Perfluorocarbon liquid-assisted vitreo-dissection in eyes with firmly adherent posterior hyaloid.

BACKGROUND: Induction of posterior vitreous detachment (PVD) is a critical step during pars plana vitrectomy. Multiple techniques and utilities have been proposed for assistance with this step with no consensus on the safest and most effective means, especially in eyes with firmly adherent posterior hyaloid. Viscodissection or the utilization of perfluorocarbon liquid (PFCL) can be used to dissect the posterior hyaloid and widely adherent epiretinal membranes. METHODS: A technique of PFCL dissection of the posterior hyaloid in eyes with abnormal adhesion of the posterior hyaloid. After core vitrectomy, breaking into the posterior hyaloid face is made via active aspiration and cutting or a sharp dissection. This is followed by active and slow injection of PFCL into the potential space between the posterior cortical vitreous and the neurosensory retina. A wave of PFCL propagates anteriorly causing "vitreo-dissection" of the peripheral cortical vitreous. RESULTS: The technique was effective and safe in 8 successive cases, 4 cases with vitreoretinal traction syndrome and 4 with diabetic tractional membranes. CONCLUSION: The technique can be considered in cases with abnormal firmly adherent posterior hyaloid when induction of PVD proves difficult.

Two-staged surgery as an alternative to buckle-vitrectomy for rhegmatogenous retinal detachment complicated by choroidal detachment.

AIM: To evaluate the outcome and safety profile of short-term perfluorocarbon liquids (PFCL) tamponade in comparison with buckle-vitrectomy in case of rhegmatogenous retinal detachment (RRD) associated with choroidal detachment (CD). METHODS: Records of patients who underwent surgery for RRD/CD from January 2016 to July 2019 were reviewed retrospectively. The patients were allocated into two groups-group 1 patients underwent buckle-vitrectomy, while those in group 2 underwent a two-staged vitrectomy with short-term (5 days) PFCL tamponade. RESULTS: The study included 33 eyes (33 patients) with mean age of 50.3 ± 17.2 years. Group 1 included 15 patients, while group 2 included 18. The pre-operative characteristics were similar in both the groups. The mean pre-operative intraocular pressure in group 1 and 2 was 9.1 ± 4.0 and 8.6 ± 5.2 mmHg, respectively (p = 0.755). Retinal re-attachment after single surgery was achieved in 10 (66.7%) and 14 eyes (77.8%), respectively. All the eyes achieved retinal re-attachment after repeat surgery in both the groups (1.40 vs 1.39 surgeries, p = 0.963). Post-surgery visual improvement was seen in 13 (86.7%) and 17 eyes (94.4%), respectively (p = 0.579). Final visual acuity of ≥ 6/60 was obtained in 7 (46.7%) and 9 eyes (50.0%), respectively (p > 0.999). None of the patients needed retinectomy during repeat surgery. None of the patients experienced exaggerated inflammation or intractable raised IOP spike which could not be controlled with medications. CONCLUSION: Surgical outcomes were similar in both the groups. No clinically apparent toxicity was seen with post-operative short-term PFCL tamponade. Two-staged surgery is a good alternative to buckle-vitrectomy for eyes with RRD associated with CD.

A case of silicone oil adhered to the retinal surface via perfluorocarbon liquid.

BACKGROUND: Perfluorocarbon liquid (PFCL) is widely used as an intraoperative heavy tamponade to flatten the retina and is replaced with silicone oil (SO) at the end of the surgery. Due to the long tamponade period, the SO is known to remain attached to the retina at the time of removal, and is commonly termed "sticky oil". The aim of this present study was to report a case of SO stickily attached to the retina via PFCL without tamponade period. CASE PRESENTATION: A 39-year-old male was referred to our hospital due to decreased vision and visual field defect in his right eye. Upon examination, he was diagnosed with rhegmatogenous retinal detachment in that eye. For treatment, he underwent vitrectomy with the use of PFCL and SO. The direct exchange of PFCL with SO resulted in residual subretinal fluid, so we subsequently attempted to remove the SO. However, a SO bubble adhering to the PFCL was visible on the posterior pole. After aspiration of the PFCL beneath the sticky SO, the SO was easily separated and removed from the retina. CONCLUSIONS: Our findings show that SO can become tightly adhered to the retinal surface via PFCL during vitrectomy, and that the sticky SO can be safely removed via aspiration of the PFCL layer underneath the SO.

Massive subretinal and subretinal pigment epithelial hemorrhage displacement with perfluorocarbon liquid using a two-step vitrectomy technique.

PURPOSE: The purpose of this study was to evaluate the efficacy and visual outcome of massive submacular hemorrhage (SMH) displacement with a planned two-step pars plana vitrectomy (PPV) using tissue plasminogen activator (tPA) and perfluorocarbon liquid (PFCL) tamponade. METHODS: A retrospective case series of patients with age related macular degeneration and SMH was used. All patients underwent a 23G PPV, subretinal tPA injection and a medium term PFCL tamponade. A second stage PPV for PFCL removal was performed 7-17 days later. The main outcome was the change in macular and sub-RPE thickness after 6 months. Secondary outcomes were visual acuity and complications. RESULTS: Seven patients (seven eyes) with mean age of 79.85 years were enrolled. The average SMH size was 17.5 disc area (range 4.5-33) with mean symptoms of a duration of 9.5 days (range: 2-21). SMH was successfully displaced in six eyes. Mean macular and sub-RPE thickness decreased from 1505µ to 711.3µ and 900 µ to 457µ, respectively. Visual acuity (VA) remained stable in five eyes. Complications included corneal edema and transient intraocular pressure elevation in three patients. CONCLUSIONS: SMH displacement using subretinal tPA injection and medium term PFCL tamponade is an effective alternative treatment option. In our experience, it can be safely performed, avoiding complications commonly attributed to other techniques.

Optimizing Retinal Thermofusion in Retinal Detachment Repair: Achieving Instant Adhesion without Air Tamponade.

Purpose: Rhegmatogenous retinal detachment repair by intraoperative sealing of the tear without a tamponade agent should enable faster restoration of vision and resumption of normal activities. It avoids the need for further surgery in the case of silicone oil endotamponade. This study evaluated the retinal thermofusion (RTF) retinopexy method of subretinal space dehydration before photocoagulation to create an instantaneous intraoperative retina reattachment in a preclinical model. Design: Preclinical study. Participants: Twenty Dutch Belt, pigmented rabbits that underwent RTF repair after experimental retinal detachment. Methods: This ex vivo model quantified adhesion force between the retina and underlying retinal pigment epithelium and choroid after treatment of 1 retinal edge using postmortem porcine or human retina (6 × 12 mm). We compared (1) control, (2) laser photocoagulation alone, (3) dehydration alone, and (4) dehydration followed by photocoagulation (RTF). Optimized parameters for RTF were then applied in the in vivo rabbit model of retinal detachment. Animals were followed up for 14 days. Main Outcome Measures: For this ex vivo model, we measured adhesion force and related this to tissue temperature. For the in vivo study, we assessed retinal attachment using funduscopy and histologic analysis. Results: The ex vivo model showed that RTF repair produced significantly higher adhesion force than photocoagulation alone independent of dehydration method: warm (60° C) high airflow (50-70 ml/minute) or using laser wavelengths targeting water absorption peaks (1470 or 1940 nm) with coaxial low airflow (10-20 ml/minute). The latter approach produced a smaller footprint of dehydration. Application of RTF (1940-nm laser with coaxial airflow) in an in vivo retinal detachment model in rabbit eyes resulted in immediate retinal adhesion, achieving forces similar to those in the ex vivo experiments. Retinal thermofusion repair resulted in stable reattachment of the retina over the 2-week follow-up period. Conclusions: We showed that a short preliminary dehydrating laser treatment of a retinal tear margin before traditional laser photocoagulation creates an immediate intraoperative waterproof retinopexy adhesion independent of tamponade and a wound-healing response. This approach potentially will allow rapid postoperative recovery regardless of the tear location and improved vision.

An in-vitro study of subretinal perfluorocarbon liquid (PFCL) droplets and the physics of their retention and evacuation.

PURPOSE: To investigate the physics associated with the retention and removal of subretinal perfluorocarbon liquid (PFCL), as inspired by a series of anecdotal cases of spontaneous 'disappearance' of subretinal PFCL. METHODS: The profiles of subretinal PFCL in situ from published OCT images were studied and compared with that of PFCL droplets resting on a hydrophilic surface in vitro. A mathematical model based on Sampson's and Poiseuille's formula was developed to explain how evacuation of subretinal PFCL without aspiration could occur. RESULTS: The mathematical model suggested that in vivo subretinal PFCL can completely evacuate in less than a second via a 41-guage retinal hole. Perfluorocarbon liquid (PFCL) droplets in situ subretinally substantially varied in their aspect ratios (from 0.28 to 2.71) and their contact angles with the retinal pigment epithelium (from 98° to 155°). Conversely, PFCL in vitro had aspect ratios and contact angles close to 1 and 150° respectively. CONCLUSION: This study showed evidence that stretching of the retina to accommodate subretinal PFCL occurs, which might be responsible for the varied profile of the droplets and resultant forces that can cause retinal holes, and spontaneous evacuation of large PFCL droplets. By filling the vitreous cavity with PFCL, a small retinotomy alone might allow spontaneous evacuation without the need for aspiration.

Fully Automated Direct Perfluorocarbon Liquid-Silicone Oil Exchange.

PURPOSE: To demonstrate a modified technique of fully automated direct perfluorocarbon liquid (PFCL)-silicone oil (SO) exchange. MATERIALS AND METHODS: This technique is indicated for cases that require direct PFCL-SO exchange as in giant retinal tear or large retinectomies to avoid retinal slippage. Pars plana vitrectomy (PPV) is carried out in standard fashion; then the dual active injection/extrusion mode is activated in the vitrectomy machine. The machine parameters are set at approximately 30-40 psi for SO injection and 150-250 mmHg for active PFCL aspiration. In this method, both the SO injection and the PFCL extrusion are simultaneously controlled by the foot pedal. RESULTS: We used this technique for a total of 24 cases: 6 cases of giant retinal tears and 18 retinectomies. We did not encounter any complications related to significant IOP spike during surgery or complete removal of the PFCL. CONCLUSION: This automated technique for direct PFCL-SO exchange maintains a controlled balance between SO injection and PFCL aspiration, that mitigates the risk of intraoperative IOP spikes. It is safe, quick, and can be performed without the need of an assistant or extra chandelier light or high-pressure viscous tubing.

Influence of Perfluorocarbon Liquids on Peripapillary Retinal Nerve Fiber-Layer Thickness Following Pars Plana Vitrectomy with Silicone Oil-Based Endotamponade.

BACKGROUND: Inner retina-layer modifications after pars plana vitrectomy (PPV) can be objectively assessed through spectral domain optical coherence tomography (SD-OCT). METHODS: This study explored prospectively changes in retinal nerve-fiber layer (RNFL) thickness with SD-OCT in eyes undergoing PPV with silicone oil-based tamponade with and without use of perfluorocarbon liquids (PFCLs) during the early postoperative phase (up to 3 months) at the Research Institute of Ophthalmology, Egypt. RESULTS: Thirty patients were recruited who underwent PPV and silicone oil-based tamponade for either retinal detachment or diabetic retinopathy between April 2019 and September 2019. Mean RNFL thickness showed no significant change during follow-up at the first week (102.90±30.68 mm), 1 month (107.30±32.27), or three months (105.90±36.68; p=0.46, 0.68). There were significant correlations noticed between RNFL thinning and axial length of eyes, intraocular pressure, and use of PFCLs during the follow-up period. CONCLUSION: The RNFL tends to change postvitrectomy, but not significantly. Careful examination and consistent follow-up is required for postvitrectomy patients with larger axial length and intraoperative PFCL use.

Removal of subfoveal perfluorocarbon liquid: Report of 3 cases.

PURPOSE: To report removal of retained subfoveal perfluorocarbon liquid (PFCL) after vitrectomy for retinal detachment. METHODS: Three patients underwent 3-port 23-gauge vitrectomy in an attempt to remove retained subfoveal PFCL bubble secondary to retinal detachment surgery. In two patients, removal was achieved via a 23-G needle whereas the third patient with multiple small subfoveal droplets, multiple punctures were required and in that case a small 40-G needle was used.We assessed best corrected visual acuity (BCVA), fundus imaging, and spectral domain optical coherence tomography (SD-OCT) of all patients before and after surgery. RESULTS: The subfoveal PFCL was successfully removed in all 3 eyes and although a functional improvement was documented, outer retinal atrophy and photoreceptor loss was observed in all our cases. CONCLUSIONS: SD-OCT allows early recognition of retained subfoveal PFCL. Surgical removal may lead to retinal morphologic restoration and functional improvement. While we achieved complete removal of PFCL with both 23-G and 40-G instrumentation, we believe the versatility and ease justifies the universal usage of 40-G retinotomy needles.

Dashed line relaxing retinotomy in the management of retinal detachment with anterior proliferative vitreoretinopathy.

BACKGROUND: We describe the anatomical and functional outcomes of eyes that underwent a modified technique of relaxing retinotomy, dashed line relaxing retinotomy, in the management of retinal detachment with anterior proliferative vitreoretinopathy. METHODS: We retrospectively reviewed 54 consecutive eyes in 52 patients who received pars plana vitrectomy with relaxing retinotomy during retinal detachment repair. Perfluorocarbon liquid (PFCL) was used as a standard procedure to stabilize the retina during retinotomy to prevent slippage or inversion of the posterior flap. If PFCL was not available due to economic reasons, dashed line relaxing retinotomy was performed instead. Best-corrected visual acuity, slit-lamp biomicroscopy, intraocular pressure measurement, lens status, and fundus examination were analyzed. We excluded patients who were followed up <4 months. RESULTS: Regarding anatomical success rates and visual outcomes, we found no significant differences between patients treated with intraoperative PFCL and those treated with dashed line relaxing retinotomy without PFCL. CONCLUSION: Compared to the simple and efficient PFCL-assisted relaxing retinotomy, dashed relaxing retinotomy is not the first choice when PFCL is available. Based on our results, this modified technique may offer an alternative in patients with anterior proliferative vitreoretinopathy for whom PFCL is not available.

A Study on The Corneal Toxicity of Perfluorocarbon Liquid in The Rabbit Eye

Perfluorocarbon liquids(PFCL) have been used as an intraoperative tool for repair of complicated retinal detachment with improving surgical results. However, little is known about the potential toxic effect of PFCL that remain in the eye after surgery to anterior segment tissue. In this study we evaluated the effect of this substance on the corneal tissue. Eight rabbits underwent injection of 50 micro l of perfluorodecalin in the anterior chamber of the right eyes. The left eyes were injected with the same amount of balanced salt solution(BSS) as a control. The clinical appearance of the eyes were recorded at three days, one week and two weeks after injection, and histological examination was done two weeks after injection. The differences of intraocular pressure(IOP) between the right and left eyes were not statistically significant at three days, one week and two weeks after injection, and all of right eyes showed inferior bulbar counctival injection for same periods. In the histological examination of cornea exposed to PFCL, the number and the height of endothelial cells were reduced and decreased, respectively. These findings suggested that PFCL may have a toxic effect on the corneal endothelial cells.