The Effect of Photodynamic Therapy with Rose Bengal on Posterior Capsule Opacification in Rabbit Eyes

Abstract

We investigated the in vivo effect of photodynamic therapy (PDT) using rose bengal on the development of posterior capsule opacification (PCO). Endocapsular phacoemulsification was performed on white rabbits, which were divided into 4 groups: control group; group 1, treated with visible light only; group 2, treated with rose bengal only, and group 3, treated with PDT. In the case of the PDT group, rose bengal dissolved in sodium hyaluronate was injected into the empty capsular bag and treated with visible light. Three months after surgery, the rabbits were sacrificed and the eyeballs enucleated. The obstruction rate of visible light caused by PCO was measured with an optical powermeter. The mean obstruction rate was 30.6% in the control group, 28.3% in group 1, 19.3% in group 2, and 14.3% in group 3. Group 3 showed a statistically significant decrease in PCO compared with the control group and group 1 (p = 0.0014). Our results suggest that PDT using rose bengal effectively decreased PCO in rabbit eyes.

Toward New Engagement Paradigms For Intraocular Lenses: Light-Initiated Bonding of Capsular Bag to Lens Materials

“…16,24 The photoinitiator used is a standard of eye care used topically, 17 and experimental studies in rabbit eyes have revealed that it is nontoxic intracapsularly and does not compromise corneal endothelial cell integrity. 18 Exposure times and fluences of the green light used are comparable to those used in two other applications of green light and RB, namely, photobonding amniotic membrane to cornea and photo-crosslinking of the cornea. 16,20 These studies have shown that exposure times and fluences did not cause retinal damage and were below the damage thresholds established by American National Standards Institute (ANSI).…”

“…17 In addition, intracapsular use of RB was shown to be nontoxic in rabbit eye models, actually reducing the rate of posterior capsular opacification. 18 The use of photochemical tissue bonding using RB and green light has been demonstrated in ophthalmology for heatfree bonding repair of damaged tissue, thus replacing sutures or staples. 19,20 It is thought that activation of the photoinitiator by light absorption produces structural changes in the amino acids of the proteins of the tissue and formation of covalent bonds between collagen molecules on opposing surfaces of the two tissues in contact.…”

Impact of posterior subcapsular opacification on vision and visual function among subjects undergoing cataract surgery in rural China: Study of Cataract Outcomes and Up-Take of Services (SCOUTS) in the Caring is Hip Project, Report 5

“…Can the long-term follow-up required to detect a high proportion of eventual PCO be delivered sustainably in rural Asia? What will be the role in this setting of prophylactic interventions such as primary capsulotomy with posterior optic buttonholing,34 and various techniques to reduce PCO prevalence, including alternative lens designs13 – 16 and materials,12 17 and pharmacological,18 – 20 radiological,21 and phototherapeutic22 techniques? Given that cataract is the world’s leading cause of blindness, and PCO the most common postoperative complication of cataract surgery,1 more research is needed in this critical area.…”

“…Opportunities for follow-up and treatment may be limited or non-existent. A number of approaches to the primary prevention of PCO have been proposed, including alternative lens designs13 – 16 or material,12 17 and a variety of pharmacological,18 – 20 radiological,21 phototherapeutic22 and gene-based23 interventions. Before committing resources to primary prevention technologies or comprehensive programmes of laser treatment, it is necessary for programme planners to place the impact of PCO on visual function into the context of other postoperative interventions such as refraction, which may be simpler and cheaper to apply.…”

Photodynamic Therapy‐Induced Apoptosis of HeLa Cells

“…However, cell death in PDT may also occur by autophagy or by necrosis (depending on the sensitizer), on the PDT dose, intracellular localization of PS and cell metabolic potential, and on the cell genotype 1,5 . Among the several PSs which may be modified to fluorogenic substrates, Rose Bengal Acetate (RBAc) (an iodinated xanthene derivative that has been chemically modified by the introduction of acetate groups) is of special interest 6 . RBAc is an efficient cell‐permeant generator of singlet oxygen 7 and can actively react with several chemical groups that may serve as substrates for enzyme activities.…”