incidence and identify associated risk factors of scleral penetrations and perforations resulting from strabismus surgery.

METHODS

A prospective observational study of patients undergoing strabismus surgery by residents or fellows was conducted. The surgical techniques employed included recessions, resections, advancements, posterior fixation sutures, and transpositions. Indirect ophthalmoscopy was performed on each operated eye following surgery to identify any retinal changes indicative of a penetration or perforation.

RESULTS

Of the 144 patients and 217 operated eyes, 11 sustained penetrations (5.1%), and 6 perforations (2.8%). On a per muscle procedure basis, the incidence of penetrations was 4.3% and of perforations 1.9%. The mean age at surgery for patients who experienced perforations was 4.8 years (+/- 5.3), which was less than those with penetrations or those without any complications (P = .016). The surgeon's experience was not related to the frequency of these complications. Penetrations or perforations were more likely to occur with rectus muscle recessions than resections (P = .0067). Horizontal rectus muscles were most frequently associated with penetrations and perforations when compared to vertical rectus and oblique muscles (P = .003). The S-24 needle was more frequently involved in the penetrations and perforations than other needles (P = .027).

CONCLUSIONS

In order to reduce the risk of scleral penetrations or perforations, surgeons should exercise caution when performing strabismus surgery in younger patients, when using S-24 needles, and when performing rectus muscle recessions. This study has demonstrated, for the first time with statistical significance, that recessions are more often associated with penetrations and perforations than other types of strabismus procedures.

Needle sterility during strabismus surgery

BACKGROUND

Infection after strabismus surgery is uncommon and its cause remains unanswered. The source of the bacteria and the manner in which it enters the eye is often unknown. Most pediatric ophthalmologists now use 5% povidone-iodine to reduce the bacterial population before surgery. The needles used during strabismus surgery may be a source of bacterial contamination.

METHODS

One hundred six needles were cultured after their use in strabismus surgery.

RESULTS

Sixteen of 106 needles (15.1%) and 15 of 61 cases (24.6%) were culture positive. The organisms recovered closely resembled indigenous bacterial flora.

CONCLUSION

This study suggests that the needles used during strabismus surgery may be the source of bacteria that can lead to infections after strabismus surgery.

Slipped and lost muscles and other tales of the unexpected. Philip Knapp Lecture

Loss of a rectus muscle may occur as a rare complication of strabismus surgery. In addition, extraocular muscles may become traumatically detached from the globe when they rupture or are transected as the result of an injury or during the course of retinal detachment or paranasal sinus or orbital surgery. Although the clinical features of a slipped muscle may resemble those of a lost muscle, the findings at the time of reoperation are distinct. Also the etiology, and therefore the prevention, of a slipped muscle differs from that of a lost muscle. It is likely that slipped muscles and even some lost muscles are underdiagnosed and represent a significant cause of unexpected overcorrection or undercorrection. Unless the displaced muscle is appropriately advanced, it can be extremely difficult to correct the associated strabismus, yet locating and repairing either a lost or slipped muscle can be challenging and is by no means always successful. Current concepts pertaining to the etiology, recognition, and management of slipped and lost muscles will be discussed.

Vitreoretinal surgery after inadvertent globe penetration during local ocular anesthesia

OBJECTIVE

This study aimed to review visual morbidity resulting from inadvertent globe penetration during administration of local anesthetic and to identify the most appropriate management.

DESIGN

The records of 20 consecutive patients referred to a specialist vitreoretinal unit over a 2-year period were reviewed.

PARTICIPANTS

Twenty eyes of 20 consecutive patients were included.

INTERVENTION

Observations included type of local anesthetic administered (e.g., retrobulbar or peribulbar), level of training of person administering the block, type of needle used for the block, and findings at presentation to the vitreoretinal unit. The authors also observed results of B-scan ultrasound evaluation of the retina, interval between the recognition of the complication and referral, as well as nature and timing of subsequent surgical intervention.

MAIN OUTCOME MEASURES

Final visual acuity and retinal status (attached versus detached) were measured.

RESULTS

The most common presentation was vitreous hemorrhage observed from the first postoperative day. Ten eyes were found to have an associated retinal detachment on initial assessment in the vitreoretinal unit. These eyes generally had a poor visual outcome despite vitrectomy with long-acting gas or silicone oil tamponade. Seven (70%) of the remaining eyes with attached retina at the time of presentation achieved good visual recovery after vitrectomy.

CONCLUSIONS

The authors recommend prompt referral for consideration of early vitrectomy in eyes with dense vitreous hemorrhage after inadvertent globe penetration. This management may improve the overall visual prognosis by preventing subsequent retinal detachment.

Retinal perforation in strabismus surgery

PURPOSE

Perforation of the retina is a major complication of strabismus surgery. The reported incidence of perforation varies from 0.13% to 12%. This study was undertaken to determine, from a large collaborative database, the incidence of suspected and unsuspected retinal and choroidal injury in pediatric horizontal muscle surgery.

METHOD

All children with horizontal strabismus surgery seen between September 1992 and October 1995 were examined with Indirect ophthalmoscopy immediately following their procedure. Surgery was performed by both resident and attending physicians. Cases involving muscle reoperation, high myopia, or patients with connective tissue disorders were excluded.

RESULTS

Strabismus surgery was performed on 765 patients, who underwent 1129 muscle recessions and 349 muscle resections. These children also had 161 vertical or oblique muscle procedures performed. Intraocular trauma resulting from horizontal muscle surgery was noted in 14 patient, including three retinal perforations. One of these patients was treated with cryotherapy; the other two received no therapy other than intraoperative and postoperative antibiotics.

DISCUSSION

The incidence of retinal perforation was 0.4% and the incidence of choroidal injury without perforation was 1.4% in this large series of children undergoing horizontal strabismus surgery. Retinal detachment or endophthalmitis did not develop during the 6-week follow-up period.

Management of experimental globe perforation during strabismus surgery

BACKGROUND

The incidence of potentially vision-threatening globe perforation during strabismus surgery is reportedly between less than 1% and 12% of cases. Optimal treatment of globe perforation is not known; however, traditionally it has been treated with cryotherapy at the time of surgery or observation without treatment. The indirect-ophthalmoscope-directed diode laser may provide a safe and effective alternative treatment.

METHODS

We perforated the globes of six adult Dutch rabbits (12 eyes) and treated four eyes with cryotherapy and four with diode laser; the remaining four were not treated.

RESULTS

Histologic examination of the untreated eyes revealed a cellular reaction around the polyglactin suture that formed a non-uniform chorioretinal adhesion. The cryotherapy eyes had a tenuous chorioretinal adhesion and retinal pigment epithelium (RPE) cells in the vitreous on several sections. The laser-treated eyes had a firm, wide chorioretinal adhesion, with minimal tissue disruption and no release of RPE cells. No complications occurred.

CONCLUSION

We conclude that indirect-ophthalmoscope-directed diode laser retinopexy was safe and efficacious for globe perforation during strabismus surgery on rabbits and could be expected to be useful in humans.

New materials for rectus muscle tendon extension in strabismus surgery

Conventional strabismus surgery has both limitations and complications. Some of these have been overcome by the use of 'hang-back' sutures. Here we describe a new technique using Mersilene and Teflon as extraocular muscle implants for large muscle recessions. Results of initial studies in rabbits are presented and discussed. Mersilene implants evoked a marked fibroblastic reaction which limits their usefulness. Results with Teflon were more encouraging and suggest that it would be a useful spacer material in tendon extensions.

Recognized scleral perforation during eye muscle surgery: incidence and sequelae

Inadvertent perforation of the sclera is a widely recognized complication of eye muscle surgery. In the 1960s and 1970s, it was estimated to occur in 9% to 12% of patients operated. Fortunately, dreaded vision-threatening sequelae have been much less common. To better define the occurrence and sequelae of this complication, we sent a questionnaire to all 342 members of the American Association for Pediatric Ophthalmology and Strabismus. Scleral perforations, defined to include known retinal damage, occurred in 728 of nearly 554,000 eye muscle procedures performed by 223 surgeons. Perforations were two times more common with residents or fellows operating. They occurred not only during muscle reattachment (633 cases), but also during muscle disinsertion (24 cases), muscle dissection (6 cases), passage of traction sutures beneath the lateral rectus (5 cases), and preplacement of muscle sutures (5 cases). Many other perforations may have been unrecognized and uncounted. Visual loss was uncommon, occurring in only nine patients. Fourteen retinal detachments included four cases with partial and two with total loss of vision. Only three cases of endophthalmitis occurred, one resulting in partial visual loss and two in total visual loss. Techniques suggested by respondent surgeons to avoid perforations are discussed.