Anterior retinal cryotherapy in diabetic vitreous hemorrhage

Evidence-Based Treatment of Diabetic Retinopathy

Diabetic retinopathy (DR) is the most frequent microvascular complication from diabetes and requires annual screening and at least annual follow-up. A systemic approach to optimize blood glucose and blood pressure may halt progression to severe stages of DR and obviate the need for ocular treatment. Although there is evidence of benefit from fenofibrate or intravitreous antiVEGF treatment for eyes with nonproliferative DR (NPDR), these therapies are not standard care for NPDR at this time. Some patients with severe NPDR, especially those with type 2 diabetes, benefit from early panretinal photocoagulation (PRP). Once DR progresses to proliferative DR (PDR), treatment is often necessary to prevent visual loss. PRP remains mainstay treatment for PDR with high-risk characteristics. However, intravitreous antiVEGF injections appear to be a safe and effective treatment alternative for PDR through at least two years. Vitreoretinal surgery is indicated for PDR cases with non-clearing vitreous hemorrhage and/or tractional retinal detachment.

Anterior retinal cryotherapy and intravitreal injection of bevacizumab in the treatment of nonclearing vitreous hemorrhage in proliferative diabetic retinopathy

PURPOSE

To evaluate the efficacy of intravitreal bevacizumab (IVB) injection combined with anterior retinal cryotherapy (ARC) in the treatment of proliferate diabetic retinopathy (PDR) with vitreous hemorrhage (VH).

METHODS

A retrospective case controlled study was performed on 67 cases (67 patients) with PDR and persistent VH obscuring the fundus detail for ≧3 weeks. The follow-up period was ≧6 months. Cases with extensive vitreo-retinal adhesion by ultrasonography were excluded. In the study group, transconjunctival ARC (a total of 12 spots) followed by IVB 1.25 mg was performed in the same setting; in the control group, only IVB was given. Panretinal photocoagulation was performed when possible. Repeated IVB was performed in both groups if VH persisted for >4 weeks following the initial treatment. Vitrectomy was performed if VH showed no improvement for 12 to 16 weeks. The vitreous clear-up time (VCUT) in the posterior pole and the rate of vitrectomy were compared between the 2 groups.

RESULTS

In the study group (n=35), second treatment was required in 7 out of 35 patients (20.0%). Vitrectomy was performed in 5 (14.3%) patients. In the control group (n=32), 8 out of 32 eyes (25.0%) underwent second injection. Four eyes (12.5%) had vitrectomy within the follow-up time. VCUT in the study and the control group was 6.9±8.7 weeks and 13.0±9.3 weeks respectively (P=0.003).

CONCLUSION

Combined treatment of ARC and IVB is associated with more rapid clearing of VH in eyes with PDR compared with IVB alone.

Intravitreal bevacizumab and panretinal photocoagulation for proliferative diabetic retinopathy associated with vitreous hemorrhage

PURPOSE

To evaluate the efficacy of intravitreal bevacizumab with panretinal photocoagulation (PRP) in the treatment of proliferate diabetic retinopathy (PDR) with vitreous hemorrhage (VH).

METHODS

Forty cases (40 patients) with PDR and persistent VH were prospectively enrolled, with a follow-up period of 12 months or more. Intravitreal bevacizumab injection (1.25 mg) was given, followed by PRP when visualization of peripheral fundus could be obtained. A second injection was administered 4 weeks to 6 weeks after the first injection if no signs of VH decrease were noted. Vitrectomy was performed if VH persisted >12 weeks. The vitreous clear-up time (VCUT) and the rate of vitrectomy were compared with those in a historical control group (40 eyes in 40 patients) who were treated with conventional methods.

RESULTS

Thirty-one eyes had 1 injection and 9 eyes (22.5%) received 2 injections. Vitreous clear-up time in the study and control groups were 11.9 +/- 9.5 weeks and 18.1 +/- 12.7 weeks (P = 0.02), respectively. Rates of required vitrectomy were 10% in the study group and 45% in the control group (P = 0.01).

CONCLUSION

One or 2 intravitreal injections of 1.25 mg bevacizumab with PRP are associated with rapid regression of VH and may reduce the need for vitrectomy.

Cryotherapy of the Anterior Retina and Sclerotomy Sites in Diabetic Vitrectomy to Prevent Recurrent Vitreous Hemorrhage

OBJECTIVE

To evaluate the role of cryotherapy of the anterior retina and sclerotomy sites in the prevention of fibrovascular ingrowth (FVIG) at sclerotomy sites and postoperative recurrent vitreous hemorrhage in patients undergoing pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

DESIGN

Retrospective, nonrandomized, observational case series.

PARTICIPANTS

Eighty-one eyes in 71 patients who had undergone PPV for complications of PDR in the previous 2 years, with postoperative retinal reattachment for at least 3 months.

METHODS

Cases were divided into 3 groups: (1) having panretinal or supplementary endophotocoagulation; (2) having anterior peripheral retinal cryotherapy (ARC) in addition to panretinal endolaser treatment; and (3) having endophotocoagulation, ARC, and cryotherapy on the 3 sclerotomy sites added. Ultrasound biomicroscopy (UBM) examination of the 3 sclerotomy sites was performed > or =2 months after surgery. The UBM findings were separated into 4 categories: well-healed, gap, vitreous incarceration, and FVIG. History and management of recurrent vitreous hemorrhage were recorded.

MAIN OUTCOME MEASURES

Ultrasound biomicroscopy findings and the percentage of recurrent vitreous hemorrhage in the 3 groups were compared to determine the effectiveness of the adjunct cryotherapy in inhibiting FVIG and preventing recurrent vitreous hemorrhage.

RESULTS

The recurrent vitreous hemorrhage rates in groups 1, 2, and 3 were 12 of 32 (37.5%), 3 of 26 (11.5%), and 1 of 23 (4.3%), respectively (P = 0.0004). In each group, different sclerotomy sites had similar distributions of the 4 UBM categories. Among the 3 groups, gap was found in 9.4%, 20.5%, and 52.2% of eyes, respectively (P<0.001), whereas FVIG was found in 36.5%, 15.4%, and 0% of eyes (P<0.001). Fibrovascular ingrowth was noted in 87.5% (14/16) of all eyes experiencing recurrent vitreous hemorrhage. Of those with rebleeding but no FVIG (2 eyes), 1 had vitreous lavage combined with additional cryotherapy, and 1 had no treatment. Of those with FVIG (14 eyes), 5 needed > or =2 operations.

CONCLUSIONS

The presence of FVIG had good correlation with the development of recurrent postoperative vitreous hemorrhage. Anterior peripheral retinal cryotherapy combined with cryotherapy of sclerotomy sites might be helpful adjunct procedures in diabetic vitrectomy for inhibition of FVIG and prevention of recurrent vitreous hemorrhage.

Evaluation of the blood–aqueous barrier by laser flare cell photometry following retinal cryocoagulation

PURPOSE

To evaluate the influence of peripheral 360 degrees retinal cryocoagulation on the blood-aqueous barrier of patients with retinal vascular disorders.

METHODS

The aqueous of 50 eyes of 50 patients with diabetic retinopathy or central vein occlusion was measured by laser flare photometry (FC-2000, Kowa) before peripheral 360 degrees retinal cryocoagulation and 1 day, 1 week, and 1 month thereafter.

RESULTS

Mean aqueous flare values before treatment were 15.7 (+/-8.2) photon counts/ms; mean cell count was 9.8 (+/-14.8) cells/0.5 mm(3). One day after retinal cryocoagulation flare values had increased statistically significantly to a mean of 39.2 (+/-85.8) photon counts/ms, while the increase in mean cell number to 15.0 (+/-37.2) cells/0.5 mm(3) did not reach statistical significance. One week following treatment, mean flare values had dropped to 30.9 (+/-49.6) photon counts/ms and were no longer significantly elevated compared with baseline, while the mean cell count of 11.1 (+/-27.0) cells/0.5 mm(3) was now statistically significantly elevated compared with baseline. One month after treatment the flare values had decreased to a mean of 19.7 (+/-12.0) photon counts/ms, and mean cell count had decreased to 8.1 (+/-10.4) cells/0.5 mm(3); at this point neither parameter showed a statistically significant difference from baseline values.

CONCLUSION

Peripheral 360 degrees retinocryocoagulation does not lead to permanent disturbance of the blood-aqueous barrier.

Eales disease--an update

Eales disease, first described by Henry Eales in 1880, remains an enigma. The disease, observed more commonly in the Indian subcontinent than in the rest of the world, occurs in young healthy adult males, initially presenting as retinal periphlebitis and later as retinal ischemia that may lead to vascular alterations and neovascularization. Recurrent vitreous hemorrhage with or without retinal detachment is the common sequelae. In recent years, immunological, molecular biological, and biochemical studies have indicated the role of human leukocyte antigen, retinal autoimmunity, mycobacterium tuberculosis genome, and free radical mediated damage in the etiopathogenesis of this disease. However, its etiology appears to be multifactorial. The management depends on the stage of the disease and consists of medical treatment with oral corticosteroids in the active inflammatory stage and laser photocoagulation in the advanced retinal ischemia and neovascularization stages. The results of vitreoretinal surgery have been found to be satisfactory in case of vitreous hemorrhage with or without retinal detachment.

Retinal cryoapplication and fibrinolysis in experimental vitreous hemorrhage

Retinal cryoapplication accelerates blood resorption of experimental vitreous hemorrhages shortening the time until fundus visualization is possible. For the animals that underwent cryoapplication five days after blood injection into the vitreous cavity, the mean time to fundus visualization was 3.75 weeks versus 5.06 weeks for the control group (p less than 0.001). Retinal cryoapplication also causes an increase in the concentration of fibrin degradation products in the vitreous cavity, indicating an activation of fibrinolysis, one of the most important processes involved in hemorrhage resolution. Use of topical indomethacin slightly lessens the effect of cryoapplication on acceleration of blood resorption (mean 4.06 weeks until visualization), but does not influence the effect on fibrinolysis.

Panretinal cryotherapy in neovascular disease

Panretinal cryotherapy (PRC) was used to treat 15 eyes with rubeosis, nine of which had established neovascular glaucoma, and seven eyes with proliferative diabetic retinopathy. The rubeosis regressed, with preservation of vision and return to normal of intraocular pressure, in all but one eye. With one exception all eyes with proliferative retinopathy also showed new vessel regression after treatment. PRC may be considered an effective alternative to retinal photocoagulation in the treatment of advanced rubeosis, early rubeotic glaucoma, and in certain circumstances proliferative diabetic retinopathy.

Peripheral retinal cryopexy for subtotal vitreous hemorrhage

We used peripheral retinal cryopexy to treat 20 eyes in 15 patients with subtotal vitreous hemorrhage secondary to proliferative diabetic retinopathy. In 18 eyes, complete panretinal photocoagulation had been performed before the subtotal vitreous hemorrhage and the subsequent cryopexy. The length of follow-up averaged 16 months. The vitreous hemorrhage completely cleared in 11 eyes (55%) and partially cleared in six eyes (30%). Visual acuity after treatment improved in 13 eyes (65%), remained unchanged in six eyes (30%), and decreased in one eye (5%).

Transconjunctival anterior retinal cryotherapy for proliferative diabetic retinopathy

Transconjunctival anterior retinal cryotherapy (ARC) for proliferative diabetic retinopathy (PDR) in 408 eyes was reviewed retrospectively. Of 266 eyes available for analysis for treatment effect on neovascularization, 138 (52%) had reduced neovascularization at 6 months. Eighty (30%) had no change in neovascularization, and 48 (18%) had increased neovascularization at 6 months. Factors having a significant effect on reduction of neovascularization were duration of diabetes and severity of retinopathy. Of 238 eyes available for analysis for treatment effect on vitreous hemorrhage at 6 months, 118 (50%) had reduced vitreous hemorrhage, 80 (33%) had no change, and 40 (17%) had increased vitreous hemorrhage. Severity of vitreous hemorrhage significantly affected the outcome in the subgroup of eyes with both neovascularization and vitreous hemorrhage. Of the total 408 eyes in this series, at 6 months, 172 (44%) had improved visual acuity, 89 (23%) had no change, and 126 (33%) had decreased visual acuity. Retinal detachments developed in 17 eyes (4%) post-treatment, 68 eyes (17%) had significant recurrent vitreous hemorrhage, and 61 eyes (15%) eventually underwent vitrectomy.

Cryoapplication in diabetic retinopathy

Thirty-five patients with diabetic retinopathy were treated with cryoapplication. This was used as an alternative to Argon laser or Zenon photocoagulation because the media was opaque from vitreous hemorrhage or cataract. It was difficult or impossible to treat with photocoagulation. The clinical impression indicates that cryoapplication is effective, showing adequate pigmentation and chorioretinal scarring with regression of diabetic retinopathy changes. However patients with vitreo-retinal fibrosis became frequently worse weeks later. This is considered a contraindication. The use of cryoapplication in diabetic retinopathy is recommended in situations where the ocular media is not clear, such as vitreous hemorrhage and cataract. It can also be used if there is difficulty with laser photocoagulation following lens implantation. It may be valuable in some developing countries where photocoagulation is not available. Cryomachines are frequently used in eye camps. It is inexpensive and does not necessarily require electricity.