Results and complications of temporary silicone oil tamponade in patients with complicated retinal detachments

Factors affecting the development of cystoid macular edema following pars plana vitrectomy with silicone oil placement: a retrospective cohort study

BACKGROUND

Cystoid macular edema (CME) can develop following silicone oil placement in complex vitreoretinal surgeries, contributing to poor visual outcomes. In this study, we investigated the clinical and surgical characteristics associated with the development of CME following the use of silicone oil (SO) in pars plana vitrectomy (PPV) surgeries.

METHODS

We conducted a retrospective chart review of patients who underwent implantation of SO during PPV from 2010 to 2020 by a single surgeon. Patient demographics, type of oil, duration of oil tamponade, retinectomy size, diabetic status, lens status, prior panretinal photocoagulation, visual acuity, and incidence of CME were reviewed.

RESULTS

This study included 43 eyes from 40 patients who underwent SO tamponade for retinal detachment (RD) surgery. The mean duration of SO tamponade was 15.7 ± 12.7 months (range: 1-58 months). The most common indication for surgery was diabetic tractional RD (32.7%), followed by traumatic RD (16.3%) and rhegmatogenous RD with proliferative vitreoretinopathy (11.6%). Of the 43 eyes, 18 (41.9%) developed CME for the first time after PPV with SO placement, with 8 (44%) resolving within a year of oil removal. The mean duration for the development of CME was 9 months. A logistic regression model showed that a scleral buckle procedure and poor initial vision were statistically significant factors for predicting the development of CME (ORs: 11.65 and 16.06, respectively). Overall, 91% of the patients had stable or improved vision after surgery.

CONCLUSIONS

The use of a scleral buckle procedure and poor initial vision are significant factors for predicting CME following silicone oil tamponade in PPV surgeries, with 41.9% of patients developing CME with an average duration of 9 months. Recognizing such factors can lead to early monitoring and prompt management of CME.

MEETING PRESENTATION

Partial analyses were presented at the ASRS 2020 conference.

CLINICAL TRIAL NUMBER

Not applicable.

Recurrent retinal detachment after pars plana vitrectomy with silicone oil tamponade for rhegmatogenous retinal detachment

BACKGROUND

The recurrence of retinal detachment following rhegmatogenous retinal detachment (RRD) is a relatively common complication that can lead to reduced visual acuity and requires further surgery. The purpose of this study was to investigate the risk factors and visual outcomes of recurrent RRD following pars plana vitrectomy (PPV) with silicone oil tamponade for primary RRD.

METHODS

This was a retrospective follow-up study of 343 eyes that underwent initial PPV surgery with silicone oil tamponade for primary RRD. Patients were divided into a recurrence group and a reattachment group. The main outcome measures included causative factors, visual outcomes related to the recurrence of RRD, and the perioperative factors most affecting the recurrence of RRD.

RESULTS

After retinal reattachment, we observed RRD recurrence after PPV for primary RRD in 42 out of 343 eyes (12.2%) during the follow-up period. Most causes of recurrence (69%) occurred within 6 months of surgery. Multivariate logistic regression analysis showed that a PVR ≥ Grade C (odds ratio [OR]: 4.015; 95% confidence interval [CI] 1.721-9.367; P = 0.001) was a significant predictor for the development of recurrent RRD. Compared with the reattachment group, the recurrence group exhibited a significant decline in best-corrected visual acuity (BCVA) at the last follow-up visit (P = 0.000). Eyes with PVR prior to primary surgery, or at the diagnosis of re-detachment, showed a worse final BCVA.

CONCLUSIONS

Our analysis shows that the predominant risk factor for the recurrence of RRD is a PVR ≥ Grade C. PVR prior to primary surgery, or at the diagnosis of re-detachment, was also shown to limit the recovery of final visual acuity.

Outcomes of combined phacoemulsification/intraocular lens implantation and silicon oil removal

PURPOSE

To evaluate the outcomes and complications of simultaneous silicon oil removal (SOR) and phacoemulsification and intra ocular lens implantation.

METHODS

In this retrospective non-comparative case series, the visual, refractive and anatomical outcomes of patients who underwent combined phacoemulsification/silicone oil removal (5700 centistokes) surgery between 2017 and 2019 in a single center were evaluated.

RESULTS

Forty-four eyes of 44 patients (eighteen males) were included. The mean age of the patients was 51.45 ± 11.59 years. The primary pathology was tractional retinal detachment (TRD) secondary to diabetic retinopathy in 36 eyes and rhegmatogenous retinal detachment (RRD) in 8 eyes. The median time period between silicone oil tamponade and removal was 9 months. There was no statistically significant difference between best corrected visual acuity (-0.14 ± 0.69 LogMAR, p= 0.19) and intraocular pressure (p= 0.26) before and after the surgery. Mean post-operative spherical equivalent (SE) at last visit was 0.36 ± 1.64 which was different from the target refraction (- 0.5D). After cataract/SOR surgery, one eye (2.3%) developed retinal re-detachment in RRD patient. Vitreous hemorrhage occurred in nine eyes (20.5%) which all had TRD as the primary pathology.

CONCLUSION

Combined phacoemulsification, silicone oil and IOL implantation removal surgery seems to be a safe and useful procedure with high success rate and acceptable visual, refractive and anatomical outcomes.

Long-Term Safety and Efficacy of Siluron2000 with Pars Plana Vitrectomy in the Treatment of Patients with Severe Vitreoretinopathy and Chronic Macular Holes

PURPOSE

Silicone oil intraocular retinal tamponade is a useful adjunct to pars plana vitrectomy (PPV) in the treatment of complex vitreoretinal conditions. Siluron2000, a modified silicone oil product containing an additional small, high molecular weight and low viscosity, very-long-chain silicone molecule, was developed to reduce post-operative silicone oil emulsification, a non-infrequent complication that occurs with low molecular weight silicone oil. This study was designed to assess the safety and efficacy of long-term Siluron2000.

PATIENTS AND METHODS

This was a single-center, retrospective, observational study. All consecutive patients undergoing PPV with intravitreal Siluron2000 injection between January 2017 and September 2019 with at least 6-month follow-up were identified based on billing codes.

RESULTS

A total of 57 eyes of 57 consecutive patients comprising 51 cases of proliferative vitreoretinopathy and 6 cases of recurrent full thickness macular hole were included. Median follow-up was 18 months. Emulsification occurred in 9 patients (15%). Retinal re-attachment was achieved in 47 patients (82%). The median time without silicone oil emulsification was 17 months. Of the cases with residual retinal detachment (RD) despite intravitreal Siluron2000, 4 (7%) were total RDs and 6 (10%) were inferior RDs with attached macula. The most common complications were glaucoma 12 (21%), cataract 11 (19%), and epiretinal membrane 2 (3.5%). There was no association between the duration of Siluron2000 and visual outcomes.

CONCLUSION

Siluron2000 is an effective long-term tamponade agent in the treatment of complex vitreoretinopathy. Visual and anatomical outcomes are similar to those reported with higher mw silicone oil tamponade agents but with a lower emulsification rate.

Intraocular Pressure Rise Linked to Silicone Oil in Retinal Surgery: A Review

Silicone oil represents the main choice for intraocular tamponade in cases of complicated retinal detachment surgery. The intraocular pressure of an eye filled with silicone oil could increase, driven by a variety of different forces, according to several mechanisms. Two main conditions have been highlighted, depending on the onset: early hypertension or late glaucoma. The different types of silicone oils and their physico-chemical properties are varied and may play a role in the determination of intraocular pressure rise. The current body of literature allows for the illustration and categorization of the incidence and risk factors, as well as the pathogenesis and the management of the early postoperative hypertension subtended by an open- and closed-angle, along with the late onset silicone oil-induced glaucoma. Understanding the leading actors on the stage of ocular pressure elevation concurrently with silicone oil application for retinal surgery could help in guiding the timely and appropriate course of treatment.

Unexplained Visual Loss After Silicone Oil Removal: A 7-Year Retrospective Study

Introduction

Unexplained visual loss after removal of silicone oil from the eye has been described. The purpose of this study is to determine the incidence of unexplained loss of visual acuity after SO removal and to provide possible explanations for this phenomenon.

Methods

This retrospective study included patients that underwent vitreoretinal surgery, at Centro Hospitalar São João, between January of 2012 and October of 2018. Inclusion criterion was vitreoretinal surgery in which the chosen endotamponade was SO, followed by removal of SO and exchange with balanced salt solution (BSS) or air. After SO removal, patients with documented loss of best corrected visual acuity (BCVA) on two or more Snellen lines were analyzed and patients in which the cause of the visual loss was identified, namely OHT (intraocular pressure > 21 mmHg), retinal re-detachment, glaucoma, retinal proliferative membrane formation, or corneal decompensation, were excluded. All patients with unexplained visual loss underwent spectral domain optical coherence tomography (SD-OCT) to exclude causes of visual reduction such as cystoid macular edema, epiretinal membrane, or ellipsoid/interdigitation zone disruption. A p value less than 0.05 was considered statistically significant.

Results

A total of 46 eyes underwent SO tamponade and SO removal during the study period. In 34.8% of the cases (n = 16) there was visual acuity loss in at least two Snellen lines. Of 46 eyes, 23.9% (n = 11) showed vision loss due to known secondary causes. Unexplained loss of visual acuity after SO removal occurred in 10.9% of cases. OHT during silicone endotamponade (p = 0.046) and silicone emulsification (p = 0.001) were identified as factors associated with unexplained visual loss after SO removal.

Conclusion

Unexplained loss of visual acuity after SO removal occurred in 10.9% of cases. OHT during silicone endotamponade and SO emulsification were identified as important factors in the ethology of this phenomenon.

Outcomes After the Use of Silicone Oil in Complex Retinal Detachment Repair

Purpose:

This study compares visual acuity (VA), anatomic outcomes, and complications in eyes that underwent complex retinal detachment (RD) repair in which silicone oil (SO) was retained vs removed.

Methods:

A retrospective chart review of patients undergoing vitrectomy with SO tamponade. The eyes were divided into 2 groups based upon SO removal or retention. Main outcome measures were corrected VA, anatomic outcomes, and the presence of SO-related complications.

Results:

Fifty-seven eyes with removed SO and 53 eyes with retained SO were identified. In both groups, the mean best-corrected VA (BCVA) at the final visit was significantly better than at baseline. In the retained-SO group, vision improved from 1.79 ± 0.6 to 1.2 ± 0.7 logarithm of the minimum angle of resolution (logMAR) (Snellen, 20/1200 to 20/350) at the final visit ( P < .001). In the removed-SO group, mean BCVA improved from 1.84 ± 0.5 at baseline to 1.55 ± 0.6 logMAR units (Snellen, 20/1400 to 20/700) at the visit preceding SO removal ( P < .002) and to 1.43 ± 0.6 logMAR units (Snellen, 20/500) at the final visit ( P < .001). Complication rates were similar in both groups, apart from RD, which occurred more frequently in the removed-SO group ( P = .03).

Conclusions:

There was similarity in VA and complications among patients with removed or retained SO. Removal of SO may benefit eyes with SO-related complications, but SO retention may decrease the chance of RD and may be indicated in selected cases.

INTRAOCULAR PRESSURE OUTCOMES AFTER SURGERY FOR RHEGMATOGENOUS RETINAL DETACHMENT IN SCHWARTZ SYNDROME

PURPOSE

To study intraocular pressure (IOP) outcomes after surgery for rhegmatogenous retinal detachment in Schwartz syndrome.

METHODS

We reviewed records of 32 eyes of 32 patients with Schwartz syndrome (patients with rhegmatogenous retinal detachment, IOP above 21 mmHg, and open angles without angle recession, chronic steroid use or other secondary causes of increased IOP) who had undergone surgical treatment consisting of scleral buckling or vitrectomy. Intraocular pressure, number of medication, best-corrected visual acuity were compared at baseline and postsurgery visits and also studied association of various factors on long-term IOP.

RESULTS

The median duration of rhegmatogenous retinal detachment was 2 months, and the inter quartile range was 1 to 12 months. Follow-up was 15 months (inter quartile range: 7-33 months). Sixteen (50%) had prior ocular trauma. Baseline IOP was 35 ± 8 mmHg, and 12% (4/32) of patients were on IOP-lowering medication at presentation. At the final visit, mean IOP was 17 ± 6 mmHg and 59% patients (19/32) required additional IOP-lowering medication or surgery for IOP control.

CONCLUSION

Surgical management of rhegmatogenous retinal detachment resulted in significant reduction in IOP. At the final visit, 41% did not require any IOP-lowering medication or surgical intervention for IOP control.

Current management of diabetic tractional retinal detachments

Twenty-five percent of diabetes-related vision loss stems from complications of proliferative diabetic retinopathy (PDR). Panretinal photocoagulation has been the preferred treatment of high-risk PDR for decades and more recently intravitreal injections of drugs that inhibit the actions of vascular endothelial growth factor have become popular. But despite these treatments PDR may progress uncontrollably to advanced pathologies such as traction retinal detachments (TRDs), combined traction/rhegmatogenous retinal detachments (TRD/RRDs), vitreous hemorrhages, rubeosis iridis, and traction maculopathies, which produce mild-to-severe loss of vision. TDR have long been the most common indication for PDR-related vitreoretinal surgery. Vitrectomy surgery is indicated for recent (<6 months duration) TRD involving the macula, progressive TRD that threatens the macula, and recent data suggest that chronic macula-involving TRDs (>6 months duration) may also benefit. Combined TRD/RRD represents a particularly challenging surgical condition but advances in surgical instrumentation, dissection techniques, and post-operative tamponade have produced excellent success rates. The recent development of small-gauge vitrectomy systems has persuaded most surgeons to switch platforms since these appear to produce shorter surgical times and quicker post-operative recoveries. Pre-operative injections of bevacizumab are frequently administered for persistent neovascularization to facilitate surgical dissection of pre-retinal fibrosis and reduce the incidence of post-operative hemorrhages. Recent trends toward earlier surgical intervention and expanded indications are likely to continue as surgical instrumentation and techniques are further developed.

The Correlation of Pars Plana Incision and Transient Hypotony After Silicone Oil Removal

BACKGROUND AND OBJECTIVE

To evaluate the correlation between pars plana incision and transient hypotony after silicone oil removal in aphakic eyes PATIENTS AND METHODS:Twenty-two patients with aphakia and a high degree of myopia with silicone oil tamponade were recruited for this prospective study and randomly scheduled to two groups for silicone oil removal: 3.5-mm corneal incision with suture corneal or 20-gauge pars plana incision with suture. Intraocular pressure (IOP) was measured and fundus and anterior structure were examined preoperatively on the first, third, and seventh postoperative day and at 1 month after surgery.

RESULTS

IOPs in the pars plana group were significantly lower than the corneal group on the first and third day after surgery (P < .001). Nine of the 11 patients in the pars plana group suffered ciliary detachment accompanied by hypotony (IOP < 8 mm Hg), among whom three patients exhibited excessive hypotony (IOP < 5 mm Hg), whereas the ciliary bodies remained tightly attached and IOP was normal in the corneal group. Among these nine patients, six eyes were observed to have multiple silicone oil granules in the supraciliary cavity, three exhibited gaps of pars plana below the scleral incision site, and two had vitreous hemorrhage. Hypotony spontaneously relieved at the seventh postoperative day for all patients.

CONCLUSION

Pars plana incision is the crucial cause of ciliary detachment and consequent transient hypotony after silicone oil removal. Using corneal limbus incision in patients with aphakic eyes to avoid the par plana incision is expected to reduce the incidence of hypotony with minimal complications. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e44-e51.].

Macular Changes on Optical Coherence Tomography Before, During, and After Silicone Oil Tamponade for Macula-On Retinal Detachment: A Case Series

Purpose:

Assess changes on spectral domain optical coherence tomography (OCT) before, during, and after removal of silicone oil (SO).

Methods:

Retrospective series of patients who underwent SO tamponade for macula-on rhegmatogenous retinal detachment. OCT scans of the affected eye were taken before, during, and 3 months after SO tamponade. Qualitative assessment of foveal contour and quantitative comparison of OCT parameters (central macular, cube, ganglion cell layer [GCL], and outer retinal thicknesses) were done between 3 time points.

Results:

Ten eyes of 9 patients were included. Flattening of the foveal contour during SO tamponade was completely reversed after SO removal. Average cube and GCL thicknesses decreased with SO tamponade and increased after SO removal ( P = .01 and P = .02, respectively). Outer retinal thicknesses did not vary among 3 time points ( P = .09).

Conclusions:

SO tamponade causes foveal flattening and thinning of the inner retinal layers, which is reversible on removal.

Risk Factors for Retinal Redetachment After Silicone Oil Removal: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

This systematic review and meta-analysis was made to measure risk factors for retinal redetachment (re-RD) after silicone oil removal (SOR) in a quantitative method.

PATIENTS AND METHODS

A comprehensive literature review relating to risk factors for re-RD after SOR was conducted before March 2017. Odds ratio (OR) with 95% confidence interval (CI) was calculated after data combination.

RESULTS

Sixteen studies were included, and risk factors with significant differences found between the re-RD and control groups are as follows: aphakic eye (OR = 1.50), high myopia (OR = 2.47), previous failed retinal surgery (OR = 1.71), and ocular trauma (OR = 3.52). Peripheral 360° laser retinopexy (OR = 0.40) and scleral encircling band (OR = 0.58) were found to be protective factors of re-RD after SOR.

CONCLUSION

Aphakic eye, high myopia, previous failed retinal surgery, ocular trauma, lack of 360° laser, and scleral encircling band were possible risk factors relating to the occurrence of re-RD after SOR. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:416-424.].

Incidence and Risk Factors of Cystoid Macular Edema after Vitrectomy with Silicone Oil Tamponade for Retinal Detachment

PURPOSE

To investigate the incidence and risk factors of cystoid macular edema (CME) after silicone oil (SO) injection for retinal detachment.

METHODS

Fifty-eight patients with retinal detachment treated by vitrectomy with SO tamponade during 2011 to 2015 were retrospectively assigned to CME and non-CME groups. Patients underwent complete ophthalmological examination, including color fundus photography and preoperative and postoperative optical coherence tomography. Risk factors for CME during SO tamponade were determined by regression analyses.

RESULTS

Of the 58 eyes, 21 (36.2%) exhibited CME. The presence of posterior staphyloma in the CME group was significantly more frequent than in the non-CME group (p = 0.026). There were no significant differences in other demographic or clinical characteristics between the CME and non-CME groups. Significant correlations were observed between CME after vitrectomy with SO tamponade and the presence of posterior staphyloma (odds ratio, 4.03; p = 0.031). Of the 21 eyes with CME, 13 underwent SO removal, among which 11 experienced resolution of CME with or without further intervention.

CONCLUSIONS

The presence of posterior staphyloma is significantly associated with CME after vitrectomy with SO tamponade. Patients with retinal detachment exhibiting posterior staphyloma should be evaluated for potential CME during SO tamponade.

RISK OF MULTIPLE RECURRING RETINAL DETACHMENT AFTER PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT REPAIR

PURPOSE

To evaluate functional and anatomical outcomes of patients with retinal redetachments (re-RD) after surgery for primary rhegmatogenous retinal detachment.

METHODS

Medical records of eyes with re-RD after rhegmatogenous retinal detachment surgery between 1999 and 2014 at the Department of Ophthalmology, University of Cologne, Germany, were retrospectively evaluated. Data included preoperative and postoperative clinical findings, best-corrected visual acuity, presence and grade of proliferative vitreoretinopathy, surgical procedures, and complication rates.

RESULTS

Three hundred and twenty-eight eyes of 2,457 developed a re-RD (13.3%). Of these 328 eyes, 242 eyes (73.8%) had only one re-RD, whereas 86 eyes (26.2%) had 2 or more re-RDs. Visible presence of proliferative vitreoretinopathy during first redetachment surgery increased risk of re-RD with relative risk ratio of 1.46 (P = 0.05). Best-corrected visual acuity deteriorated with every additional re-RD (P < 0.001). Two hundred and thirty-seven eyes received oil endotamponde at least once. In 91 cases, oil endotamponade was left for long-term until last follow-up.

CONCLUSION

Multiple re-RD (≥2 re-RDs) is an infrequent complication after rhegmatogenous retinal detachment surgery. After a first re-RD occurred, risk for multiple re-RD doubles compared with the risk of a first redetachment. Mean functional outcome is unfavorable, whereas predictability remains nevertheless poor because of the wide range of interindividual postoperative best-corrected visual acuity.

Macular Effects of Silicone Oil Tamponade: Optical Coherence Tomography Findings During and After Silicone Oil Removal

OBJECTIVE

To investigate retinal morphologic changes during silicone oil tamponade and after its removal using spectral domain OCT (SD-OCT) imaging.

MATERIALS AND METHODS

Retrospective review of 12 patients who underwent silicone oil tamponade for repair of retinal detachments. Macular OCT scans and volumetric thickness maps were examined qualitatively and quantitatively.

RESULTS

Volumetric OCT revealed two distinct patterns during silicone oil: macular thickening (Group A) and macular thinning (Group B). In Group A, mean foveal thickness (507 ± 169 µm vs. 407 ± 163 µm, p = 0.003) and mean macular volume (11.6 ± 2.4 mm³ vs. 9.9 ± 1.5 mm³) were significantly increased during tamponade compared to post-oil removal. Group B had significantly decreased mean foveal thickness (210 ± 38 µm vs. 276 ± 58 µm, p = 0.009) and macular volume (7.3 ± 1.8 mm³ vs. 8.4 ± 1.8 mm³) during tamponade. Importantly, resolution of macular changes occurred without further intervention and was associated with improved visual acuity in both groups.

CONCLUSION

Our series suggests that when faced with unexplained macular edema or macular thinning during tamponade, silicone oil removal alone can achieve resolution of these structural changes.

Glaucoma management after vitreoretinal surgeries

PURPOSE OF REVIEW

The surgical management of retinal disorders, including scleral buckling procedures, pars plana vitrectomy, and intravitreal injections of gas or silicone oil, can lead to short-term elevations in intraocular pressure (IOP) and ultimately long-term glaucomatous damage if not treated in a timely manner. Glaucoma in these cases is commonly refractory to conventional therapies. This review highlights the treatment strategies for glaucoma in eyes that have previously undergone vitreoretinal surgery.

RECENT FINDINGS

Although medical therapy is often used initially to control a temporary rise in IOP, laser and surgical therapy may be required to treat sustained IOP elevation and subsequent glaucomatous damage in eyes that have undergone intraocular surgery for retinal disorders. Glaucoma drainage devices are an important treatment modality, particularly when there is high risk of failure with filtering surgery.

SUMMARY

Previous vitreoretinal surgery is a known risk factor for the development of glaucoma. Treatment is usually initiated with medical therapy, however, surgical intervention is frequently required to control IOP and prevent progressive glaucomatous damage in patients with refractory glaucoma.

COHORT SAFETY AND EFFICACY STUDY OF SILURON2000 EMULSIFICATION-RESISTANT SILICONE OIL AND F4H5 IN THE TREATMENT OF FULL-THICKNESS MACULAR HOLE

Silicone oils that are easier to inject and remove with smaller-gauge instruments, and in surplus have a reduced propensity for emulsification, offer great potential in vitreoretinal procedures. Safety and efficacy of Siluron2000 silicone oil in treatment of full-thickness macular hole were compared with those of Siluron5000 oil. We also assessed the efficacy of perfluorobutylpentane in removing emulsified oil droplets from the eye using ultrasound imaging.

To evaluate safety and efficacy of using Siluron2000 silicone oil in the treatment of full-thickness macular hole by comparing its propensity to emulsify with emulsification of the “gold standard” Siluron5000, and to assess safety and efficacy of F4H5 (perfluorobutylpentane) in removing emulsified oil droplets from the eye.

Surgical and visual outcome for recurrent retinal detachment surgery

Purpose. To evaluate the anatomical and functional outcome of repeated surgeries for recurrent retinal detachment. Methods. We retrospectively reviewed 70 cases with refractory retinal detachment of various etiologies that required multiple operations. Anatomical success (attached retina) or failure (totally/partially-detached retina) was assessed biomicroscopically. The BCVA was used for the evaluation of the functional outcome, at presentation and at the end of follow-up. Various pre-, intra-, and postoperative factors were associated with anatomical success or failure as well as with final functionality. Results. The mean number of surgeries was 4 (range: 2 to 10). The anatomical success rate was 80% (56 attached cases, 14 detached cases). 29% of the attached cases had a BCVA better than 20/40 (Snellen chart). The number of operations doesn't seem to affect significantly the final visual acuity. The PVR was found to affect both the anatomical and functional outcome (P = 0.014 & P = 0.002, respectively). Conclusions. In the present study, it is suggested that multiple operations for refractory retinal detachment may result in successful anatomic results, with a fare functional outcome at the same time. Eventually, we verified that the existence of PVR worsens the prognosis.

Corneal endothelial cell density after vitrectomy with silicone oil for complex retinal detachments

PURPOSE

To evaluate the endothelial cell density changes in eyes with silicone oil tamponade after vitrectomy for complex rhegmatogenous retinal detachment.

METHODS

A prospective controlled study with 81 eyes with complex rhegmatogenous retinal detachment undergoing vitrectomy and silicone oil tamponade. Fellow eyes that fulfilled specific inclusion criteria served as controls. Endothelial cell density (in cells per square millimeter), coefficient of variance (standard deviation per mean cell area × 100), percentage of hexagonal cells, and corneal thickness were documented preoperatively and compared with values obtained at 3, 6, and 12 months postoperatively. For the purpose of the study analysis, all study eyes were divided into 5 groups, according to their lens status during the follow-up.

RESULTS

High endothelial cell density loss was found in Group 3, (eyes that underwent an additional phacoemulsification procedure) and Group 4 (eyes that underwent lens and/or intraocular lens removal during the follow-up) at 12 months with a mean cell loss of 19% and 39%, respectively (P < 0.001).

CONCLUSION

An intact natural or artificial lens-iris diaphragm may provide a protective barrier against corneal endothelial cell damage from long-term silicone oil tamponade.

[Complications of silicone oil tamponade]

Silicone oil tamponade is used for the management of complicated retinal detachment. Patients should be closely monitored as many complications may occur with intraocular silicone oil. Short-term complications include temporarily increased intraocular pressure and anterior segment inflammation. Long-term complications include cataract, emulsification, ocular hyper- or hypotension, keratopathy and retinal redetachment associated with proliferative vitreoretinopathy.

Glaucoma associated with the management of rhegmatogenous retinal detachment

Transient or permanent elevation of intraocular pressure (IOP) is a common complication following vitreoretinal surgery. Usually secondary glaucoma, which develops after scleral buckling procedures, or pars plana vitrectomy for repair of rhegmatogenous retinal detachment, is of multifactorial origin. It is essential, for appropriate management, to detect the cause of outflow obstruction. An exacerbation of preexisting open-angle glaucoma or a steroid-induced elevation of IOP should also be considered. Scleral buckling may be complicated by congestion and anterior rotation of the ciliary body resulting in secondary angle closure, which can usually resolve with medical therapy. The use of intravitreal gases may also induce secondary angle-closure with or without pupillary block. Aspiration of a quantity of the intraocular gas may be indicated. Secondary glaucoma can also develop after intravitreal injection of silicone oil due to pupillary block, inflammation, synechial angle closure, or migration of emulsified silicone oil in the anterior chamber and obstruction of the aqueous outflow pathway. In most eyes medical therapy is successful in controlling IOP; however, silicone oil removal with or without concurrent glaucoma surgery may also be required. Diode laser transscleral cyclophotocoagulation and glaucoma drainage devices constitute useful treatment modalities for long-term IOP control. Cooperation between vitreoretinal and glaucoma specialists is necessary to achieve successful management.

Comprehensive analysis of inflammatory immune mediators of the intraocular fluid aspirated from the foldable capsular vitreous body filled-eyes

PURPOSE

To analyze the level of human inflammatory immune mediators in the intraocular fluid aspirated from foldable capsular vitreous body (FCVB) filled-eyes during FCVB removal surgery, 3 months after implantation.

METHODS

8 samples of intra-FCVB fluids (n = 8) were collected from 8 FCVB filled patients in our previous FCVB exploratory clinical trial. The intra-FCVB fluids were aspirated from the FCVB filled-eyes during the FCVB removal surgeries at the third month. For the control groups, the vitreous fluids were collected from patients with idiopathic macular hole (n = 9) or rhegmatogenous retinal detachment (n = 6) during pars plana vitrectomy. A multiplex immunoassay was used to determine levels of 9 cytokines (IL-1β, IL-2, IL-6, IL-8, IL-10, IL-17, TNF-α, IFN-γ and VEGF) in these samples. The VEGF level of some intra-FCVB fluids (n = 6) were re-tested using enzyme-linked immunosorbent assay (ELISA).

RESULTS

In the intra-FCVB fluids, 9 cytokines concentrations of most samples (n = 5) measured by Multiplex immunoassay showed low values, except for Patient 02, 06, and 09. The VEGF concentrations of some intra-FCVB fluids (n = 6) tested by ELISA were in accordance with Multiplex immunoassay results. For all eight patients (n = 8), the concentrations of IL-1β, IL-2, IL-6, TNF-α, IFN-γ and VEGF were slightly higher as compared to the idiopathic macular hole control group. While, the concentrations of IL-8, IL-10, and IL-17 were not statistically significant different compared with the idiopathic macular hole control samples. Most cytokines concentrations (IL-2, IL-6, IL-8, IL-10, IL-17, TNF-α, IFN-γ, VEGF) were not statistically significant different compared to the rhegmatogenous retinal detachment control group except IL-1β.

CONCLUSIONS

The FCVB had sufficient porosity to allow cytokines to pass through. This study first discovered that the FCVB possesses favorable permeability of proteins in the human eye.

[Long-term use of silicone oil: indications and tolerance]

PURPOSE

The aim of this study was to analyze the indications and the effect of permanently maintaining silicone oil in the treatment of certain cases of vitreoretinal pathology.

PATIENTS AND METHODS

Twenty-seven cases seen from January 2002 to December 2008 were retrospectively studied. Silicone oil was kept in the eyes for more than 2years. The surgical file was analyzed in all cases. The evaluation criteria were ocular pressure, emulsification, cataract, corneal dystrophy, and the functional response of the retina and optic nerve. Ultrasound echography (12 MHz), magnetic resonance imaging, and electrophysiological explorations (visual evoked potential and electroretinography) were performed.

RESULTS

Twenty-seven eyes of 27 patients were included in this study. The main reasons for maintaining long-term silicone oil are recurrent vitreous hemorrhage, retinal detachment with severe proliferative vitreoretinopathy, and penetrating injury. The patients were distributed into two groups: group 1 included patients with both functional and anatomic failure, group 2 patients had achieved ambulatory vision. Follow-up ranged from 27 to 72months. Cataract incidence was approximately 91% in group 2. Emulsification was noted without high pressure in 50% of the cases in group 1. High pressure averaged 31.8% in group 2. Keratopathy was observed in 9% of the cases in group 2. Intraorbital migration of silicone oil was found in one case. The visual field was improved in 77% of the cases in group 2.

CONCLUSION

This study provided interesting insights into certain clinical situations in which silicone oil has to be maintained permanently. The complications stem not only from the presence of silicone oil, but also from the preoperative status of the eye and the vitreoretinal surgery.

Primary 23-gauge vitreoretinal surgery for rhegmatogenous retinal detachment

AIM

To report the effectiveness and safety of primary 23-Gauge (G) vitreoretinal surgery for rhegmatogenous retinal detachment (RRD).

METHODS

In this retrospective study, 49 eyes of 49 consecutive patients who underwent primary 23-G transconjunctival sutureless vitrectomy (TSV) for RRD between January 2007 and July 2009 at our institution were evaluated.

RESULTS

Mean follow-up time was 8.9±7.7 months (1-28 months). Retinal reattachment was achieved with a single operation in 47(95.9%) of 49 eyes. In two eyes (4.1%), retinal redetachment due to new breaks was successfully treated with reoperation using the 23-G TSV system. Mean logMAR visual acuity was 2.01±0.47 preoperatively and 1.3±0.5 postoperatively (P<0.001, Paired t-test). Mean preoperative intraocular pressure (IOP) was 14.1±2.8mmHg. Mean postoperative IOP was 12.3±3.6mmHg at 1 day, 13.1±2.1mmHg at 1 week, 14.3±2.2mmHg at 1 month. Iatrogenic peripheral retinal break was observed in 1 eye (2.0%) intraoperatively. No sutures were required to close the scleral or conjunctival openings, and no eyes required convertion of surgery to 20-G vitrectomy.

CONCLUSION

Primary 23-G TSV system was observed to be effective and safe in the treatment of RRD.

Encircling band, laser retinopexy and lens removal as standard procedure in complicated retinal detachment shows a good clinical outcome

PURPOSE

To evaluate vitrectomy in conjunction with the use of perfluorocarbon, cerclage, laser retinopexy, lens removal and silicone oil as surgical treatment of proliferative vitreoretinopathy associated with retinal detachment.

METHODS

Sixty-two eyes of 62 patients were treated for complicated retinal detachment following failed prior scleral buckling. Outcome measures were; retinal reattachment rate 6 months after silicone oil removal, status of the retina, visual acuity (VA), duration of silicone tamponade and frequency of reoperations.

RESULTS

The final reattachment rate was 95%. Reoperations had to be performed in 25% of patients. Eighty-one per cent of these patients received one and 19% two or more operations following silicone oil implantation. The mean time to reoperation was 1.8 ± 1.4 months. Silicone oil was removed after 5.6 ± 4.1 months following the last vitreoretinal procedure in 90%, respectively, 95% with attached retina. Five per cent experienced retinal detachment after silicone oil removal. At the end of follow-up, the mean VA was 0.13 ± 0.26 Snellen. Seventy per cent of patients achieved a vision of 20/200 or better (mean 0.25 ± 0.27).

CONCLUSION

Our study demonstrates good final outcomes when a rigorous surgical approach was used. Furthermore, this standard procedure reduces the need for reoperations and consequently improves the functional outcome.

Outcome after silicone oil removal and simultaneous 360° endolaser treatment

PURPOSE

To evaluate the outcome after silicone oil removal combined with a 360° endolaser treatment in complex retinal detachment (RD) cases and to assess prognostic factors.

METHODS

This is a retrospective, consecutive interventional study in Vienna, Austria with data from 111 patients following silicone oil removal and simultaneous 360° endolaser treatment for at least 6 months. Stepwise regression analysis between anatomic and visual outcome, baseline demographics, and type and number of RD procedures was performed.

RESULTS

One hundred and one patients (91%) showed a retinal reattachment after silicone oil removal, which was associated with a low overall number of RD procedures (p = 0.01) and male gender (p < 0.03). Sixty-five patients (59%) showed an improvement (two or more lines) of best-corrected visual acuity (BCVA) at the final follow-up visit. Improvement of BCVA and a better BCVA after silicone oil removal were associated with a better BCVA before silicone oil removal (p < 0.01) and a low overall number of RD procedures (p < 0.01).

CONCLUSION

The overall number of RD procedures can be used to predict the anatomic and visual outcome after silicone oil removal. Adding a simultaneous 360° endolaser therapy to silicone oil removal is associated with a high anatomic success rate and an excellent visual outcome.

Intraocular lens capture in combined cataract extraction and pars plana vitrectomy: comparison of 1-piece and 3-piece acrylic intraocular lenses

PURPOSE

To report and compare the incidence of pupillary capture and posterior synechiae formation after combined cataract extraction and pars plana vitrectomy (PPV) with a 1-piece versus a 3-piece acrylic intraocular lens (IOL).

SETTING

Royal Alexandra Hospital Eye Clinic, University of Alberta, Edmonton, Alberta, Canada.

DESIGN

Comparative case series.

METHODS

Consecutive patients who had combined cataract extraction with PPV were retrospectively reviewed. The outcomes in patients who received a 1-piece acrylic IOL and those who received a 3-piece acrylic IOL were compared. The proportion of patients with pupillary IOL capture and/or posterior synechiae postoperatively was recorded.

RESULTS

The cohort comprised 145 patients. All cases of IOL capture occurred in eyes with a 1-piece IOL (n = 7; 7.7%); the difference between the 1-piece IOL group and the 3-piece IOL group was statistically significant (P = .043). There was no significant difference between the 2 IOL types in the rate of posterior synechiae formation. Regression analysis showed that the odds of posterior synechiae formation were significantly higher in cases in which perfluoropropane (C(3)F(8)) (odds ratio [OR], 24.01; P = .006), sulfur hexafluoride (SF(6)) (OR, 25.23; P = .007), or silicone oil (OR, 47.78; P<.001) was used.

CONCLUSIONS

The incidence of IOL capture was significantly greater after implantation of a 1-piece IOL than after implantation of a 3-piece IOL during combined cataract extraction and PPV. Posterior synechiae formation was associated with the use of silicone oil, SF(6), or C(3)F(8).

Incidence of redetachment 6 months after scleral buckling surgery

PURPOSE

The preoperative and intraoperative clinical variables associated with redetachment and/or a poor visual outcome following scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD) have mainly been studied after a short follow-up. This study aimed to analyse long-term effects by following patients for at least 6 months.

METHODS

In a retrospective survey we evaluated the data of 436 eyes that underwent SB surgery. Postoperative data were collected at 3-month intervals.

RESULTS

After a mean follow-up period of 51 months, anatomic reattachment was achieved in 76% after one SB procedure, with a final reattachment rate of 97% after additional vitreoretinal procedures. In total, 104 eyes developed redetachment during follow-up. After more than 6 and 12 months of follow-up, 32 eyes (7%) and 20 eyes (5%), respectively, developed redetachment. Multivariate regression analysis showed that recurrent redetachment and more than 7 days of visual field loss were significant predictors for a poor postoperative visual outcome at 12 months. A cumulative size of the tear of more than three disc diameters was a significant predictor of recurrent RRD.

CONCLUSION

Conventional SB surgery is a reliable procedure in a selected group of eyes with primary RRD. However, in eyes with a retinal tear with a cumulative size of more than three disc diameters, a primary vitrectomy should be considered. Taking into account that 7% of eyes developed redetachment after 6 months, a longer follow-up period seems necessary to evaluate the anatomical and visual outcomes after SB surgery.

High-density silicone oil (Densiron) as a primary intraocular tamponade: 12-month follow up

BACKGROUND

The high-density silicone oil (Densiron 68), a mixture of F6H8 with silicone oil, seems to be a therapeutic option, at least in selected patients with complex inferior retinal re-detachment, where standard procedures have already failed. In an interventional case series we used Densiron as a primary endotamponade.

METHODS

Twelve eyes of 12 patients aged 31 years to 85 years with inferior complex rhegmatogenous retinal detachment with secondary proliferative vitreoretinopathy (PVR) grades CP2 to CA8 were included. Surgical techniques (pars plana vitrectomy, membrane peeling, retinotomy, retinectomy, endophotocoagulation, cryocoagulation, endotamponade) did not include a scleral buckling procedure (except one eye). Mean duration of the Densiron endotamponade was 78.3 +/- 29.74 days, with a mean follow up after removal of 400.6 +/- 85.4 days.

RESULTS

After Densiron removal, four patients (33.3%) showed a stable reattached retina without further interventions, while, in six patients (50%), recurrent retinal re-detachment appeared during endotamponade, generally within 2 months. One patient (8.3%) developed re-detachment 5 months after Densiron removal. One eye (8.3%) lost light perception due to severe intraretinal fibrosis with chronic hypotonia, despite complete retinal re-attachment. Visual acuity improved from mean logarithm of the minimum angle of resolution (logMAR) of 2.95 +/- 1.21 to 1.87 +/- 1.32 (statistically significant, P = 0.022). Side effects included temporary inflammatory reaction/fibrin accumulation (n = 2/2), moderate-to-severe intraretinal fibrosis (n = 3), elevated intraocular pressure (IOP) (n = 3), emulsification (n = 2), sterile hypopyon (n = 1), vitreous haemorrhage (n = 1) and chronic hypotony (n = 1).

CONCLUSION

Primary anatomical success rate of 33.3% was less encouraging than as expected. Especially, re-detachments within the posterior staphyloma in highly myopic patients were common during Densiron endotamponade. However, the surgical success increased to 75% after reintervention, even without the use of an additional encircling band. The observed adverse effects and the functional outcomes do not contraindicate the use of Densiron as an internal tamponade for a period of 3 months.

Risk factors for redetachment and worse visual outcome after silicone oil removal in eyes with complicated retinal detachment

PURPOSE

The goal of this study was to identify risk factors for redetachment and/or a worse visual outcome after silicone oil removal (SOR) for complicated retinal detachment.

METHODS

The authors retrospectively analyzed 287 consecutive eyes with SOR between January 1999 and December 2003.

RESULTS

Anatomic success after SOR was achieved in 81% of the eyes. The overall anatomic success at the end of follow-up was 94%. Postoperative ocular hypertension was found in 8% of the eyes, hypotony in 6% of the eyes, and keratopathy in 29% of the eyes. After SOR 43% of the eyes had an improvement in visual acuity of at least two Snellen lines. After multivariate analysis, male sex, the presence of preoperative rubeosis, and proliferative diabetic retinopathy (PDR) were found to be risk factors for recurrent retinal detachment. Male sex, preoperative visual acuity of <0.1 Snellen lines, PDR, the performance of three more operations, any size of retinectomy, and hypotony were found to be associated with a poor visual outcome of Snellen visual acuity <0.1.

CONCLUSIONS

Retinal detachment after SOR in the current unselected series of eyes occurred in approximately 20%, which is comparable to the Silicone Oil Study reports, published approximately 20 years ago. However, preoperative selection was then made, and less than 50% of the silicone oil-filled eyes had SOR. The higher overall anatomic success in the current study may be due to improved vitreoretinal surgical techniques.

Corneal perforation associated with silicone oil in the anterior chamber

PURPOSE

To describe the management of three cases of corneal perforation associated with silicone oil in the anterior chamber.

METHODS

Review of 3 case records.

RESULTS

Three cases of perforation associated with silicone oil in the anterior chamber are reviewed. One patient required gluing and a bandage contact lens, whereas the second patient required an emergency corneal transplantation. The third patient responded to conservative measures, including the use of topical antibiotic ointment.

CONCLUSIONS

Corneal perforation associated with silicone oil in the anterior chamber is rare and can be difficult to manage. Potential treatments including the use of cyanoacrylate glue, application of antibiotic ointments, use of aqueous suppressants, and other conservative measures may be effective. In extreme cases, corneal transplantation may be necessary.

Anatomical and Functional Results of Endotamponade with Heavy Silicone Oil – Densiron® 68 – in Complicated Retinal Detachment

BACKGROUND

High-density silicone oils are newly developed long-term tamponade agents for the treatment of complicated retinal detachment in the inferior retina. Previous studies describe satisfying anatomical and functional results. In this study we examined the largest cohort so far for a 9-month follow-up and performed a comparison to conventional silicone oil.

METHODS

Our study documents results and adverse effects after vitreoretinal surgery and endotamponade with Densiron 68 in 99 cases of complicated retinal detachment. A 9-month follow-up was performed. Data of 21 patients with intraocular conventional silicone oil tamponade in complicated retinal detachment were retrospectively analyzed and served as control.

RESULTS

Anatomical success was achieved in 78 of 89 eyes (87.6%) with completed follow-up; visual acuity did not change significantly (from mean preoperative logMAR 1.88 to postoperative logMAR 1.96 (p = 0.9). Compared to control a higher anatomical success but a similar number of adverse effects were observed with heavy silicone oil in vitreous. Nevertheless, patients who received Densiron 68 twice due to redetachment showed a significantly higher rate of intraocular inflammation with the tamponade agent in situ.

CONCLUSION

Our results support the hypothesis of Densiron 68 as potent tamponade agent for complicated retinal detachment in the inferior retinal segments especially in eyes where a previous operation failed.

Scleral Buckling Surgery after Macula-Off Retinal Detachment

PURPOSE

To determine the effect of duration of macular detachment (DMD) on visual acuity (VA) in patients with macula-off rhegmatogenous retinal detachment (RD).

DESIGN

Retrospective observational case series.

PARTICIPANTS

Two hundred two consecutive patients (202 eyes) with primary uncomplicated macula-off RD, preoperative VA of 10/100 or worse, a precise history of when macular function was lost, successful reattachment surgery, and a minimal follow-up of 3 months.

INTERVENTION

All RDs were repaired with a primary scleral buckling procedure performed by 3 vitreoretinal surgeons.

MAIN OUTCOME MEASURE

Visual acuity (best corrected and 3, 6, and 12 months postoperatively).

RESULTS

Considering all eyes, the cumulative mean of the best-corrected postoperative VA (logarithm of the minimum angle of resolution [logMAR]) as a function of DMD shows a rapid worsening when DMD exceeds 6 days. Eyes were divided into 3 groups, corresponding to the DMD intervals immediate (within 10 days), delayed (11 days-6 weeks), and late (>6 weeks). Mean postoperative VAs (in logMAR) were 0.35+/-0.31 (between 20/40 and 20/50 Snellen equivalent) in eyes with DMD up to 10 days, 0.48+/-0.26 (20/60 Snellen equivalent) in the delayed group, and 0.86+/-0.30 (8/60 Snellen equivalent) in eyes with DMD longer than 6 weeks.

CONCLUSIONS

The cumulative mean of the best-corrected postoperative VA (logMAR) as a function of DMD shows a rapid worsening when DMD exceeds 6 days. Our results indicate that the scleral buckling procedure should be done preferably within a 7-day DMD.

[Results of treating rhegmatogenous retinal detachment with vitrectomy and silicone oil tamponade]

INTRODUCTION

Silicone oil is used in the treatment of rhegmatogenous retinal detachment when there is a high risk of postoperative proliferative vitreoretinopathy (PVR). This type of internal tamponade can be responsible for serious side effects. Removal of silicone oil is necessary to ensure a long-lasting functional result. The purpose of this study was to evaluate the results of using a transient internal tamponade with silicone oil.

PATIENTS AND METHODS

A retrospective review of cases of rhegmatogenous retinal detachment treated with internal tamponade with silicone oil for the first time in a 1-year period (January 2001 to December 2001) was conducted. We studied the type of retinal detachment, treatment before vitrectomy and silicone oil tamponade, indication for silicone oil tamponade, surgical steps and their results, causes of recurrent retinal detachment, and final visual acuity. Anatomical success was defined as a reattached retina after silicone oil removal.

RESULTS

Ninety-three patients were included. Anatomical success was achieved, after one or several procedures, in 71 patients (76.3%). The mean total number of surgical procedures was 2.6. After initial surgery, recurrence of retinal detachment after removal of silicone oil occurred in 17.0% of the cases. Recurrence of retinal detachment under silicone oil occurred in 45.1% of the cases; the cause of the recurrence was PVR in 97.6% of those patients. No serious complication of silicone oil tamponade occurred. The mean duration of the tamponade was 6.7 months. The best results were achieved among patients showing no recurrence with silicone oil: visual acuity above 4/200 in 84.6% of the patients, above 20/200 in 61.5% of the patients and above 80/200 in 20.5% of the patients. In case of recurrence with silicone oil treatment, visual acuity reached 4/200 in 70.4% of the patients and was above 20/200 in 25.9% of the patients.

DISCUSSION AND CONCLUSION

The results of this study are equivalent to those of studies in which analysis was made after removal of silicone oil. Proliferative vitreoretinopathy remains the only risk factor of retinal detachment recurrence with silicone oil (p<0.01). The number of previous surgeries is not a risk factor for postoperative PVR. Retinectomy is a surgical procedure that seems to improve the results in cases of severe PVR.

Correlation of optical coherence tomography pattern and visual recovery after vitrectomy with silicone oil for retinal detachment

PURPOSE

To assess prospectively the features of the macular surface in silicone oil-filled eyes after surgery by analyzing whether silicone oil affects optical coherence tomography (OCT) measurements and their reproducibility and whether a statistical correlation exists between postoperative best-corrected visual acuity (BCVA) and foveal thickness measured by OCT.

METHODS

Twenty eyes of 20 patients underwent vitrectomy with silicone oil tamponade for retinal detachment. After vitrectomy, complete ophthalmic examination including determination of BCVA and OCT was performed to quantify the visual recovery and the foveal thickness.

RESULTS

Ophthalmoscopy revealed that the retina appeared to be reattached in all 20 eyes at 3 months after surgery. BCVA ranged from 0.4 logMAR to 1.7 logMAR, and foveal thickness ranged from 80 microm to 500 microm. Postoperative foveal thickness and BCVA had a strong correlation (r = 0.93; P = 0.003).

CONCLUSION

The presence of silicone oil in the vitreous chamber does not change the reproducibility of OCT measurements of foveal thickness (coefficient of reproducibility, 1.48%). This study showed high statistical correlation between BCVA and foveal thickness. Therefore, postoperative BCVA is affected by postoperative foveal thickness, and visual improvement is limited in eyes with increased or decreased foveal thickness.

Increased glutamate levels in the vitreous of patients with retinal detachment

Experimental models have implicated glutamate in the irreversible damage to retinal cells following retinal detachment. In this retrospective study we investigated a possible role for glutamate and other amino acid neurotransmitters during clinical rhegmatogenous retinal detachment (RRD). Undiluted vitreous samples were obtained from 176 patients undergoing pars plana vitrectomy. The study group consisted of 114 patients (114 eyes) with a rhegmatogenous retinal detachment. Controls included 52 eyes with an idiopathic macular hole or idiopathic epiretinal membrane and 10 eyes with a traction retinal detachment due to proliferative diabetic retinopathy. Vitreous concentrations of glutamate, gamma-aminobutyric acid (GABA), taurine, glycine, and aspartate were determined by high-pressure liquid chromatography (HPLC). Multivariate analysis was used to examine a possible association between amino acid neurotransmitter levels and several clinical variables including visual acuity. The mean vitreous concentration of glutamate in eyes with a rhegmatogenous retinal detachment (16.6 +/- 5.6 microM) was significantly higher as compared to the controls (13.1 +/- 5.2 microM) (P = 0.001). Taurine levels were also increased in RRD, whereas no significant difference could be observed in glycine, aspartate and GABA levels when comparing RRD with controls. A correlation was found between increased vitreous glutamate and a lower pre-operative visual acuity. No association was, however, observed between post-operative visual acuity and the level of any of the five amino acid neurotransmitters. RRD was associated with a significantly increased vitreous glutamate concentration. Using visual acuity as a functional parameter in this study, we could not demonstrate a correlation between vitreous glutamate, or any of the other tested amino acid neurotransmitters and visual outcome.