Evolving guidelines for intravitreous injections

Intravitreal triamcinolone acetonide for treatment of intraocular oedematous and neovascular diseases

Intravitreal triamcinolone acetonide (IVTA) has increasingly been applied as treatment for various intraocular neovascular and oedematous diseases. Comparing the various diseases with respect to effect and side-effects of the treatment, the best response in terms of gain in visual acuity (VA) has been achieved for intraretinal oedematous diseases such as diffuse diabetic macular oedema, branch retinal vein occlusion, central retinal vein occlusion and pseudophakic cystoid macular oedema. In eyes with various types of non-infectious uveitis, including acute or chronic sympathetic ophthalmia and Adamantiadis-Behcet's disease, VA increased and the degree of intraocular inflammation decreased. Some studies have suggested that intravitreal triamcinolone may be useful as angiostatic therapy in eyes with iris neovascularization and proliferative ischaemic retinopathies. Intravitreal triamcinolone may possibly be helpful as adjunct therapy for exudative age-related macular degeneration (AMD), particularly in combination with photodynamic therapy. In eyes with chronic, therapy-resistant ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure (IOP) and may stabilize the eye. The complications of intravitreal triamcinolone therapy include: secondary ocular hypertension in about 40% of the eyes injected; medically uncontrollable high IOP leading to antiglaucomatous surgery in about 1-2% of the eyes; posterior subcapsular cataract and nuclear cataract leading to cataract surgery in about 15-20% of elderly patients within 1 year of injection; postoperative infectious endophthalmitis occurring at a rate of about one per 1000; non-infectious endophthalmitis, perhaps due to a reaction to the solvent agent, and pseudo-endophthalmitis with triamcinolone acetonide crystals appearing in the anterior chamber. Intravitreal triamcinolone injection can be combined with other intraocular surgeries, including cataract surgery, particularly in eyes with iris neovascularization. Cataract surgery performed some months after the injection does not show a markedly elevated complication rate. The injection may be repeated if the resultant benefits decrease after the initial IVTA injection. In non-vitrectomized eyes, the duration of the effect and side-effects of a single intravitreal injection of triamcinolone is about 6-9 months for a dosage of about 20 mg, and about 2-4 months for a dosage of 4 mg. So far, it has remained unclear whether the solvent agent should be removed, and if so, how.

National survey of the technique of intravitreal triamcinolone injection in the United Kingdom

OBJECTIVES

Intravitreal injection of steroids is a rapidly evolving treatment option for a variety of retinal pathologies. There is wide variation among ophthalmologists regarding dose of steroid and the technique of injection. Through this survey we aim to describe the current practice of injection of intravitreal steroid among ophthalmic consultants in the United Kingdom and review the literature.

METHODS

A postal questionnaire was sent to all the 901 ophthalmic consultants in the United Kingdom. The questions covered frequency of intravitreal steroid injections, subspecialty interest, dosage and volume of steroid, patient preparation, surgeon preparation, and postoperative management.

RESULTS

The response rate to the questionnaire was 63%. A total of 24.7% perform intravitreal steroid injections regularly with 90% of users performing five or fewer injections per month. In all, 94% use a dose of 4 mg. Among surgeons, 38% do not prescribe postoperative antibiotics or steroids and 59% check intraocular pressure either on the same or the next day.

CONCLUSION

The relatively short experience with this technique has not yet allowed a clear picture to emerge of indications, complications or best practice administration. Published descriptions of intravitreal steroid injection techniques vary widely and variations are not evidence based. Observed UK practice is diverse.

Description des pratiques pour la réalisation des injections intravitréennes

Drugs to treat retinal diseases are often injected intravitreally. This procedure can cause severe complications. We present ways to minimize the risk for complications. Rigorous preoperative antisepsis with povidone iodine, a sterile environment (using gloves and a mask for the injector, a lid speculum, and a drape on the eye to be injected), and immediate follow-up after injection are key issues of the injection technique.

A new treatment regimen in combined intravitreal injection of triamcinolone acetonide and photodynamic therapy

BACKGROUND

Combined photodynamic therapy (PDT) and intravitreal injection of triamcinolone acetonide is a new option in the treatment of the neovascular form of age-related macular degeneration. With the aim of increasing safety and efficacy we examined whether it is possible to administer the intravitreal injection prior to PDT.

METHODS

Patients with retinal angiomatous proliferation, who have an unfavourable prognosis when treated with PDT alone, were recruited to this study. Intravitreal injection of triamcinolone acetonide was applied 1 day before PDT. Distance acuity testing, retinal thickness measurement and fluorescein angiography were performed before treatment and 6 weeks and 3 months thereafter.

RESULTS

Twenty-five patients were included: 18 were female, 7 male. Their mean age was 79 years. The distance acuity was 68 letters before treatment and at the follow-up examinations. The retinal thickness decreased significantly from mean 470.8 microm to 335.4 microm at week 6 and 360.8 microm at month 3. At month 3, 48% showed signs of activity in the fluorescein angiography needing retreatment. Visualisation of the fundus was not reduced by the triamcinolone crystals.

DISCUSSION

PDT was possible without difficulty after intravitreal injection of triamcinolone acetonide. Stabilisation of the visual acuity was possible, although only eyes with retinal angiomatous proliferation were included.

Intravitreal triamcinolone acetonide for treatment of intraocular proliferative, exudative, and neovascular diseases

Within the last three years, triamcinolone acetonide has increasingly been applied intravitreally as treatment option for various intraocular neovascular edematous and proliferative disorders. The best response in terms of gain in visual acuity after the intravitreal injection of triamcinolone acetonide was found in eyes with intraretinal edematous diseases such as diffuse diabetic macular edema, branch retinal vein occlusion, central retinal vein occlusion, and pseudophakic cystoid macular edema. Visual acuity increased and degree of intraocular inflammation decreased in eyes with various types of non-infectious uveitis including acute or chronic sympathetic ophthalmia and Adamantiadis-Behcet's disease. Intravitreal triamcinolone may be useful as angiostatic therapy in eyes with iris neovascularization and proliferative ischemic retinopathies. Possibly, intravitreal triamcinolone may be helpful as adjunct therapy for exudative age-related macular degeneration, possibly in combination with photodynamic therapy. In eyes with chronic, therapy resistant, ocular hypotony, intravitreal triamcinolone can induce an increase in intraocular pressure and may stabilize the eye. The complications of intravitreal triamcinolone therapy include secondary ocular hypertension in about 40% of the eyes injected, cataractogenesis, postoperative infectious and non-infectious endophthalmitis, and pseudo-endophthalmitis. Intravitreal triamcinolone injection can be combined with other intraocular surgeries including cataract surgery. Cataract surgery performed some months after the injection does not show a markedly elevated rate of complications. If vision increases and eventually decreases again after an intravitreal triamcinolone acetonide injection, the injection can be repeated. The duration of the effect of a single intravitreal injection of triamcinolone depended on the dosage given. Given in a dosage of about 20mg to non-vitrectomized eyes, the duration of the effect and of the side-effects was 6-9 months. Intravitreal triamcinolone acetonide may offer a possibility for adjunctive treatment of intraocular edematous and neovascular disorders. One has to take into account the side-effects and the lack of long-term follow-up observations.

Zystoides Makulaödem bei Uveitis

Cystoid macular edema (CME) is the most frequent cause of visual deterioration in uveitis patients. Intraocular inflammation disturbs the blood-retina barrier and leads to retinal edema. The basis of successful treatment is the anti-inflammatory and immunosuppressive therapy of uveitis. Restoration of the blood-retina barrier is mediated by corticosteroids and nonsteroidal anti-inflammatory agents. Resorption of extracellular fluid is improved by systemic carboanhydrase inhibitors. Despite aggressive therapy loss of visual acuity is frequent. Therefore, early diagnosis of CME and initiation of treatment, even if visual acuity is not yet impeded, is mandatory.

Pegaptanib for neovascular age-related macular degeneration

BACKGROUND

Pegaptanib, an anti-vascular endothelial growth factor therapy, was evaluated in the treatment of neovascular age-related macular degeneration.

METHODS

We conducted two concurrent, prospective, randomized, double-blind, multicenter, dose-ranging, controlled clinical trials using broad entry criteria. Intravitreous injection into one eye per patient of pegaptanib (at a dose of 0.3 mg, 1.0 mg, or 3.0 mg) or sham injections were administered every 6 weeks over a period of 48 weeks. The primary end point was the proportion of patients who had lost fewer than 15 letters of visual acuity at 54 weeks.

RESULTS

In the combined analysis of the primary end point (for a total of 1186 patients), efficacy was demonstrated, without a dose-response relationship, for all three doses of pegaptanib (P<0.001 for the comparison of 0.3 mg with sham injection; P<0.001 for the comparison of 1.0 mg with sham injection; and P=0.03 for the comparison of 3.0 mg with sham injection). In the group given pegaptanib at 0.3 mg, 70 percent of patients lost fewer than 15 letters of visual acuity, as compared with 55 percent among the controls (P<0.001). The risk of severe loss of visual acuity (loss of 30 letters or more) was reduced from 22 percent in the sham-injection group to 10 percent in the group receiving 0.3 mg of pegaptanib (P<0.001). More patients receiving pegaptanib (0.3 mg), as compared with sham injection, maintained their visual acuity or gained acuity (33 percent vs. 23 percent; P=0.003). As early as six weeks after beginning therapy with the study drug, and at all subsequent points, the mean visual acuity among patients receiving 0.3 mg of pegaptanib was better than in those receiving sham injections (P<0.002). Among the adverse events that occurred, endophthalmitis (in 1.3 percent of patients), traumatic injury to the lens (in 0.7 percent), and retinal detachment (in 0.6 percent) were the most serious and required vigilance. These events were associated with a severe loss of visual acuity in 0.1 percent of patients.

CONCLUSIONS

Pegaptanib appears to be an effective therapy for neovascular age-related macular degeneration. Its long-term safety is not known.

MINIMIZING THE RISK OF ENDOPHTHALMITIS FOLLOWING INTRAVITREOUS INJECTIONS

PURPOSE

To review techniques that are important in preventing endophthalmitis following intravitreous injections based on the available evidence.

METHODS

A review of the literature regarding existing evidence that is relevant to post-injection endophthalmitis prophylaxis.

RESULTS

The available evidence regarding endophthalmitis prophylaxis is largely based on intraocular surgery, particularly cataract surgery. Despite the controversy and the paucity of evidence regarding endophthalmitis prophylaxis for intravitreous injections, it is recommended that povidone-iodine should be used prior to intravitreous injections to minimize or eliminate the presence of ocular surface bacteria. Administration of topical antibiotics may also be considered before and after the intravitreous injections. Strict adherence to aseptic techniques, including the use of an eyelide speculum is also important.

CONCLUSION

Endophthalmitic can occur following intravitreous injections. Prophylaxis with topical povidone-iodine, and possibly antibiotics, as well as adherence to aseptic technique may minimize the risk of post-injection endophthalmitis.