Int Ophthalmol (2014) 34:913 917 DOI 10.1007/s10792-013-9862-z CASE REPORT Silicone oil pupillary block after laser retinopexy in aphakic eyes with presumed closed peripheral iridectomy: report of three cases Ali Reza Majidi Reza Soltani Moghadam Received: 22 January 2011 / Accepted: 14 September 2013 / Published online: 1 October 2013 Ó Springer Science+Business Media Dordrecht 2013 Abstract Closure of the peripheral iridectomy (PI) may lead to forward displacement of silicone oil (SO) in some but not all SO-filled aphakic eyes. In this study, we report three patients with a history of a combined three-port pars plana vitrectomy and cataract surgery, SO injection and inferior PI who underwent laser retinopexy a few months postoperatively. The postoperative courses of these patients were unremarkable except for the closure of the PI without anterior displacement of SO; however, a few hours after laser therapy the SO was displaced to the anterior chamber, leading to acute glaucoma in one of the cases. Yttrium aluminium garnet (YAG) laser was successfully used to reopen the PI in all three patients. The induction of a pupillary block following laser retinopexy in SO-filled aphakic eyes with a closed PI and no forward displacement of SO underscores the necessity of a follow-up examination after laser therapy in such patients and the importance of the prophylactic use of a YAG laser to reopen the PI before laser therapy. Keywords Silicone oil Glaucoma Laser therapy Aphakia A. R. Majidi (&) R. Soltani Moghadam Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Qazvin Square, 1336616351 Tehran, Iran e-mail: dralirezamajidi@yahoo.com R. Soltani Moghadam e-mail: reza_sm76@yahoo.com Introduction In silicone oil (SO)-filled aphakic eyes, a SO bubble may block the pupillary aperture and prevent the aqueous humor from entering the anterior chamber (AC). The accumulation of aqueous in the vitreous cavity pushes the SO to the AC [1]. A SO-filled AC may lead to corneal opacity or glaucoma; the latter is referred to as SO pupillary block glaucoma (SOPBG) [2]. These complications can be prevented by peripheral iridectomy (PI), which allows aqueous to flow from the posterior chamber to the AC, bypassing the blockage of the pupillary aperture [1]. Late closure of the PI can also lead to forward displacement of SO [3], although this does not take place in all SO-filled aphakic eyes with a closed PI [1, 4]. There are few reports in the literature of extended follow-up of SO-filled aphakic eyes with closed PI and no SO in the AC. This report describes three such patients who developed SOPB following laser retinopexy. Case reports Case 1 A 56-year-old male underwent pars plana vitrectomy, phacoemulsification, inferior PI and SO injection for recurrent retinal detachment secondary to tractional
914 Int Ophthalmol (2014) 34:913 917 diabetic retinopathy in the right eye. The postoperative course of the patient was unremarkable except for a closed PI with no forward migration of the SO and a normal intraocular pressure (IOP). He underwent laser retinopexy 6 months later, and a few hours after the procedure, he presented with severe eye pain, eye injection, a clear cornea, a deep AC, an elevated IOP (56 mmhg) and a shiny reflex of SO at the iris. A diagnosis of SOPBG was made, and the closed PI was opened by yttrium aluminium garnet (YAG) laser. The SO was completely retracted to the posterior chamber of the eye. No recurrence of SO displacement occurred after laser PI. The SO was removed one month later (Fig. 1). Case 2 A 45-year-old male with a history of unsuccessful scleral buckling and two pars plana vitrectomy surgeries to repair a rhegmatogenous retinal detachment in the left eye underwent a third vitrectomy combined with phacoemulsification, SO injection and inferior PI. The postoperative course was uncomplicated except for a closed PI with no SO in the AC and a normal IOP. The patient underwent 360-degree laser retinopexy 6 months postoperatively. The patient returned to the emergency room a few hours later complaining of ocular irritation. A slit-lamp examination revealed a corneal epithelial defect around an Fig. 1 Case 1. a, b At presentation after SOPBG development, a deep AC, clear cornea and SO shiny reflex at the iris can be seen. c 1 hour and d 3 hour after treatment with YAG laser PI. The border of the SO bubble (shown by the arrow) in the AC is visible and the size of bubble is diminishing. e, f 24 hour after YAG laser PI, the SO is completely retracted to the posterior and the shiny reflex of SO has disappeared and the cornea is edematous
Int Ophthalmol (2014) 34:913 917 915 Fig. 2 Case 3. a A closed PI and an SO-free AC 2 months after surgery. b Forward displacement of the SO to the AC a few hours after laser retinopexy. c The SO retracted to the posterior following laser reopening of the PI. d Laser opening within the membranous closed PI (arrow) unremoved corneal suture (probably induced by the contact lens used to apply the laser) and the presence of SO in the AC with a mushroom configuration. The forward migration of SO did not respond to prone positioning and progressed after a few hours. YAG laser was used to reopen the PI and this terminated the block; complete posterior retraction of the SO was achieved. Case 3 A 22-year-old female underwent pars plana vitrectomy, lensectomy and SO injection to repair a longstanding high myopic retinal detachment and complicated cataracts. Her postoperative course was unremarkable except for a closed PI with a normal IOP and no SO in the AC. The patient underwent laser retinopexy 5 month postoperatively. A slit-lamp examination a few hour after laser therapy revealed a forward migration of the SO in a mushroom configuration. YAG laser was used to reopen the closed PI and terminate the block so that complete retraction of the SO was achieved in a few minutes (Fig. 2). Discussion All three patients had a SO-filled aphakic eye with a closed PI, normal IOP and no forward migration of SO before laser retinopexy. In SO-filled aphakic eyes, closure of the PI occurs in 11 32 % of patients [3]; forward migration of SO has been reported in 80 % of patients [4]. Indeed, not all eyes with a closed PI have a SO-filled AC [1, 4]. There are several possible explanations for this observation: (1) some patients have a PI that appears to be closed but is functionally open, perhaps due to an inaccuracy in assessing the functional status of the PI [4]; (2) in some eyes, the posterior segment of the eye is not completely filled by SO and the silicone bubble is not large enough to completely close the pupil so that the lower part of the iris diaphragm is not in contact with the SO and aqueous can flow through the pupil to the AC [1]; and (3) in some eyes, iris configurations such as a superior PI from a previous cataract surgery may prevent the anterior displacement of SO [4]. All three of our patients had undergone cataract surgery, posterior capsule removal, preservation of the anterior capsule with an intact round opening and surgical PI including both the anterior capsule and the iris. Closure of the PI and iridiocapsular adhesion developed during followup examinations in all three cases. It appears that the preservation of the anterior capsule may have led to iridiocapsular adhesion and subsequent PI closure [5]; however, some functional space between the anterior capsule and the iris may have existed that allowed the exit of aqueous toward the pupillary aperture, preventing the development of SOPB in these cases despite inferior PI closure.
916 Int Ophthalmol (2014) 34:913 917 Prophylactic 360-degree laser retinopexy, intraoperatively or as a separate session before silicone removal, has been demonstrated to decrease the incidence of retinal detachment twofold after silicone removal [6]. The three patients included in our study underwent laser retinopexy using a slit-lamp laser delivering device (double frequency YAG laser 532 nm) delivered by a contact lens (Super Quad Ò 160 Volk). The forward displacement of SO developed a few hours after laser retinopexy, and laser YAG PI relieved the problem and facilitated the posterior migration of SO, suggesting that the closure of the PI was the cause of the disease. Other mechanisms of forward displacement of SO include posterior spaceoccupying lesions like retinal detachment, choroidal effusion and hemorrhage; low aqueous production and the resultant hypotony, especially in complicated and multiple retinal surgeries; and SO overfill usually with an elevated IOP in the early postoperative period [1]. The IOP measurements during the follow-up of these patients were within the normal limits, and clinical examination did not support these pathologies. SOPBG developed a few hours after laser retinopexy in our first patient and SOPB developed in the other two cases. One explanation may be the mechanical effect of the contact lens on the eye during laser therapy. The pressure exerted on the globe by the contact lens during the laser therapy, especially while trying to photocoagulate the peripheral retina, can distort the globe, alter the SO pupillary aperture contact and induce a complete pupillary block. After the induction of a pupillary block, SOPB may have occurred because of the closed status of the PI. The alternation of SO iris contact by mechanical pressure on the globe has been suggested by other authors. In a report by Bartov et al. [7], mechanical pressure on the cornea and face-down positioning had altered SO iris contact and broken SOPB certainly in one case and possibly in another case. Inflammation may have been increased after laser therapy in our patients and induced the real closure of the PI and the complete iridiocapsular adhesion that led to SOPB. Ciliochoroidal effusion is a rather frequent complication of laser therapy which is usually free of clinical observable complications [8]. It may have decreased the posterior segment volume in our patients and induced a relative silicone-overfill state and possibly pushed the SO forward. This condition may have induced a pupillary block by the SO because of the closed status of the PI. Ciliochoroidal effusion can also induce anterior displacement of the iris lens complex and a shallowing of the AC [9]. Ciliochoroidal effusion is usually not observed until a few days after laser therapy and the aqueous flare reaches its peak 5 10 days after laser therapy [8]; however, SOPB developed within a few hours after laser therapy in our patients. Although it appears that these complications typically develop at a slower rate than SOPB developed in our cases, we cannot reject the contribution of these mechanisms to development of SOPB in our patients. Regardless of the mechanism, the development of SOPB shortly after laser retinopexy in three SO-filled aphakic eyes with a closed PI and no forward migration of SO highlights the importance of followup examinations after laser retinopexy. Our observations also suggest using a YAG laser prophylactically to reopen the PI to prevent the induction of SOPB or performing laser therapy with an indirect laser ophthalmoscope. Conflict of interest The authors have no financial interest in any material or equipment used in the study. Ethical standard The report of these cases is approved by the Ethic Committee of Farabi Eye Hospital. References 1. Beekhuis WH, Ando F, Zivojnović R, Mertens DA, Peperkamp E (1987) Basal iridectomy at 6 o clock in the aphakic eye treated with silicone oil: prevention of keratopathy and secondary glaucoma. Br J Ophthalmol 71:197 200 2. Zalta AH, Boyle NS, Zalta AK (2007) Silicone oil pupillary block: an exception to combined argon Nd:YAG laser iridotomy success in angle-closure glaucoma. Arch Ophthalmol 125:883 888 3. Ichhpujani P, Jindal A, Jay Katz L (2009) Silicone oil induced glaucoma: a review. Graefes Arch Clin Exp Ophthalmol 247:1585 1593 4. Madreperla SA, McCuen BW II (1995) Inferior peripheral iridectomy in patients receiving silicone oil. Rates of postoperative closure and effect on oil position. Retina 15:87 90 5. MacCumber MW, Packo KH, Civantos JM, Greenberg JB (2002) Preservation of anterior capsule during vitrectomy and lensectomy for retinal detachment with proliferative vitreoretinopathy. Ophthalmology 109:329 333 6. Laidlaw DA, Karia N, Bunce C, Aylward GW, Gregor ZJ (2002) Is prophylactic 360-degree laser retinopexy protective? Risk factors for retinal redetachment after removal of silicone oil. Ophthalmology 109:153 158
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