Intravitreal triamcinolone safe in retrospective study of cataract, AMD

Prophylactic injection of triamcinolone was well tolerated in patients with AMD undergoing cataract surgery.

ByLawrence R. Lee, FRANZCO

ByFreda Sii II, MBBS

Age-related macular degeneration is the leading cause of irreversible blindness in people over 50 years of age in the Western world, whereas age-related cataract is the most common cause of reversible blindness worldwide. There is overwhelming evidence that a significant proportion of older people have both conditions. Cataract surgery is the most common ophthalmic surgical procedure performed in some countries. Several large epidemiologic studies have assessed the possibility of association between cataract surgery and AMD. Some studies have found previous cataract surgery as one of the risk factors for the development or worsening of AMD while other studies found no increase risk of maculopathy in patients with AMD.

The purpose of this retrospective study was to determine if intravitreal triamcinolone acetonide (TA) injection is safe when combined with cataract surgery for eyes with AMD in the effort to possibly reduce the risk of AMD progression.

Study

The list of all of the patients with cataracts and AMD from an eye center in Brisbane, Australia, who had undergone combined cataract surgery and intravitreal TA injection between June 2000 and December 2002 was obtained. The charts were reviewed and only those with a minimum follow-up of 3 months were included. Information collected included best corrected Snellen visual acuity (VA) and IOP, which was measured using Tonopen (Medtronic) at baseline and at 1 week, 1 month, 3 months, 6 months and 12 months follow-up periods. Ocular history such as neovascular AMD, glaucoma and the management of these conditions prior to the cataract surgery were noted. Any subsequent management after the combined procedure was also noted. For the purpose of data analysis, Snellen VA was converted to logMAR VA. In eyes with more than 12 months follow-up, data up to 12 months was presented. The main outcome measure was change in IOP. Secondary measures were VA and progression of AMD to the exudative type.

All of the operated eyes showed evidence of AMD, but none were exudative at the time. The cataract surgery was standard and involved a clear corneal incision, phacoemulsification and aspiration of the cataract, and implantation of a foldable posterior chamber IOL. At the conclusion of the routine cataract surgery, 4 mg/0.1 ml of Kenacort A-40 (triamcinolone acetonide, Bristol-Myers Squibb) was injected into the vitreous cavity through the superonasal or superotemporal pars plana. Paracentesis of the anterior chamber was performed to control IOP.

Routine postoperative management included topical steroid, apraclonidine 0.5% and chloramphenicol for 2 months. Topical apraclonidine 0.5% was given prophylactically to minimize the risk of IOP elevation (defined as >2 mm Hg from baseline IOP). Any significant IOP elevations, as judged by the surgeon, despite topical apraclonidine, were treated with additional topical medications. Choroidal neovascular (CNV) membranes that developed postoperatively were also treated.

Results

Sixteen patients (19 eyes), six men (38%) and 10 women (62%), were included in this study. The mean age at the time of surgery was 80 ± 4.7 years (range: 69 to 89 years). Nineteen eyes had follow-ups up to 3 months and 15 eyes up to 6 months. There were 10 eyes at 12 months.

IOP

The mean baseline IOP was 14.6 ± 5 mm Hg (range: 6 to 25 mm Hg). The highest mean IOP was 15.5 ± 4.9 mm Hg (range: 6 to 24 mm Hg) at 3 months. The mean IOPs at each follow-up visit are shown in Figure 1. The maximum IOP elevation from baseline was 8 mm Hg. None of these eyes received additional topical antihypertensive medications as IOPs were less than 30 mm Hg and the elevations were short term.

Figure 2 shows the percentage of eyes with a stable IOP (± 2 mm Hg), a small IOP elevation (3 to 5 mm Hg) and a large IOP elevation (6 to 8 mm Hg). Eight of 19 eyes (44%) experienced IOP elevations (>2 mm Hg) at 1 month, but large elevations occurred in three of 19 eyes (17%) at 3 months. By 6 months, 80% of the eyes had baseline IOP.

One eye was on a topical beta-blocker for primary open-angle glaucoma (baseline 19 mm Hg). This eye did not experience any IOP elevation postoperatively (maximum 18 mm Hg). Preoperatively, two eyes (10%) had baseline IOP of 21 mm Hg or greater, and postoperatively three (16%) eyes had IOP of 21 mm Hg or greater. One eye received further treatment with the addition of topical dorzolamide and brimonidine. IOP was reduced to 24 mm Hg at 2 months and 18 mm Hg at 6 months. Postoperative topical steroid was ceased at 2 months.

Visual acuity

The mean baseline logMAR VA was 0.9 ± 0.33 (range: 0.4 to 1.3) [Snellen equivalent 6/48 (6/18-6/120)]. The mean postoperative logMAR VA was 0.74 ± 0.46 (range: 0.18 to 1.3) [6/33 (6/9-6/120)] at 3 months, and 0.76 ± 0.46 (range: 0.1 to 1.3) [6/34 (6/7.5-6/120)] at 12 months. The mean logMAR VA at each follow-up visit are shown in Figure 3. Improvement in mean VA achieved by 1 month was maintained at 12 months. Thirteen (68%) of 19 eyes achieved VA greater than 6/60 at 3 months, and this was maintained at 12 months (70%) comparing with nine of 19 eyes (47%) at baseline.

Macular degeneration

Seven eyes (37%) had a history of CNV due to AMD and were treated preoperatively with various modalities. Two eyes (10%) developed CNV postoperatively and were treated. Both eyes were stabilized, with final VA of 6/30 and 6/48 respectively at 12 months. No other adverse effects were encountered in this study.

Figure 1. Mean IOP before and after surgery (n = 19)

Figure 2. Postop IOP change from baseline (n = 19)

Figure 3. Mean visual acuity before and after surgery (n = 19)

Source: Lee LR, Sii F

Discussion

An association between cataracts and AMD has long been recognized. It is not unusual to find both conditions in the same eye, as they both share common etiological risk factors. It has been suggested that cataract surgery may be a risk factor for AMD progression. There are also many anecdotal reports in the literature where CNV membrane have been noted to occur in the immediate postoperative period.

Combining intravitreal TA injection with cataract surgery may reduce inflammation induced by the surgery and, hence, may reduce the risk of AMD progression or CNV membrane development. As far as we know, the concept of using intravitreal TA as a preventive measure has not been previously explored. However, intravitreal TA has been found to be safe and efficacious for treatment of conditions such as uveitis, macular edema, proliferative vitreoretinopathy and neovascular AMD.

Potential side effects of the intravitreal TA injection include IOP elevation, endophthalmitis, retinal detachment and vitreous hemorrhage. In this study, most of the significant IOP elevations occurred within 1 to 3 months postoperatively but resolved without additional treatment by 6 months, which corresponds to the duration of action of TA injected intravitreally. These eyes were prophylactically treated with topical apraclonidine 0.5%. One eye required additional topical ocular antihypertensive medications to control postoperative IOP elevation without any adverse sequelae. Intravitreal TA at a dose of 4 mg had been found to significantly increase the risk of mild to moderate IOP elevation but this risk was reduced in this study with prophylactic topical apraclonidine 0.5% postoperatively for 2 months. Other potential adverse effects were not encountered in this study.

The cataract surgery was the procedure aimed to improve vision while intravitreal TA was to reduce the risk of vision loss due to AMD progression, which may occur after intraocular surgery. Therefore, it is important to stress that postoperative visual improvement in this study was not aimed to reflect the beneficial effect of the drug in the treatment of CNV, but to report the lack of adverse visual outcome with the combined procedure.

Pollack and colleagues found that 19% of the eyes which had undergone extracapsular cataract extraction alone vs. 4% of the eyes from the control group developed neovascular AMD. These eyes had poor visual outcomes (mostly count fingers). These results were not duplicated by Armbrecht and colleagues who found only 2% of eyes which had cataract surgery (extracapsular extraction and phacoemulsification) progressed to develop CNV membrane. The two eyes in this study (10%) that developed CNV membrane 3 to 6 months after the combined cataract surgery and intravitreal TA had reasonable final visual outcome (6/30 and 6/48).

Although this case series was small and uncontrolled, intravitreal TA injection when combined with cataract surgery was safe and well tolerated. It may also be beneficial in other conditions such as in preventing postoperative cystoid macular edema in high-risk eyes such as those with uveitis and diabetic retinopathy undergoing cataract surgery. Large controlled studies are required to evaluate the risk of AMD progression and CNV development in eyes undergoing cataract surgery and the benefit of intravitreal TA in reducing that risk.

For Your Information:

Lawrence R. Lee, FRANZCO, can be reached at City Eye Centre, Level 10, 135 Wickham Terrace, Brisbane, Queensland 4000, Australia, +61-7-38316888; fax: +61-7-38316883; e-mail: eye@cityeye.com.au. Dr. Lee has no financial or commercial interest in any of the products mentioned in this article.

References:

Armbrecht AM, Findlay C, et al. Cataract surgery in patients with age-related macular degeneration. One-year outcomes. J Cataract Refract Surg. 2003;29:686-693.

Armbrecht AM, Findlay C, et al. Br J Ophthalmol. 2000;84:1343-1348.

Beer PM, Bakri SJ. Intraocular concentration and pharmacokinetics of triamcinolone acetonide after a single intravitreal injection. Ophthalmology. 2003;110:681-686.

Chaine G, Hullo A, et al. Case-control study of the risk factors for age-related macular degeneration. Br J Ophthalmol. 1998;82:996-1002.

Pollack A, Bukelman A, et al. The course of age-related macular degeneration following bilateral cataract surgery. Ophthalmic Surg Lasers. 1998;29:286-294.

Pollack A, Marcovich A, et al. Age-related macular degeneration after extracapsular cataract extraction with intraocular lens implantation. Ophthalmology. 1996;103:1546-1554.