Hyperplasia of the retinal pigment epithelium secondary to subthreshold laser treatment in chronic central serous chorioretinopathy.

Purpose: To assess the development of hyperplasia of the retinal pigment epithelium (HRPE) secondary to subthreshold laser treatment (STL) in chronic central serous chorioretinopathy (CSCR).

Methods: Prospective study including 149 eyes of 146 patients with CSCR with persistent subretinal fluid (SRF) that have undergone STL using the Navilas® device. Visual acuity (VA) optical coherence tomography (OCT) and fundus autofluorescence (FAF) were performed before and after the treatment. The HRPE was identified on OCT as a hyperreflective and dense material at the expense of the RPE that did not exist prior to the treatment. The demographics of the patients as well as the parameters of the STL treatments employed were registered.

Results: Seven HRPE cases after STL were identified, observing an incidence of 4.7% (7 out of 149 eyes). The mean age was 52.1 ± 3.6 years, being 6/7 males. The mean number of STL sessions was 1.3 ± 0.5. The mean total fluence applied was 52.2 ± 12.4 J/cm2 (range 35.37 to 76.39 J/cm2), using a duty cycle of 10% in all cases. The HRPE was subfoveal in 6 of the 7 cases. The SRF was resolved in 6 of the 7 patients. The mean VA loss was -14.1 ± 14.3 ETDRS letters.

Conclusion: The development of HRPE secondary to STL in CSCR is an uncommon but severe adverse effect, probably related to the excessive energy employed. Further studies are warranted to minimize the incidence and to know the predictors of this complication after STL treatment to optimize the parameters that should be used.