Intraoperative perfluorocarbon liquids in the management of proliferative vitreoretinopathy

Iatrogenic macular hole following PFCL injection: Implications of retinal dimpling as an intraoperative indicator

Background

Perfluorocarbon liquid (PFCL) revolutionized retinal detachment (RD) management in vitreoretinal surgery but introduced unique risks. Complications like subretinal migration are documented, yet specific warnings for macular hole (MH) formation during PFCL injection are lacking.

Case presentation

In a rhegmatogenous RD case, a localized retinal dimpling during PFCL jet stream injection, preceded subsequent complications-an immediate MH and subretinal PFCL migration. Subsequently, an internal limiting membrane peeling with PFCL mobilization was performed.successfully managed the situation. Post-surgery, optical coherence tomography (OCT) confirmed a closed MH with improved vision.

Conclusion

This case report not only sheds light on a previously undocumented complication associated with PFCL injection but also underscores the critical need for adherence to proper injection technique to minimize traumatic effects. Understanding the mechanism underlying this complication and implementing corrective measures are essential for enhancing intraoperative strategies and minimizing adverse outcomes in retinal surgeries involving PFCL.

Long-term Outcomes of Submacular Perfluorocarbon Liquid Removal with Internal Limiting Membrane Peeling and Transretinal Aspiration

BACKGROUND

An important complication associated with perfluorocarbon liquid (PFCL) use during pars plana vitrectomy (PPV) is its retention in the submacular area. The aim of this study was to present the long-term outcomes of the surgical method used in this study to remove submacular PFCL and to shed light on the advantages and disadvantages compared to other methods.

MATERIAL AND METHODS

This is a retrospective, single-center, observational study. Patients who underwent surgical intervention due to submacular PFCL were included in this study. The surgical procedural includes internal limiting membrane (ILM) peeling, transretinal aspiration of submacular PCFL with a 25/27-gauge soft-tipped cannula, then perfluoropropane (C3F8) gas tamponade, and facedown positioning for 5 days. The long-term anatomical and functional outcomes were evaluated with an ophthalmological examination and optical coherence tomography (OCT).

OUTCOMES

A total of 15 patients with submacular PFCL were included in this study, and the mean age of the patients was 64.33 ± 10.36 years (47 - 83). The localization of submacular PFCL was subfoveal in nine patients (60.00%), non-subfoveal in four patients (26.67%), and both subfoveal and non-subfoveal in two patients (13.33%). The mean time of submacular PFCL diagnosis was 4.86 ± 1.02 weeks (2 - 8) and the mean time of the surgery was 9.80 ± 1.17 weeks (8 - 14). Complete removal of submacular PFCL was achieved in all cases (100%) and no significant treatment-associated complications were observed. The mean follow-up time was 37.60 ± 14.00 months (18 - 60) and the best-corrected visual acuity was significantly improved (p = 0.001). At the end of the follow-up time, prominent ellipsoid zone disruption was observed in six patients (40.00%), while in nine patients (60.00%), there was no prominent ellipsoid zone disruption.

CONCLUSIONS

The surgical procedural for submacular PFCL removal is a reasonable option and improves visual acuity in the long term without any significant treatment-associated complications.

Effects of Perfluorocarbon Use during Rhegmatogenous Retinal Detachment Surgery on Postoperative Outcomes

INTRODUCTION

The aim of this study was to determine whether the use of perfluorocarbon liquid (PFCL) affects the rate of retinal re-attachments after an initial attachment by vitrectomy in eyes with rhegmatogenous retinal detachment (RRD).

METHODS

This was a retrospective, observational, multicenter study of 3,446 eyes registered in the Japanese vitreoretinal surgery treatment information database. Of these, 2,648 eyes had undergone vitrectomy as the first surgery for RRD. The re-attachment rates after the primary vitrectomy with or without PFCL were evaluated. In addition, the significance of factors affecting the re-detachments was determined by univariate and multivariate analyses. The measured outcomes were the rates of re-attachments after the primary vitrectomy with or without the use of PFCL.

RESULTS

A total of 2,362 eyes in the database were analyzed: 325 had and 2,037 did not have PFCL injected into the vitreous cavity during the vitrectomy. The rate of re-attachments was 91.5% in the PFCL group and 93.2% in the non-PFCL group (p = 0.46, χ2 test). Although there were several risk factors associated with the re-detachments in eyes without PFCL (p < 0.05, Welch's t tests, and Fisher's exact tests), they were not associated in eyes with PFCL use. However, multivariate analyses showed that there was no significant association between the use and the non-use of PFCL in the rate of re-detachments (β = -0.08, p = 0.46).

CONCLUSIONS

The use of PFCL during the initial vitrectomy for RRD does not affect the rate of re-attachments.

Vitreous Substitutes from Bench to the Operating Room in a Translational Approach: Review and Future Endeavors in Vitreoretinal Surgery

Vitreous substitutes are indispensable tools in vitreoretinal surgery. The two crucial functions of these substitutes are their ability to displace intravitreal fluid from the retinal surface and to allow the retina to adhere to the retinal pigment epithelium. Today, vitreoretinal surgeons can choose among a plethora of vitreous tamponades, and the tamponade of choice might be difficult to determine in the ever-expanding range of possibilities for a favorable outcome. The currently available vitreous substitutes have disadvantages that need to be addressed to improve the surgical outcome achievable today. Herein, the fundamental physical and chemical proprieties of all vitreous substitutes are reported, and their use and clinical applications are described alongside some surgical techniques of intra-operative manipulation. The major upcoming developments in vitreous substitutes are extensively discussed, keeping a translational perspective throughout. Conclusions on future perspectives are derived through an in-depth analysis of what is lacking today in terms of desired outcomes and biomaterials technology.

Perfluorodecalin-based oxygenated emulsion as a topical treatment for chemical burn to the eye

Chemical injuries to the eye are emergencies with limited acute treatment options other than prompt irrigation and can cause permanent vision loss. We developed a perfluorodecalin-based supersaturated oxygen emulsion (SSOE) to topically deliver high concentration of oxygen to the eye. SSOE is manufactured in hyperbaric conditions and stored in a ready-to-use canister. Upon dispensation, SSOE rapidly raises partial oxygen pressure 3 times over atmospheric level. SSOE is biocompatible with human corneal cells and safe on mouse eyes in vivo. A single topical application of SSOE to the eye after alkali injury significantly promotes corneal epithelial wound healing, decreases anterior chamber exudation, and reduces optical opacity and cataract formation in mice. SSOE treatment reduces intraocular hypoxia, cell death, leukocyte infiltration, production of inflammatory mediators, and hypoxia-inducible factor 1-alpha signaling, thus hastening recovery of normal tissue integrity during the wound healing process. Here, we show that SSOE is an effective topical therapeutic in the acute treatment of ocular chemical injuries.

Retinal and Corneal Changes Associated with Intraocular Silicone Oil Tamponade

Silicone oils (SO) are used as long-term intraocular tamponades and have an irreplaceable role in vitreoretinal surgery. They can, however, be associated with multiple and potentially severe complications, involving different ocular tissues, in particular retina and cornea. Recent advances in ophthalmic imaging have allowed the precise characterization of retinal and corneal microstructural changes, at a subclinical level. This detailed analysis of SO-related retinal and corneal changes has improved our understanding of their pathogenesis and offer the potential for optimized monitoring and management of patients with SO-filled eyes. This review aims to provide clinicians and ophthalmic scientists with an updated and comprehensive overview of the corneal and retinal changes associated with SO tamponade.

Vitreous Substitutes as Drug Release Systems

Vitreous substitutes are traditionally used to stabilize the retina after vitrectomy. In recent years, various approaches have been developed for using the vitreous substitute not only as a tamponade but also as a drug release system to tackle ocular diseases. This review provides an overview of the requirements for vitreous substitutes and discusses the current clinically applied as well as novel polymer-based vitreous substitutes as drug delivery systems, including their release mechanisms, efficiencies, challenges, and future perspectives.

Pigmentary lesions in eyes with rhegmatogenous retinal detachment with flap tears: a retrospective observational study

We included 97 patients with unilateral rhegmatogenous retinal detachment (RRD) with posterior vitreous detachment who underwent vitrectomy, and examined pigmentary lesion (PL) characteristics around the sites of original tears using pre- and postoperative ultra-widefield scanning light ophthalmoscopy, green light fundus autofluorescence (FAF) imaging, and intraoperative digital video. If PL did not involve RRD, we used OCT to preoperatively assess any pathologic changes to the lesion. A total of 116 retinal tears (mean count, 1.2 ± 0.5; range, 1–4 per eye) were observed in the detached retina. Overall, 102 (88%), 63 (54%), 14 (12%), and 25 (22%) tears were accompanied by lattice degeneration (LD) or PL, both LD and PL, only LD, and only PL, respectively. In green FAF images, LD showed normal to mild-hyper fluorescence, whereas all PL showed hypofluorescence. On OCT, PL were located at the RPE level, while choroid abnormalities were unclear. In the retinal areas of 22 eyes, which were not affected by RRD, we observed PL without retinal tears; some were accompanied by vitreous traction and tractional retinal detachment. Pre-, intra-, and post-operative assessments of original flap tears suggested that PL might be a risk factor for RRD, developing alongside or separately from LD.

Heavy Silicone Oil as an Endotamponade in Recurrent or Complicated Retinal Detachment and Macular Hole

Objectives

To evaluate the efficacy and safety of heavy silicone oil as an endotamponade in patients with recurrent or complicated retinal detachment and macular hole.

Materials and Methods

Nineteen eyes of 19 patients who underwent heavy silicone oil endotamponade for different indications were included in the study and evaluated by retrospective chart review. At each visit, patients underwent detailed ophthalmological examination and anatomical and functional outcomes, silicone oil emulsification, intraocular inflammation, presence of proliferative vitreoretinopathy, preoperative and postoperative visual acuity, and postoperative complications were recorded.

Results

The study included 19 eyes of 19 consecutive patients: 13 women (68.4%) and 6 men (31.6%). The patients' median age was 60 years (interquartile range [IQR]: 44-70 years) and the median follow-up time was 19 months (IQR: 9-31 months). Indications for heavy silicone oil endotamponade were recurrent retinal detachment in 11 eyes (57.8%), inferior retinal detachment in 5 eyes (26.3%), inferior rhegmatogenous retinal detachment, recurrent macular hole in 2 patients (10.5%), and macular hole in 1 patient (5.2%). Median best corrected visual acuity was 2 logMAR (IQR: 1-2.6) preoperatively and 0.99 logMAR (IQR: 0.4-2) postoperatively (p<0.001). Postoperative anatomical success was achieved in all patients. Densiron 68 was used for endotamponade in 14 patients (73.7%), Densiron XTRA in 3 patients (15.8%), and AlaHeavy 1.07 in 2 patients. Heavy silicone oil emulsification was observed in only 3 patients (15.8%).

Conclusion

Although heavy silicone oil has limitations as an endotamponade, such as intraocular pressure increase, emulsification, intraocular inflammation, and the risk of complications during removal, it is a safe and effective alternative in eyes requiring inferior retinal tamponade for indications like proliferative vitreoretinopathy and recurrent macular holes.

Acute intraocular toxicity caused by perfluorocarbon liquids: safety control systems of medical devices

BACKGROUND

Acute retinal toxicity has been demonstrated to be associated with the intraoperative use of perfluorocarbon liquids (PFCLs), especially perfluorooctane (PFO). Recently, several cases of PFO-associated blindness have been reported in Spain, Holland, France, Italy, the Middle East, and South America.

METHODS

As a result, a new ISO guideline (ISO 16672:2020) was drafted, discussed, approved, and released in 2019. This recent ISO16672:2020 guideline recommends performing direct cytotoxicity tests as an option along with chemical analysis to measure PFCL quality (purity and safety).

RESULTS

In this review paper, it has been emphasized why an appropriate biological test, specifically direct exposure of PFCL to live cells, for measuring cytotoxicity must be performed with each PFCL batch along with chemical analysis.

CONCLUSIONS

The paper intends to compile all available information to discuss possible approaches for avoiding adverse clinical cases in future.

NOVEL SURGICAL TECHNIQUE TO REMOVE RETAINED SUBFOVEAL PERFLUOROCARBON LIQUID

PURPOSE

To describe a novel surgical technique to remove retained subfoveal perfluorocarbon liquid (PFCL).

METHODS

After setting up for 23-G pars plana vitrectomy, a 38-G flexible-tip macular hydrodissection cannula connected to the automated viscous fluid infusion kit was used to create a small retinotomy approximately 700 μm to 800 μm inferior to the fovea and induce macular detachment involving the retained PFCL bubble. The flexible cannula was bent at its junction with the shaft and was carefully advanced through the same retinotomy into the subretinal space to access and directly aspirate the retained subfoveal PFCL bubble. Fluid-air exchange was then performed, and surgery was concluded.

RESULTS

The retained subfoveal PFCL bubble was successfully removed with restoration of normal foveal architecture on optical coherence tomography and with objective and subjective improvement of central vision.

CONCLUSION

We report a novel surgical technique combining macular detachment with direct aspiration of the retained subfoveal PFCL without direct perforation of the foveal center. This technique may provide an alternative approach to manage this difficult complication.

Vitreous inflammation and macular edema secondary to perfluoro-n-octane toxicity

Although it is not frequent, residual perfluoro-n-octane elicits an inflammatory response in form of macroscopic white flake-like material on intraocular structures formed by macrophages with intracellular vacuoles containing it. Macular edema could be another manifestation of this entity which, to our knowledge, has not been described so far. We describe an unusual case of intravitreal inflammation and macular edema secondary to the presence of residual perfluoro-n-octane after a surgical intervention of retinal detachment.

Vitrectomy without encircling band for rhegmatogenous retinal detachment with inferior break utilizing 3D heads up viewing system

Purpose:

This study aimed to determine the anatomical and functional outcomes of pars plana vitrectomy without encircling band for primary rhegmatogenous retinal detachments with inferior breaks utilizing 3D heads up viewing system.

Method:

This prospective, single-center study included 22 consecutive eyes with primary rhegmatogenous retinal detachments with only inferior breaks with proliferative vitreoretinopathy (PVR) CP2 or less, who underwent pars plana vitrectomy without encircling band, with silicon oil as tamponade. All surgeries were performed by a single surgeon. The single operation success rate was recorded after silicon oil removal.

Results:

The patient population consisted of 08 women (36%) and 14 men (64%) with a mean age of 56.6 +/− 14.7 years. The mean follow-up period was 8 months. A single break was present in 13 cases (59%), and 2–4 breaks were present in 9 cases (40.9%). The mean time for the surgical procedure was 35 min (range: 25–50). The macula was found to be detached in 19 cases (86.36%) and attached in 3 cases (13.6%). Single operation success rate (SOSR) of vitrectomy, after silicon oil removal without encircling band, for primary rhegmatogenous retinal detachment (RRD) with inferior breaks was 95.4%. One case redetached due to PVR changes and underwent re-surgery. Final reattachment was achieved in all 22 cases (100%). Mean best-corrected visual acuity (BCVA) significantly improved from 1.43 ± 0.59 logarithm of the minimum angle of resolution (logMAR) to postoperative BCVA was 0.48 ± 0.34 logMAR (P = 0.001).

Conclusion:

Pars plana vitrectomy without encircling band, utilizing 3D heads up the system in RRDs with inferior breaks in eyes with PVR grade C2 or less, provides good outcome.

Trimanual vitrectomy for severe proliferative diabetic retinopathy

PURPOSE

To describe and evaluate a novel technique of pars plana vitrectomy (PPV) under chandelier illumination which is aided with the vital dyes and perfluorocarbon liquids for the management of the complex diabetic vitrectomy cases.

METHODS

We conducted a prospective interventional comparative study on 40 eyes of 36 patients with advanced diabetic eye disease requiring PPV. The study was conducted in a single tertiary referral center. Eyes were divided on 1:1 basis by stratified randomization into two groups. Group 1 had trimanual vitrectomy done assisted with chandelier illumination, perfluorocarbon liquid (PFCL) and vital dyes. Group 2 had the conventional bimanual vitrectomy done assisted with chandelier illumination only. All patients were followed up for a minimum of 6 months after the surgery.

RESULTS

Forty eyes of 36 patients with the mean age of 51.42 years (range 28-69) were evaluated. The anatomical success at 6 months could be achieved in all the eyes in both groups. The complete removal of the pre-retinal proliferations could be accomplished in all the eyes in the trimanual PPV group, and only in 85% of the eyes in the bimanual PPV group. Operative time was significantly shorter in the trimanual PPV group (p < 0.001). More eyes in the trimanual PPV group (55.0%) could achieve better vision (> 6/60) 6 months after the operation compared to the bimanual PPV group (50.0%), but this difference was not statistically significant.

CONCLUSION

Trimanual PPV is a novel, safe and effective technique that can improve the results of the complex diabetic PPV.

Vitreous substitutes: An overview of the properties, importance, and development

Vitreous or vitreous humor is a complex transparent gel that fills the space between the lens and retina of an eye and acts as a transparent medium that allows light to pass through it to reach the photoreceptor layer (retina) of the eye. The vitreous humor is removed in ocular surgery (vitrectomy) for pathologies like retinal detachment, macular hole, diabetes-related vitreous hemorrhage detachment, and ocular trauma. Since the vitreous is not actively regenerated or replenished, there is a need for a vitreous substitute to fill the vitreous cavity to provide a temporary or permanent tamponade to the retina following some vitreoretinal surgeries. An ideal vitreous substitute could probably be left inside the eye forever. The vitreous humor is transparent, biocompatible, viscoelastic and highly hydrophilic; polymeric hydrogels with these properties can be a potential candidate to be used as vitreous substitutes. To meet the tremendous demand for the vitreous substitute, many scientists all over the world have developed various kinds of vitreous substitutes or tamponade agent. Vitreous substitutes, whatsoever developed till date, are associated with several advantages and disadvantages, and there is no ideal vitreous substitute available till date. This review highlights the polymer-based vitreous substitutes developed so far, along with their advantages and limitations. The gas-based and oil-based substitutes have also been discussed but very briefly.

Benchmarking different brands of perfluorocarbon liquids

PURPOSE

To compare the analytical quality characteristics of currently available CE-marked perfluorocarbon liquids (PFCL) applied intraoperatively during vitreoretinal surgery.

METHODS

Twenty-one samples of 8 brands of perfluorooctane (PFO) and 25 samples of 13 brands of perfluorodecalin (PFD) were analysed. Gas chromatography coupled with mass spectroscopy (GC/MS) was used to determine the content of the main product. The amount of reactive and underfluorinated impurities was analysed and expressed as an H-value using fluoride selective potentiometry after a chemical transformation reaction to detect impurities that triggered both acute and latent toxic effects. UV-active substances were determined in order to draw conclusions on the integrity of primary packaging components. Moreover, we controlled for any 1H-PFO contamination in PFO, as it is known to modify PFO's surface characteristics.

RESULTS

Significant differences in the tested products' purity profiles were detected. The PFO batches revealed H-values ranging from < 10 to 1230 ppm and 1H-PFO concentrations ranging from < 1 to 376 ppm. Leachable substances from packaging components cause UV absorption in the 0.1 to > 3 AU range. The PFD batches revealed H-values ranging from < 10 to 70 ppm and leachables from packaging components resulting in absorbances in the 0 AU to 3.2 AU range.

CONCLUSION

The quality characteristics of the analysed PFCL vary significantly, not only among different brands but among batches from the same manufacturer as well. Manufacturers should communicate the purity of their products in an understandable and clear manner. This would require providing a complete certificate of analysis focussing especially on quality characteristics to enable vitreoretinal surgeons to differentiate between the effects from the PFCL itself and those from impurities.

PFOh No: Spontaneous Globe Rupture During Injection of Perfluoro-n-Octane (PFO) During Retinal Detachment Repair

The authors describe a case of spontaneous globe rupture during instillation of perfluoro-n-octane (PFO) during retinal surgery. A 71-year-old male with a macular-involving rhegmatogenous retinal detachment underwent pars plana vitrectomy. During instillation of PFO manually on a single-bore cannula by the assisting resident, spontaneous globe rupture occurred superotemporally in an area with no visible underlying structural abnormalities. Factors that led to this complication include the use of single-bore cannula, error in judgment of resistance during PFO injection, and inexperience. This is the first report of this complication without an identifiable structural abnormality predisposing patient to perforation.

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.

Natural History of a Large Bubble of Migratory Submacular Perfluorocarbon

Purpose

To report the natural history of a large bubble of perfluorocarbon liquid (PFCL) in a parafoveal subretinal position which was monitored using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). The bubble of PFCL was removed when it migrated to the subfoveal position; outcome after removal is also reported.

Observation

A 62-year-old male, after repair of a giant retinal tear (GRT) detachment, regained Snellen acuity of 6/18 from preoperative vision of CF at 1 meter. A large bubble of subretinal PFCL was in the superior parafoveal area. For 18 months, the PFCL bubble was monitored using OCT and OCTA until it migrated into the subfoveal position after 22 months, coinciding with a decrease in vision to 6/36. Surgical removal of subfoveal PFCL was performed. This involved detachment of the foveomacular, epiretinal membrane (ERM) peel (complicated by iatrogenic macular hole (MH) formation), intravitreal injection of PFCL to displace subretinal PFCL to the periphery, creation of an inverted internal limiting membrane (ILM) flap to repair the MH and air exchange. Postoperative vision remained 6/36. His postoperative OCT showed significant loss of subfoveal outer retina. On OCTA, the superficial and deep vascular plexi and choriocapillaris appeared to be intact after the removal of the subfoveal PFCL.

Conclusion and Importance

This report suggests that a large superior parafoveal bubble of PFCL may take as much as 18 months to migrate to the subfoveal position. Before this time, vision does not appear to be affected, though macular edema is present. Therefore, removal of the PFCL can be delayed until a convenient time for surgeon and patient. A large bubble of parafoveal PFCL ought to be removed before migrating to a subfoveal position and vision loss, since its removal will reduce the risk of outer retina loss.

Release and extraction of retained subfoveal perfluorocarbon liquid facilitated by subretinal BSS, vibration, and gravity: a case report

Background

Perfluorocarbon liquid (PFCL) is an effective surgical adjuvant in performing vitrectomy for severe vitreoretinal pathologies such as proliferative vitreoretinopathy and giant retinal tears. However, subretinal retention of PFCL can occur postoperatively and retained PFCL causes severe visual disorders, particularly when PFCL was retained under the fovea. Although several procedures have been proposed for subfoveal PFCL removal, such as direct aspiration or submacular injection of balanced salt solution (BSS) to dislodge the subfoveal PFCL, the retinal damage associated with these procedures has been a major problem. Here, we report a case of subfoveal retention of PFCL for which we performed a novel surgical technique that attempts to minimize retinal damage.

Case presentation

A 69-year-old man presented with subfoveal retained PFCL after surgery for retinal detachment. To remove the retained PFCL, the internal limiting membrane overlying the subretinal injection site is first peeled to allow low-pressure (8 psi) transretinal BSS infusion, using a 41-gauge cannula, to slowly detach the macula. A small drainage retinotomy is created with the diathermy tip at the inferior position of the macular bleb, sized to be slightly wider than that of the PFCL droplet. The head of the bed is then raised, and the surgeon gently vibrates the patient’s head to release the PFCL droplet to allow it to migrate inferiorly towards the drainage retinotomy. The bed is returned to the horizontal position, and the PFCL, now on the retinal surface, can be aspirated. The subfoveal PFCL is removed while minimizing iatrogenic foveal and macular damage. One month after PFCL removal, the foveal structure showed partial recovery on optical coherence tomography, and BCVA improved to 20/40.

Conclusion

Creating a macular bleb with low infusion pressure and using vibrational forces and gravity to migrate the PFCL towards a retinotomy can be considered as a relatively atraumatic technique to remove subfoveal retained PFCL.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12886-020-01698-1.

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.

Medium-term tamponade with vitrectomy and perfluorodecalin for the management of complex retinal detachments

PURPOSE

To describe the clinical presentation, anatomical and visual outcome of a series of patients in our department with complex retinal detachments, managed with vitrectomy and perfluorodecalin (PFD) for medium-term tamponade.

STUDY DESIGN

Retrospective case series.

METHODS

Retrospective analysis of the medical records of all patients in the last 6 years presenting with complex retinal detachment managed with vitrectomy where PFD was used as a medium-term tamponade.

RESULTS

A total of 85 eyes in 85 patients were included in the study, with a mean follow-up period of 16.0 ± 2.67 months (range 3-59). About 26 detachments presented with associated PVR-C, and 10 had giant retinal tears. The location of the retinal detachment was inferior in 40% of cases, and total in 18.9% of cases. Anatomical success, defined as retinal reattachment at 12 months, was achieved in 98.8% of cases, and there was a mean improvement in BCVA of logMAR 0.64 ± 0.20, which was statistically significant (p < 0.001, paired t-test 6.23). Of the 41 phakic eyes included in the study, 20 underwent cataract surgery within the follow-up period.

CONCLUSION

In this case series, we have demonstrated a 98.8% anatomical success and significant improvement in BCVA, with no reports of retinal toxicity. Medium-term tamponade PFD appears to be an efficacious and safe technique for management of a variety of complex retinal detachments, including those secondary to GRT, the presence of PVR-C, inferior location, tractional, traumatic, and re-detachments.

Tamponade in surgery for retinal detachment associated with proliferative vitreoretinopathy

BACKGROUND

Retinal detachment (RD) with proliferative vitreoretinopathy (PVR) often requires surgery to restore normal anatomy and to stabilize or improve vision. PVR usually occurs in association with recurrent RD (that is, after initial retinal re-attachment surgery), but occasionally may be associated with primary RD. Either way, for both circumstances a tamponade agent (gas or silicone oil) is needed during surgery to reduce the rate of postoperative recurrent RD.

OBJECTIVES

The objective of this review was to assess the relative safety and effectiveness of various tamponade agents used with surgery for RD complicated by PVR.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (the Cochrane Library 2019, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2019), Embase (January 1980 to January 2019), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2019), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 2 January 2019.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) on participants undergoing surgery for RD associated with PVR that compared various tamponade agents.

DATA COLLECTION AND ANALYSIS

Two review authors screened the search results independently. We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified four RCTs (601 participants) that provided data for the primary and secondary outcomes. Three RCTs provided data on visual acuity, two reported on macular attachment, one on retinal reattachment and another two on adverse events such as RD, worsening visual acuity and intraocular pressure. Study Characteristics Participants' characteristics varied across studies and across intervention groups, with an age range between 21 to 89 years, and were predominantly men. The Silicone Study was conducted in the USA and consisted of two RCTs: (silicone oil versus sulfur hexafluoride (SF₆) gas tamponades; 151 participants) and (silicone oil versus perfluropropane (C₃F₈) gas tamponades; 271 participants). The third RCT compared heavy silicone oil (a mixture of perfluorohexyloctane (F₆H₈) and silicone oil) with standard silicone oil (either 1000 centistokes or 5000 centistokes; 94 participants). The fourth RCT compared 1000 centistokes with 5000 centistokes silicone oil in 85 participants. We assessed most RCTs at low or unclear risk of bias for most 'Risk of bias' domains. Findings Although SF₆ gas was reported to be associated with worse anatomic and visual outcomes than was silicone oil at one year (quantitative data not reported), at two years, silicone oil compared to SF₆ gas showed no evidence of a difference in visual acuity (33% versus 51%; risk ratio (RR) 1.57; 95% confidence interval (CI) 0.93 to 2.66; 1 RCT, 87 participants; low-certainty evidence). At one year, another RCT comparing silicone oil and C₃F₈ gas found no evidence of a difference in visual acuity between the two groups (41% versus 39%; RR 0.97; 95% CI 0.73 to 1.31; 1 RCT, 264 participants; low-certainty evidence). In a third RCT, participants treated with standard silicone oil compared to those receiving heavy silicone oil also showed no evidence of a difference in the change in visual acuity at one year, measured on logMAR scale ( mean difference -0.03 logMAR; 95% CI -0.35 to 0.29; 1 RCT; 93 participants; low-certainty evidence). The fourth RCT with 5000-centistoke and 1000-centistoke comparisons did not report data on visual acuity. For macular attachment, participants treated with silicone oil may probably experience more favorable outcomes than did participants who received SF₆ at both one year (quantitative data not reported) and two years (58% versus 79%; RR 1.37; 95% CI 1.01 to 1.86; 1 RCT; 87 participants; low-certainty evidence). In another RCT, silicone oil compared to C₃F₈ at one year found no evidence of difference in macular attachment (RR 1.00; 95% CI 0.86 to 1.15; 1 RCT, 264 participants; low-certainty evidence). One RCT that compared 5000 centistokes to 1000 centistoke reported that retinal reattachment was successful in 67 participants (78.8%) with first surgery and 79 participants (92.9%) with the second surgery, and no evidence of between-group difference (1 RCT; 85 participants; low-certainty evidence). The fourth RCT that compared standard silicone oil with heavy silicone oil did not report on macular attachment. Adverse events In one RCT (86 participants), those receiving standard 1000 centistoke silicone oil compared with those of the 5000 centistoke silicone oil showed no evidence of a difference in intraocular pressure elevation at 18 months (24% versus 22%; RR 0.90; 95% CI 0.41 to 1.94; low-certainty evidence), visually significant cataract (49% versus 64%; RR 1.30; 95% CI 0.89 to 1.89; low-certainty evidence), and incidence of retina detachment after the removal of silicone oil (RR 0.36 95% CI 0.08 to 1.67; low-certainty evidence). Another RCT that compared standard silicone oil with heavy silicone oil suggests no difference in retinal detachment at one year (25% versus 22%; RR 0.89; 95% CI 0.54 to 1.48; 1 RCT; 186 participants; low-certainty evidence). Retinal detachment was not reported in the RCTs that compared silicone oil versus SF₆ and silicone oil versus to C₃F₈.

AUTHORS' CONCLUSIONS

There do not appear to be any major differences in outcomes between C₃F₈ and silicone oil. Silicone oil may be better than SF₆ for macular attachment and other short-term outcomes. The choice of a tamponade agent should be individualized for each patient. The use of either C₃F₈ or standard silicone oil appears reasonable for most patients with RD associated with PVR. Heavy silicone oil, which is not available for routine clinical use in the USA, may not demonstrate evidence of superiority over standard silicone oil.

Evaluation of Cytotoxicity of Perfluorocarbons for Intraocular Use by Cytotoxicity Test In Vitro in Cell Lines and Human Donor Retina Ex Vivo

Purpose

To validate the cytotoxicity test of perfluorocarbon liquids (PFCLs) for intraocular use according to the ISO 10993-5 standard.

Methods

BALB/3T3, ARPE-19 cell lines, and 3-mm human retina ex vivo samples were cultured in 96-well plates. Contact areas of 22%, 59%, and 83% and 2.5-, 12-, and 24-hour contact times were tested in cell lines. Cell viability was quantified by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in ARPE-19 and neutral red uptake (NRU) viability assay for BALB/3T3. Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay in ARPE-19 cells. 1-H perfluorooctane (1H PFO) and purified perfluorooctane (PFO) were used as cytotoxic and not cytotoxic controls, respectively. Cell viability was assessed by MTT assay in retina ex vivo samples.

Results

Qualitative evaluation showed that cytotoxic control induced apoptosis, severe reactivity zones, and cytotoxicity according to ISO 10993-5 in all tested conditions. Quantitative evaluation of 1H PFO showed no cytotoxicity according to ISO 10993-5 on 22% areas, whereas cytotoxicity was detected on 59%, and 83% contact areas. The PFO was confirmed not to be cytotoxic in all tested conditions. Quantitative evaluation in retina ex vivo samples confirmed no cytotoxicity with PFO and cytotoxicity with 1H PFO.

Conclusions

The direct contact cytotoxicity test according to ISO 10993-5 is a suitable method to detect the cytotoxicity of PFCLs and was validated using quantitative and qualitative approaches in ARPE-19 and BALB/3T3 cells covering 59% of the cell surface areas for 24 hours.

Translational Relevance

Direct contact cytotoxicity test using specific conditions was validated, whereas different test conditions could not be validated.

[Current importance of heavy fluids as intraoperative aids in vitreoretinal surgery]

A major milestone in the treatment of complex retinal detachment was the development of heavy fluids as intraoperative short-term tamponades. Since the introduction liquid perfluorocarbons and hydrofluorocarbons are particularly noteworthy. Irrespective of the suitability of the substances in principle, the purity during the manufacturing process is a decisive factor that determines possible side effects. Also, the direct exchange with silicone oil can lead to mixing with disadvantageous results. Retinal surgeons should be informed about the properties of the tamponades used. Despite all expectations, the heavy liquids could not become established compared to silicone oil as a long-term tamponade, which is why their domain is the short-term intraoperative use.

Short-term postoperative perfluoro-n-octane tamponade for pediatric recurrent retinal detachment

We report a case with multiple recurrences of retinal detachment (RD) with severe proliferative vitreoretinopathy in a 12-year-old child who underwent vitrectomy using a heavy liquid perfluoro-n-octane (PFO) as a short-term postoperative tamponade. He had an encircling band and three vitrectomies with gas, followed by silicone oil tamponade for retinal redetachment prior to the use of PFO as a short-term tamponade. Short-term PFO tamponade was used in which inferior retinal reattachment was considered to be difficult with conventional gas or silicone oil tamponade, especially in regard to proper postoperative posturing. The PFO was left in the eye for 1 week, and the retina remained reattached after removal of the PFO which was replaced with silicone oil tamponade in this case. PFO appears feasible and tolerable as a short-term postoperative tamponade in the management of complex pediatric RD.

Application of Light Scattering Techniques to Nanoparticle Characterization and Development

Over the years, the scientific importance of nanoparticles for biomedical applications has increased. The high stability and biocompatibility, together with the low toxicity of the nanoparticles developed lead to their use as targeted drug delivery systems, bioimaging systems, and biosensors. The wide range of nanoparticles size, from 10 nm to 1 μm, as well as their optical properties, allow them to be studied using microscopy and spectroscopy techniques. In order to be effectively used, the physicochemical properties of nanoparticle formulations need to be taken into account, namely, particle size, surface charge distribution, surface derivatization and/or loading capacity, and related interactions. These properties need to be optimized considering the final nanoparticle intended biodistribution and target. In this review, we cover light scattering based techniques, namely dynamic light scattering and zeta-potential, used for the physicochemical characterization of nanoparticles. Dynamic light scattering is used to measure nanoparticles size, but also to evaluate their stability over time in suspension, at different pH and temperature conditions. Zeta-potential is used to characterize nanoparticles surface charge, obtaining information about their stability and surface interaction with other molecules. In this review, we focus on nanoparticle characterization and application in infection, cancer and cardiovascular diseases.

A New, Heavier-Than-Water Silicone Oil: A Solution of Perfluorohexyloctane in Polydimethylsiloxane

Purpose

To prepare and explore new solutions of semifluorinated alkane in silicone oil, which have a specific gravity slightly higher than silicone oil and vitreous fluid (referred to in the following as heavier-than-water silicone oils (HWSs), and to investigate, in vitro, whether HWSs can be used to plug retina holes, while allowing dehydration of the subretinal space.

Methods

HWS solutions were prepared with silicone oil 5000 and perfluorohexyloctane (F6H8). The stability was investigated under different conditions. The viscosity was determined by means of a capillary viscometer. The surface and interface tension were measured using the ring method.

Results

HWSS are insoluble in an aqueous medium. Densiron®68 (HWS 1.06) is a transparent homogeneous liquid which is slightly heavier (1.06 g/cm3) than water and has a refractive index close to that of vitreous liquid. Densiron®68 (HWS 1.06) has a low viscosity (1480 mPas) and interface tension (40.82 mN/m), making it an effective tamponade in the surgical treatment of an inferior detached retina. In addition, the interfaces between Densiron®68 and other perfluorocarbon liquids are clearly visible. However, the interface layer between Densiron®68 and water is not clear. Finally, all HWSs are stable over the long term at ambient temperatures, as well as physically and thermally resistant.

Conclusions

Due to its physiochemical properties, Densiron®68 could meet the requirements for a heavier-than-water tamponade.

Intraoperative Macula Protection by Perfluorocarbon Liquid for the Metallic Intraocular Foreign Body Removal during 23-Gauge Vitrectomy

Purpose. To evaluate visual and safety outcomes of 23-gauge (G) pars plana vitrectomy (PPV) with application of perfluorocarbon liquid (PFCL) for intraoperative protection of the macula during intraocular foreign body (IOFB) removal. Methods. Retrospective study of 42 patients who underwent 23 G PPV for IOFB removal from posterior segment with intraoperative PFCL application for the macula shielding. Collected data included corrected distance visual acuity (CDVA), size of IOFB, and complication rate. The mean follow-up period was 12 months. Results. The mean preoperative CDVA was 0.54 logMAR (SD 0.46), and the final mean CDVA was 0.68 logMAR (SD 0.66). All IOFBs were metallic with mean dimensions of 4.6 mm × 2.1 mm. Twenty-two IOFBs were removed through the corneal tunnel and 20 IOFBs through the sclerotomy. No intraoperative iatrogenic lesion of the macula was observed. As a tamponade, silicon oil was applied in 31 eyes, SF₆ gas in 5 eyes, air in 4 eyes, and 2 eyes required no tamponade. Secondary retinal detachment was observed in 17% of cases, but at the end of the follow-up, all the retinas were attached. Conclusion. PFCL application during PPV is a safe method of protecting the macula from unexpected falling of the metallic IOFB during its removal.

Vitreous Substitutes: Old and New Materials in Vitreoretinal Surgery

Recent developments in vitreoretinal surgery have increased the need for suitable vitreous substitutes. A successful substitute should maintain all the physical and biochemical properties of the original vitreous, be easy to manipulate, and be long lasting. Substitutes can be gaseous or liquid, both of which have associated advantages and disadvantages related to their physical properties and use. Furthermore, new surgical techniques with smaller vitreoretinal instruments have driven the use of more viscous substitutes. In this review, we analyze and discuss the most frequently used vitreous substitutes and look ahead to future alternatives. We classify these compounds based on their composition and structure, discuss their clinical use with respect to their associated advantages and disadvantages, and analyze how new vitreoretinal surgical techniques have modified their use.

Soft shell technique during vitrectomy for proliferative vitreoretinopathy

PURPOSE

To determine whether ophthalmic viscoelastic devices (OVDs) can be used during vitrectomy to prevent perflorocarbon liquid (PFCL) from leaking into the subretinal space through retinal tears in eyes with proliferative vitreoretinopathy (PVR). The OVDs are adhesive materials that can temporally close retinal breaks. We introduce a "soft shell technique", which allows the unfolding of the retina by PFCL.

METHODS

We studied five eyes of five patients with proliferative vitreoretinopathy that underwent vitrectomy using the soft shell technique. After removing the core vitreous, the OVDs were carefully injected over the area where confluent retinal folds were formed with possible retinal breaks. This created a soft shell shield on the retina that can prevent the intravitreal PFCL from leaking into the subretinal space.

RESULTS

The soft shell technique still allowed the PFCL to unfold the retina even if iatrogenic breaks are present. The high viscosity of OVDs sealed the iatrogenic retinal breaks and thus prevented the PFCL from leaking into the subretinal space during the vitrectomy. All patients had an improvement of the visual acuity, and four eyes had a reattachment of the retina.

CONCLUSIONS

Although only five eyes were examined, the success of the soft shell technique indicates that it can be used with PFCL, which facilitates the unfolding of the contracted retina.

Perfluorocarbon liquid: its application in vitreoretinal surgery and related ocular inflammation

The application of perfluorocarbon liquids has been well acclaimed in vitreoretinal surgery. Its unique physical properties make it an ideal intraoperative tool to improve the efficiency and safety of surgical procedures in complicated cases. The main functions of perfluorocarbon liquids in vitreoretinal surgery include relocating and fixing the detached retina, displacing the subretinal and subchoroidal to fluid anteriorly, revealing proliferative vitreous retinopathy (PVR) for further maneuvers, protecting the macula from exposure to chemicals with potential toxicity, and assisting the removal of foreign body. The related clinical applications include retinal detachment with severe proliferative vitreoretinopathy, giant tear, diabetic retinopathy (DR), retinopathy of prematurity (ROP), and posterior dislocated crystalline and intraocular lenses. The application of perfluorocarbon liquids has been expended over the past fewer years. Several PFCLs related ocular inflammations have been observed in in vitro studies, animal studies, and clinical follow-up. The complete removal of PFCLs is recommended at the end of the surgery in most cases.

Tamponade in surgery for retinal detachment associated with proliferative vitreoretinopathy

BACKGROUND

Retinal detachment (RD) with proliferative vitreoretinopathy (PVR) often requires surgery to restore normal anatomy and to stabilize or improve vision. PVR usually occurs in association with recurrent RD (that is, after initial retinal re-attachment surgery) but occasionally may be associated with primary RD. Either way, a tamponade agent (gas or silicone oil) is needed during surgery to reduce the rate of postoperative recurrent RD.

OBJECTIVES

The objective of this review was to assess the relative safety and effectiveness of various tamponade agents used with surgery for retinal detachment (RD) complicated by proliferative vitreoretinopathy (PVR).

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2013), EMBASE (January 1980 to June 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to June 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 26 June 2013.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of participants undergoing surgery for RD associated with PVR that compared various tamponade agents.

DATA COLLECTION AND ANALYSIS

Two review authors screened the search results independently. We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

The review included 516 participants from three RCTs. One study was conducted in the USA and consisted of two trials: the first trial randomized 151 adults to receive either silicone oil or sulfur hexafluoride (SF6) gas tamponades; and the second trial randomized 271 adults to receive either silicone oil or perfluropropane (C3F8) gas tamponades. The third trial was a multi-center international trial and randomized 94 participants (age range not specified) to receive heavy silicone oil (a mixture of perfluorohexyloctane (F6H8) and silicone oil) versus standard silicone oil (either 1000 centistokes or 5000 centistokes, per the surgeon's preference).In participants with RD associated with PVR, outcomes after pars plana vitrectomy and infusion of either silicone oil, perfluropropane gas, or sulfur hexafluoride gas appeared comparable for a broad variety of cases. There were no significant differences between silicone oil and perfluoropropane gas in terms of the proportion of participants achieving at least 5/200 visual acuity (risk ratio (RR) 0.97; 95% confidence interval (CI) 0.73 to 1.31) or achieving macular attachment (RR 1.00; 95% CI 0.86 to 1.15) at a minimum of one year. Although sulfur hexafluoride gas was reported to be associated with significantly worse anatomic and visual outcomes than was silicone oil at one year (quantitative data not reported), there were no significant differences between silicone oil and sulfur hexafluoride gas in terms of achieving at least 5/200 visual acuity at two years (RR 1.57; 95% CI 0.93 to 2.66). For macular attachment, participants treated with silicone oil received significantly more favourable outcomes than did participants who received sulfur hexafluoride at both one year (quantitative data not reported) and two years (RR 1.37; 95% CI 1.01 to 1.86). The first two trials did not perform any sample size calculation or power detection. In the third trial, which had a power of 80% to detect differences, heavy silicone oil was not shown to be superior to standard silicone oil. There were no significant differences between standard silicone oil and heavy silicone oil in the change in visual acuity at one year using adjusted mean logMAR visual acuity (mean difference -0.03 logMAR; 95% CI -0.35 to 0.29). Adverse events were not reported for the first two trials. For the third trial, only the total number of adverse events was reported, and adverse events for each group were not specified. Of the 94 participants, four died, 26 had recurrent retinal detachment, 22 developed glaucoma, four developed a cataract, and two had capsular fibrosis.All three trials employed adequate methods for random sequence generation and allocation concealment. None of the trials employed masking of participants and surgeons, and only the third trial masked outcome assessors. The first trial had a large portion of participants excluded from the final analyses, while the other two trials were at low risk of attrition bias. All trials appear to be free of reporting bias. The first two trials were funded by the National Eye Institute, and the third trial was funded by the German Research Foundation.

AUTHORS' CONCLUSIONS

The use of either perfluropropane or standard silicone oil appears reasonable for most patients with RD associated with PVR. Because there do not appear to be any major differences in outcomes between the two agents, the choice of a tamponade agent should be individualized for each patient. Heavy silicone oil, which is not available for routine clinical use in the USA, has not demonstrated evidence of superiority over standard silicone oil.

Pars plana vitrectomy with medium-term postoperative perfluoro-N-octane for recurrent inferior retinal detachment complicated by advanced proliferative vitreoretinopathy

PURPOSE

To describe a series of patients with recurrent inferior retinal detachment complicated by proliferative vitreoretinopathy (PVR) treated with pars plana vitrectomy and postoperative perfluoro-n-octane (PFO).

METHODS

Consecutive patients with recurrent inferior retinal detachment and Grade C PVR were prospectively treated with 25-gauge pars plana vitrectomy and postoperative "medium-term" PFO for 2- to 3-week duration. All patients had subsequent PFO removal in a planned staged procedure.

RESULTS

Forty-four eyes of 44 patients were included. Mean follow-up time was 30.71 ± 12.92 months. Successful reattachment was achieved in 86% of eyes (38/44). Reattachment rates were statistically equivalent between eyes with and without previous scleral buckle. Reasons for redetachment were recurrent inferior PVR (four of six) and new superior break without PVR (two of six). Additional complications observed were cataract progression requiring surgery (42%), persistent intraocular pressure elevation (36%), and transient inflammation (32%). Macula-off status (P = 0.02) and persistent intraocular pressure elevation (P = 0.02) were factors associated with worse visual outcome.

CONCLUSION

Medium-term PFO was found to be an efficacious technique for operative management of recurrent inferior retinal detachments complicated by Grade C PVR. The method of primary repair (scleral buckle vs. pars plana vitrectomy) did not affect reattachment rates. Transient inflammation and intraocular pressure elevation are potential complications associated with this technique. Persistent intraocular pressure elevation was associated with worse visual outcome.

25-gauge pars plana vitrectomy with medium-term postoperative perfluoro-n-octane tamponade for inferior retinal detachment

BACKGROUND AND OBJECTIVE

To describe a series of patients with inferior retinal detachments managed with primary 25-gauge pars plana vitrectomy (PPV), 2 to 3 weeks of postoperative perfluoro-n-octane (MT-PFO) tamponade, and upright positioning followed by secondary PPV and PFO removal.

PATIENTS AND METHODS

Interventional case series of 157 patients with inferior retinal detachments with and without proliferative vitreoretinopathy. Eyes were treated with 25-gauge PPV, endophotocoagulation, and MT-PFO tamponade. Patients underwent postoperative upright positioning followed by repeat PPV and PFO removal in a planned, staged procedure.

RESULTS

Mean follow-up was 32 ± 4.6 months. Successful reattachment was achieved in 87.5% of 159 eyes. Main initial postoperative complications were persistent intraocular pressure (IOP) elevation in 34% (n = 54), excessive inflammation in 27% (n = 43), and PFO in the anterior chamber in 21% (n = 34). Additional complications occurring after PFO removal included cataract surgery in 16% (n = 22) of initially phakic eyes, redetachment in 13% (n = 21), and need for filtering surgery in 6% (n = 10). Logistic regression analysis revealed macula status (P = .003) and progression to filtering surgery (P = .001) as significant factors predicting visual outcome at 1-year follow-up.

CONCLUSION

MT-PFO tamponade and upright head positioning may be efficacious for inferior retinal detachment repair in patients unable to assume face-down postoperative positioning. Anatomic and visual outcomes are similar to previously described reattachment procedures. A characteristic granulomatous inflammatory reaction presents in some patients, but does not appear to leave long-term visual or anatomic sequelae. Persistent IOP elevation and progression to filtering surgery may occur in a small percentage of patients and portends a worse visual outcome.

Unanticipated vision loss after pars plana vitrectomy

Although advances in vitreoretinal surgical techniques and technology have helped to minimize the risks associated with surgical manipulation of the retina, retinal pigment epithelium, and optic nerve, unanticipated or unexplained visual loss still occurs. We review causes of vision loss encountered after pars plana vitrectomy, including retinal toxicities, vascular events, and optic neuropathies, and we suggest strategies to limit or prevent them.

Perfluorocarbon-perfused 23 gauge three-dimensional vitrectomy for complicated diabetic tractional retinal detachment

Background

Perfluorocarbon liquid (PCL)-perfused vitrectomy has been shown in previous studies to be feasible, safe, and to have advantages in managing complicated cases of tractional retinal detachment. The present study had the objectives of describing the anatomical results and measuring surgical time and PCL consumption when combining PCL-perfused techniques with modern vitrectomy equipment.

Methods

A prospective, interventional consecutive case series was investigated. We enrolled patients with diabetic tractional retinal detachment, complicated by proliferative vitreoretinopathy and poor vision. A 23 gauge PCL-perfused vitrectomy was done with three-dimensional settings. During the procedure, we assessed the degree of surgical bleeding, visualization quality, and difficulty of membrane dissections. Visual acuity, intraocular pressure, and anatomical success were assessed at one and 3 months of follow-up.

Results

Twelve patients were enrolled in this study. There were no statistical significant changes in intraocular pressure and visual acuity throughout the follow-up period. Surgery was performed in a hemorrhage-free environment in almost all cases, with good visualization and low technical difficulty. The mean complete surgical time was 94.92 ± 25.03 minutes. The mean effective vitrectomy time was 22.50 ± 19.04 minutes and the mean PCL consumption was 25.08 ± 9.76 mL, with a speed of 1.11 mL/minute. Anatomical success was 67% at 3 months.

Conclusion

Although the technique proved to have some advantages in managing complicated cases of diabetic tractional retinal detachment, there was a high consumption of PCL. A redesign of the entire system is needed in order to decrease the amount of PCL needed for the technique.