Background/aims To analyse quantitatively the anterior segment configuration in eyes with nanophthalmos before and after cataract surgery.

Methods This was a retrospective, non-comparative, interventional case series. Eleven eyes in eight patients with nanophthalmos who underwent phacoemulsification and intraocular lens implantation were identified from the department's surgical log, and their clinical records were retrospectively reviewed. Main outcome measures were as follows: visual acuity, intraocular pressure (IOP), axial length and the following ultrasound biomicroscopy parameters: angle opening distance at 500 μm anterior to the scleral spur (AOD500), trabecular–iris angle (TIA) and trabecular ciliary process distance.

Results The mean axial length of the eyes was 17.3±1.7 mm. AOD500 and TIA increased after cataract surgery (p<0.005). Smaller axial length, AOD500 and TIA before cataract surgery were observed in eyes with preoperative IOP elevation than those without preoperative IOP elevation (p<0.05). Lower postoperative IOP was correlated with greater AOD500 and TIA before cataract surgery (p<0.05).

Conclusions Cataract surgery deepened the anterior chamber and widened the anterior chamber angle in nanophthalmic eyes. Cataract surgery may have beneficial effects on IOP in eyes with nanophthalmos.