Giant retinal tears

Incidence of Epiretinal Membrane Formation After Pars Plana Vitrectomy for Giant Retinal Tear-Associated Retinal Detachment

Objective

To report the incidence of postoperative epiretinal membrane (ERM) formation after primary pars plana vitrectomy (PPV) for giant retinal tear associated retinal detachment (GRT-RD) repair as well as its clinical characteristics and visual outcomes at a level one trauma and tertiary referral academic center.

Patients and Methods

Patients with primary RD repair for GRT-RD at West Virginia University from September 2010 to July 2021 were identified using the ICD-10 codes (H33.031, H33.032, H33.033 and H33.039). Imaging studies including optical coherence tomography (OCT) were manually reviewed pre- and post-operatively for ERM formation after PPV for GRT-RD repair in patients who underwent PPV or combined PPV and scleral buckle (SB). Univariate analysis was performed to analyze clinical factors for ERM formation.

Results

The study included 17 eyes of 16 patients who underwent PPV for GRT-RD. Postoperative ERM was observed in 70.6% (13 of 17 eyes) of the patients. Anatomic success was achieved in all patients. The mean (range) preoperative and final best corrected visual acuity (BCVA) in logMAR units by macula status was 0.19 (0-0.5) and 0.28 (0-0.5) for macula-on and 1.7 (0.5-2.3) and 0.7 (0.2-1.9) for macular-off GRT-RDs. Clinical variables including use of medium-term tamponade with perfluorocarbon liquid (PFCL), cryopexy, endodiathermy, number of tears or total clock hours of tears did not correlate with an increased risk of ERM formation.

Conclusion

Post-vitrectomized eyes for GRT-RD repair have a significantly higher incidence of ERM formation, nearing 70% in our study. Surgeons may consider prophylactic ILM peel at the time of removal of tamponade agents or weigh in ILM peel at the time of primary repair, a more challenging surgical technique in our opinion.

Giant Retinal Tears: Long-Term Outcomes of Fellow Eyes

BACKGROUND AND OBJECTIVE

Determine clinical characteristics and long-term outcomes of fellow eyes for patients with prior repair of rhegmatogenous retinal detachments due to a giant retinal tear (GRT).

STUDY DESIGN

Retrospective case series of patients who underwent vitreoretinal surgery between January 2005 and August 2017 for GRT at the Bascom Palmer Eye Institute with a minimum of one year of follow-up information. Patients with a traumatic or post-vitrectomy GRT were excluded.

MAIN OUTCOME MEASURES

Visual acuity and rate of retinal events in fellow eyes.

RESULTS

The study group included 51 patients; 40 others were excluded due to having less than one year of follow-up (n = 27), a history of inciting trauma (n = 11), or a GRT occurring post-vitrectomy (n = 2). The mean age was 49.9 years (range 14 to 81) and mean follow-up duration was 6.9 years (range 1 to 16). During the follow-up interval, prophylactic laser retinopexy was performed in 5 fellow eyes for retinal breaks (9.8%) and in one fellow eye with a progressing retinoschisis cavity (2.0%). One patient had a previous history of a retinal break in the fellow eye. Vitreoretinal surgery was performed in 6 (11.8%) fellow eyes for rhegmatogenous retinal detachments, of which one was caused by a GRT. Three patients (5.9%) already had a retinal detachment repair in the fellow eye prior to presentation and one patient presented with bilateral giant retinal tear associated retinal detachments (GRT-RDs) at the initial visit. Overall, there was a retinal event in 33.3% of fellow eyes. Myopia was the most commonly documented associated factor (31%), followed by lattice degeneration (22%), and known or suspected inherited vitreoretinopathy (4%).

CONCLUSIONS

Retinal tears and/or detachments were encountered relatively frequently in the fellow eye of patients with a history of GRT-RD during follow-up, but the rate of GRTs in the fellow eye (4%) was below what has been generally reported in the literature. Regular dilated fundus exams are warranted for patients with a history of GRT. [Ophthalmic Surg Lasers Imaging Retina 2022;53:619-625.].

A Novel Transcriptome Approach to the Investigation of the Molecular Pathology of Vitreous and Retinal Detachment

Retinal detachment (RD) is one of the most common, sight-threatening ocular conditions requiring emergency intervention. Posterior vitreous detachment (PVD) occurs in the majority of an aging population whereby the vitreous body separates from the retina. It is well established that PVD is the common precursor to the most common forms of RD; however, it remains unknown why in most individuals PVD will cause no/few complications (physiological PVD) but in a small percentage will cause retinal tears and detachment (pathological PVD). Despite over 100 years of scientific research, the anatomical definitions of PVD and its pathogenesis remain controversial. Recent research has identified a novel cell population (laminocyte), present at significantly higher numbers in pathological PVD when compared to physiological PVD. We review and summarise the seven distinct clinical sub-groups of retinal breaks and focus on the role of the laminocyte in those secondary to PVD and the transcriptomic profile of this unique cell. Provisional whole transcriptome analysis using bulk RNA-Seq shows marked differentially expressed genes when comparing physiological PVD with PVD associated with RD. The limitations of bulk RNA-Seq are considered and the potential to address these using spatial transcriptomics are discussed. Understanding the pathogenesis of PVD-related retinal tears will provide a baseline for the development of novel therapeutic targets and prophylactic treatments.

Vitrectomy versus Vitrectomy with Scleral Buckling in the Treatment of Giant Retinal Tear Related Retinal Detachments: An International Multicenter Study

PURPOSE

To determine the practice pattern for treating giant retinal tear (GRT) related detachments, and their anatomic and visual outcomes with pars plana vitrectomy (PPV) with or without scleral buckling (SB).

DESIGN

Retrospective cohort study.

SUBJECTS

Eyes with GRT detachments repaired from 2008-2020 with at least 6 months of follow-up from seven institutions in North and South America, Europe, and Asia.

METHODS

Eyes repaired using PPV versus PPV/SB were compared.

MAIN OUTCOME MEASURES

Anatomic and functional outcomes.

RESULTS

A comparable number of eyes underwent PPV (n=101) and PPV/SB (n=99). Except for prior intraocular surgery and lens status, no differences in baseline demographics, ocular characteristics, or intraoperative surgical adjuncts were observed. Overall single surgery anatomic success (SSAS) at 6 months and 1 year was similar between the groups (82.2% and 77.2% of PPV, and 87.9% and 85.7% of PPV/SB). However, when stratified by age, the 1-year SSAS rate was higher for PPV/SB (88.5%) than PPV (56.3%) (p=0.03) for children < 18 years. For both children and adults, mean best corrected visual acuity (BCVA) at baseline did not differ between the PPV and PPV/SB groups. However, for children, mean BCVA at 1 year was better in the PPV/SB than PPV groups (p=0.001) while for adults, no difference was found between the two groups. The mean time to first redetachment was 7.9 months in the PPV group and 5.5 months in the PPV/SB group (p=0.8). PVR was the most common cause for redetachment (70.4% of PPV and 93.8% of PPV/SB in redetached eyes; p=0.1). Postoperative complications were also similar between the two groups including ocular hypertension, epiretinal membrane, and cataract.

CONCLUSIONS

PPV and PPV/SB are equally popular among surgeons globally for managing GRT detachments and have comparable anatomic and visual outcomes in adults. In children, PPV/SB is superior to PPV for anatomic and functional success at one year. In adults, the relief of traction by the GRT may reduce peripheral traction and obviate the need for a SB. However, in children, a supplemental SB can be beneficial as complete vitreous shaving and posterior hyaloid detachment, and postoperative positioning are difficult in this group.

Successful surgical outcomes after 23-, 25- and 27-gauge vitrectomy without scleral encircling for giant retinal tear

PURPOSE

Retinal detachment due to giant retinal tears (GRTs), tears larger than 90°, is rare and difficult to treat. Here, we show and compare surgical results of 23-, 25- and 27-gauge (G) micro-incision vitrectomy surgery (MIVS) for GRT.

STUDY DESIGN

Retrospective and interventional case series.

METHODS

Retrospective review of 41 eyes of 38 patients with GRT who underwent MIVS. Surgical outcomes after MIVS, including reattachment rates and postoperative complications, were compared between instrument gauges. All patients were followed for at least 6 months postoperatively.

RESULTS

MIVS with 23G, 25G and 27G instruments was performed in 7, 19 and 15 eyes, respectively. Silicone oil (SO) was used in 34 of 41 eyes (83%) with a mean removal time of 43.8 days after first surgery. Best-corrected visual acuity (BCVA) was recovered or maintained in 39 eyes (95%). Reattachment was attained after initial surgery in 38 of 41 eyes (93%) (23G: 6/7 [86%]; 25G: 17/19 [89%]; 27G: 15/15 [100%]). Final reattachment was eventually achieved in all eyes (two eyes needed support from scleral encircling). Postoperative complications occurred in 16 eyes (39%) (23G: 3/7 [43%]; 25G: 8/19 [42%]; 27G: 5/15 [33%]), including macular pucker, cystoid macular edema, macular hole, subretinal perfluorocarbon liquid, retinal folds, vitreous hemorrhage and redetachment. There were no significant differences between the three groups in rate of high myopia, GRT size, operation time, phacovitrectomy rate, SO usage rate, initial reattachment rate, final reattachment rate, preoperative BCVA, final BCVA or rate of postoperative complications.

CONCLUSION

Despite occasional postoperative complications, primary MIVS, regardless of gauge size, appears to be a safe and feasible option for GRT surgery.

Pars plana vitrectomy combined with scleral buckle versus pars plana vitrectomy for giant retinal tear

BACKGROUND

A giant retinal tear (GRT) is a full-thickness neurosensory retinal break extending for 90° or more in the presence of a posterior vitreous detachment.

OBJECTIVES

To evaluate the effectiveness and safety of pars plana vitrectomy combined with scleral buckle versus pars plana vitrectomy alone for eyes with giant retinal tear.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 8), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Literature on Health Sciences (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in our electronic search. We last searched the electronic databases on 16 August 2018.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) comparing pars plana vitrectomy combined with scleral buckle versus pars plana vitrectomy alone for giant retinal tear regardless of age, gender, lens status (e.g. phakic or pseudophakic eyes) of the affected eye(s), or etiology of GRT among participants enrolled in these trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed titles and abstracts, then full-text articles, using Covidence. Any differences in classification between the two review authors were resolved through discussion. Two review authors independently abstracted data and assessed risk of bias of included trials.

MAIN RESULTS

We found two RCTs in abstract format (105 participants randomized). Neither RCT was published in full. Based on the data presented in the abstracts, scleral buckling might be beneficial (relative risk of re-attachement ranged from 3.0 to 4.4), but the findings are inconclusive due to a lack of peer reviewed publication and insufficient information for assessing risk of bias.

AUTHORS' CONCLUSIONS

We found no conclusive evidence from RCTs on which to base clinical recommendations for scleral buckle combined with pars plana vitrectomy for giant retinal tear. RCTs are clearly needed to address this evidence gap. Such trials should be randomized, and patients should be classified by giant retinal tear characteristics (extension (90º, 90º to 180º, > 180º), location (oral, anterior, posterior to equator)), proliferative vitreoretinopathy stage, and endotamponade. Analysis should include both short-term (three months and six months) and long-term (one year to two years) outcomes for primary retinal reattachment, mean change in best corrected visual acuity, study eyes that required second surgery for retinal reattachment, and adverse events such as elevation of intraocular pressure above 21 mmHg, choroidal detachment, cystoid macular edema, macular pucker, proliferative vitreoretinopathy, and progression of cataract in initially phakic eyes.

Analysis of genetic networks regulating refractive eye development in collaborative cross progenitor strain mice reveals new genes and pathways underlying human myopia

BACKGROUND

Population studies suggest that genetic factors play an important role in refractive error development; however, the precise role of genetic background and the composition of the signaling pathways underlying refractive eye development remain poorly understood.

METHODS

Here, we analyzed normal refractive development and susceptibility to form-deprivation myopia in the eight progenitor mouse strains of the Collaborative Cross (CC). We used RNA-seq to analyze gene expression in the retinae of these mice and reconstruct genetic networks and signaling pathways underlying refractive eye development. We also utilized genome-wide gene-based association analysis to identify mouse genes and pathways associated with myopia in humans.

RESULTS

Genetic background strongly influenced both baseline refractive development and susceptibility to environmentally-induced myopia. Baseline refractive errors ranged from - 21.2 diopters (D) in 129S1/svlmj mice to + 22.0 D in CAST/EiJ mice and represented a continuous distribution typical of a quantitative genetic trait. The extent of induced form-deprivation myopia ranged from - 5.6 D in NZO/HILtJ mice to - 20.0 D in CAST/EiJ mice and also followed a continuous distribution. Whole-genome (RNA-seq) gene expression profiling in retinae from CC progenitor strains identified genes whose expression level correlated with either baseline refractive error or susceptibility to myopia. Expression levels of 2,302 genes correlated with the baseline refractive state of the eye, whereas 1,917 genes correlated with susceptibility to induced myopia. Genome-wide gene-based association analysis in the CREAM and UK Biobank human cohorts revealed that 985 of the above genes were associated with myopia in humans, including 847 genes which were implicated in the development of human myopia for the first time. Although the gene sets controlling baseline refractive development and those regulating susceptibility to myopia overlapped, these two processes appeared to be controlled by largely distinct sets of genes.

CONCLUSIONS

Comparison with data for other animal models of myopia revealed that the genes identified in this study comprise a well-defined set of retinal signaling pathways, which are highly conserved across different vertebrate species. These results identify major signaling pathways involved in refractive eye development and provide attractive targets for the development of anti-myopia drugs.

Giant retinal tears: clinical features and outcomes of vitreoretinal surgery at a university teaching hospital (2011-2017)

Purpose

The purpose of this study was to report clinical features and outcomes in patients with giant retinal tears (GRTs) undergoing vitreoretinal surgery and to compare data from this contemporary series to a previous study from the same institution.

Materials and methods

A retrospective, interventional, consecutive case series was conducted for all patients diagnosed with GRTs who underwent vitreoretinal surgery between January 2011 and August 2017. Intraoperative data including the use of scleral buckling, perfluorocarbon liquid, and intraocular tamponade were collected and compared according to GRT size. These parameters, along with postoperative anatomic success and best-corrected visual acuity (BCVA), were compared with the previous series.

Results

The study included 80 eyes of 79 patients with a presentation of retinal detachment with a GRT. Management approach for repair of GRT-associated retinal detachments included scleral buckle (SB) alone (three eyes, 4%), pars plana vitrectomy (PPV) (16 eyes, 20%), and combined SB/PPV (61 eyes, 76%). Perfluorocarbon liquids were used in 60/77 eyes (78%) undergoing PPV, and silicone oil was used in 54/77 eyes (70%). Single surgery success rate was in 69/80 eyes (86%). Eyes managed with SB (including SB alone and SB/PPV) or PPV without SB had similar rates of recurrent retinal detachment (16% vs 6%; P=0.33). Anatomic success was achieved in 76/80 eyes (95%) with one or more surgical procedures, and 54/80 eyes (68%) achieved postoperative BCVA of ≥20/400.

Conclusions

In the current series, repairs of retinal detachment due to GRTs were most commonly managed with combined PPV/SB and perfluorocarbon liquid, resulting in reasonably generally favorable anatomic and visual outcomes.

TWENTY-FIVE-GAUGE PARS PLANA VITRECTOMY IN COMPLEX RETINAL DETACHMENTS ASSOCIATED WITH GIANT RETINAL TEAR

PURPOSE

To study the structural and functional outcomes of 25-gauge pars plana vitrectomy in giant retinal tear-associated retinal detachments.

METHODS

Seventeen eyes of 17 patients with giant retinal tear, who underwent 25-gauge pars plana vitrectomy over a period of 15 months at a tertiary eye care center by a single surgeon, were recruited in this retrospective interventional study.

RESULTS

Giant retinal tears were mostly traumatic (35.3%) or associated with myopia (35.3%) and occurred in young (mean age 25.7 years) males (94.1%). Most eyes had best-corrected visual acuity ≤20/1,200 (in 82.3%), foveal detachment (in 88.2%), and proliferative vitreoretinopathy ≤Grade B (in 82.3%). The giant retinal tear extent was more than 180° in 29.4% and the fellow eye was involved in 35.2% of eyes. All eyes underwent 25-gauge pars plana vitrectomy with encircling band in 41.1%, perfluorocarbon liquid use in 82.3%, and endotamponade with sulphur hexafluoride (23.6%) or silicone oil (76.4%). At mean follow-up of 10.2 months, reattachment rate was 88.2%. Only 35.2% of eyes achieved final visual acuity ≥20/80 with a cause of poor vision being cataract, secondary glaucoma, macular pucker, and corneal edema.

CONCLUSION

Twenty-five-gauge pars plana vitrectomy can achieve excellent attachment rates in eyes with giant retinal tear-associated retinal detachment. It can be as efficient as larger-gauge vitrectomy, at the same time retaining all advantages of smaller-gauge surgery.

The importance of early diagnosis of Stickler syndrome: Finding opportunities for preventing blindness

Stickler Syndrome (SS) is a significant cause of retinal blindness in children. The immediate cause of blindness is retina detachment from giant retinal tear (GRT). It is frequently diagnosed late and the giant retinal tear (GRT) may be complicated by high-grade proliferative vitreoretinopathy (PVR). The surgery for the combined GRT with PVR has limited structural results and the vision mainly remains impaired. In order to improve the visual outcomes, we propose an organized program oriented toward early diagnosis and surveillance. Adding an effective prophylaxis may maintain normal vision in a high percent of patients. The critical diagnostic moments for this program are prenatal and at birth. The tools include a directed history, general physical exam and advanced ophthalmologic exam looking for the particular features of SS. Some features may need advanced skills transfer, because they are not reliably taught in retina fellowships. Much of this program requires a partnership with obstetricians, pediatricians, neonatologists and geneticists. Finally, we review the evidence regarding prophylaxis and discuss our approach in the absence of guidance from a randomized clinical trial.

Silicone oil versus gas tamponade for giant retinal tear-associated fovea-sparing retinal detachment: a comparison of outcome

PurposeSilicone oil is the most common choice of tamponade agent used when managing a giant retinal tear (GRT). Concern exists regarding its potential detrimental effect on vision. We herein report on visual and surgical outcomes of all patients treated at Moorfields Eye Hospital for a GRT over a five year period. We further analysed a subgroup of fovea-sparing retinal detachments (RD) treated by pars plana vitrectomy (PPV) with either silicone oil or gas tamponade.MethodsRetrospective comparative, non-randomised, cross-sectional review of patients with a new diagnosis of GRT from 1 September 2005 to 31 August 2010ResultsOne hundred twenty four eyes of 118 patients were identified with mean age of 45.5 years and median follow-up of 24 months. Subgroup analysis of fovea-sparing RDs (Silicone Oil n=49, Gas n=15) revealed visual loss (≥2 Snellen Lines of vision) in 49.0% (n=24) of patients managed with oil compared to 13.3% (n=2) of gas patients (P=0.019). In all, 73.3% (n=11) in the gas group achieved a final vision of 6/12 or better, compared to 36.7% (n=18) in the oil group (P=0.031). No difference was observed in eventual or primary anatomical success rate (100 vs 93.9%, and 66.7 vs 79.6%, gas vs oil, respectively, (P>0.1)). Postoperative complications were absent in 66.7% (n=10) of gas patients compared with 14.3% (n=7) of oil patients (P=0.002). Multiple variable linear regression determined tamponade choice as the only variable predictive of final visual acuity (P=0.046).ConclusionEyes with fovea-sparing GRT-related RDs managed with gas achieved a better visual outcome with fewer postoperative complications and no significant difference in anatomical success. A multicentre approach to investigate this further is advised.

Management of Giant Retinal Tear Detachments

Giant retinal tears (GRTs) are full-thickness circumferential tears of more than 90 degrees of the retina that are associated with vitreous detachment. They are related to ocular trauma, high myopia, aphakia, pseudophakia, genetic mutations involving collagen and young age. GRTs comprise 1.5% of all rhegmatogenous retinal detachments and the average age of incidence is 42 years. GRTs are more common in males, as 72% of all cases occur in males. The incidence of GRTs in the general population is estimated to be 0.05 per 100,000 individuals. Common techniques used in the management of GRTs include fluid-air exchange, pneumatic retinopexy, scleral buckling, primary vitrectomy with gas or silicone oil tamponade, and combined scleral buckle-vitrectomies. However, management of GRTs poses a great challenge to physicians due to the high risk of intra- and post-operative complications and the many technical difficulties involved. The advent of perfluorocarbon liquids (PFCL) and the use of micro-incisional surgery for the treatment of GRTs has provided new opportunities for the management of GTRs. Today, retinal reattachment can be achieved in 94-100% of cases.

Contemporary Management of Rhegmatogenous Retinal Detachment Due to Giant Retinal Tears: A Consecutive Case Series

BACKGROUND AND OBJECTIVE

To investigate outcomes of contemporary surgical techniques for repair of rhegmatogenous retinal detachments (RRD) associated with giant retinal tears (GRT).

PATIENTS AND METHODS

Retrospective, consecutive case series including 58 eyes of 58 patients. Mean age was 52 years (range: 16 to 83 years). All patients underwent 23-gauge pars plana vitrectomy with use of perfluorocarbon liquid and intravitreal tamponade (28 with silicone oil, 25 with octafluoropropane gas, and five with sulfur hexafluoride gas). Scleral buckle (SB) was placed in 30 eyes (52%).

RESULTS

At a mean follow-up of 17 months, mean visual acuity improved from 20/500 preoperatively to 20/88 at final follow-up. Fifty-one patients (88%) had single-surgery anatomic success, and all patients achieved final retinal reattachment. Use of SB (P = 1.0), silicone oil (P = .1), or 360° endophotocoagulation (P = .7) did not correlate with higher rates of successful repair.

CONCLUSION

Contemporary vitreoretinal surgery techniques achieve high rates of primary anatomic success in GRT-related RRDs.

Giant retinal tears

A giant retinal tear (GRT) is a full-thickness neurosensory retinal break that extends circumferentially around the retina for three or more clock hours in the presence of a posteriorly detached vitreous. Its incidence in large population-based studies has been estimated as 1.5% of rhegmatogenous retinal detachments, with a significant male preponderance, and bilaterality in 12.8%. Most GRTs are idiopathic, with trauma, hereditary vitreoretinopathies and high myopia each being causative in decreasing frequency. The vast majority of GRTs are currently managed with a pars plana vitrectomy; the use of adjunctive circumferential scleral buckling is debated, but no studies have shown a clear anatomical or visual advantage with its use. Similarly, silicone oil tamponade does not influence long-term outcomes when compared with gas. Primary and final retinal reattachment rates are achieved in 88% and 95% of patients, respectively. Even when the retina remains attached, however, visual recovery may be limited. Furthermore, fellow eyes of patients with a GRT are at higher risk of developing retinal tears and retinal detachment. Prophylactic treatment under these circumstances may be considered but there is no firm evidence of its efficacy at the present time.

Interventions for prevention of giant retinal tear in the fellow eye

BACKGROUND

A giant retinal tear is a full-thickness retinal break that extends circumferentially around the retina for 90 degrees or more in the presence of a posteriorly detached vitreous. It causes significant visual morbidity from retinal detachment and proliferative vitreoretinopathy. The fellow eye of patients who have had a spontaneous giant retinal tear has an increased risk of developing a giant retinal tear, a retinal detachment or both. Interventions such as 360-degree encircling scleral buckling, 360-degree cryotherapy and 360-degree laser photocoagulation have been advocated by some ophthalmologists as prophylaxis for the fellow eye against the development of a giant retinal tear and/or a retinal detachment, or to prevent its extension.

OBJECTIVES

To evaluate the effectiveness of prophylactic 360-degree interventions in the fellow eye of patients with unilateral giant retinal tear to prevent the occurrence of a giant retinal tear, a retinal detachment or both.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 11), MEDLINE (January 1950 to December 2011), EMBASE (January 1980 to December 2011), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to December 2011), 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). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 6 December 2011. In addition, we searched the proceedings of the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) up to 2008 for information about other relevant studies.

SELECTION CRITERIA

Prospective randomised controlled trials (RCTs) comparing one prophylactic treatment for fellow eyes of patients with giant retinal tear against observation (no treatment) or another form of prophylactic treatment. In the absence of RCTs, we planned to discuss case-control studies that met the inclusion criteria but we would not conduct a meta-analysis using these studies.

DATA COLLECTION AND ANALYSIS

We did not find any studies that met the inclusion criteria for the review and therefore no assessment of methodological quality or meta-analysis could be performed.

MAIN RESULTS

No studies met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

No strong evidence in the literature was found to support or refute prophylactic 360-degree treatments to prevent a giant retinal tear or a retinal detachment in the fellow eye of patients with unilateral giant retinal tears.

Interventions for prevention of giant retinal tear in the fellow eye

BACKGROUND

A giant retinal tear is a full-thickness retinal break that extends circumferentially around the retina for 90 degrees or more in the presence of a posteriorly detached vitreous. It causes significant visual morbidity from retinal detachment and proliferative vitreoretinopathy. The fellow eye of patients who have had a spontaneous giant retinal tear has an increased risk of developing a giant retinal tear, a retinal detachment or both. Interventions such as 360-degree encircling scleral buckling, 360-degree cryotherapy and 360-degree laser photocoagulation have been advocated by some ophthalmologists as prophylaxis for the fellow eye against the development of a giant retinal tear and/or a retinal detachment, or to prevent its extension.

OBJECTIVES

To evaluate the effectiveness of prophylactic 360-degree interventions in the fellow eye of patients with unilateral giant retinal tear to prevent the occurrence of a giant retinal tear and/or a retinal detachment.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2008, Issue 4), MEDLINE (January 1950 to December 2008), EMBASE (January 1980 to December 2008) and Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to December 2008). In addition, we searched the proceedings of the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) up to 2008 for information about other relevant studies. There were no language or date restrictions in the search for trials. The electronic databases were last searched on 15 December 2008.

SELECTION CRITERIA

Prospective randomised controlled trials (RCTs) comparing one prophylactic treatment for fellow eyes of patients with giant retinal tear against observation (no treatment) or another form of prophylactic treatment. In the absence of RCTs, we planned to discuss case-control studies that met the inclusion criteria but we would not conduct a meta-analysis using these studies.

DATA COLLECTION AND ANALYSIS

We did not find any studies that met the inclusion criteria for the review and therefore no assessment of methodological quality or meta-analysis could be performed.

MAIN RESULTS

No studies met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

No strong evidence in the literature was found to support or refute prophylactic 360-degree treatments to prevent a giant retinal tear or a retinal detachment in the fellow eye of patients with unilateral giant retinal tears.

Clinical features and surgical management of retinal detachment secondary to round retinal holes

AIMS

The majority of rhegmatogenous retinal detachments result from pathological posterior vitreous detachment (PVD) and secondary horseshoe or giant retinal tears. Retinal detachment without PVD is usually associated with either retinal dialysis or round retinal holes. This study characterises the features, surgical outcome, and incidence of bilateral involvement of detachment associated with round retinal holes.

METHODS

In all, 110 retinal detachments from 96 consecutive patients with retinal detachment secondary to round retinal holes were studied. Analysis of patient age, sex, refraction, preoperative visual acuity, presented symptoms, position and extent of detachment, number and distribution of holes present, posterior hyaloid membrane status, surgical management, outcome of surgery, and postoperative visual acuity were studied.

RESULTS

The mean age for patients was 34 years with a marked female preponderance (64%) and myopia (83%). The posterior hyaloid membrane remained attached in 95 eyes (86%). In all, 45% patients had bilateral pathology, of which 33% had 'mirror image' distribution. Detachments were predominantly shallow (93%) and slow in progression (17%). A total of 100 detachments were repaired with cryotherapy and scleral buckling, eight with cryotherapy alone, and one with laser retinopexy. In all, 99% detachments were successfully reattached with a single procedure. The mean follow-up period was 2 years. There were no instances of redetachment.

CONCLUSIONS

Round hole detachments are slowly evolving detachments with attached vitreous gel in young, predominantly female myopes. Examination of the fellow eye should be mandatory as there is a high incidence of bilateral pathology. Scleral buckling procedures remained highly effective in this selected group of patients.

A model for the fluid motion of vitreous humour of the human eye during saccadic movement

During saccadic motion the eyewall moves in a manner similar to a sinusoid or at least can be represented by a sine Fourier series. Motion of the vitreous is induced by the saccade and the vitreo-retinal interface is subjected to a time-dependent shear. This force may be a significant factor for retinal tearing in the neighbourhood of small retinal holes or tears. An analytical viscoelastic model and a numerical, Newtonian model of the motion of the vitreous are presented and compared. Under sinusoidal boundary motion the analytical model shows that a viscous wave propagates inward toward the axis of rotation and the characteristic length of this wave is a function of the Womersley number. The numerical solution indicates that the vitreous moves similarly to the analytical result with small secondary motion; however, this motion allows complete recirculation of the vitreous over large timescales. Excellent agreement is found between the analytical and numerical models. The time-dependent fluid shear is evaluated and from the analytical solution the maximum value of this is found to be proportional to R0 square root of v(omega)3, where R0 is the eye radius, v the modified complex viscosity and omega the sinusoidal frequency. This indicates that myopes have a larger shear force exerted on them by virtue of the larger eye size. Further work is directed toward a model which links the stress found in the sclera to that exerted on the vitreo-retinal interface by the vitreous fluid motion.

Time-dependent stress and displacement of the eye wall tissue of the human eye

Myopia or short sightedness, is the most important predisposing factor to retinal detachment. The relative risk of detachment rises with increasing myopia. The model characterizes that because the severity of myopia increases with the axial length (antero-posterior diameter) of the eyeball, the relative risk of retinal detachment rises with increasing eye size. We present a mathematical model of the time-dependent shear stress force that occurs in the thin eye wall shell supporting the vitreous humour inside the eye globe during the acceleration and deceleration phases of saccadic eye movement. Results show that the shear force increases as the thickness of the eye wall decreases. It is common for myopes to have thinner eye wall tissue than emmetropes. In addition, if account is taken of the increased force required to provide normal saccadic movement of myopic (larger) eyes, then the shear force is up to seven times greater than that experienced for emmetropes.

Vitrectomy and fluid/silicone-oil exchange for giant retinal tears: results at six months

The results of vitrectomy combined with fluid/silicone-oil exchange in 73 eyes with giant retinal tears are reported at six months after surgery. Initial anatomical success was achieved in 71 out of 73 eyes (97%) and, prior to removal of silicone-oil, in 66 out of 73 eyes (90%). In 63 eyes (86%) the retina remained attached six months after surgery. Of these visual acuity was 6/60 or better in 44 (70%). The high proportion of eyes with macular detachment before surgery and the frequency of macular abnormalities are thought to account for reduced vision in many of the anatomically successful cases.