SILICONE OIL VERSUS GAS TAMPONADE FOR PRIMARY�RHEGMATOGENOUS RETINAL DETACHMENT TREATED�SUCCESSFULLY WITH A PROPENSITY SCORE ANALYSIS: JAPAN�RETINAL DETACHMENT REGISTRY
ABSTRACT
To compare the effects of SOT to GT on BCVA after successful vitrectomy for RD
Methods
Methods
DISCUSSION
RD eyes that were reattached after 6 months with SOT had significantly poorer BCVA than the eyes with GT .
This might be because more severe RDs, such as those with PVR grade C or giant tear, were in SOT group
Since there were reports that SOT group showed a lower anatomical success rate than the GT group and the 15% of eyes with silicone oil removal showed redetachment,
we restricted the cases that silicone oil was removable within 6 months postoperatively and did not have redetachment.
DISCUSSION
There are cases in which simply removing the silicone oil causes a decrease in the BCVA,we excluded four cases in which the BCVA decreased from 1 month to 6 months after the removal of silicone oil to exclude this effect.
Nevertheless, the BCVA of the SOT group was still significantly poorer.
Multiple linear regression analysis using propensity scores and inverse probability treatment weighting estimations found that the results were similar confirming that these results were not obtained by chance but were rather robust.
DISCUSSION
There have been studies reporting the presence of retinal cysts, thinning of the retina and central scotoma in silicone-filled eyes, and these findings have been reported as factors that deteriorate postoperative visual acuity.
However, we could not determine the exact reason because we did not have such data in this registry.
RCTs on surgical procedures, where the surgeons and patients already have preferences, make RCTs not only difficult to perform but also unethical.
Propensity score matching studies using real-world data have been recommended for the evaluation of such conditions
DISCUSSION
Currently, SOT is mainly used to treat severe retinal diseases, but they may also be used for relatively mild cases, for example, patients with only one eye, needing flight travel and those who cannot maintain a specific posture.
In this study, the proportion of mild cases, such as the case with preoperative BCVA of better than 0.8 logMAR units, was 35% in the SOT group.
The results of an RCT that compared GT to SOT in eyes with diabetic retinopathy were recently reported.The results showed that the postoperative BCVA was poorer in the SOT eyes than the GT eyes at 6 months.
That study was limited to cases with diabetic retinopathy and tractional RD with preoperative visual acuity of Snellen 20/1125 in GT eyes and Snellen 20/1149 in SOT eyes.
The comparable preoperative BCVAs in our study were Snellen 20/182 in the GT eyes and Snellen 20/364 in the SOT eyes
DISCUSSION
Thus, their subjects had poorer preoperative BCVA than our cases. The average period from the onset to the symptoms and signs of RD to the time of surgery was >11 months in their study, which is longer than that in our registry in which 89.8% of our patients underwent surgery within 1 month after the onset.
One of the advantages of the present study is the far shorter time to reach a conclusion than RCT. Because this study used an established database registry it required only 1 week to obtain the first results.
It took 2.5 years to collect the data for the RCT and the difference was significant. It has become too expensive to organise a well-powered RCT. More importantly, RCTs are now considered to be experimental in nature and should not expose patients to needless risks. Studies using registries rarely raise serious ethical issues. The data were from 128 surgeons nationwide and have the advantage of generalising the results
Limitations
Retrospective observational study and there is a possibility that unmeasured confounding factors may not have been adjusted for. This is an inevitable problem of propensity score matching analysis.
Number of cases in which SOT was chosen was small in the registry data, which could have created a bias. Propensity matching is suitable for the analysis of such rare diseases or rare conditions. Considering the rarity of SOT among all RD cases, the present approach should be reasonable.
Database did not contain information on OCT and defined methods for SOR, such as whether the removal was performed manually with a syringe, automatically with a vitreous machine or with fluid–air replacement, we cannot eliminate the possibility that they may have affected the results.
Conclusion
the propensity score analysis of the real-world data showed that SOT may be related to a poorer postoperative vision than eyes treated with GT even after the completely successful surgery.
In cases of RD where the use of SOT is being considered, the use of SOT should be selected very cautiously. More specifically in eyes with possible damaged retina, such as glaucoma, diabetic retinopathy or optic neuropathy.
In future studies, it will be necessary to construct a database that includes information on OCT findings and the condition of the fellow eyes
ABSTRACT
To describe the factors associated with ERM formation in eyes treated with PPV for RRD.
METHODS
2239 cases treated with PPV for RRD repair registered in the Japan-Retinal Detachment Registry between February 2016 and March 2017.
Associations of 13 baseline characteristics and eight surgical procedures with ERM formation were evaluated using univariate analysis. We conducted a propensity score-matched analysis for the significantly associated clinical factors.
Main Outcome Measures: ERM formation after six months of vitrectomy.
DISCUSSION
To date, there has been no large-scaled study to determine risk factors for postoperative ERM formation after PPV for RRD repair.
In addition, only a few studies assessed ERM risk using OCT, which enables accurate ERM evaluation, but with low certainty due to their small sample size.
RCT would be the best study design to determine the effectiveness of the intervention, it may be intolerable to evaluate the treatment outcome in comparing the groups with and without invasive surgical interventions such as ILM peeling and drainage retinotomy during PPV for RRD repair
DISCUSSION
The J-RD Registry, a large-scaled registry study, collects detailed and standardized information about the clinical profiles of patients with RD in multiple institutes. In the analysis of the registry data, our statistical method based on propensity score reports that drainage retinotomy increases the risk of ERM formation after PPV for RRD.
A drainage retinotomy is a surgical technique in conjunction with PPV that can allow the removal of subretinal fluid in RRD, and has been long performed as a standard surgical technique accompanied with advancements in the instrument such as soft silicone tip enabling active suction or extrusion as a fluted needle with less tissue damage.
DISCUSSION
The peripheral drainage retinotomy can be used if the retinal break is not in a dependent location for drainage.
Without the use of PFCL, the posterior drainage retinotomy during fluid-air exchange is a commonly used technique to re-attach the retina for internal drainage of subretinal fluid.
Some techniques are used in performing the posterior retinotomy, such as no laser around the created hole and drainage with a 41G tip in the posterior retina without endodiathermy
DISCUSSION
leaving subretinal fluid at the end of surgery is an option, which does not necessarily cause retinal fold and damage if the patient is correctly positioned after surgery.
Possible intraoperative complications related to drainage retinotomy include hemorrhage from the retina and choroid; however, postoperative complications are less common. While previous reports described subretinal neovascularization and cellular proliferation at the drainage site.
Nowadays less frequently used due to the advantage of MIVS with a wide-angle viewing system and the availability of perfluorocarbon liquid (PFCL), 677 cases (30.3%) still underwent drainage retinotomy performed by well-trained qualified surgeons between 2016 and 2017 in the J-RD Registry data
DISCUSSION
The increased risk of macular pucker after a drainage retinotomy may help surgeons to reconsider its application and case selection. In addition, prophylactic ILM peeling may be necessary in the cases that undergo drainage retinotomy to avoid a re-operation for ERM removal after RRD repair.
ERM after RRD repair can be considered a mild form of PVR. The mechanism of increased ERM risk after drainage retinotomy may be associated with its damage to the retina, choroid, and their vessels, followed by glial cell activation and migration of RPE and inflammatory cells, which result in pre-macular fibrous membrane formation
RESULT
In order to balance the patients’ backgrounds, we created a propensity score matched dataset composed of 492 pairs of the cases with and without drainage retinotomy.
inIcidence of ERM significantly differed between the two groups after six months of vitrectomy (8.3% and 2.6% in cases with and without drainage retinotomy, respectively; OR = 3.35, 95% CI 1.77–6.33; P < 0.001)
LIMITATION
indication of drainage retinotomy can be particularly owing to the surgeon’s discretion, there may be unexplored confounders related to the bias associated with surgeons’ difference.
Type and location of the drainage retinotomy, such as in the posterior or peripheral and nasal or lateral retina, are important for further illustrating their association with EMR formation, these data cannot be identified in the registry data.
More detailed information, such as OCT-based ERM grading and the morphology of the retinal layer, would determine the severity, which can help identify the drainage retinotomy procedure at risk for ERM formation.
Given that the location influences the following macular pucker formation, it can help surgeons choose the drainage retinotomy site to reduce the risk and may foster better understanding of the precise mechanism of postoperative ERM formation.
CONCLUSION
Our analyses indicate that a drainage retinotomy is associated with increased risk of ERM formation in eyes treated with PPV for RRD repair.
Our result suggests that a careful consideration is needed whether to apply drainage retinotomy for the removal of subretinal fluid during PPV
ABSTRACT
Suboptimal functional outcomes following RRD repair may be related to photoreceptor abnormalities including alterations of the EZ which may not be apparent on cross sectional OCT.
This study assessed EZ recovery using en face OCT following RRD repair and its association with visual acuity.
METHODS
Post hoc analysis of a randomized controlled trial.(PIVOT)
Patients with macula-off RRD were followed at 3, 6, 12 and 24 months postoperatively and annually thereafter. En face OCT of the EZ slab were analyzed. Hyporeflective areas were co-localized with EZ abnormalities on cross-sectional OCT B-scans and measured by two masked graders.
Primary outcome was change in area of EZ hyporeflectivity from 3 to 24 months and its association with ETDRS visual acuity recovery was also assessed
DISCUSSION
This study assessed hyporeflectivity of the EZ en face slab following repair of macula-off RRD in the context of a randomized controlled trial.
Although EZ hyporeflectivity may occur with other retinal conditions, the absence of areas of EZ hyporeflectivity in the normal control eyes validates this imaging biomarker as an abnormality of the EZ that can occur following the development of RRD and its subsequent treatment.
We demonstrated that the improvement in EZ hyporeflectivity may be protracted, occurring over a period of 2 years and in some cases up to 6 years
DISCUSSION
we found that the change in EZ hyporeflectivity over time is associated with duration of macula-off RRD to intervention in hours.
Patients with a longer duration of macula-off to intervention had less recovery of EZ hyporeflectivity over time.
There is an association between EZ recovery and improvement in ETDRS visual acuity letter score over time. This suggests that earlier intervention for macula-off RRD may lead to greater EZ recovery and greater improvement in ETDRS visual acuity.
DISCUSSION
Conventional wisdom is that patients who undergo retinal reattachment surgery may expect to achieve maximum visual recovery at one to two years post operatively.
However, this study highlights that EZ recovery can in fact continue for up to 4 years and perhaps longer after surgery.
The results of this study demonstrate the great clinical value of en face OCT when advising patients regarding their visual prognosis. For example, for patients with a prior history of RRD who are undergoing cataract surgery, assessment of the EZ on the en face OCT may provide a qualitative assessment of photoreceptor integrity. This may inform the discussion regarding the potential visual function and quality of vision after cataract surgery and may also influence management
DISCUSSION
The EZ consists primarily of the mitochondria rich area within the outer portion of the inner segments of the photoreceptors.
Following retinal detachment and the subsequent repair procedure, local hypoxia and structural changes may influence the reflectivity of this layer. The area of hyporeflectivity corresponds exactly to the area of the retina that was detached pre-operatively.
Several other investigators have assessed the relationship between abnormalities of the EZ and functional outcomes following PPV for RRD repair. These studies were all based on the OCT cross-sectional B-scan images rather than the ellipsoid zone en face slab as assessed in this study.
DISCUSSION
A recent study demonstrated that patients having surgery within 3 days may fare better than those waiting longer than 3 days.
The application of imaging biomarkers such as retinal displacement on fundus autofluorescence, discontinuity of the EZ and ELM on cross-sectional B-scan, and now enface OCT provides clinicians with a range of ways to assess the structural integrity of the retina after repair of RRD.
There are no other studies in the literature that have longitudinally followed EZ recovery over a 4-year period following RD repair.
LIMITATION
significant loss of follow-up after the 24-month visit (57%), segmentation errors, and poor-quality scans.
the mean grey value of hyporeflectivity (50% of RPE/Bruch’s reflectivity) was used as a threshold to identify abnormal hyporeflective regions, we were not able to reliably measure the intensity of the hyporeflectivity. A reliable quantitative measure of the intensity of hyporeflectivity could possibly provide a more accurate assessment of photoreceptor damage following macula-off RRD
Media opacity such as vitreous floaters can cause hyporeflectivity within the EZ slab.
CONCLUSION
measurement of the en face area of EZ hyporeflectivity may represent a novel biomarker that provides a quantitative assessment of photoreceptor integrity which is correlated with long-term visual acuity outcomes.
This study also suggests that duration of macula-off detachment to intervention impacts the speed of photoreceptor recovery, which can continue over a period of at least 4 years and likely longer.
REPORT
RD has been associated with colobomatous malformations.
We sought to estimate the prevalence by age of acquired RD in children with optic nerve coloboma (ONC) or chorioretinal coloboma (CRC) to inform the study of the potential benefit and timing of prophylactic laser retinopexy, as well as guide recommendations for periodic surveillance retinal examinations.
Retrospective cross-sectional study at the Children’s Hospital of Philadelphia of children examined between May 2009 and July 2020
all examinations were performed by attending pediatric ophthalmologists. Coloboma size was categorized as small, medium, or large based on the recorded ophthalmologic examination findings and photographs if available.
Eyes with RD present during first examinations in infants aged less than1 year were excluded as presumed congenital RDs. Eyes with presumed retinal dysplasia were also excluded.
A total of 387 eyes of 258 children had ONC or CRC.
We found that the risk of acquired RD in children with CRC or ONC was considerably lower than in previous reports of RD in patients with coloboma.
Despite the low rate of RDs, there is nevertheless some non zero risk of RD during childhood. Moreover, children are unlikely to report painless monocular vision loss.
We could not evaluate a potential association between coloboma size and risk of detachment and cannot suggest screening intervals based on coloboma features.
ABSTRACT
To assess the incidence of post-operative outer retinal folds (ORFs) in PPV vs PnR following RRD repair and to determine the association of ORFs with functional outcomes at 1 year.
METHOD
Post-hoc analysis of the PIVOT trial.
Incidence and quantitative morphological features of ORFs were assessed with en face and cross-sectional OCT at 1 month post-operatively by two masked graders.
ETDRS letter score and quantitative metamorphopsia were measured at 1 year.
DISCUSSION
PPV was associated with a greater risk of ORF development compared to PnR at the 1-month post-operative time point, and that the presence of ORFs at this early interval was associated with worse ETDRS visual acuity letter score at 1 year.
It is important to note that ORFs do tend to resolve over the course of several months. However, patients with ORFs achieved a clinically important mean 9.4 ETDRS letters less than those without ORFs at 1 year.
These results have significant implications, as they reinforce the concept that the mechanism of achieving retinal reattachment can influence both the integrity of attachment and functional outcomes.
DISCUSSION
Outer retinal corrugations (ORCs) of the detached retina are well documented with both histological and OCT studies. ORCs may occur secondary to cystoid degeneration of the retina intraretinal proliferation, and changes in the cytoskeleton of photoreceptors occurring within hours after a retinal detachment.
Once a retinal break is closed, for example with a small gas bubble as in PnR, the retina reattaches in 5 specific stages.
One characteristic of Stage 2 of this process is a resolution or improvement of ORCs (possibly due to reduced hydration of the retina with improved retina-RPE exchange) as the retina slowly approaches the RPE and Stage 3 occurs when there is contact of the neurosensory retina with the RPE.
DISCUSSION
When some parts of the retina remain in Stage 2 with significant ORCs while neighboring parts of the retina progress to Stage 3, this sets the stage for the development of ORFs.
Procedures such as PPV, where subretinal fluid is rapidly drained from the subretinal space during air fluid exchange may forcefully reattach the retina. Sudden rapid reattachment may result in the retina having insufficient time for the outer retinal corrugations to resolve in stage 2 prior to adjacent areas being forced to reattach.
In PnR, by contrast, the subretinal fluid is reabsorbed naturally by the RPE pump. This slower and more natural reattachment process may give more time for the outer retinal corrugations to slowly resolve, possibly preventing the formation of ORFs.
DISCUSSION
Minimal gas vitrectomy
a complete vitrectomy is performed and the retinal break is marked with endodiathermy or treated with cryopexy.
The retina is then left detached with no air-fluid exchange being performed. At the completion of surgery all wounds are closed with sutures and a small gas bubble is injected (0.6cc pure SF6).
The patient is then asked to position with initial face down after which they are positioned to the retinal break. The small gas tamponade may reduce the risk of retinal displacement as there is less buoyant force applied to the retina and residual subretinal fluid.
Minimal gas vitrectomy and scleral buckle for patients with both inferior and superior retinal tears.
DISCUSSION
It is important to differentiate retinal displacement from ORFs.
Retinal displacement occurs when the retina gets stretched due to the movement of subretinal fluid under the thin elastic retina at the completion of surgery by the buoyant force of a large gas bubble in a direction related to gravity and head positioning.
The best evidence we have to date suggests that retinal displacement can be minimized by reducing the size of the gas tamponade in addition to immediate face down positioning.
DISCUSSION
This study demonstrated that the occurrence of ORFs at 1 month was associated with worse ETDRS visual acuity letter score at 1 year.
To eliminate any possible confounding by treatment group, we performed a sensitivity analysis for the association of the occurrence of ORFs at 1 month with ETDRS letter score at one year in only the PPV subgroup. This analysis confirmed the substantial difference (12.6 letters) in ETDRS letter score favoring patients without ORFs compared to those with ORFs.
There was a correlation between the shortest distance of the ORFs from the fovea and vertical metamorphopsia, which has not previously been assessed.
DISCUSSION
This study highlights how enface OCT offers an efficient way to screen the entire macula for ORFs with a single image.
We utilized a customized slab that was designed to easily detect ORFs as well defined curved hyperreflective lines on en face OCT .
Our customized slab extended from the junction of the outer plexiform and outer nuclear layers to the junction of the myoid and ellipsoid zone (EZ) of the photoreceptors. This segmentation caused the ORFs to be hyperreflective as the slab was capturing the folded outer retina with a “double” layer of the EZ.
CONCLUSION
Higher risk of ORFs in PPV vs PnR at one month post-operatively with worse ETDRS visual acuity at one year in patients with ORFs compared to those without.
Different surgical treatments for RRD result in varying integrity of retinal reattachment.
This study adds to the increasing evidence that PnR should be strongly considered in patients meeting clinical trial criteria to minimise the likelihood of potentially avoidable post-operative anatomic abnormalities that can occur with other treatment approaches such as PPV.
Although single operation reattachment rate is a useful outcome measure for studies assessing RRD repair, is not the only outcome measure of interest. The importance of striving for a high integrity of retinal reattachment is increasingly being recognised.
ABSTRACT
To compare PPV to PPV/SB for repair of primary RRD with associated VH.
Main Outcome Measures: Single surgery anatomic success (SSAS) at 6 months, defined as no recurrent retinal detachment requiring surgical intervention.
METHOD
Patients with RRD and associated VH who underwent PPV or PPV/SB from January 1,2010 through August 31, 2020 were analyzed.
single-institution, retrospective, observational study of 224 eyes with RRD and VH at the time of detachment.
We excluded eyes with less than 6 months of follow up, prior history of retinal detachment repair with vitrectomy or scleral buckle, VH that resolved before surgical intervention, tractional or combined tractional and rhegmatogenous detachment.
DISCUSSION
Our current study demonstrates greater single surgery success rates in eyes with concurrent VH and RD undergoing combined PPV/SB vs. PPV alone.
A superior SSAS in PPV/SB eyes was found despite on average a greater area of detachment (clock hours), higher rates of inferior pathology and pre-operative PVR, and a larger proportion of phakic eyes.
PPV/SB was more successful in repairing VH associated RRD regardless of tamponade agent used (SF6, C3F8, silicone oil), with the choice of C3F8 being statistically significant.
DISCUSSION
On secondary outcome analysis, PPV/SB resulted in greater visual acuity improvement compared to PPV in attached eyes at 6 months.
Rates of documented PVR at 6 months were lower in the PPV/SB cohort post-operatively despite higher baseline PVR rates compared to the PPV cohort.
In examining final success rate, nearly all (137/138 and 84/85 eyes in the PPV and PPV/SB groups, respectively) patients achieved anatomical success at last follow up visit, and a similarly high success rate was achieved after excluding those with retained oil tamponade. As expected however, the number of surgeries to achieve this final attachment status was significantly higher in the PPV group vs. those with PPV/SB
DISCUSSION
19.6% of cases in the PPV cohort were documented to have post-operative PVR vs. 11.8%in the PPV/SB cohort.
The discrepancy between these cohorts can be explained by several factors.
An adjunctive SB provides support to the vitreous base and relieves unwanted secondary traction.
Because of higher rates of re-detachment, it is conceivable more cases of PVR were documented in PPV cohort than in the PPV/SB cohort, where minor cases of PVR were supported by a buckle not leading to further pathology.
Placing a buckle reduces the need for close shaving of the vitreous base potentially resulting in iatrogenic breaks, reducing the risk of PVR development
CONCLUSION
The results of our study show superior anatomical outcomes in eyes undergoing combined PPV/SB vs. PPV alone (91.1% vs 77.4%; OR=0.33; p=0.010).
This data aligns with other studies comparing surgical techniques for retinal detachment repair and at a time where the use of an adjunctive scleral buckle has continued to diminish.
Nevertheless, placing a scleral buckle in addition to vitrectomy may prove beneficial in achieving favorable surgical outcomes in these patients.
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