Concentric retinal pigment epithelium atrophy after a single photodynamic therapy

Abstract

We are unable to explain the exact mechanism of the observed RPE changes; however, they did not lead to loss of visual acuity. Different reasons for the RPE atrophy such as collateral damage of the choriocapillaris with a subsequent secondary RPE atrophy, a direct photochemical effect due to the early localization of the photosensitizer in the RPE, or a depigmentation or photobleaching of the RPE, which led to a window defect in the fluorescein angiogram without loss of the major functional properties of the RPE, are possible mechanisms involved in the development of the documented lesion.

Effect of photodynamic therapy on the function of the outer blood-retinal barrier in an in vitro model

“…window defects) after PDT have been observed in FA studies [27,38]. Wachtlin and co-workers suspect depigmentation or photobleaching of the RPE following PDT leading to a window defect in the FA without loss of the major RPE functional properties.…”

“…Evaluation of the transient, PDT-induced neurosensory detachment showed that its size correlated more closely to the diameter of the laser treatment spot than to that of the CNV, suggesting that non-thermal laser may result in an outer BRB dysfunction causing transient retinal elevation [20]. Recently, persistent RPE cell destruction that was particularly evident in younger subjects was described using FA [27,38]. These results indicate that both thermal and nonthermal laser treatment can induce alterations in the RPE and breakdown of the BRB.…”

Intravitreous bevacizumab to treat subfoveal choroidal neovascularization in highly myopic eyes: short-term results

“…The better outcome of the patients reported by Chan et al and Mandal et al may be secondary to the previous PDT sessions performed in 11/26 eyes in our series, which are known to induce RPE and choriocapillaris atrophy. 25 The number of intravitreal injections needed to achieve CNV closure in highly myopic eyes is not known. Several different protocols are presently being used with antiangiogenic drugs as has been reported for the PIER, PrONTO, and SAILOR trials with ranibizumab.…”

Comparison of laser beam intensity profiles produced by photodynamic therapy (PDT) and transpupillary thermotherapy (TTT) lasers

“…Some pigment alterations have been reported in the follow up of PDT session [7,8]. Multiple and complex factors probably influence the location of a recurrence of choroidal neovascularization after laser based treatments or even after translocation surgery [9][10][11].…”