Deadbolt cataract due to misplanted minishunt
Authors: Ten Hulzen Richard D. , Wagner Isabella V. , Aref Ahmad A. , Provencher Lorraine M. , Razeghinejad Reza , Danesh-Meyer Helen V. , Goyal Saurabh , De Francesco Ticiana , Ahmed Iqbal Ike K. 
Published: June 2022

A 62-year-old woman with stable unilateral glaucoma in the left eye presented for a cataract consultation. In 2010, laser peripheral iridotomies (LPI) were performed on both eyes by a different provider. Her postoperative course was complicated by a recalcitrant steroid response with a highest intraocular pressure (IOP) of 65 mm Hg in the left eye. A trabeculectomy with a glaucoma minishunt (EX-PRESS, Alcon) was then performed by that provider (Supplemental Figure 1, http://links.lww.com/JRS/A603). Thereafter, IOP control of the left eye was normalized and maintained without topical antiglaucoma medications.

Historically, her right eye has been always her better eye. Recently, she noticed metamorphopsia in her left eye. Her ocular history was also notable for high refractive errors requiring continuous spectacles wear, possible mild refractive amblyopia of the left eye, history of submacular choroidal nevus with drusen in the right eye, and an epiretinal membrane (ERM) with macular pucker in the left eye. Her husband is an optician. Both inquire about refractive cataract surgery options to correct astigmatism and presbyopia; both have reservations regarding cost and visual quality associated with diffractive optic intraocular lenses (IOLs). Her deteriorating visual acuity in both eyes affects her ability to work.

Her corrected distance visual acuity was 20/40 in both eyes (pinhole, no help) while wearing spectacles according to a prescription of −8.50 diopters (D) +1.50 D × 106 for the right eye and −13.00 D +3.25 D × 057 for the left eye. Her corrected near visual acuity was 14/14 in both eyes with the abovementioned prescription and a +3.00 D add. Central corneal thickness was 618 µm in the right eye and 631 µm in the left eye. IOP was 20 mm Hg in the right eye and 10 mm Hg in the left eye on no antiglaucoma medications. Pertinent findings on slitlamp examination included bilateral dermatochalasis, a shallow diffuse thick bleb superiorly in the left eye only, patent LPI superiorly in both eyes, nuclear sclerotic and cortical cataracts in both eyes (with prominent focal spoke superiorly left eye only) (Figure 1, A-C). Fundus photos show posterior vitreous detachment in both eyes, ERM with macular pucker in the left eye, and submacular choroidal nevus (2.5 × 3.0 disc diameter size) with overlying drusen in the right eye (Supplemental Figure 2, A, http://links.lww.com/JRS/A604). Gonioscopy revealed open angles in both eyes, albeit with focal narrowing without synechiae superiorly in the left eye only (Figure 1, D-F

JOURNAL/jcrs/04.03/02158034-202207000-00020/figure1/v/2023-08-19T002635Z/r/image-tiff

). Most importantly, however, the distal tip of the minishunt was not positioned as expected in the anterior chamber; rather, it was noted to pierce the peripheral iris near the iris root superiorly. Most of the minishunt shaft and spur were positioned in the posterior chamber with the distal tip penetrating into the superior aspect of the capsular bag and cataract in the left eye—like a deadbolt.

Visual field testing showed a full field in the right eye and an inferior nasal step in the left eye (Supplemental Figure 2, B, http://links.lww.com/JRS/A604). In addition to slitlamp, gonioscopic, and fundus photos, we also obtained optical coherence tomography of the macula and nerve (Supplemental Figure 2, C, http://links.lww.com/JRS/A604), optical biometry, ultrasound biomicroscopy, endothelial cell counts, and corneal topography (Supplemental Figure 3, http://links.lww.com/JRS/A605).

How would you counsel this patient regarding her glaucoma condition, the misplanted minishunt, and her cataract surgery and IOL options? How would you manage the misplanted minishunt? What surgical approaches or specific techniques would you consider for cataract removal and visual rehabilitation?