Pseudophakic Reverse Pupillary Block After Transscleral Intraocular Lens Fixation: Diagnostic Tools And The Impact Of Laser Iridotomy Management

Pseudophakic reverse pupillary block( PRPB) is an underrecognized complication following transscleral intraocular lens(IOL) fixation. An inadequate pressure gradient between the anterior and posterior chambers leads to this condition. It involves posterior iris bowing, iris–optic contact and disturbed aqueous dynamics, which may potentially result in pigment dispersion syndrome and intraocular pressure spikes. We present two cases of PRPB syndrome detected after different IOL transsceral fixation techniques and emphasize the diagnostic value of anterior segment imaging and the role of laser peripheral iridotomy( LPI) in restoring physiological anterior segment position.

Two male patients were evaluated at a clinic after transscleral posterior chamber IOL fixation. In both cases the implantation was preceded by the removal of the dislocated in the bag IOL as a separate surgical step. Postoperative assessment included slit-lamp biomicroscopy, intraocular pressure measurement, anterior segment optical coherence tomography (AS OCT), and ultrasound biomicroscopy( UBM) to evaluate anterior chamber depth, iris configuration, and iris–IOL relationships.

Two patients developed PRPB following transscleral fixation of posterior chamber intraocular lenses.

Case 1: After Yamane flanged intrascleral fixation, accompanied by anterior vitrectomy, the patient presented with deep anterior chamber, dispersed pigment on the corneal endothelium and concave iris configuration. Patient was initially treated with pilocarpine drops unsuccessfully. AS OCT and UBM confirmed posterior bowing of the iris with iris–IOL optic adherence as a result of impaired aqueous flow. Nd:YAG LPI, weeks after Yamane fixation, was performed, resulting in flattening of the iris profile and restoration of normal anterior chamber depth.

Case 2: Significant posterior bending of the iris developed within days after four-point suture scleral fixation of the IOL. Early imaging with both AS OCT and UBM demonstrated posterior iris malposition and iris-IOL optic adhesion. Prompt laser peripheral iridotomy produced immediate anatomical correction and normalization of fluid dynamics.
In both cases, anterior segment configuration and physiological aqueous circulation were restored and remained stable throughout follow-up.

Reverse pupillary block can occur after different scleral fixation techniques and should be suspected in pseudophakic eyes presenting with a deep anterior chamber and concave iris configuration. AS OCT and UBM facilitate early diagnosis by depicting posterior iris bowing and iris–optic proximity. Laser peripheral iridotomy immediately and effectively restores normal aqueous flow and anterior segment position. Early recognition and treatment may prevent prolonged iris–optic contact resulting in pigment dispersion syndrome, intraocular pressure elevation and secondary glaucoma.