Verteporfin Therapy Combined with Intravitreal Triamcinolone in All Types of Choroidal Neovascularization due to Age-Related Macular Degeneration

High incidence of vitreomacular traction in recurrent choroidal neovascularisation after repeated photodynamic therapy

BACKGROUND

The causes of recurrent choroidal neovascularisation (CNV) after photodynamic therapy (PDT) remain controversial. Subretinal surgery was carried out after unsuccessful PDT.

AIMS

To determine intraoperatively the status of the posterior vitreous interface.

DESIGN

Interventional case series.

METHODS

Conventional three-port vitrectomy was carried out in 10 eyes with CNV that had undergone 1-4 PDT sessions. The vitreous cutter was held close to the edge of the optic nerve to evaluate the status of the posterior vitreous.

RESULTS

Lesion size showed an increase from 1.5 (standard deviation (SD) 0.53) to 2.3 (SD 0.83) macular photocoagulation study disc diameters, between the first and the last PDT. Intraoperative findings during vitrectomy showed little liquefaction of the vitreous gel and an incomplete posterior-vitreous detachment, with remarkably firm attachments at the macula in all cases (10/10).

CONCLUSION

We determined an abnormally high incidence of vitreous attachments in eyes with recurrent CNV. Vitreomacular attachments may trigger the progression or recurrence of CNV.

Intravitreal triamcinolone acetonide: a change in a paradigm

BACKGROUND

Based on experimental studies and clinical observations by Robert Machemer, Gholam Peyman and others, the vitreous cavity has increasingly been used as a reservoir of drugs for the direct treatment of intraocular diseases.

METHODS AND RESULTS

The most widely injected drug so far has been triamcinolone acetonide for various intraocular neovascular and edematous 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 has been achieved for intraretinal edematous diseases such as diffuse diabetic macular edema, branch retinal vein occlusion, central retinal vein occlusion, and pseudophakic cystoid macular edema. In eyes with various types of noninfectious uveitis including acute or chronic sympathetic ophthalmia and Adamantiadis-Behçet's disease, visual acuity increased and the degree of intraocular inflammation decreased. Some studies have suggested that intra- vitreal triamcinolone may be useful as an angiostatic agent in eyes with iris neovascularization and proliferative ischemic retinopathies. Intravitreal triamcinolone may possibly be helpful as adjunct therapy for exudative age-related macular degeneration, particularly 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; medically uncontrollable high intraocular pressure 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% in elderly patients within 1 year after injection; postoperative infectious endophthalmitis with a rate of about 1:1,000; noninfectious endophthalmitis, perhaps due to a reaction to the solvent agent, and pseudoendophthalmitis with triamcinolone acetonide crystals appearing in the anterior chamber. Intravitreal triamcinolone injection can be combined with other types of intraocular surgery 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 vision redecreases. In nonvitrectomized 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. It has remained unclear so far, whether and how to remove the solvent agent. In the future, intravitreal triamcinolone may be combined with other antiangiogenic drugs for the treatment of exudative age-related macular degeneration or with neuroprotective drugs for treatment of diabetic retinopathy.

CONCLUSIONS

Despite an exponentially increasing number of mostly case-series studies, the intravitreal injection of triamcinolone may still be considered an experimental procedure until randomized studies have been presented.

Duration of the Effect of Intravitreal Triamcinolone Acetonide in Eyes with Exudative Age-Related Macular Degeneration

OBJECTIVE

The aim of this study was to evaluate the duration of the effect of an intravitreal injection of approximately 20 mg of triamcinolone acetonide (TA) on visual acuity and intraocular pressure (IOP) in patients with exudative age-related macular degeneration (AMD) with subfoveal choroidal neovascularization.

PARTICIPANTS

The prospective, clinical, interventional, case series study included 69 patients (71 eyes) with exudative AMD who showed an increase in visual acuity by at least 2 Snellen lines after an intravitreal injection of approximately 20 mg TA. Mean follow-up was 11.5 +/- 7.4 months (3.3-35.7 months). The main outcome measure was visual acuity.

RESULTS

Within the first week after the injection, visual acuity and IOP started to increase significantly (P < 0.001) by reaching a plateau-like maximum at 1-6 months after the injection. Visual acuity and IOP returned to baseline values 7-9 months after the injection. Increase of IOP was statistically (P = 0.72) independent of the change in visual acuity.

CONCLUSIONS

In patients with exudative AMD, who have shown an increase of at least 2 Snellen lines in visual acuity, the effect of intravitreal TA (dosage approximately 20 mg) lasts 7-9 months with respect to an increase in visual acuity and IOP.

ART AND SCIENCE OF PHOTODYNAMIC THERAPY

1. Photodynamic therapy is an established modality for the treatment of solid tumours and other accessible lesions. Although the concept and practice of combining light with a photosensitizing agent for the treatment of disease states has been around for almost a century, the understanding of the art and science therein has been tremendously enhanced over the past few years. 2. Photosensitized reactions are dependent on the generation of reactive oxygen species, in particular singlet oxygen, which accounts for the damaging effects on biological macromolecules, such as membrane lipids and proteins. Therefore, compounds that give a good yield of (1)O(2) are used as photosensitizers. 3. The main photosensitizers used in the clinical setting belong to the photofrin family; however, newer and more effective sensitizers are being evaluated for their potential clinical effectiveness. 4. Light sources have moved from the use of white light with specific filters in the old days to the more recent use of monochromatic light sources, such as lasers, to more sophisticated light-emitting diodes. However, dosimetry remains a big issue mainly because of difficulties in establishing the optimum treatment conditions for an approach that requires the fine-tuning of several variables, such as sensitizer and light doses and drug-to-light interval, as well as the issues of skin photosensitivity and low selectivity. A newer development to circumvent these and provide a broader application for this concept has been the phenomenon of photo-activation, whereby photo-exposure of chromophores to generate novel, small biologically active compounds has been demonstrated successfully. 5. The aim of the present review was to provide a general overview of the art and science of photodynamic therapy and to highlight some of the issues and recent developments in further advancing this modality of treatment.

Retinal angiomatous proliferation treated by intravitreal triamcinolone and photodynamic therapy with verteporfin

PURPOSE

To examine combined treatment of intravitreal triamcinolone acetonide (IVT) and photodynamic therapy (PDT) for retinal angiomatous proliferation (RAP).

METHODS

Ten eyes of eight consecutive patients with RAP underwent a single injection (about 20 mg) of IVT followed 1 month later by PDT. Best-corrected visual acuity (BCVA) was measured by standardized protocol refraction.

RESULTS

Median BCVA was 20/160, 20/64, 20/98, 20/89, 20/89, 20/125 at baseline and 1, 3, 6, 9 and 12 months, respectively. Of ten eyes, six (60%) improved BCVA of at least 3 lines at 1, 3, 6 and 9 months. Four (40%) eyes improved BCVA of at least 3 lines at 12 months. Three eyes (30%) lost >3 lines at 12 months. In all patients intraocular pressure was well controlled. No endophthalmitis, retinal detachment or vitreous haemorrhage developed.

CONCLUSIONS

Improvement of BCVA suggests that combination treatment with IVT and PDT for RAP merits further investigation.

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.

Follow-up after intravitreal triamcinolone acetonide for exudative age-related macular degeneration

PURPOSE

To report on the follow-up of patients who received an intravitreal triamcinolone acetonide injection (IVTA) as treatment of exudative age-related macular degeneration.

METHODS

The clinical interventional case-series study included 205 patients (222 eyes) with progressive exudative age-related macular degeneration with subfoveal neovascularization who consecutively received an IVTA of about 20 mg as only therapeutic procedure and for whom follow-up was at least 3 months. Mean follow-up was 10.4+/-7.1 months (range, 3-35.7 months).

RESULTS

Visual acuity improved significantly (P<0.001) from baseline (0.90+/-0.45 logarithm of the minimum angle of resolution (LogMar)) to a mean minimum of 0.79+/-0.42 LogMar during follow-up. In 86 (38.7%) eyes and in 55 (24.8%) eyes, best visual acuity increased by at least two and three Snellen lines, respectively. Comparing the measurements at specific postinjection examination dates showed that visual acuity measurements taken at 1, 2, and 3 months after injection were not significantly different from the baseline value. Measurements taken at 6, 9, and 12 months after the injection were significantly (P<0.001) lower than the measurements at baseline. Mean loss at 6 months was 1.4+/-3.8 Snellen lines, at 9 months, 2.5+/-4.6 lines, and at 12 months after the injection, 2.6+/-4.0 lines. Intraocular pressure increased significantly (P<0.001) during the first 6 months, and returned to baseline at 9 months after injection.

CONCLUSIONS

Single injection high-dosage IVTA did not show an apparent benefit at 12 months after injection in patients with neovascular age-related macular degeneration.

Verteporfin

Photodynamic therapy (PDT) with verteporfin (Visudyne), a photosensitising protoporphyrin derivative, is used in the management of subfoveal choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD) or pathological myopia (PM). PDT with verteporfin over 1 and 2 years reduces the decline in visual acuity in patients with classic-containing subfoveal CNV secondary to AMD. Verteporfin is generally well tolerated by most patients. Verteporfin is also effective in patients with CNV secondary to PM, although data in this indication are limited and further controlled studies are required. Although verteporfin has shown efficacy in patients with occult AMD-related subfoveal CNV lesions in early trials, data are currently limited on its first-line use in this indication; fully published data from the Verteporfin In Occult (VIO) trial are therefore awaited with interest. Verteporfin should be considered as a first-line treatment in patients with predominantly classic subfoveal CNV secondary to AMD, and in patients with smaller minimally classic subfoveal CNV lesions. It may also be considered an option for the treatment of patients with occult AMD-related subfoveal CNV in whom visual acuity decreases or predominantly classic features develop over time.