Surgical management of intraretinal foreign bodies

Intraocular Foreign Body: Diagnostic Protocols and Treatment Strategies in Ocular Trauma Patients

Intraocular foreign bodies (IOFBs) are critical ophthalmic emergencies that require urgent diagnosis and treatment to prevent blindness or globe loss. This study aimed to examine the various clinical presentations of IOFBs, determine the prognostic factors for final visual outcomes, establish diagnostic protocols, and update treatment strategies for patients with IOFBs. We retrospectively reviewed patients with IOFBs between 2005 and 2019. The mean age of the patients was 46.7 years, and the most common mechanism of injury was hammering (32.7%). The most common location of IOFBs was the retina and choroid (57.7%), and the IOFBs were mainly metal (76.9%). Multivariate regression analysis showed that poor final visual outcomes (<20/200) were associated with posterior segment IOFBs (odds ratio (OR) = 11.556, p = 0.033) and retinal detachment (OR = 4.781, p = 0.034). Diagnosing a retained IOFB is essential for establishing the management of patients with ocular trauma. To identify IOFBs, ocular imaging modalities, including computed tomography or ultrasonography, should be considered. Different strategies should be employed during the surgical removal of IOFBs depending on the material, location, and size of the IOFB.

Open Globe Injury with Intraocular Foreign Body

Purpose

To investigate characteristics of Open Globe Injuries (OGI) that presented with Intra-Ocular Foreign Body (IOFB), along with their long-term visual outcomes, complications and need for subsequent surgeries.

Methods

Retrospective interventional consecutive case series of OGIs with IOFBs that presented to the Eye Trauma service at the Massachusetts Eye and Ear from 2010 to 2015. Data collected included time from injury to OGI repair, location of injury and IOFB, retinal detachment (RD) rate, presenting and final visual acuity (VA) and subsequent surgeries.

Results

Fifty-seven consecutive cases of OGIs with IOFBs were included. The majority of patients were male (93%), mean age was 37 years and mean follow-up was 28 +/- 22 months. The median time from injury to OGI repair was 0 days (range: 0-16 days). Overall, 38/57 (66.7%) eyes achieved final vision of 20/40 or better and 43/57 (75.4%) vision of 20/150 or better. Zone I injuries were the most common (86%), followed by Zone II (16%), and Zone III (10%). 33 cases had IOFBs in the anterior segment only and 24 cases had posterior segment involvement. In total, 30% of cases (17/57) were complicated by an RD, 58.3% (14/24) in the posterior versus 9.1% (3/33) in the anterior IOFB group.( p<0.01). There were no cases of endophthalmitis. Posterior IOFB and higher zone of injury were found to be risk factors for RD both at presentation (all p<0.05) and post-primary repair.(all p<0.05) Posterior IOFB was associated with higher vitrectomy rates both at presentation (p<0.0001) and post-primary repair (p=0.002) and worse long-term visual outcome (p = 0.014).

Conclusion

OGIs with IOFB involving the posterior segment are associated with higher complication and re-operation rates and worse visual prognosis compared to those involving the anterior segment only.

Proliferative Vitreoretinopathy After Combat Ocular Trauma in Operation Iraqi Freedom and Operation Enduring Freedom: 2001-2011

BACKGROUND AND OBJECTIVE

To determine the risk factors associated with developing proliferative vitreoretinopathy (PVR) from combat ocular injuries in U.S. service members.

PATIENTS AND METHODS

Retrospective review of associated risk factors and outcomes of PVR within the Walter Reed Ocular Trauma Database. Ocular injuries in U.S. service members wounded during Operation Enduring Freedom and Operation Iraqi Freedom from 2001 to 2011 were assessed, and of these all cases of PVR were studied. Principal outcome measures were the risk factors associated with PVR development and rate of final visual acuity (VA) less than 20/200.

RESULTS

Eight hundred ninety eyes of 651 U.S. service members were evaluated. A total of 76 eyes (8.5%) of 66 patients developed PVR. Five patients had bilateral PVR. Nineteen patients had bilateral eye injuries. Sixty-one eyes (80.2%) had a final VA less than 20/200. PVR was found to be a significant risk factor for a poor final VA (P < .001). Retinal detachment (RD) was found in 52 eyes (68.4%) of patients. In patients with a RD, intraocular foreign bodies (IOFBs) (P < .001), unsuccessful repair (P = .002), and macular hemorrhage (P = .04) were significant risk factors for the development of PVR. Time to initial retina surgery was not found to be a risk factor for PVR development (P = .5). Time to initial retina surgery was available in 41 patients and the time to surgery on average was 22.56 days (range: 3 to 87 days).

CONCLUSIONS

PVR occurs frequently in combat trauma and is a significant cause of poor final VA. In patients with PVR and RD, injuries caused by an IOFB, macular hemorrhage, or unsuccessful repair were significant risk factors for the development of PVR. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:556-563.].

Low-cut, low-vacuum vitrectomy for releasing an embedded intraocular foreign body

Background

Removal of an embedded intraocular foreign body remains challenging due to the risks of bleeding and retinal damage. We present a novel technique to deal with this situation.

Case report

A 32-year man presented with two months of decreased vision in one eye (best corrected visual acuity of 20/200), a year after a workplace injury that necessitated surgery for an open globe injury. Examination revealed the sequalae of his previous surgery, a subtotal retinal detachment and an embedded intraocular foreign body close to inferior ora serrata at the 6 'o clock position confirmed by imaging. The other eye was normal. A pars plana vitrectomy was performed and the embedded intraocular foreign body was released from surrounding dense adhesions using the vitrectomy probe set at 1000 cuts/minute and 100 mm Hg vacuum, followed by fluid air exchange and endolaser with silicon oil injection. The retinal detachment settled well post-operatively, and at the end of one month, the patient had best corrected visual acuity of 20/60.

Conclusions

The low-cut, low-vacuum vitrectomy technique can be considered as a safe option for releasing the embedded intraocular foreign body in complex ocular trauma scenarios.

Predictive factors of visual outcome in posterior segment intraocular foreign body

BACKGROUND

To identify the predictive factors for visual outcomes of patients with posterior segment intraocular foreign body (IOFB) after open-globe injury.

METHODS

A retrospective, interventional study was conducted to evaluate consecutive patients with retained posterior segment IOFB who underwent vitrectomy over a 10-year period from 2007 to 2016. Multivariate linear regression analysis was used to identify the potential predictive factors for final visual outcomes.

RESULTS

Forty-two patients were evaluated, with predominantly males (97.6%) and mean age 37.21 years. Hammering on metal (47.62%) was the major mechanism of injury. The majority of foreign bodies were metallic (95.24%) with a mean dimension of 4.3 mm. Twenty-four (57.14%) patients initially presented with a Snellen visual acuity <6/60. After surgery, 19 (45.24%) eyes had final visual outcomes of 6/12 or better; however, visual outcomes worse than 6/60 were documented in 17 (40.48%) eyes. Multivariate linear regression analysis revealed that the occurrence of retinal detachment (RD; p<0.01) and larger IOFB dimension (p=0.02) independently predicted worse final visual outcomes after adjusting for age and initial VA. Eyes with entry wounds located posteriorly into the sclera significantly increased the risk of RD compared to eyes with entry wounds involving cornea only (p=0.03). There was no association between time interval for IOFB removal and development of endophthalmitis.

CONCLUSION

RD and larger IOFB dimension are significant predictive factors associated with worse final visual outcomes. Increased time to IOFB removal is not associated with either a higher risk of endophthalmitis or worse visual outcomes.

Intraocular Foreign Body Trauma in Operation Iraqi Freedom and Operation Enduring Freedom: 2001 to 2011

PURPOSE

We update the incidence of intraocular foreign bodies (IOFB) in soldiers admitted to Walter Reed Army Medical Center from 2001 to 2011 after sustaining combat injuries in Operation Iraqi Freedom and Operation Enduring Freedom.

DESIGN

This consecutive retrospective case series included 890 eyes of 652 patients.

METHODS

Data were collected in the Walter Reed Ocular Trauma Database. Inclusion criteria were any American soldier or Department of Defense civilian with an IOFB injured in Operation Iraqi Freedom/Operation Enduring Freedom. Closed globe injuries with orbital foreign bodies, injury outside of a combat zone, or non-Department of Defense civilian trauma were the exclusion criteria.

MAIN OUTCOME MEASURES

Primary outcome measures were final visual outcome and the number, size, and location of IOFBs. Secondary outcome measures included surgical procedures, use of eye protection, associated complications, source of injury and Ocular Trauma Score.

RESULTS

There were 890 eye injuries in 652 patients evacuated to Walter Reed Army Medical Center between 2001 and 2011. IOFBs were found in 166 eyes of 149 patients (18.6%; 95% confidence interval [CI], 16.2%-21.3%). Most patients had a single IOFB (80.7%). An IOFB was positively associated with Ocular Trauma Score grade 1 or 2 (0-65) injuries (odds ratio [OR], 1.58; 95% CI, 1.07-2.38; P = 0.01). There were 130 eyes (78.33%) that had recorded time from initial visual acuity to final visual acuity and it ranged from 8 to 2421 days (mean, 433.24 days). Thirty-eight (25.16%; 95% CI, 18.89%-32.67%) eyes had no change in visual acuity, 98 (64.90%; 95% CI, 57.00%-72.07%) had improved visual acuity, and 15 (9.93%; 95% CI, 6.01%-15.84%) had decreased visual acuity. IOFB was not found to predict final visual acuity of <20/200 in multivariate analysis when other injury features were known (P = 0.1). Pars plana vitrectomy was completed on 124 eyes (74.70%). Removal of IOFB was performed in 118 eyes (71.08%; average of 31.67 days after initial injury) with a delayed procedure occurring after primary closure and antibiotics owing to a lack of surgical capacity in Iraq and Afghanistan. Retinal detachment occurred in 48 eyes (28.92%) and proliferative vitreoretinopathy in 44 eyes (26.5%).

CONCLUSIONS

IOFBs occur frequently in combat ocular trauma and are significantly associated with more severe injuries. However, IOFBs were not found to be a significant risk factor for visual acuity of <20/200.

Perfluorocarbon liquid-assisted intraocular foreign body removal

We describe the benefits of perfluoro-N-octane (PFO), a perfluorocarbon liquid, in the removal of nonmagnetic intraocular foreign bodies (IOFBs) from the macula and posterior segment. Two consecutive cases of posterior segment IOFB were reviewed. An 18-year-old male presented to the emergency room after a motor vehicle accident with a zone 1 open globe injury and large glass IOFB in the left eye. A 53-year-old male presented to the emergency room with a history of a 3-week delayed presentation of a zone 1 open globe injury from a nail to the right eye. He was found to have a metallic IOFB. In both cases, PFO was used to slide the nonmagnetic IOFBs outside of the macula for safer retrieval. PFO was also able to protect the posterior pole from IOFB drops during early attempts at removal. PFO can be a useful surgical adjunct to pars plana vitrectomy in the removal of certain nonmagnetic IOFBs.

Surgical Treatment of Penetrating Ocular Injuries with Retained Intraocular Foreign Bodies

A total of 40 cases of retained intraocular foreign bodies (IOFB) presenting to the University Eye Clinic of Novi Sad between January 1988 and December 1994 were evaluated and surgically treated. The group most affected were males with a mean age of 33 years, who had been occupationally injured, presenting with either corneal or scleral single laceration. Thirty-seven injuries (92%) were due to metallic foreign bodies. Two eyes presented with initial clinical signs of endophthalmitis (5%). Five eyes (12.5%) were war-injuries, with tremendous destruction of all ocular structures. After an average of 12 months follow-up 70% of total eyes achieved postoperative good or useful vision, 50% of these with visual acuity 0.5 or better.

Intraocular Foreign Bodies: Myths and Truths

Over the centuries, the management of eyes with intraocular foreign bodies (IOFB) has posed a special challenge to the physician, and the anxiety created by such injuries has never abated. During the past few decades, several new diagnostic tests, IOFB removal techniques, and methods to treat the complications of the injury have been introduced. Nevertheless, old habits die hard: many of the management options that used to be standard are not appropriate any more but have proved difficult to change. This article reviews over forty of these die-hard myths and confronts them with factual statements published in the peer-review international literature.

23 gauge pars plana vitrectomy for the removal of retained intraocular foreign bodies

Background

To evaluate the morpho-functional outcomes and safety of transconjuctival 23-gauge pars plana vitrectomy(PPV) for removal of intraocular foreign bodies (IOFBs).

Methods

A retrospective study of 36 consecutive cases (mean age; 34,2 ± 10,9 years (between 15 and 60), 27 M,9 F) of 23-G PPV for the removal of IOFBs during the period of April 2009 and December 2011 and followed 9,4 ± 6,4(2–27) months were conducted. Visual outcomes, slit lamp biomicroscopy, intraocular pressure (IOP), and posterior segment visualization by indirect ophthalmoscopy, A-B mode ultrasonography, and computed orbital tomography were performed for all cases. Main outcomes including anatomic and visual outcomes, and both intraoperative and postoperative complications were recorded.

Results

Of the 36 cases available for the study, the IOFBs (size range, 3 to 12 mm) could be removed in all eyes. Mean preoperative LogMAR BCVA was 1.44 ± 138 (range, 1.00 to 0.00) and mean postoperative LogMAR BCVA at final visit was 0,78 ± 0,98 (range, 1.00 to 0.00). (P = 0,007) Anatomic success was obtained in 97.2 % of eyes. 16 patients needed primary wound repair due to the leakage in insertion sites before the PPV, however remaining 20 cases were not. Fibrin reaction was seen in 8 (22.2 %) patients in early postoperative period, intraocular pressure elevation was detected in 12 (33.3 %) patients in which the silicone oil was used as an intravitreal tamponade, one patient with silicone oil tamponade developed band keratopathy and phthisis bulbi.

Conclusions

23-Gauge PPV is a feasible, effective approach in the surgical management of the patients with posterior segment intraocular foreign bodies.

Vitrectomy for posterior segment intraocular foreign bodies, visual and anatomical outcomes

PURPOSE

To evaluate the visual and anatomic results and determine the prognostic factors after pars plana vitrectomy and posterior segment intraocular foreign body (IOFB) removal.

MATERIALS AND METHODS

This retrospective study reviews the patients' charts of 48 consecutive patients with posterior segment IOFB who underwent pars plana vitrectomy and IOFB removal over a 4-year period, recently. Association between visual outcome and various preoperative, operative, and postoperative variables was statistically analyzed. Data were analyzed with the paired t-test and the chi square test. Statistical significance was indicated by P < 0.05.

RESULTS

The mean interval between the time of injury and IOFB removal was 24 ± 43.1 days and 27 (53%) eyes underwent IOFB removal within 7 days of the injury. Nine (19.1%) patients achieved a visual acuity of 20/40 or better. An improvement of visual acuity of at least three lines occurred in 21 (44.6%) eyes and the vision remained unchanged in 15 (31.9%) eyes. Postoperative retinal detachment occurred in five (10.6%) eyes. Visual improvement was more likely to occur in eyes with lower levels of presenting visual acuity (P = 0.2). Visual improvement was not associated with an entry site and IOFB location, lens injury, time to surgery, and pre- and post-operative retinal detachment. At the end of follow up, anatomical success was achieved in 97.9% of eyes.

CONCLUSIONS

High anatomical success could be achieved after the removal of posterior segment IOFBs by vitrectomy, despite a delay in surgery. Poor visual outcome may be mainly due to the initial ocular injury.

Retained subretinal date palm tree thorn in a child

A 3-year-old boy presented with severe eye pain and nausea after colliding with a date palm tree branch. Examination under anesthesia revealed a self-sealed corneal laceration and traumatic cataract in his left eye. Cultures were taken and the patient received prophylactic subconjunctival, intravitreal, and systemic antibiotics because of the high risk of endophthalmitis. A thorn from the same tree grew Bacillus cereus. Examination after 2 weeks of the injury revealed a subretinal foreign body (a palm tree thorn), although there were no signs of endophthalmitis or retinal detachment. The patient underwent cataract extraction and laser demarcation of the subretinal foreign body, which was not removed. He was fitted for an aphakic contact lens. With alternate patching, his best-corrected visual acuity improved to 20/30.

Experimental measure of retinal impact force resulting from intraocular foreign body dropped onto retina through media of differing viscosity

BACKGROUND

To evaluate and compare the perfluorocarbon liquid, silicone oil, and viscoelastic against standard saline, in their ability to dampen the impact force of a foreign body, dropped within the eye. In an experimental surgical model in where cohesive and adhesive forces of the substances are not enough to float heavy-than-water foreign bodies.

METHODS

A model of ophthalmic surgery was constructed. A BB pellet was dropped from 24 mm onto a force transducer through four different fluids: balanced salt solution, perfluoro-n-octane, viscoelastic, and silicone oil. The impact energy (force) for each case was measured and recorded by the force transducer. The mean force of impact for each fluid was compared using the Student t-test.

RESULTS

Silicone oil resulted in the lowest force of impact. Both silicone oil and viscoelastic dampened the impact an order of magnitude more than perfluoro-n-octane and balanced salt solution.

CONCLUSIONS

Silicone oil and viscoelastic cushioned the force from a dropped BB. They may be useful adjuncts to prevent iatrogenic retinal injury during vitrectomy for intraocular foreign body removal.

[Intraocular foreign bodies (IOFB) of the posterior segment: retrospective analysis and management of 57 cases]

PURPOSE

To determine the influence of prognostic factors and the type of tamponade agent in surgical management of intraocular foreign bodies (IOFBs) for better visual outcome.

PATIENTS AND METHODS

Fifty-seven consecutive cases were retrospectively reviewed at the XV-XX National Hospital (Paris) between 1 January 2004 and 31 December 2007. Univariate and multivariate analyses were performed to identify prognostic variables. Several parameters were measured: pre- and postoperatively: best corrected visual acuity (BCVA), material and size of the foreign body, entry site, time from trauma to surgical removal, IOFB location, initial retinal detachment, choice of vitreous tamponade agent (none, gas, silicone oil), postoperative visual outcome, and complications (siderosis, endophthalmitis, and vitreoproliferative retinal detachment).

RESULTS

Metal IOFBs accounted for the majority with 80.7% (n=46). The inferior retinal segment was the most frequent location found: 47.4% (n=27). Initial and final mean BCVAs were, respectively, 1.47 (±0.99) and 1.03 (±0.96) (LogMar scale). The mean follow-up was 20.7 months (range, 12-60 months). Initial retinal detachment was found in 24.56% (n=14), with a statically worse prognosis. The BCVA was better in the group with gas tamponade (n=16) than in the group with silicone tamponade (n=21) and the group without a tamponade agent (n=20). Initial BCVA was the most important predictive factor for final BCVA. Time to surgery was a predictive factor of final visual outcome with a cut-off in the first week. The scleral or corneoscleral entry site had a better prognosis than the corneal site. Five cases of siderosis (8.7%) related to delayed management and two cases of endophthalmitis (3.5%) were found (despite use of prophylactic systemic antibiotics). No statistical difference was found regarding the IOFB location on the retina, its size, or the material. Finally, the retina remained detached in nine cases (15.78%). A final BCVA of 20/40 or more was obtained in 39.3 and 17.5% had light perception or worse.

CONCLUSION

The prognosis of an IOFB injury is for the most part uncertain due to a complex combination of parameters. Nevertheless, good postoperative results can be achieved without a silicone tamponade agent. The main prognostic factors related to better visual outcome were initial BCVA, time to surgery (first week), initially attached retina, and the scleral entry site. The main complications were vitreoproliferative retinal detachment, endophthalmitis, and siderosis. The location, type, and size of IOFBs were not statistically significant predictive factors in this study.

Semiautomated intraocular laser surgery using handheld instruments

BACKGROUND AND OBJECTIVE

In laser retinal photocoagulation, hundreds of dot-like burns are applied. We introduce a robot-assisted technique to enhance the accuracy and reduce the tedium of the procedure.

MATERIALS AND METHODS

Laser burn locations are overlaid on preoperative retinal images using common patterns such as grids. A stereo camera/monitor setup registers and displays the planned burn locations overlaid on real-time video. Using an active handheld micromanipulator, a 7 x 7 grid of burns spaced 650 microm apart is applied to both paper slides and porcine retina in vitro using 30 milliseconds laser pulses at 532 nm. Two scenarios were tested: unaided, in which the micromanipulator is inert and the laser fires at a fixed frequency, and aided, in which the micromanipulator actively targets burn locations and the laser fires automatically upon target acquisition. Error is defined as the distance from the center of the observed burn mark to the preoperatively selected target location.

RESULTS

An experienced retinal surgeon performed trials with and without robotic assistance, on both paper slides and porcine retina in vitro. In the paper slide experiments at an unaided laser repeat rate of 0.5 Hz, error was 125+/-62 microm with robotic assistance and 149+/-76 microm without (P < 0.005), and trial duration was 70+/-8 seconds with robotic assistance and 97+/-7 seconds without (P < 0.005). At a repeat rate of 1.0 Hz, error was 129+/-69 microm with robotic assistance and 166+/-91 microm without (P < 0.005), and trial duration was 26+/-4 seconds with robotic assistance and 47+/-1 seconds without (P < 0.005). At a repeat rate of 2.0 Hz on porcine retinal tissue, error was 123+/-69 microm with robotic assistance and 203+/-104 microm without (P < 0.005).

CONCLUSION

Robotic assistance can increase the accuracy of laser photocoagulation while reducing the duration of the operation.

Chorioretinectomy for perforating or severe intraocular foreign body injuries

BACKGROUND

To report the outcomes of chorioretinectomy versus non-chorioretinectomy in combat ocular injuries where a foreign body penetrated the choroid or perforated the globe.

METHODS

Retrospective, comparative, consecutive interventional case series of 32 perforating or severe intraocular foreign body combat ocular trauma injuries sustained by United States military soldiers and treated at a single institution from March 2003 to March 2009. Final best-corrected visual acuity (BCVA) in 19 non-chorioretinectomy-treated eyes was compared to 13 chorioretinectomy-treated eyes. The chorioretinectomy group was repaired with a 20 gauge three-port pars plana vitrectomy (PPV) by removing the choroid and/or retina at the impact or perforation site of the foreign body following evacuation from a combat zone. The main outcome measures were best-corrected visual acuity and rates of globe survival, retina reattachment and proliferative vitreoretinopathy.

RESULTS

Thirty-two eyes of 31 patients with a mean age of 29 +/- 9 years (range, 19-53 years) were followed for a median of 463 +/- 226 days (range, 59-1022 days). The mean time of injury to the operating room in the chorioretinectomy group was 12.6 +/- 9.8 days, compared to that of the non-chorioretinectomy group of 22.1 +/- 16.4 days (P = 0.05) Final BCVA > or =20/200 occurred in seven of 13 (54%) of the chorioretinectomy group, compared to two of 19 (11%) in the non-chorioretinectomy group (P = 0.04). Globe survival rates were higher in the chorioretinectomy group [11 of 13 (85%) vs 9 of 19 (45%); P = 0.06], as well as the final retinal reattachment rate [8 of 13 (62%) vs 8 of 19 (42%); P = 0.47]. The proliferative vitreoretinopathy rate was eight of 13 (62%) in the chorioretinectomy group, compared to 14 of 19 (74%) in the non-chorioretinectomy group (P = 0.70). Graft failure occurred in five of six eyes (83%) of non-chorioretinectomy cases, requiring temporary keratoprosthesis and penetrating keratoplasty.

CONCLUSION

Chorioretinectomy is a surgical option that may improve final BCVA and increase globe survival rates when a foreign body penetrates the choroid or perforates the globe.

Tiny ferromagnetic intraocular foreign bodies detected by magnetic resonance imaging: a report of two cases

We report two cases with tiny ferromagnetic intraocular foreign bodies (FBs) that were demonstrated only on magnetic resonance imaging (MRI) and confirmed by subsequent ophthalmologic operation. Both of the patients had a history of ocular trauma and their clinical symptoms were compatible with an intraocular FB. Plain x-ray film, 3 mm slice thickness computed tomography (CT) scans (Toshiba TXT 600 system and GERP22 system), B-scan ultrasonography, and an MRI study (Siemens Impact 1.0 MR system) were acquired. MR examinations were performed using spin-echo (SE) T1, T2, and PD-weighted axial and sagittal or coronal images with 3 mm slice thickness. Plain x-ray film, 3 mm slice thickness CT scans and B-scan ultrasonography all failed to demonstrate any tiny intraocular FBs in these two patients, whereas MRI revealed tiny ferromagnetic FBs due to their characteristic magnetic susceptibility artifact. A ferromagnetic FB was found in the vitreous body of each patient, which were 0.375x0.3x0.15 mm and 0.5x0.4x0.2 mm, respectively, and there was no evidence of MR-induced damage. We suggest that tiny ferromagnetic fragments with a diameter below 0.5 mm, which are too small to be visualized by x-ray plain films and CT images, may be visualized on MR images. These tiny ferromagnetic particles may not be large enough to cause ocular damage during a 1.0T MRI examination. MRI may be a useful tool in the evaluation of tiny intraocular ferromagnetic FBs if other imaging modalities such as plain s-ray, CT scan, and ultrasonography failed to do so. Further evaluation with a large-scale study (in vitro and in vivo animal study) for the safety of detecting tiny (<0.5 mm) intraocular ferromagnetic particles is warranted.

Metallic intraocular foreign bodies: characteristics, interventions, and prognostic factors for visual outcome and globe survival

PURPOSE

To describe metallic intraocular foreign body (IOFB) injuries and identify prognostic factors for visual outcome and globe survival.

DESIGN

Interventional, consecutive, retrospective case series.

METHODS

setting: Wills Eye Hospital. study population: Ninety-six eyes of 96 patients with metallic intraocular foreign bodies. procedures: Metallic IOFB injuries between January 1991 to June 2002 were reviewed for clinical characteristics, surgical intervention, and outcome. Univariate and multivariate analyses were performed to identify prognostic variables. main outcome measures: Final visual acuity and globe survival.

RESULTS

The average patient age was 33.0 years with a male predominance (94%). Forty percent of eyes had a presenting vision of 20/50 or better. Following IOFB removal, 40% of patients required additional interventions. Thirty-one percent of eyes had a final acuity of 20/50 or better. Eight percent of patients ultimately required enucleation or evisceration. Excellent visual outcome (defined as > or =20/50) was associated with multiple variables, including normal lens at presentation and anterior segment IOFB (P< .003). Factors associated with poor visual outcome (defined as <20/200) included uveal prolapse and posterior segment IOFB (P < .0003). Globe loss was associated with younger age, presenting light perception (LP) or no light perception (NLP) vision, BB/pellet injury, and the presence of an afferent pupillary defect (P < .01).

CONCLUSIONS

Multiple prognostic factors were identified in this large analysis of metallic IOFB injuries, which may help predict visual outcome and globe survival. Most of these variables were independent of intervention and can be identified at the time of initial presentation.

Prognostic factors in vitrectomy for posterior segment intraocular foreign bodies

BACKGROUND

The aim of this study was to identify the prognostic factors influencing outcome after the removal of retained posterior segment intraocular foreign bodies (IOFBs) by pars plana vitrectomy.

METHODS

We reviewed the records of 42 consecutive patients (39 men and 3 women with a mean age of 26.8 years) operated between January 2001 and January 2005 by the same surgeon for IOFB after penetrating ocular injury. All eyes underwent IOFB removal via pars plana vitrectomy. Postoperative retinal detachment was considered as the anatomic failure. Associations between anatomic outcome and various preoperative, operative, and postoperative variables were statistically analyzed. Chi-square test and Mann-Whitney U test were used to evaluate the association between two categorical variables.

RESULTS

The mean time interval between the trauma and the IOFB removal was 5.3 days (range, 1 day to 30 days). The mean length of follow-up was 18.3 months (range, 6 months to 3 years). Preoperative retinal detachment was present in 19% of patients. After the IOFB removal, the retina was detached in 28.5% of patients (12 of 42 patients). After a second vitrectomy performed in 10 patients, final anatomic success rate was 89.8% (37 of 42 patients). Time between trauma and IOFB extraction, presence of intraocular hemorrhage, preoperative retinal detachment and primary surgical repair combined with the IOFB removal were significantly associated with the postoperative retinal detachment. Age, sex, entrance wound location, presence of endophthalmitis, location of IOFB, nature of IOFB, preoperative visual acuity, use of an encircling band, type of endotamponade, use of lensectomy were not significantly associated with the presence of postoperative retinal detachment.

CONCLUSIONS

Delay in IOFB extraction, presence of intraocular hemorrhage, preoperative retinal detachment, primary surgical repair combined with IOFB removal are the predictive factors for anatomic failure.

Incidence and visual outcome of endophthalmitis associated with intraocular foreign bodies

PURPOSE

To determine the risk factors and visual outcome of endophthalmitis associated with traumatic intraocular foreign body (IOFB) removal and its allied management.

METHODS

A retrospective review was conducted of patients with penetrating eye trauma and retained IOFB with associated endophthalmitis managed at King Khaled Eye Specialist Hospital over a 22 year period (1983 to 2004).

RESULTS

There were 589 eyes of 565 patients (90.3% male; 9.7% female) which sustained ocular trauma and had retained IOFB that required management. Forty-four eyes (7.5%) developed clinical evidence of endophthalmitis at some point after trauma. From these 44 eyes, initial presenting visual acuity (VA) of 20/200 or better was recorded in 8 eyes (18.1%) and the remaining 36 eyes (81.9%) had VA ranging from 20/400 to light perception. Eleven eyes (25%) underwent IOFB removal and repair within 24 hours after trauma while 33 eyes (75%) had similar procedures done 24 hours or more after trauma. Thirty-one eyes (70%) underwent primary pars plana vitrectomy (PPV) at the time of removal of posteriorly located IOFBs. Definite positive cultures were obtained from 17 eyes (38.6%). Over a mean follow-up of 24.8 months, 21 eyes (47.7%) had improved VA, 6 eyes (13.6%) maintained presenting VA while 17 eyes (38.7%) had deterioration of their VA, including 10 eyes (22.7%) that were left with no light perception (NLP) vision. After the treatment of endophthalmitis, 20 eyes (45.4%) had VA of 20/200 or better at their last follow-up. Four eyes (12.9%) from the vitrectomy group (31 eyes) and 5 eyes (45.4%) from non-vitrectomy (11 eyes) group had final VA of NLP. Predictive factors for the good visual outcome included good initial presenting VA, early surgical intervention to remove IOFB (within 24 hours), and PPV. Predictors of poor visual outcome included IOFB removal 48 hours or later, posterior location and no PPV for the posteriorly located IOFB.

CONCLUSIONS

Delayed removal of IOFB following trauma may result in a significant increase in the development of clinical endophthalmitis. Other risk factors for poor visual outcome may include poor initial presenting VA, posterior location of IOFB and no vitrectomy at the time of IOFB removal.

Pars Plana Vitrectomy in Ocular Injury with Intraocular Foreign Body

BACKGROUND

We evaluated 70 cases of ocular injuries with intraocular foreign bodies to determine the results of surgical management.

METHODS

The site of penetration was cornea in 58 (82.9%), sclera in 8 (11.4%), and limbus in 4 (5.7%) eyes. The foreign body was in the vitreous in 40 (57.1%) and embedded in the retina in 30 (42.9%) cases. Before pars plana vitrectomy, the most common findings were found to be lens perforation (77.1%), vitreous hemorrhage (45.7%), endophthalmitis (20%), hyphema (4.3%), and retinal detachment (2.9%).

RESULTS

After pars plana vitrectomy, visual acuity improved in 39 (55.7%), did not change in 19 (27.2%), and decreased in 8 (11.4%) cases. We observed secondary glaucoma in 11 (15.7%), retinal detachment in 10 (14.3%), and phthisis bulbi in 3 (4.3%) cases postoperatively.

CONCLUSION

Pars plana vitrectomy is found to be an effective therapeutic approach in removing intraocular foreign bodies, but the preoperative and postoperative complications determine the visual outcome.

Intraocular foreign body injuries during Operation Iraqi Freedom

OBJECTIVE

To evaluate the number of intraocular foreign body (IOFB) injuries that occurred in Operation Iraqi Freedom, and to determine the cause of injury, the type of foreign body, and the associated injuries to other body systems.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Fifty-five United States military personnel with an IOFB injury during Operation Iraqi Freedom.

INTERVENTION

Pars plana vitrectomy, foreign body removal, and additional surgical procedures as the clinical situation dictated.

MAIN OUTCOME MEASURES

Cause of injury, size of corneal/scleral laceration, number of foreign bodies, type of foreign body, time to foreign body removal, visual acuity, number of enucleations, and injuries to other body systems.

RESULTS

The foreign body was caused by a propelled explosive in 20 patients (36%) and a nonpropelled explosive in 31 patients (56%), and the cause of the foreign body was not known in 4 patients (7%). The size of the laceration of the cornea and/or sclera averaged 5.4 mm (range, 0.2-18). There were an average of 1.7 foreign bodies in the injured eye (range, 1-6). The size of those foreign bodies measured ranged from <1 mm to 12 x 14 mm. The most common type of foreign body was metal (68%), followed by glass (14%), stone/cement (14%), bone (5%), and cilia (3%). The time from injury to foreign body removal averaged 20.6 days (range, 0-90). No cases of endophthalmitis were seen. The most common associated injury was to the upper extremity, face, lower extremity, and neck.

CONCLUSIONS

Unlike trauma in the civilian sector, IOFB injuries in a military setting tend to be caused by explosive devices, which often result in multiple foreign bodies and simultaneous injuries to other body systems. Because of the lack of availability of specialty care in the combat theater, there is often a delay in removal of the foreign body.

VITRECTOMY FOR POSTERIOR SEGMENT INTRAOCULAR FOREIGN BODIES

PURPOSE

To evaluate the visual results and determine the prognostic factors after the removal of retained posterior segment intraocular foreign bodies (IOFBs) by pars plana vitrectomy.

METHODS

A retrospective study of 40 consecutive cases of pars plana vitrectomy for the removal of IOFBs during the period of January 1991 to June 2000 was conducted. Association between visual outcome and various preoperative, operative, and postoperative variables was statistically analyzed.

RESULTS

Of the 40 cases available for the study, the IOFBs could be removed in 36 eyes. Half the patients had removal of the IOFB within 14 days of the injury. Nineteen patients (47.5%) achieved a visual acuity of 20/40 or better. Postoperative retinal detachment occurred in 13 patients (32.5%). Poor visual outcome was found to be significantly associated with poor initial visual acuity and postoperative retinal detachment, whereas good visual outcome was significantly associated with the absence of lens injury and absence of postoperative retinal detachment.

CONCLUSIONS

Acceptable visual results could be achieved after the removal of posterior segment IOFBs by vitrectomy, despite a delay in surgery. Postoperative retinal detachment, poor initial visual acuity, and the absence of lens injury were the factors that played a significant role in determining the visual outcome.

Visual outcome and prognostic factors after vitrectomy for posterior segment foreign bodies

PURPOSE

To identify the prognostic factors that predict final visual outcome in eyes with posterior segment intraocular foreign body (IOFB) injuries managed by primary pars plana vitrectomy.

METHODS

Ninety-six consecutive patients with posterior segment IOFB injuries were retrospectively reviewed. Factors analyzed included initial visual acuity (VA), time between injury and presentation, site of entrance wound, uveal prolapse, vitreous prolapse, traumatized iris, endophthalmitis, location and size of IOFB, use of scleral buckling and/or an encircling band, gas tamponade, lensectomy, number of surgical procedures, and development of retinal detachment. Data were analyzed using univariate and multivariate logistic regression analysis.

RESULTS

After a mean follow-up of 8.6 months, 63 eyes (65.6%) achieved VA of 20/200 or better, and 9 eyes (9.4%) had total retinal detachment complicated by inoperable proliferative vitreoretinopathy. On univariate analysis, predictors of poor vision (hand movements or less) were poor initial VA, corneoscleral entrance wound, uveal prolapse, vitreous prolapse, traumatized iris, and development of retinal detachment. In contrast, predictors of good visual outcome (20/200 or better) were absence of uveal prolapse, no endophthalmitis, and no retinal detachment. Multivariate analysis identified corneoscleral entrance wound, uveal prolapse, and development of retinal detachment as the only factors significantly associated with poor visual outcome. Absence of uveal prolapse was the only factor significantly associated with good visual outcome.

CONCLUSIONS

Final visual outcome is greatly determined by the severity of the primary injury. On multivariate analysis, significant predictive factors of final VA were corneoscleral entrance wound, presence or absence of uveal prolapse, and development of retinal detachment.

Ferrous intraocular foreign bodies retained in the posterior segment: management options and results

PURPOSE

Analysis of traditional versus comprehensive management techniques for eyes with ferrous IOFBs in the posterior segment.

PATIENTS AND METHODS

Retrospective review of 30 eyes undergoing IOFB removal by EM and of 34 eyes managed by PPV techniques.

RESULTS

Vitreous hemorrhage occurred commonly (EM group: 40%, PPV group: 50%). Only in the EM group did the intervention cause iatrogenic vitreous hemorrhage (23%) and has postextraction endophthalmitis developed (10%). Vision improved in 23% of eyes, deteriorated in 53%; >0.5 vision was achieved in 20%. Five EM eyes (17%) were anatomically lost; PVR developed in 48% of the remaining eyes. In the PPV group, no eye was anatomically lost and PVR developed in 12%. Vision improved in 68% of eyes, deteriorated in 15%; >0.5 vision was achieved in 68%. A single retinal impact site occurred in 71%, < or =2 impact sites in 21% of eyes.

CONCLUSIONS

Approximately one of two eyes with posterior segment IOFB develops vitreous hemorrhage, over two-thirds sustain at least one retinal lesion, and one-fifth of eyes suffer multiple retinal injuries. Both the anatomical (p = 0, 003) and the functional (p = 0, 005) prognoses are significantly better in eyes undergoing PPV compared to eyes with EM use. Timely PPV appears to markedly reduce the risk of endophthalmitis development. These results confirm the need to abandon the EM and perform PPV for eyes with posterior segment IOFBs.

Controversies in the management of open-globe injuries involving the posterior segment

There are numerous unresolved issues and controversies regarding the management of open-globe injuries involving the posterior segment. These areas include, but are not limited to, the following issues. Although vitrectomy has been shown to improve visual outcomes and allow retention of the eye in many cases, the extent of visual improvement is often limited because of the nature of the injury. Timing of vitrectomy surgery has been and will continue to be debated by proponents of early versus delayed intervention. The multiple features of acute ocular injury make it very difficult to interpret retrospective data regarding the most appropriate timing for surgical intervention. The use of prophylactic cryotherapy, in the setting of a scleral laceration with possible retinal damage, is not as controversial at present, as there is now sufficient data indicating that cryotherapy may actually exacerbate intraocular proliferation and worsen the situation. The role and benefit of a prophylactic scleral buckle is very widely contested, and it is not known if it truly decreases the risk of subsequent retinal detachment. Another area of debate centers on the use of antibiotics. When there is a known clinical infection, intravitreal antibiotics are the mainstays of therapy. However, in the absence of clinical infection, the use of prophylactic antibiotics and their routes of administration are quite controversial. Although there are significant data regarding the use of antibiotics in the postoperative setting, this information cannot be extrapolated into the setting of open-globe injuries, as organisms and virulence factors differ. Similarly, the use of vitrectomy versus vitreous tap in the setting of traumatic endophthalmitis is not fully resolved, although vitrectomy is used in most cases to repair concurrent damage from the injury itself. Finally, the placement of intraocular lenses in the acute trauma setting is controversial, as the risk of complications is quite high. Prospective, controlled clinical studies have not been done. This article reviews pertinent data regarding these management issues and controversies, and provides recommendations for treatment based on the available published data and the authors' personal experience.

Management of intra-ocular foreign bodies impacting or embedded in the retina

PURPOSE

To identify both the clinical features of eyes suffering penetrating ocular injury with intra-ocular foreign bodies (FB) impacting or embedded in the retina and the results of surgical outcome and complication rates.

METHODS

Thirty-eight consecutive cases of penetrating ocular injuries with intra-ocular FB impacting or embedded in the retina were retrospectively analysed.

RESULTS

The FB were metallic in 30 eyes (78.9%; 19 ferromagnetic) and were non-metallic in eight eyes (21.1%). Magnetic extraction was performed in 17 cases (44.7%) and instrumental extraction was performed in 21 cases (55.3%). In two cases, pars plana vitrectomy and FB removal was combined with penetrating keratoplasty, temporary keratoprosthesis and anterior segment reconstruction because of severe explosive injury to the eye. At the final postoperative examination, 32 eyes (84.2%) had completely attached retinas. Visual acuity (VA) improved postoperatively in 18 eyes (47.4%). A final VA of 0.5 or better was achieved in nine of 23 eyes (39.1%) with FB in the peripheral retina and in one of 15 eyes (6.7%) with posterior pole and/or optic nerve head involvement. There was no difference in the final VA regarding the time elapsed between trauma and the removal of the FB.

CONCLUSION

The late anatomical and functional outcome in eyes with penetrating ocular injury and FB impacting or embedded in the retina is mostly uncertain, despite immediate and complex surgery. Final anatomical and functional outcome in the present study was influenced by location and extent of the initial damage to the posterior pole. The time that had elapsed between trauma and removal of the FB did not influence final visual function.