Vitreoretinal surgery for complications of branch retinal vein occlusion

Case series of branch retinal vein occlusion secondary to rhegmatogenous retinal detachment and its surgical management

BACKGROUND

To review cases of branch retinal vein occlusion (BRVO) secondary to rhegmatogenous retinal detachment (RRD) and its surgical management and presume their mechanism.

METHODS

Medical records of patients who underwent surgery for RRD between 2015 and 2019 at a single tertiary care center were retrospectively reviewed. New BRVO secondary to RRD or its surgical procedure was diagnosed based on the fundus examination and its clinical course.

RESULTS

A total of 734 RRD surgeries were performed for five years, and six cases of new BRVOs were noticed in the first year after surgery (incidence was 0.68%: six cases of BRVO / 734 cases of surgical RRD); five cases occurred after vitrectomy, and one occurred after scleral buckling. In three cases, retinal veins were presumed to already be partially occluded related due to a kink of the retinal vein seen before surgery. In the other three cases, the retinal veins were presumed to have incurred damage during vitrectomy.

CONCLUSION

In the present cohort, RRD or its related procedures caused BRVO within a year of surgery at an incidence of 0.68%. The proposed mechanisms are kinks of the retinal vein on the detached retina and damage to the retinal vein during vitrectomy.

Update on Retinal Vein Occlusion

Retinal vein occlusion represents the second leading cause of retinal vascular disorders, with a uniform sex distribution worldwide. A thorough evaluation of cardiovascular risk factors is required to correct possible comorbidities. The diagnosis and management of retinal vein occlusion have changed tremendously in the last 30 years, but the assessment of retinal ischemia at baseline and during follow-up examinations remains crucial. New imaging techniques have shed light on the pathophysiology of the disease and laser treatment, once the only therapeutic option, is now only one of the possible approaches with antivascular endothelial growth factors and steroid injections being preferred in most cases. Nowadays long-term outcomes are better than those achievable 20 years ago and yet, many new therapeutic options are under development, including new intravitreal drugs and gene therapy. Despite this, some cases still develop sight-threatening complications deserving a more aggressive (sometimes surgical) approach. The purpose of this comprehensive review is to reappraise some old but still valid concepts and to integrate them with new research and clinical data. The work will provide an overview of the disease's pathophysiology, natural history, and clinical features along with a detailed discussion on the advantages of multimodal imaging and of the different treatment strategies with the aim of providing retina specialists with the most updated knowledge in the field.

Risk Factors and Treatment Strategy for Retinal Vascular Occlusive Diseases

Retinal occlusive diseases are common diseases that can lead to visual impairment. Retinal artery occlusion and retinal vein occlusion are included in the clinical entity, but they have quite different pathophysiologies. Retinal artery occlusion is an emergent eye disorder. Retinal artery occlusion is mainly caused by thromboembolism, which frequently occurs in conjunction with life-threatening stroke and cardiovascular diseases. Therefore, prompt examinations and interventions for systemic vascular diseases are often necessary for these patients. Retinal vein occlusion is characterized by retinal hemorrhage and ischemia, which may impair visual function via several complications such as macular edema, macular ischemia, vitreous hemorrhage, and neovascular glaucoma. Even though anti-vascular endothelial growth factor therapy is the current established first-line of treatment for retinal vein occlusion, several clinical studies have been performed to identify better treatment protocols and new therapeutic options. In this review, we summarize the current findings and advances in knowledge regarding retinal occlusive diseases, particularly focusing on recent studies, in order to provide an update for a better understanding of its pathogenesis.

Modeling retinal detachment associated with hemorrhage by Monte Carlo simulation

In this work we study fundus reflection in the case of retinal detachment. Vitreous humor builds up beneath the retina through a break in the retina or when there is traction on the retina. Further, we assume that this detachment is associated with hemorrhage in regions both above and below the retina. To investigate hemorrhage, we assume erythrocytes to be spheres of different radii. Then we apply Mie scattering theory to these spheres and calculate the scattering coefficient, the absorption coefficient, and the anisotropy factor. Using these parameters, we apply Monte Carlo simulation to calculate reflection. In order to model fundus reflection under retinal detachment, we define three types of reflection: reflection from the vitreous body, retinal reflection where photons are reflected from the retinal vitreous interface once, and retinal reflection where photons are reflected many times from the retinal vitreous interface.

Guidelines for the Management of Retinal Vein Occlusion by the European Society of Retina Specialists (EURETINA)

The high prevalence of cardiovascular disease particularly in the elderly population is associated with retinal vascular disease. Retinal vein occlusions represent severe disturbances of the hypoxia-sensitive neurosensory retina. Acute and excessive leakage leads to the diagnostic hallmarks of retinal hemorrhage and edema with substantial retinal thickening. Advanced diagnostic tools such as OCT angiography allow to evaluate retinal ischemia and identify the risk for late complications and will soon reach clinical routine besides fluorescein angiography. Accordingly, the duration of non-perfusion is a crucial prognostic factor requiring timely therapeutic intervention. With immediate inhibition of vascular leakage, anti-VEGF substances excel as treatment of choice. Multiple clinical trials with optimal potential for functional benefit or a lesser regenerative spectrum have evaluated aflibercept, ranibizumab, and bevacizumab. As retinal vein occlusion is a chronic disease, long-term monitoring should be individualized to combine maintenance with practicability. While steroids may be considered in patients with systemic cardiovascular risk, surgery remains advisable only for very few patients. Destructive laser treatment is an option if reliable monitoring is not feasible. Ophthalmologists are also advised to perform a basic systemic workup to recognize systemic concomitants. The current edition of the EURETINA guidelines highlights the state-of-the-art recommendations based on the literature and expert opinions in retinal vein occlusion.

The Efficacy of Intravitreal Triamcinolone Acetonide on Macular Edema in Branch Retinal Vein Occlusion

PURPOSE

To evaluate the effectiveness of intravitreal triamcinolone acetonide as primary treatment of macular edema in branch retinal vein occlusion.

METHODS

Fifteen eyes of 15 patients with macular edema due to branch retinal vein occlusion (Group 1) who received 8 mg/0.2 ml of intravitreal triamcinolone injection as primary treatment were retrospectively evaluated. The control group (Group 2) consisted of 19 eyes of 19 patients who had received laser treatment for macular edema. The main outcome measures included best-corrected visual acuity, intraocular pressure, and macular edema map values of Heidelberg Retinal Tomograph II.

RESULTS

In Group 1, mean visual acuity improved significantly from a mean logMAR (logarithm of minimal angle of resolution) value of 0.98+/-0.19 at baseline to a maximum of 0.24+/-0.24 during a mean follow-up time of 6.3 months. In the control group, the mean baseline log-MAR visual acuity before laser treatment was 1.02+/-0.22, and it was 0.50+/-0.28 at 6-month examinations. Mean improvement in visual acuity at 1-, 3-, and 6-month examinations was significantly higher in Group 1 when compared with the control group (for each, p<0.001). The mean edema map value of Group 1 significantly decreased by 40% at 6-month examinations when compared with preinjection value (p<0.001). In Group 1, mean increase in intraocular pressure elevation was 19.8% at the 1-month, 26.9% at 3-month, and 5.7% at 6-month visits, but intraocular pressures were under control with topical antiglaucomatous medications.

CONCLUSIONS

Intravitreal triamcinolone acetonide injection may be a new and promising approach as initial therapy for macular edema due to branch retinal vein occlusion.

Effect of prophylactic 360° laser treatment for prevention of retinal detachment after phacovitrectomy: (Prophylactic 360° laser treatment for prevention of retinal detachment)

Background

To investigate the effect of intraoperative 360° laser retinopexy anterior to the equator for the prevention of retinal detachment after phacovitrectomy.

Methods

The patients were part of two consecutive case series cohorts in macular hole (MH) and rhegmatogenous retinal detachment (RRD), one which did not receive intraoperative prophylactic 360° laser, and one which received intraoperative prophylactic 360° laser. For the 360° laser treatment group, three rows of medium-white burns were positioned anterior to the equator. The baseline characteristics and the risk of retinal detachment over time were analyzed and compared between the groups.

Results

Prophylactic intraoperative 360° laser treatment was performed on 77 MH cases (67.3 years) and compared to a control group of 35 MH cases (65.8 years). Additionally, prophylactic intraoperative 360° laser treatment was performed on 108 RRD cases (64.0 years) and compared to 270 RRD cases (64.4 years). The 360° laser group showed a significant reduction (0%, 0/77 eyes) in the rate of the incidence of retinal detachment after vitrectomy at 12 months after surgery in MH cases, compared with the control group (5.7%, 2/35 eyes) (p = 0.034). Kaplan-Meier survival analysis demonstrated that the rate of retinal detachment in the control group was significantly higher than that in the 360° laser group (p = 0.035). There was no significant difference between the groups in RRD cases (p = 0.092).

Conclusions

Intraoperative 360° laser retinopexy following phacovitrectomy resulted in a significant reduction in the rate of postoperative retinal detachment in MH cases.

Investigation of gold-coated bare fiber probe for in situ intra-vitreous coherence domain optical imaging and sensing

We have investigated the usage of gold-plated bare fiber probes for in situ imaging of retinal layers and surrounding ocular tissues using time-domain common-path optical coherence tomography. The fabricated intra-vitreous gold-plated micro-fiber probe can be fully integrated with surgical tools working in close proximity to the tissue to provide subsurface images having a self-contained reference plane independent to the Fresnel reflection between the distal end of the probe and the following medium for achieving reference in typical common-path optical coherence tomography. We have fully characterized the probe in an aqueous medium equivalent to the vitreous humor in the eye and were able to differentiate various functional retinal tissue layers whose thickness is larger than the system's resolution.

Sheathotomy in complicated cases of branch retinal vein occlusion

PURPOSE

To report the clinical experience and results of using a microsurgical technique to decompress the arteriovenous connection in complicated branch retinal vein occlusion (BRVO) combined with haemorrhage, oedema and ischaemia.

METHODS

We carried out a retrospective, non-randomized, interventional case study of the surgical sheathotomy decompression procedure. We enrolled 12 patients (seven women, five men; median age 64 years) with BRVO and decreased visual acuity (VA) caused by haemorrhage, oedema and ischaemia. The mean duration of thrombosis was 7 months (2-15 months). The patients were examined for pre- and postoperative best corrected VA (BCVA), intraocular pressure (IOP) and fundus photography. Ten patients were examined with fluorescein angiography and eight with ocular coherence tomography (OCT). Postoperative progression of cataract was recorded, as were other complications. The mean follow-up time was 20 months (8-39 months).

RESULTS

Best corrected VA had improved in nine patients, was unchanged in one patient and had deteriorated in two patients at the last follow-up. Noted complications were venous haemorrhage at surgery in five patients, retinal detachment in one patient and progression of cataract in four patients.

CONCLUSIONS

Microsurgical treatment with sheathotomy of BRVO is a technically feasible procedure with few complications. Postoperative increased reperfusion could explain the resolution of macular haemorrhage, oedema and ischaemia, and may improve visual function in patients with this common vascular eye disease.

Evaluation of arteriovenous crossing sheathotomy for decompression of branch retinal vein occlusion

PURPOSE

To report the effects of arteriovenous adventitial sheathotomy on anatomical and functional improvements in patients with macular oedema due to branch retinal vein occlusion (BRVO).

METHODS

Pars plana vitrectomy and arteriovenous sheathotomy was performed on 11 patients with BRVO who had vision loss due to macular oedema. Ten patients with macular oedema due to BRVO and who have been treated with grid laser photocoagulation were included in the control group. The measurement of visual acuity with ETDRS chart was taken preoperatively and at 1, 3, 6, and 9 months follow-up in the study group and at 1, 3, 6, and 9 months after grid laser in the control group.

RESULTS

The mean preoperative logMAR visual acuity was 0.84+/-0.3 in the surgical group and 1.06+/-0.4 in the control group. The postoperative mean logMAR visual acuity was 0.41+/-0.2, 0.40+/-0.2, 0.40+/-0.3, and 0.36+/-0.3 at 1, 3, 6, and 9 months follow-up, respectively. In the control group the postlaser mean logMAR visual acuity was 0.92+/-0.3, 0.87+/-0.4, 0.85+/-0.3, and 0.82+/-0.3 at 1, 3, 6, and 9 months follow-up, respectively. The improvements of visual acuity in both groups were statistically significant when compared to pretreatment (P=0.003 and P=0.007 at 9 months in the study and control group, respectively).

CONCLUSION

Arteriovenous sheathotomy for decompression of BRVO in patients who have vision loss due to macular oedema was safe and effective for anatomical and functional improvement and resulted in significantly better visual outcomes than a matched control group of laser-treated eyes.

Safety results of two phase III trials of an intravitreous injection of highly purified ovine hyaluronidase (Vitrase) for the management of vitreous hemorrhage

PURPOSE

To evaluate the safety of intravitreous ovine hyaluronidase for the management of vitreous hemorrhage.

DESIGN

Two prospective, randomized, placebo-controlled, double-masked studies. Pooled efficacy data are presented in a companion article in this issue of The Journal.

METHODS

Subjects with vitreous hemorrhage > or = 1 month, severe at entry and best corrected visual acuity (BCVA) worse than 20/200 in the study eye were randomized to 7.5 IU, 55 IU, 75 IU ovine hyaluronidase, saline, or no injection. Assessments occurred on day 1, week 1, months 1, 2, 3, 6, and then every 6 months for as long as 32 months. Assessments included history, ocular symptoms, adverse events, BCVA, intraocular pressure, external eye examination, slit-lamp biomicroscopy, fundus examination, B-scan ultrasonography, and fundus photography.

RESULTS

Of 1362 subjects in the safety population, 1344 received hyaluronidase or saline and 18 no treatment. Iritis was the most common ocular adverse event, occurring in 33.3%, 62.1%, 58.9%, and 62.1% of saline, 7.5 IU, 55 IU, and 75 IU-treated subjects. In eyes with more than mild iritis, a dose response was observed: 8.9%, 20.2%, 33.7%, and 39.7% of saline, 7.5 IU, 55 IU, and 75 IU-treated subjects, respectively, were noted to have moderate or severe iritis. Retinal detachments (RDs) were reported in 9.5% of study eyes: 26 (6.9%), 22 (11.1%), 35 (9.3%), and 45 (11.5%) in the saline, 7.5 IU, 55 IU, and 75 IU-treated subjects. Overall, 1.8% of study eyes had rhegmatogenous RD: 1.1%, 2.5%, 1.6%, and 2.3% of saline, 7.5, 55, and 75 IU treated subjects. Cataracts occurred similarly across treatment groups. No injection-related infectious endophthalmitis was reported.

CONCLUSIONS

No serious safety issues were reported after a single intravitreous injection of ovine hyaluronidase. RD incidence was not statistically different between groups. Iritis manifesting as an acute self limited inflammation was the most common adverse event, occurred in a dose response fashion, but was not noted to result in a serious adverse event in any hyaluronidase treated eye.

Pooled efficacy results from two multinational randomized controlled clinical trials of a single intravitreous injection of highly purified ovine hyaluronidase (Vitrase) for the management of vitreous hemorrhage

PURPOSE

To evaluate the efficacy of intravitreous ovine hyaluronidase for the management of vitreous hemorrhage.

DESIGN

Two prospective, randomized, placebo-controlled, double-masked studies. Safety data are presented in a companion article in The Journal.

METHODS

Eligible patients with vitreous hemorrhage > or = 1 month duration; severe at entry with best corrected visual acuity (BCVA) worse than 20/200 were randomized to 55 IU or 75 IU ovine hyaluronidase or saline. Primary efficacy (clearance of hemorrhage sufficient to see the underlying pathology and completion of treatment when indicated) was measured at months 1, 2, and 3. Key secondary endpoints were: > or = 3-line improvement in BCVA; hemorrhage density reduction; and therapeutic utility assessment.

RESULTS

The intent-to-treat population for common dose groups (55 IU, 75 IU, saline) consisted of 1125 patients. At baseline, 76.3% had diabetes, 90.4% were not able to read any letters on the eye chart, and mean hemorrhage duration was 120 days. Statistical significance was reached in the 55 IU dose group by months 1 and 2 for the primary efficacy endpoint based on an adjusted P-value. By months 1, 2, and 3, 13.2%, 25.5%, and 32.9% of patients (55 IU) reached primary efficacy compared with 5.5%, 16.2%, and 25.6% of saline-treated patients (P < .001; P = .002; P = .025, respectively). Key secondary endpoints confirmed the treatment effect at both doses and all timepoints (P < or = .01).

CONCLUSIONS

Fifty-five IU ovine hyaluronidase showed statistically significant efficacy as early as months 1 and 2. These results were supported by outcomes for three key secondary endpoints. These results suggest a therapeutic utility of ovine hyaluronidase in the management of vitreous hemorrhage.

Intravitreal triamcinolone acetonide for treatment of persistent macular oedema in branch retinal vein occlusion

BACKGROUND

To evaluate the efficacy of intravitreal triamcinolone acetonide injection on persistent macular oedema in branch retinal vein occlusion that fails to respond to previous laser photocoagulation.

MATERIAL AND METHODS

A total of 19 eyes of 19 patients with persistent macular oedema due to branch retinal vein occlusion were treated with 8 mg/0.2 ml of intravitreal triamcinolone acetonide injection. The main outcome measures included best-corrected visual acuity, intraocular pressure, and macular oedema map values of Heidelberg Retinal Tomograph II (HRT II) before and after intravitreal triamcinolone injection.

RESULTS

The mean follow-up time was 6.2+/-1.0 months. The mean baseline best-corrected logarithm of minimal angle of resolution (LogMAR) value for visual acuities of the patients before intravitreal triamcinolone injection was 1.01+/-0.16. After treatment, it was 0.55+/-0.22 at the 1-month, 0.56+/-0.22 at 3-month, and 0.62+/-0.22 at the last visits and the differences were statistically significant when compared with baseline values (for each, P<0.001). The mean oedema map values on HRT II significantly decreased by 28.5% at 1-month, 23.8% at 3-month, and 23.8% at the last visit when compared with preinjection values (for each, P<0.001). Intraocular pressure elevation exceeding 21 mmHg was observed in 26.3% of eyes at 1-month, 15.7% at 3-month, and 5.2% at the last visit, but was controlled with topical anti-glaucomatous medications in all eyes.

CONCLUSION

Intravitreal triamcinolone acetonide application is a promising approach in the treatment of persistent macular oedema due to branch retinal vein occlusion non-respondent to laser photocoagulation.

Management of branch retinal vein occlusion with vitrectomy and arteriovenous adventitial sheathotomy, the possible role of surgical posterior vitreous detachment

BACKGROUND

To analyze the results of vitrectomy and adventitial sheathotomy in the management of branch retinal vein occlusion (BRVO). This is a nonrandomized interventional case series.

METHODS

Patients with BRVO with progressive decrease in visual acuity underwent surgery and were prospectively evaluated in two centers. Surgical procedure included a 3-port pars plana vitrectomy, removal of the internal limiting membrane and arteriovenous crossing sheathotomy. Clinical evaluation consisted of best-corrected visual acuity, fluorescein angiography and optical coherence tomography.

RESULTS

Thirteen eyes were analyzed consecutively. An improvement in visual acuity of two ETDRS lines or more was observed in nine eyes (69%). The mean gain was 1.9 ETDRS lines. The absence of previous posterior vitreous detachment (PVD), poor initial visual acuity and the presence of retinal ischemia were correlated to the improvement in vision (P=0.014, P=0.002 and P=0.052, respectively). Eyes with initial PVD had a mean loss postoperatively of -5.7 lines, but eyes without PVD experienced a gain of 4.2 lines (P<0.001). Macular edema decreased significantly (preoperative thickness: 714 micro m, postoperative thickness: 353 micro m, P=0.04), whereas the aspect of the vein at the crossing and the non-perfused area remained unchanged.

CONCLUSION

Vitrectomy with sheathotomy seems to be of benefit in the management of BRVO, particularly in eyes with no previous PVD, and the main postoperative feature was the decrease in macular edema. The surgical detachment of posterior hyaloid could be as important (or more) as the sheathotomy itself. Further studies are needed to define the most efficient surgical management of BRVO.