Complications Associated with the Use of Expandable Gases in Vitrectomy

Morphological Change in Optical Coherence Tomography and Functional Outcomes in Epiretinal Membrane Peeling with or without SF6 Tamponade

BACKGROUND

The present study compares the anatomical and functional outcomes (best-corrected visual acuity (BCVA) and central macular thickness (CMT)) among membrane peeling with or without SF6 tamponade in patients with epiretinal membrane.

METHODS

We retrospectively reviewed patients diagnosed with macular pucker who underwent pars plana vitrectomy and membrane peeling in a tertiary center in Taiwan from January 2021 to December 2022. Subjects were categorized into with or without SF6 tamponade groups (SF6 group and BSS group). Postoperative intraocular pressure and complications were documented. Logistic regression analyses were performed to identify the prognostic factors during follow-up.

RESULTS

A total of 89 eyes were enrolled, including 34 eyes in the BSS group and 55 eyes in the SF6 group. The mean age was 66 years old, and a female predilection was demonstrated. Both groups possessed statistically significant improvement in BCVA and CMT after the operation. There was no significant difference in CMT between the groups at any time of observation, yet we observed significant differences in baseline BCVA and BCVA at last follow-up among the two groups. Both groups yielded an approximate enhancement of LogMAR 0.3 in BCVA postoperatively. There was no significant difference noted in postoperative IOP between the two groups.

CONCLUSION

Membrane peeling with or without SF6 tamponade yields comparable outcomes anatomically and functionally. This may indicate that SF6 tamponade for idiopathic macular pucker surgery may not provide extra benefit, and therefore warrants reconsideration as standard procedure.

Updates on Treatment Modalities for Primary Rhegmatogenous Retinal Detachment Repair

Rhegmatogenous retinal detachment, a severe eye condition, presents anatomic separation of the neurosensory retina from its outermost layer-the retinal pigment epithelium. Early recognition of this relatively common finding and proper referral of patients to the retinal surgery department is essential in order to minimize its consequent possible severe reduction in vision. Several major surgical methods for the repair of primary rhegmatogenous retinal detachment have been in use over the last several decades, and they all aim to find and close the break in the retina that has caused the detachment. Surgery can be performed as pneumatic retinopexy, pars plana vitrectomy, and/or episcleral surgery (buckling). General surgical trends for reattaching the retina include moving from extraocular to intraocular surgery and from bigger gauge to smaller gauge via minimal invasive vitrectomy surgery (MIVS), with implementing shorter-lasting intraocular tamponades. Surgical options for rhegmatogenous retinal detachment treatment nowadays emphasize gaining retinal reattachment, preferably with one surgery and with minimum damage to the eye. The procedure should not bring secondary eye conditions and complications with severe impairment of visual acuity, and it should be performed on as much as a smaller budget, with possibly peribulbar anesthesia, enabling the patient the quickest possible recovery. It should be adjusted to the patient's condition, not to the surgeon's skills or preferences.

Glue-Assisted Retinopexy for Retinal Detachments Study Report 2: Fibrin Glue As a Surgical Adjunct in Complex Rhegmatogenous Retinal Detachment

Purpose: To present the successful application of fibrin glue as a surgical adjunct in the management of complex rhegmatogenous retinal detachment (RRD). Methods: In this retrospective case series, fibrin glue was used as a surgical adjunct in 5 cases of complex RRD. In each case, standard pars plana vitrectomy and laser retinopexy were performed by the same surgeon. Fibrin glue was used intraoperatively as a tamponade to seal the breaks because the isolated use of conventional tamponade agents was not feasible given the variable nature of the complex RRDs, the anatomy of the eye, or an inability to maintain postoperative positioning. Results: In 1 patient previously treated for a large corneoscleral tear, fibrin glue was used to seal a large iatrogenic retinal break caused by a fragmatome-related surge that led to a quadrantic RD. In 2 patients treated for combined RRD, fibrin glue was used with silicone oil to manage recurrent RRD with incompletely drained thick subretinal fluid and blood. In 2 other cases, fibrin glue was applied to manage RRD in congenital aniridia with advanced glaucoma and aphakia. In all cases, retinal attachment without serious adverse effects was attained over a follow-up ranging from 4 to 6 months. Conclusions: Fibrin glue is an effective, safe surgical adjunct in complex RRD. It can be used to transiently seal a retinal break when use of a conventional tamponade agent is not possible or not sufficient alone.

FUNCTIONAL AND ANATOMICAL OUTCOMES AFTER SHORT-TERM HEAVY SILICONE OIL ENDOTAMPONADE FOR INFERIOR RHEGMATOGENOUS RETINAL REDETACHMENT: A Pilot Study

PURPOSE

To assess the success of the short-term location of the heavy silicone oil (Densiron 68, HSO) as endotamponade after pars plana vitrectomy for rhegmatogenous complex retinal redetachment.

METHODS

Consecutive, retrospective, nonrandomized, pilot study was conducted. Twenty-two eyes of 22 patients with complex inferior retinal redetachment previously tamponade with gas (SF6 or C3F8) or 1000 cSt standard silicone oil (SSO) were selected. All were treated with HSO endotamponade, and its removal was performed after 1 month. The main outcomes were best-corrected visual acuity and postoperative complications after the HSO removal.

RESULTS

Of the 22 eyes, 10 were treated with SSO endotamponade, 3 with fluorinated gas 14% C3F8, and 9 with 20% SF6 at first surgery. In all eyes, a complex inferior retinal redetachment was observed after the first surgery, in 1 month to 3 months after silicone oil removal or gas endotamponade introduction. In 10 eyes, the proliferative vitreoretinopathy (Grade B or C 1-3) was found. The main best-corrected visual acuity before HSO removal was 0.55 ± 0.20 the logarithm of the minimum angle of resolution (range 0.4-0.7) and after the HSO removal, it was 0.32 ± 0.29 the logarithm of the minimum angle of resolution (0.1-0.4). Among the postoperative complications, only in four eyes the macular edema was found (medically resolved), in four eyes an increase of intraocular pressure, and none of these developed the epiretinal membrane.

CONCLUSION

The main purpose of this study is to establish a short-term HSO endotamponade in eyes with complex retinal detachment recurrences, reducing the possible postoperative complications and having a better prognosis for visual acuity outcomes.

Cataract progression after primary pars plana vitrectomy for uncomplicated rhegmatogenous retinal detachments in young adults

BACKGROUND

Scleral buckling is typically implemented to repair rhegmatogenous retinal detachments (RRD) in young patients. Therefore, there is limited data on post-pars plana vitrectomy (PPV) cataract formation in this cohort. We report the rates and risk factors of cataract progression after PPV for RRD repair in young eyes.

METHODS

Retrospective single-center cohort study. Medical records of patients between the ages of 15 to 45 undergoing PPV for uncomplicated RRD between 2014 and 2020 were reviewed.

RESULTS

Twenty-eight eyes from 26 patients met inclusion criteria. Cataracts developed in 20/28 (71%) eyes after PPV. After PPV, nuclear sclerotic cataract (NSC) rates were higher in patients above 35 (65%) compared to below 35 years (18%) (p = 0.024). Cataracts developed more frequently after macula-off RRDs (88%) compared to macula-on RRDs (50%) (p = 0.044) with NSC more common in macula-off detachments (p = 0.020). At postoperative month 2, all eyes with C3F8 gas developed cataracts compared to 59% of eyes with no gas (p = 0.040).

CONCLUSIONS

Cataract formation was common and frequent after PPV. After PPV, young eyes and macula-on detachments developed cataracts less frequently than older eyes and macula-off detachments. If appropriate, a shorter acting gas tamponade should be considered in young eyes to minimize cataract formation.

Outcomes of short- versus long-acting gas tamponades in vitrectomy for rhegmatogenous retinal detachment

BACKGROUND

In vitrectomy for rhegmatogenous retinal detachment, long-acting gas tamponades (LGT) such as C3F8 or C2F6 may improve surgical success rate due to their prolonged effect compared to a short-acting gas tamponade (SGT) with SF6. On the other hand, SGT allow a significantly faster visual rehabilitation after surgery and may reduce the risk of gas-related complications. As comparative data in retinal detachment surgery is limited, we assessed the outcomes of vitrectomies using either LGT or SGT.

METHODS

We retrospectively analyzed 533 eyes of 524 consecutive patients diagnosed with primary rhegmatogenous retinal detachment not complicated by proliferative vitreoretinopathy (PVR) and treated by vitrectomy at two clinical sites. Depending on the site the patients presented at, they received either preferentially LGT (study site 1) or SGT (study site 2). Retinal re-detachment rates during a period of 6 months following surgery were analyzed.

RESULTS

At study site 1, 254 of 278 eyes (91.4%) were treated by LGT (C3F8 72.3%; C2F6 19.1%), whereas at study site 2, 246 of 255 eyes (96.5%) received SGT (SF6). Rates of retinal re-detachment in the LGT- and SGT-treated groups were similar with 23 of 254 eyes (9.1%) and 24 of 246 eyes (9.8%), respectively (p = 0.9). Median time to re-detachment was 5.7 weeks in the LGT-treated group and 4.4 weeks in the SGT-treated group (p = 0.4).

CONCLUSION

In rhegmatogenous retinal detachment repair by vitrectomy, the use of SGT results in comparable rates of successful retinal re-attachment as LGT. Given the faster visual rehabilitation with SGT, these results suggest SGT as a sensible alternative to LGT in surgery of retinal detachment without PVR.

Fibrin-Glue-Assisted Surgery for Idiopathic Macular Holes

METHODS

This pilot clinical trial included 10 eyes of 10 patients with idiopathic MH, where PPV along with ILMP was done. Fibrin glue was used as a tamponade, and no postoperative positioning was given to any patient. The primary outcome measure was successful anatomical closure of the MH. The secondary outcome measures were postoperative improvement in best-corrected visual acuity (BCVA) and any complications of the procedure.

RESULTS

The median age of patients was 62.5 years. Eight eyes were pseudophakic and two were phakic. The mean basal diameter of the MH was 1193 microns. The mean minimal linear diameter was 652 microns. Successful anatomic closure of MH was achieved in eight cases. The median BCVA improved from a Snellen equivalent of 20/100 preoperatively to 20/60 at 1 month postoperatively. The median follow-up period was 4 months.

CONCLUSION

The findings of this study suggest that the use of fibrin glue can be useful in patients where postoperative positioning is difficult.

An immunotherapeutic artificial vitreous body hydrogel to control choroidal melanoma and preserve vision after vitrectomy

Choroidal melanoma, a common intraocular malignant tumor, relies on local radiotherapy and enucleation for treatment. However, cancer recurrence and visual impairment remain important challenges. Here, a therapeutic artificial vitreous body (AVB) hydrogel based on tetra-armed poly(ethylene glycol) was developed to control the recurrence of choroidal melanoma and preserve vision after vitrectomy. AVB loaded with melphalan (Mel) and anti-programmed cell death ligand-1 (αPDL1), was injected after surgical resection in the choroidal melanoma mouse model. Afterwards, the sequentially released Mel and αPDL1 from AVB could achieve a synergistic antitumor effect to inhibit tumor recurrence. AVB with similar physical properties to native vitreous body could maintain the normal structure and visual function of eye after vitrectomy, which has been evidenced by standard examinations of ophthalmology in the mouse model. Thus, the immunotherapeutic AVB may be a promising candidate as an infill biomaterial to assist surgical treatment of intraocular malignant tumors.

Vitrectomy and ILM peeling in rhesus macaque: pitfalls and tips for success

BACKGROUND

The non-human primate (NHP) model is ideal for pre-clinical testing of novel therapies for human retinal diseases due to its similarity to the human visual system. However, intra-ocular delivery of gene therapy or cell transplantation to the retina gets hampered by the sticky vitreous body and poorly permeable inner limiting membrane (ILM) in primates. Although vitrectomy and ILM peeling are commonly performed in patients, many pitfalls exist in carrying out these procedures in the rhesus macaque, which have not been reported previously.

METHODS

We summarised common surgical pitfalls after performing vitrectomy and ILM peeling in four eyes of two rhesus macaques (one male and one female). We provided corresponding hands-on technical tips based on our surgical experience and literature search. Orbital CT scans were compared between adult rhesus macaques and humans. High-resolution surgical videos were recorded to demonstrate each critical surgical step.

RESULTS

Due to size difference, poor post-operative compliance, and high-standard requirements of a controlled experiment, there were eleven common surgical pitfalls during vitrectomy and ILM peeling in rhesus macaque. Falling into these pitfalls may produce discomfort, add fatigue, cause surgical complications, or even lead to the exclusion of the NHP from an experimental group.

CONCLUSION

Recognition and circumvention of these pitfalls during vitrectomy and ILM peeling in NHP are essential. By focusing on these surgical pitfalls, we can better carry out preclinical tests of novel therapies for retinal diseases in the NHP model.

Incidence of early complications requiring treatment plan changes after vitreoretinal surgery: a single-center study in South Korea

BACKGROUND

Information regarding incidence of treatment plan changes may be useful when discussing postoperative treatment plans for patients. Moreover, it may help establish a standardized postoperative treatment plan. This study aimed to evaluate the incidence of early complications requiring treatment plan changes in patients following vitreoretinal surgery and investigate its risk factors.

METHODS

This single-center retrospective study included 465 patients who had undergone vitreoretinal surgery. The reasons, incidence, and timing of treatment plan changes within 14 days of surgery were identified. Potential factors associated with the changes, such as patient demographics, surgeon's experience, diagnoses, and type of surgery were also analyzed.

RESULTS

The treatment plan was changed in 76 patients (16.3%) at a mean of 4.0 ± 3.2 days after vitreoretinal surgery. The reasons for the plan changes were increased intraocular pressure (IIOP) in 66(86.8%), intraocular inflammation in 2(2.6%), corneal edema in 3(3.9%), leakage from the sclerotomy wound in 3(3.9%) patients, and combined IIOP and intraocular inflammation in 2(2.6%). The date of discharge was postponed because of treatment plan changes in 17 patients (22.4%). The incidence of plan changes was higher in patients who underwent gas or oil tamponade (P < 0.001) and those who underwent surgery performed by less experienced surgeons (P = 0.034).

CONCLUSIONS

Treatment plan was changed in 16.3% of patients after vitreoretinal surgery. The risk of treatment plan changes was associated with the surgeon's experience in vitreoretinal surgery and the type of surgery. These results should be considered when establishing standardized care plans for patients who require vitreoretinal surgery.

Vision-Related Quality of Life in Patients With Rhegmatogenous Retinal Detachment Treated With Pars-Plana Vitrectomy: Impact of Gas Tamponade

PURPOSE

To investigate changes in vision-related quality of life in patients treated with pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) and compare groups according to the type of gas tamponade used.

METHODS

Participants in this study were 48 patients with RRD who were treated with PPV and gas tamponade (sulfur hexafluoride (SF₆) or perfluoropropane (C₃F₈)) without internal limiting membrane peeling. All participants underwent slit-lamp examination, fundoscopy, axial-length measurement, and completed the Vision Function Questionnaire-25 (VFQ-25) at month six postoperatively. We compared VFQ-25 composite and subscale scores in the SF₆ and C₃F₈ groups and investigated any correlations between age, best corrected visual acuity (BCVA), axial length, and VFQ-25 scores.

RESULTS

The demographic and clinical characteristics of the two groups (axial length, macular status, retinal detachment extent, duration of symptoms, and lens status) were comparable between the two groups. We found a statistically significant decrease in general vision (GV), ocular pain (OP), and driving (D) scores in the C₃F₈ group compared to the SF₆ group. The VFQ-25 composite score was comparable in the two groups. Similarly, all other subscales of the VFQ-25 did not differ significantly between the two groups. Age and BCVA did not significantly correlate with VFQ-25 composite and subscale scores.

CONCLUSION

Specific VFQ-25 subscales were decreased in patients with RRD treated with C₃F₈ as a gas tamponade compared to SF₆. This finding warrants further research in the tamponade agents used in PPV surgeries.

Air versus Gas Tamponade for Primary Rhegmatogenous Retinal Detachment: A Systematic Review and Meta-Analysis

BACKGROUND

Air tamponade's effectiveness in treatment of rhegmatogenous retinal detachment (RRD) remains unclear.

OBJECTIVE

We aimed to review the surgical outcomes between air and gas tamponade after vitrectomy for RRD.

METHOD

PubMed, Cochrane Library, EMBASE, and Web of Science were reviewed. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42022342284). The primary outcome was the primary anatomical success after vitrectomy. The secondary outcome was the prevalence of postoperative ocular hypertension. Certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system.

RESULTS

Ten studies involving 2,677 eyes were included. One study was randomized, and the others were non-randomized. The primary anatomical success after vitrectomy was not significantly different between the air and gas groups (odds ratio [OR], 1.00; 95% confidence interval [CI], 0.68-1.48). The risk of ocular hypertension was significantly lower in the air group (OR: 0.14; 95% CI: 0.09-0.24). The certainty of evidence regarding air tamponade having a comparable anatomical outcome and lower frequency of postoperative ocular hypertension in treatment of RRD were low.

DISCUSSION

The current evidence base for tamponade selection in treatment of RRD has several major limitations. Further appropriately designed studies are needed to guide tamponade selection.

Advances in Polysaccharide- and Synthetic Polymer-Based Vitreous Substitutes

The vitreous humour is a gel-like structure that composes the majority of each eye. It functions to provide passage of light, be a viscoelastic dampener, and hold the retina in place. Vitreous liquefaction causes retinal detachment and retinal tears requiring pars plana vitrectomy for vitreous substitution. An ideal vitreous substitute should display similar mechanical, chemical, and rheological properties to the natural vitreous. Currently used vitreous substitutes such as silicone oil, perfluorocarbon liquids, and gases cannot be used long-term due to adverse effects such as poor retention time, cytotoxicity, and cataract formation. Long-term, experimental vitreous substitutes composed of natural, modified and synthetic polymers are currently being studied. This review discusses current long- and short-term vitreous substitutes and the disadvantages of these that have highlighted the need for an ideal vitreous substitute. The review subsequently focuses specifically on currently used polysaccharide- and synthetic polymer-based vitreous substitutes, which may be modified or functionalised, or employed as the derivative, and discusses experimental vitreous substitutes in these classes. The advantages and challenges associated with the use of polymeric substitutes are discussed. Innovative approaches to vitreous substitution, namely a novel foldable capsular vitreous body, are presented, as well as future perspectives related to the advancement of this field.

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.

Full-Thickness Compressive Corneal Sutures with Removal of Anterior Chamber Air Bubble in the Management of Acute Corneal Hydrops

Acute hydrops is a rare complication of corneal ectatic disease, which occurs secondary to Descemet membrane break. Spontaneous resolution of this condition is associated with longstanding ocular discomfort and corneal scar. Intracameral gas/air injection with or without corneal suturing, anterior segment ocular coherence tomography (ASOCT)-guided drainage of intrastromal fluid, and penetrating keratoplasty are some of the described surgical interventions to manage this condition. The purpose of our study was to assess the effect of full-thickness corneal suturing as a solo treatment in the management of acute hydrops. A total of five patients with acute hydrops received full-thickness corneal sutures perpendicular to their Descemet break. A complete resolution of symptoms and corneal oedema was observed between 8 to 14 days post-operation with no complications. This technique is simple, safe, and effective in the management of acute hydrops and saves patients from a corneal transplant in an inflamed eye.

Inverse drainage Nd:YAG membranotomy for pre-macular hemorrhage

AIM

To report the outcomes of the "inverse drainage Nd:YAG laser membranotomy" technique for the management of pre-macular hemorrhage (PMH), which has its inferior margin near the fovea.

METHODS

This retrospective study included eyes with PMH, with its inferior margin located within 0.5 disc-diameter (DD) of the fovea. Laser membranotomy was performed near the superior margin of PMH followed by intravitreal injection of 0.3 mL undiluted sulphur hexafluoride (SF6) gas. The patients were advised to maintain a prone position for three days.

RESULTS

Twenty patients (20 eyes) with a mean age of 46.1 ± 18.6 years were included in the study. The mean duration of symptoms was 6.9 ± 7.0 days. The mean size of PMH was 4.1 ± 1.2DD. The causes of PMH were Valsalva retinopathy (n = 11) and retinal artery macroaneurysm (RAM, n = 9). The mean maximum height of the blood collection, measured by optical coherence tomography (OCT), within 1 disc-diameter from the inferior and superior borders of the PMH was 738.9 ± 232.9μm and 1240.6 ± 338.1μm respectively (p = 0.001). The mean best-corrected visual acuity (BCVA) improved from logMAR 1.32 ± 0.44 (Snellen equivalent, 20/418) to logMAR 0.11 ± 0.20 (Snellen equivalent, 20/26) (p = 0.001). Vitrectomy was not required in any case. Persistent pre-macular cavity, macular hole, epiretinal membrane (ERM), intra-ocular pressure spike, or rhegmatogenous retinal detachment (RRD) was not noted in any patient.

CONCLUSION

This technique can be safely used to treat eyes with PMH having its inferior margin near the fovea.

COMPARISON OF AIR VERSUS PERFLUOROPROPANE INTRAOCULAR TAMPONADE COMBINED WITH VITRECTOMY FOR THE TREATMENT OF MACULAR HOLE IN HIGH MYOPIA

PURPOSE

To compare the efficacy of air and perfluoropropane (C3F8) with pars plana vitrectomy (PPV) in highly myopic macular holes (HMMHs) and explore the factors related to surgical prognosis.

METHODS

A retrospective comparison of a consecutive series of HMMHs undergone vitrectomy and internal limiting membrane peeling. According to tamponade type, they were divided into air group and C3F8 group, which were further divided into subgroups based on hole diameter or axial length (AXL). Anatomical and functional outcomes were compared between tamponades. Related factors of initial closure rate and postoperative best-corrected visual acuity (BCVA) were analyzed by logistic regression.

RESULTS

The baseline characteristics in air group (n = 63) and C3F8 group (n = 37) were similar except the age of air was older ( P = 0.019). The mean follow-up period was 17.16 ± 17.97 months. After surgery, the initial closure rate of air group was 85.7% and that of C3F8 group was 83.7% ( P = 0.780). And the initial closure rate showed no difference between tamponades in the same subgroup classified by hole diameter or AXL (all P > 0.05). Postoperative BCVA improved significantly in both groups ( P < 0.001), but no difference between them ( P = 0.793). Logistic regression showed that age, minimum linear diameter, and AXL were risk factors of initial closure rate, and preoperative BCVA was the only factor associated with postoperative BCVA (all P < 0.05).

CONCLUSION

With a long-term follow-up of HMMH, we found air had a similar tamponade effect anatomically and functionally compared with C3F8. Air may also be a good choice for patients with HMMH.

HW, Albini TA. Orbital Gas after 25-Gauge Pars Plana Vitrectomy with Incorrect Gas Mixture

We present 2 cases of sutureless 25-gauge pars plana vitrectomy and fluid-gas exchange, in which incorrect gas concentrations likely led to elevated intraocular pressures and retrobulbar gas. Combined removal of orbital gas with anterior orbitotomy and pars plana vitrectomy was performed in the first case to address expanding intraocular and retrobulbar gas resulting from a suspected error in gas dilution. Vitreous and orbital gas removal by needling was effective in the second case. In patients with elevated intraocular pressure and orbital gas accumulation after vitrectomy, combined intraocular and orbital decompressions were effective in optimizing clinical outcomes. There is no consensus regarding the best management of orbital gas after vitrectomy. We propose that a multidisciplinary technique should be considered, when available.

Clinical characteristics of primary pars plana vitrectomy combined with air filling for rhegmatogenous retinal detachment

To detect the prognostic factors associated with initial reattachment after primary pars plana vitrectomy (PPV) with air tamponade for rhegmatogenous retinal detachment (RRD). We retrospectively reviewed 92 eyes of 92 patients with RRD. All eyes underwent PPV with air tamponade and a follow-up of at least 6 months. Initial anatomical success was defined as reattachment of the retina by a single operation. We performed univariate analysis to detect the presence of any difference between eyes with a successful initial reattachment and those that failed. We also performed multivariate logistic regression analysis to assess the influence of each preoperative factor on initial success. The rate of initial reattachment success was 93.5%. The percentage of retinal detachment involving the inferior quadrants in the initial success group was less than that in the initial failure group, and the difference was statistically significant (P = 0.043). There were no significant differences noted for other factors, such as symptom duration (P = 0.078) or location of retinal breaks (P = 0.065). Multiple logistic regression analysis using preoperative factors indicated that older age (odds ratio, 0.90; 95% confidence interval, 0.82–0.97; P = 0.010) and non-involvement of inferior quadrants (odds ratio, 9.90; 95% confidence interval, 1.36–71.92; P = 0.023) were significantly associated with initial success. PPV combined with air may be an effective treatment for some simple RRDs (proliferative vitreoretinopathy [PVR] grade ≤ C1). Non-involvement of the inferior quadrants and older age at presentation are associated with a greater likelihood of anatomic success. The volume of air in the eye after surgery is also very important, which may also affect the reduction of retinal detachment.

Outcomes of 25-gauge pars plana vitrectomy alone with air tamponade for the management of rhegmatogenous retinal detachment with inferior breaks

Background

This study was investigated the surgical outcomes of primary rhegmatogenous retinal detachment (RRD) with inferior retinal breaks (IRBs) that were repaired by 25-gauge pars plana vitrectomy (PPV) with air tamponade.

Methods

This retrospective review included 81 consecutive patients who had RRD with IRBs and underwent PPV with air tamponade in our hospital from January 2017 to January 2020. The main outcomes were single surgery anatomical success (SSAS) rate, postoperative best-corrected visual acuity (BCVA), and complications.

Results

The patient population consisted of 29 women and 52 men (mean age, 52.12 years); the mean follow-up interval was 8.88 months. The mean number of affected quadrants was 1.65 (range, 1–4 quadrants) and the mean number of breaks was 3.25. A single break was present in 20 cases (24.7%); two to 10 breaks were present in 61 (75.3%) cases. The SSAS rate was 91.36% (74/81) and the final anatomical success rate was 96.30% (78/81). More than half of the patients had BCVA < 0.3 logarithm of the minimum angle of resolution at the last follow-up. Axial length and patient age were candidate risk factors for redetachment (axial length, p = 0.03; age, p = 0.002). Postoperative complications included macular epiretinal membrane formation in one patient, lens opacity in three patients, and clinically significant macular edema in one patient.

Conclusions

PPV with air tamponade may be effective for the treatment of primary RRD with IRBs. Extensive preoperative discussion may be necessary for young patients and patients with particularly long axial length.

Gas Expansion Three Days after Pars Plana Vitrectomy with Sulfur Hexafluoride 20% Tamponade following Carbon Monoxide Toxicity and Oxygen Therapy

Purpose

To report an unusual case of gas expansion following oxygen therapy in a patient with sulfur hexafluoride (SF₆) 20% tamponade after pars plana vitrectomy. Case Report. A 40-year-old man came to the clinic with severe ocular pain and redness and also vision decrease in his left eye three days after uncomplicated 23-gauge pars plana vitrectomy, internal limiting membrane peeling combined with phacoemulsification, and using 20% SF₆ injection as a tamponade agent due to significant cataract and a full-thickness macular hole. In ophthalmic examinations of his left eye, high intraocular pressure (approximately 70 mmHg), a flat anterior chamber, and a gas-filled vitreous cavity were found. The patient had been hospitalized the day before due to carbon monoxide poisoning and had undergone oxygen therapy with a pure 100% mask for three hours.

Conclusion

It seems that oxygen therapy or carbon monoxide poisoning increases the volume of gas in the patient's vitreous cavity and the nonexpansile percentage of SF₆ expands.

Scleral Buckling Alone or in Combination with Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment Repair: A Meta-Analysis of 7212 Eyes

PURPOSE

The efficacy and safety of scleral buckling (SB) versus combination SB and pars plana vitrectomy (SB+PPV) for rhegmatogenous retinal detachment (RRD) repair remains unclear.

METHODS

A systematic review and meta-analysis was conducted to identify comparative studies published from Jan 2000-Jun 2021 that reported on the efficacy and/or safety following SB and SB+PPV for RRD repair. Final best-corrected visual acuity (BCVA) represented the primary endpoint, while reattachment rates and ocular adverse events were secondary endpoints. A random-effects meta-analysis was performed, and 95% confidence intervals were calculated.

RESULTS

Across 18 studies, 3912 SB and 3300 SB+PPV eyes were included. Final BCVA was non-significantly different between SB and SB+PPV (20/38 vs. 20/66 Snellen; WMD=-0.11 LogMAR; 95%CI [-0.29,0.07]; P=0.23). Primary reattachment rate was similar between procedures (P=0.74); however, SB alone achieved a significantly higher final reattachment rate (97.40% vs. 93.86%; RR=1.03; 95%CI [1.00,1.06]; P=0.04). Compared to SB+PPV, SB alone had a significantly lower risk of postoperative macular edema (RR=0.69; 95%CI [0.47,1.00]; P=0.05) and cataract formation (RR=0.34; 95%CI [0.12,0.96]; P=0.04). The incidence of macular hole, epiretinal membrane, residual subretinal fluid, proliferative vitreoretinopathy, elevated intraocular pressure, and extraocular muscle dysfunction were similar between SB and SB+PPV.

CONCLUSIONS

There was no significant difference in final BCVA between SB+PPV and SB alone in RRD. SB alone offers a slightly higher final reattachment rate along with a reduced risk of macular edema and cataract. Primary reattachment rate and the incidence of other complications were similar between the two procedures.

Environmental effect of air versus gas tamponade in the management of rhegmatogenous retinal detachment VR surgery: A multicentre study of 3,239 patients

Purpose

To report the potential reduction of carbon emissions by utilising air-tamponade (AT), where possible, instead of fluorinated gases in the management of rhegmatogenous retinal detachment (RRD). We compared the carbon CO₂ emissions produced at two large tertiary referral vitreoretinal (VR) centres where RRD are exclusively repaired using fluorinated gases to a tertiary VR mass of each gas used according to the Intergovernmental Panel on Climate Change.

Materials and methods

Retrospective, continuous, comparative multicentre study of all procedures using fluorinated gases between 01/01/17-31/12/20 at the Manchester Royal Eye Hospital (MREH) and Birmingham and Midland Eye Centre (BMEC), and between 01/01/19-31/12/2020 at the University Hospitals Coventry and Warwickshire (UHCW).

Results

We report on 3,239 (SF₆:1,415 [43.7%], C₂F₆:1,235 [38.1%], C₃F₈:541 [16.7%], Air:48 [1.5%]) procedures. UHCW and BMEC utilise single use 30ml and 75ml cannisters, respectively and MREH use multi-use gas cylinders. UHCW used AT in 48 (70%) of RRD repairs. Mean equivalent mass CO₂/patient was MREH:115.9kg, BMEC:7.9kg and UHCW:1.9kg. If assuming all centres used 30ml cannisters, the mean equivalent mass CO₂/patient was MREH:3.5 kg, BMEC:3.1kg and UHCW:1.9kg. AT enabled UHCW to greatly reduce the need for the most environmentally damaging SF₆ gas, leading to lower CO₂ emissions by 47.0% and 41.1% compared to MREH and BMEC, respectively.

Conclusion

We demonstrate how AT vs. the fluorinated gases can reduce in carbon footprint in the management of RRD. Further studies are required to determine the most ‘environment-friendly’ intraocular tamponade without compromising patient outcomes centre that also routinely employs AT in selected RRD cases.

Retinal Detachment Repair With Vitrectomy: Air Tamponade Integration to a Vitreoretinal Service, Comparison With Gas Tamponade, and Literature Review

BACKGROUND AND OBJECTIVE

Rhegmatogenous retinal detachment (RRD) repair by pars plana vitrectomy and gas tamponade (GT) has significant clinical and quality-of-life impacts compared with repair by short-acting air tamponade (AT). With AT, most authors minimize cryotherapy because of prolonged chorioretinal scar formation and use perfluorocarbon to maximize subretinal fluid drainage; this deviates from traditional technique, which discourages popularization of AT.

PATIENTS AND METHODS

Prospective 12-month study from January to December 2019 of all primary macula-on RRD cases. Patients fulfilling the inclusion criteria for the Pneumatic Retinopexy Versus Vitrectomy for Retinal Detachment Trial received AT and otherwise were assigned to receive GT.

RESULTS

Forty-six patients were enrolled: 22 (48%) receiving AT and 24 (52%) receiving GT. The primary success rate of AT was 21 (95%) and the primary success rate of GT was 23 (96%), with 100% final success. Cryopexy was used in 64% of AT cases and 58% of GT cases. Cataract surgery was required less when AT was used (1 [6%]) than when GT was used (3 [21%]). AT was used in 48% of primary macula-on RRD and 27% of all primary RRD cases.

CONCLUSIONS

AT has visual and anatomical outcomes comparable to those of GT with conventional vitrectomy techniques, with faster postoperative rehabilitation enabling a swift return to normal daily activities. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:87-95.].

High molecular weight hyper-branched PCL-based thermogelling vitreous endotamponades

Vitreous endotamponades play essential roles in facilitating retina recovery following vitreoretinal surgery, yet existing clinically standards are suboptimal as they can cause elevated intra-ocular pressure, temporary loss of vision, and cataracts while also requiring prolonged face-down positioning and removal surgery. These drawbacks have spurred the development of next-generation vitreous endotamponades, of which supramolecular hydrogels capable of in-situ gelation have emerged as top contenders. Herein, we demonstrate thermogels formed from hyper-branched amphiphilic copolymers as effective transparent and biodegradable vitreous endotamponades for the first time. These hyper-branched copolymers are synthesised via polyaddition of polyethylene glycol, polypropylene glycol, poly(ε-caprolactone)-diol, and glycerol (branch inducing moiety) with hexamethylene diisocyanate. The hyper-branched thermogels are injected as sols and undergo spontaneous gelation when warmed to physiological temperatures in rabbit eyes. We found that polymers with an optimal degree of hyper-branching showed excellent biocompatibility and was able to maintain retinal function with minimal atrophy and inflammation, even at absolute molecular weights high enough to cause undesirable in-vivo effects for their linear counterparts. The hyper-branched thermogel is cleared naturally from the vitreous through surface hydrogel erosion and negates surgical removal. Our findings expand the scope of polymer architectures suitable for in-vivo intraocular therapeutic applications beyond linear constructs.

A structured exercise to relieve musculoskeletal pain caused by face-down posture after retinal surgery: a randomized controlled trial

Face-down posture after vitrectomy physically burdens patients. Despite being of significant concern for patients, the intraoperative pain and discomfort has not been of great interest to retinal surgeons or researchers. This randomized controlled trial evaluated the effect of a 3-day novel structured exercise on reducing musculoskeletal pain from the face-down posture in 61 participants (31 in the exercise group) who underwent vitrectomy. Among the subjects, the median age was 62 years, 42 were female, 42 had macular holes, and 19 had retinal detachments. Participants in the exercise group received initial education on the exercise and performed three daily active exercise sessions. After the sessions, the exercise group had median numeric pain scores of 2, 1, and 1 at the back neck, shoulder, and lower back, respectively, while the control group had corresponding scores of 5, 3, and 4, respectively. The exercise group reported significantly lower pain scores (P = .003, .039, and .006 for the back neck, shoulder, and lower back, respectively). Application of the structured exercise would alleviate the patients' position-induced postoperative physical burden, by reducing pain and discomfort.

Recent Advances in Hydrogels: Ophthalmic Applications in Cell Delivery, Vitreous Substitutes, and Ocular Adhesives

With the prevalence of eye diseases, such as cataracts, retinal degenerative diseases, and glaucoma, different treatments including lens replacement, vitrectomy, and stem cell transplantation have been developed; however, they are not without their respective shortcomings. For example, current methods to seal corneal incisions induced by cataract surgery, such as suturing and stromal hydration, are less than ideal due to the potential for surgically induced astigmatism or wound leakage. Vitrectomy performed on patients with diabetic retinopathy requires an artificial vitreous substitute, with current offerings having many shortcomings such as retinal toxicity. The use of stem cells has also been investigated in retinal degenerative diseases; however, an optimal delivery system is required for successful transplantation. The incorporation of hydrogels into ocular therapy has been a critical focus in overcoming the limitations of current treatments. Previous reviews have extensively documented the use of hydrogels in drug delivery; thus, the goal of this review is to discuss recent advances in hydrogel technology in surgical applications, including dendrimer and gelatin-based hydrogels for ocular adhesives and a variety of different polymers for vitreous substitutes, as well as recent advances in hydrogel-based retinal pigment epithelium (RPE) and retinal progenitor cell (RPC) delivery to the retina.

Primary rhegmatogenous retinal detachment: evaluation of a minimally restricted face-down positioning after pars plana vitrectomy and gas tamponade

AIM

To evaluate the safety and efficacy of a minimally restricted face-down postoperative positioning following pars plana vitrectomy (PPV) with gas tamponade for primary rhegmatogenous retinal detachment (RRD).

METHODS

Patients with primary RRD treated with PPV and gas tamponade and followed up for at least 6mo were selected for the study. All phakic eyes underwent simultaneous cataract surgery. The patients were required to be in a postoperative position that prevented downward flow of retinal tears. Patients with macular detachment were positioned face-down for only a couple of hours. The patients were assessed for preoperative and postoperative best-corrected visual acuity (BCVA), anatomical retinal reattachment rate, and postoperative complications.

RESULTS

In total, 40 eyes of 39 patients with primary RRD were included in the study. A single tear was present in 30 eyes (75.0%), multiple retinal tears were present in nine eyes (22.5%), and oral dialysis was present in one eye (2.5%). The anatomical success rate was 90.0% (36 cases) after the primary surgery, and the final anatomical success rate was 100%. The BCVA improved significantly (P<0.001) from 0.75 logarithm angle of resolution (logMAR) preoperatively to 0.12 logMAR at the final visit. Postoperative complications included intraocular pressure elevation (≥25 mm Hg) in 11 patients (27.5%), fibrin formation in two patients (5.0%), pupillary capture of the intraocular lens in two patients (5.0%), and posterior synechia in one patient (2.5%).

CONCLUSION

A minimally restricted face-down and flexible postoperative positioning after PPV and gas tamponade for primary RRD is effective and safe.

Intraocular Pressure Change and Sustained Intraocular Pressure Elevation After Pars Plana Vitrectomy

OBJECTIVES

The aim of this study was to investigate the incidence and influential factors of changes in intraocular pressure (IOP) and sustained IOP elevation (SIOPE) after an uncomplicated pars plana vitrectomy (PPV).

METHODS

In all, 41 eyes of 41 patients who underwent PPV due to the presence of epiretinal membrane, macular hole, or vitreomacular traction syndrome were included in the study. In the vitrectomized eye, an elevated IOP of ≥21 mmHg or an increase of ≥6 mmHg from the preoperative IOP on 2 or more postprocedure visits or the addition of a new IOP-lowering medication during follow-up was defined as sustained IOP elevation. The results of procedures performed with a 20-G instrument and a 23-G instrument were compared.

RESULTS

The mean postoperative IOP was significantly higher than the preoperative IOP in vitrectomized eyes (preoperative IOP: 15.2±3.1 mmHg; postoperative 1st month: 17.4±5.8 mmHg, p=0.018; 6th month: 17.3±2.6 mmHg, p=0.02; 12th month: 16.7±2.6 mmHg, p=0.020). While no significant difference in IOP was detected between the vitrectomized and fellow eyes preoperatively, the IOP was significantly higher in the vitrectomized eyes in the 1st, 6th, and 12th months (p=0.040, p <0.001, p <0.001, respectively). SIOPE was detected in 15 vitrectomized eyes (37%) and 1 fellow eye (2%). The postoperative first day IOP was significantly lower in the vitrectomized eyes (11.1±6.1 vs 15.4±2mmHg; p<0.001) and significantly lower in the 23-G group than the 20-G group (9.3±5.2 vs 15.7±5.8; p=0.001).

CONCLUSION

IOP may rise significantly in comparison with the fellow eye or the preoperative IOP, even after an uncomplicated PPV. SIOPE and preoperative IOP values should be taken into consideration in addition to cross-sectional IOP findings in the evaluation of PPV.

Imaging of the post-operative orbit and associated complications

Dedicated post-operative radiological evaluation following ophthalmologic procedures is relatively uncommon. However, given the ever-growing ophthalmologic procedural advancements and the increasing utilization of neuroimaging for myriad indications, the orbits are often imaged incidentally in a delayed post-procedural state. Regardless of the clinical scenario, it is important for neuroradiologists and other specialists commonly exposed to orbital imaging to be aware of both expected and abnormal post-operative imaging findings because misinterpreted normal features or unrecognized complications can result in vision-threatening delays in treatment or mismanagement. In this review article, we discuss many common ophthalmologic procedures, their indications, and most likely complications. We also provide illustrative operative photographs and radiological imaging examples. By understanding the surgical intent, recognizing the devices that are commonly used, and developing familiarity with the appearance of post-operative complications, pitfalls in interpretation can be avoided and patient outcomes ultimately improved.

Current Situation and Challenges in Vitreous Substitutes

Vitreo-retinal disorders constitute a significant portion of treatable ocular diseases. These pathologies often require vitreo-retinal surgery and, as a consequence, the use of vitreous substitutes. Nowadays, the vitreous substitutes that are used in clinical practice are mainly divided into gases (air, SF₆ , C₂ F₆ , C₃ F₈ ) and liquids (perfluorocarbon liquids, silicone oils, and heavy silicone oils). There are specific advantages and drawbacks to each of these, which determine their clinical indications. However, developing the ideal biomaterial for vitreous substitution continues to be one of the most important challenges in ophthalmology, and a multidisciplinary approach is required. In this sense, recent research has focused on the development of biocompatible, biodegradable, and injectable hydrogels (natural, synthetic, and smart), which also act as medium and long-term internal tamponade agents. This comprehensive review aims to cover the main characteristics and indications for use of the extensive range of vitreous substitutes that are currently used in clinical practice, before going on to describe the hydrogels that have been developed recently and which have emerged as promising biomaterials for vitreous substitution.

The Effectiveness of the Supine Position in Managing Inferior Breaks in Rhegmatogenous Retinal Detachment After Vitrectomy with Gas Tamponade

Objective

This study aims to determine whether the supine position is effective for the management of inferior peripheral breaks after pars plana vitrectomy with gas tamponade.

Methods

A total of 29 patients (29 eyes) with acute rhegmatogenous retinal detachment and causative peripheral inferior breaks, located between the four o’clock and eight o’clock positions, underwent pars plana vitrectomy with gas tamponade. These patients maintained a face-up supine position for at least six hours each day for 14 days postoperatively. The alternate lateral position was used for the remaining hours, depending on the distribution of the retinal breaks.

Results

The final retinal reattachment rate was 100%, and the visual acuity improvement rate was 100% postoperatively, with no recurrence during the one-year follow up. No patients suffered from any sight-threatening complications. Of the 16 patients with preoperatively clear lenses, 3 were documented to have a cataract during their three-month postoperative follow up. Four patients were documented to have increased intraocular pressure, which was controllable during the early postoperative days.

Conclusion

Postoperative pars plana vitrectomy and gas tamponade in the supine position is effective for managing primary rhegmatogenous retinal detachment with causative breaks between the four o’clock and eight o’clock positions.

Reattachment of Rhegmatogenous Retinal Detachment via Fibrin Tissue Adhesive

Purpose

To manage reattachment of rhegmatogenous retinal detachment using tissue adhesive (fibrin glue) in five patients.

Methods

Five eyes of five patients with rhegmatogenous retinal detachment were treated with 23-gauge pars plana vitrectomy and the application of fibrin glue (Tisseel Lyo) into the break under air without laser photocoagulation or cryopexy.

Results

The median age of patients was 64 (range, 46–82) years, and the median duration of symptoms was 15 (range, 7–60) days. Three eyes had inferior and two had superior rhegmatogenous retinal detachments. Successful retinal reattachment was achieved in all cases and maintained during the followıng 10 to 24 months. The median best-corrected visual acuity improved from 2 / 100 preoperatively to a Snellen visual acuity of 20 / 50 by 6 months postoperatively. No postoperative complications were detected during the follow-up period.

Conclusions

Excellent adhesive effects of fibrin glue with respect to sealing retinal tears with no side effects were seen in our study. With further prospective studies, this technique could be an alternative method to conventional retinopexy.

A review of late intraocular lens opacifications

PURPOSE OF REVIEW

Phacoemulsification cataract surgery is one of the most commonly performed surgical procedure worldwide. In the majority of cases, intraocular lenses (IOLs) are implanted. Due to the increasing life expectancy and the fact that cataract surgery is performed in earlier stages, the anticipated IOL duration in the eye has increased over the last decades. The aim of this study was to review the types and describe the characteristics of late intraocular lens opacifications.

RECENT FINDINGS

Calcification was the most commonly reported type of opacification in hydrophilic IOLs; it usually negatively impacted the visual function and required IOL explantation. Glistening manifested in hydrophobic acrylic lenses and was frequent in some IOL models. In most cases glistening and subsurface nanoglistenigs do not lead to a decline in visual acuity or require IOL exchange. Current studies indicate that fluid-related phenomena may induce straylight, leading to a decrease of comfort and quality of vision.

SUMMARY

Several reports on late IOL opacifications have been published in recent years. In some cases, particularly in glistening, the development of the opacifications might be related to IOL aging. The influence of the fluid-related microvacuoles on the quality of vision requires further research.

Vitrectomy with air tamponade and cryotherapy for retinal detachment repair without perfluorocarbon use: A UK 12-month prospective case series

INTRODUCTION

Rhegmatogenous retinal detachment (RRD) is commonly managed by pars plana vitrectomy (PPV). Gas tamponade has significant clinical and quality of life factors that affect the patient. Using shorter acting air tamponade, intuitively leads to surgical concern for higher rate of primary detachment. To circumvent this, surgeons advocate the use of perfluorocarbon to maximise sub-retinal-fluid drainage when using air tamponade and/or avoid using cryotherapy due to longer duration for scar formation relative to laser. These steps are a deviation from traditional technique for otherwise routine primary RRD repair and discourages popularisation of using air tamponade despite the benefits to patients.

METHOD

Prospective 12-month, single centre, single surgeon, consecutive study from January to December 2019. Inclusion criteria was as per based on the pneumatic retinopexy versus vitrectomy for retinal detachment: (i) single retinal break or group of breaks, no larger than 1-clock-hour (30°), in detached retina; (ii) all breaks in detached retina lie above the 8 to 4 o'clock meridian; and (iii) breaks or lattice degeneration in attached retina at any location. We excluded PVR formation and RRD in the inferior 4 o'clock hours.

RESULTS

We report primary and final success rate of 96% and 100%, respectively in 23 eyes (22 macular-on and one macular-off) with RRD eyes in a 12-month period. Cryopexy was utilised in 65% patients and in isolation in 23% with no perfluorocarbon use in all eyes.

CONCLUSION

We show cryotherapy can be used safely in AT-RRD without PFCL in RRD fulfilling PIVOT trial criteria with minimal cataract formation and IOP spikes and faster post-operative visual rehabilitation.

Polymeric hydrogels as a vitreous replacement strategy in the eye

Vitreous endo-tamponades are commonly used in the treatment of retinal detachments and tears. They function by providing a tamponading force to support the retina after retina surgery. Current clinical vitreous endo-tamponades include expansile gases (such as sulfur hexafluoride (SF₆) and perfluoropropane (C₃F₈)) and also sislicone oil (SiO). They are effective in promoting recovery but are disadvantaged by their lower refractive indices and lower densities as compared to the native vitreous, resulting in immediate blurred vision after surgery and necessitating patients to assume prolonged face-down positioning respectively. While the gas implants diffuse out over time, the SiO implants are non-biodegradable and require surgical removal. Therefore, there is much demand to develop an ideal vitreous endo-tamponade that can combine therapeutic effectiveness with patient comfort. Polymeric hydrogels have since attracted much attention due to their favourable properties such as high water content, high clarity, suitable refractive indices, suitable density, tuneable rheological properties, injectability, and biocompatibility. Many design strategies have been employed to design polymeric hydrogel-based vitreous endo-tamponades and they can be classified into four main strategies. This review seeks to analyse these various strategies and evaluate their effectiveness and also propose the key criteria to design successful polymeric hydrogel vitreous endo-tamponades.

Post-operative intracranial gas migration with optic nerve infiltration and atrophy following retinal detachment repair

Purpose

To report a patient with post-operative gas migration into the optic nerve and lateral ventricles after retinal detachment repair.

Observations

A 78-year-old pseudophakic man developed a temporal visual field cut in his non-operative, right eye 3 weeks after repair of a recurrent, shallow, macula-involving retinal detachment with perfluoropropane intraocular gas in the left eye. Visual acuity in the right eye measured 20/40, and static perimetry demonstrated temporal visual field loss that respected the vertical midline. Dilated fundus examination of the right eye was unrevealing for any retinal cause, raising suspicion for an intracranial etiology. An urgent CT scan of the brain demonstrated gas in all segments of the left optic nerve and lateral ventricles, consistent with intracranial gas migration along the optic nerve. Given the absence of systemic neurologic symptoms, cautious observation was advised on consultation with neuroradiology and neurosurgery, and follow-up CT scan 1 week later showed resolution of the intracranial gas. By 10-weeks post-operatively, vision returned to 20/20 in the right eye with persistent temporal field loss, and the left eye was hand motions (20/70 pre-operatively) with evidence of optic nerve atrophy and severe cupping.

Conclusions

Intracranial gas migration is a rare complication of retinaldetachment repair with intraocular gas and may occur in the setting of structural defects of the optic nerve and high post-operative intraocular pressure. Clinicians should be alert to this rare but serious complication, which can cause neurologic symptoms and result in vision loss in both the operative and non-operative eyes.

Retinal Tamponades: Current Uses and Future Technologies

Purpose of Review

In this article, the current use and limitations of existing retinal tamponades are discussed. Potential novel developments that address those limitations are subsequently highlighted, along with areas of future improvements.

Recent Findings

While retinal tamponades have existed for decades and improved the treatment of retinal detachments, many problems still exist with their use, including inadequate tamponade of the inferior retina, toxicity from retained heavy liquids, glaucoma, and keratopathy, among others. New advancements in the components of heavy liquids and vitreous substitutes aim to mitigate those issues.

Summary

Existing retinal tamponades, including perflurocarbon heavy liquids, fluorinated gases, and silicone oil, have specific limitations that cause potentially avoidable morbidity. New developments, such as heavy silicone oil, novel vitreous gels, and future avenues of approach, such as potentially reabsorbing heavy liquids may help increase our ability to treat retinal detachments with fewer complications.

Bioinspired Thermosensitive Hydrogel as a Vitreous Substitute: Synthesis, Properties, and Progress of Animal Studies

In many vitreal diseases, the surgeon removes the natural vitreous and replaces it with silicone oils, gases, or balanced salt solutions to fill the eyeball and hold the retina in position. However, these materials are often associated with complications and have properties that differ from natural vitreous. Herein, we report an extension of our previous work on the synthesis of a biomimetic hydrogel that is composed of thiolated gellan as an analogue of type II collagen and poly(methacrylamide-co-methacrylate-co-bis(methacryloyl)cystamine), a polyelectrolyte, as an analogue of hyaluronic acid. This thermosensitive hydrogel can be injected into the eye as a viscous solution at 45 °C. It then forms a physical gel in situ when it reaches body temperature, and later forms disulfide covalent crosslinks. In this article, we evaluated two different formulations of the biomimetic hydrogels for their physical, mechanical, and optical properties, and we determined their biocompatibility with several cell lines. Finally, we report on the progress of the four-month preclinical evaluation of our bio-inspired vitreous substitute in comparison to silicone oil or a balanced salt solution. We assessed the eyes with a slit-lamp examination, intraocular pressure measurements, electroretinography, and optical coherence tomography. Preliminary results are very encouraging for the continuing evaluation of our bio-inspired hydrogel in clinical trials.

Iatrogenic ophthalmic artery occlusion and retinal artery occlusion

Iatrogenic ophthalmic artery occlusion (IOAO) is a rare but devastating ophthalmic disease that may cause sudden and permanent visual loss. Understanding the possible etiologic modalities and pathogenic mechanisms of IOAO may prevent its occurrence. There are numerous medical etiologies of IOAO, including cosmetic facial filler injection, intravascular procedures, intravitreal gas or drug injection, retrobulbar anesthesia, intraarterial chemotherapy in retinoblastoma. Non-ocular surgeries and vascular events in arteries that are not directly associated with the ophthalmic artery, can also cause IOAO. Since IOAO has a limited number of treatment modalities, which lead to poor final visual prognosis, it is imperative to acknowledge the information regarding medical procedures that are etiologically associated with IOAO. We accumulated all searchable and available IOAO case reports (our cases and previous reported cases from the literature), classified them according to their mechanisms of pathogenesis, and summarized treatment options and responses of each of the causes. Various sporadic cases of IOAO can be categorized into three mechanisms as follows: intravascular event, orbital compartment syndrome, and increased intraocular pressure. Embolic IOAO, which is considered the primary cause of the condition, was classified into three subgroups according to the pathway of embolic movement (retrograde pathway, anterograde pathway, pathway through collateral channels). Despite the practical limitations of treating spontaneous (non-iatrogenic) retinal artery occlusion, this article will contribute in predicting and improving the prognosis of IOAO by recognizing the treatable factors. Furthermore, it is expected to provide clues to future research associated with the treatment of retinal artery occlusion.