CASE REPORT
Pars plana vitrectomy for dystrophic calcification of a silicone intraocular lens in association with asteroid hyalosis David I. Ullman, BSc, Sunil Gupta, MD
We present a case in which a pars plana vitrectomy (PPV) was performed to halt the progressive dystrophic calcification of an intraocular lens (IOL) and the need for an IOL exchange. With limited follow-up, the patient’s visual complaints have resolved, the dystrophic calcification of the IOL has stabilized, and good visual acuity has been retained. To our knowledge, this is the first report of a patient with progressive dystrophic calcification of silicone IOLs in association with asteroid hyalosis treated primarily with a PPV. In certain cases, PPV may be considered in patients with dystrophic calcification in association with asteroid hyalosis and may prevent the need for a late IOL exchange. Financial Disclosure: Neither author has a financial or proprietary interest in any material or method mentioned. J Cataract Refract Surg 2014; 40:1228–1231 Q 2014 ASCRS and ESCRS
The association of dystrophic calcification of silicone intraocular lenses (IOLs) in eyes with asteroid hyalosis requiring intraocular exchange was first reported in 2004.1,2 Clinically, progressive white fleck-like deposits are localized to the posterior optic surface of the silicone IOL and occur years after initial implantation. Previous attempts to remove the dystrophic calcification with a neodymium:YAG (Nd:YAG) laser capsulotomy and “dusting” of the posterior surface of a silicone IOL have had limited success.3 The reports of successful treatment with Nd:YAG dusting of the opacity have been temporary, with a progressive reaccumulation of the deposits requiring explantation and IOL exchange. Since IOL explantation and exchange are more difficult and entail more risk after an Nd:YAG capsulotomy, the definitive primary surgical treatment for this phenomenon has been IOL explantation and exchange prior to Nd:YAG capsulotomy.4
Submitted: January 25, 2014. Final revision submitted: February 19, 2014. Accepted: February 20, 2014. From the Retina Specialists of Pensacola, Pensacola, Florida, USA. Corresponding author: Sunil Gupta, MD, Retina Specialists, 5150 North Davis Highway, Pensacola, Florida 32503, USA. E-mail: [email protected].
1228
Q 2014 ASCRS and ESCRS Published by Elsevier Inc.
To our knowledge, this is the first report of treatment of late opacification of a silicone IOL in association with asteroid hyalosis with a pars plana vitrectomy (PPV). Our patient was unique in that we had documented progressive opacification of the silicone optic with retained good visual acuity. In addition, the patient had progressive bilateral epiretinal membranes. A PPV was performed in the hopes of stabilizing the opacification of the silicone optic by removing the asteroid bodies and vitreous and simultaneously surgically repairing the epiretinal membrane. CASE REPORT A 45-year-old white man was first evaluated for cataract evaluation in July 1995. The medical history was pertinent for adult-onset diabetes. The ophthalmic examination was remarkable for a visually significant cataract in the right eye with a corrected distance visual acuity (CDVA) of 20/40. On dilated fundoscopic examination, no asteroid hyalosis or diabetic retinopathy was noted. Uneventful phacoemulsification with use of sodium hyaluronate (Vitrax) and implantation of a 3-piece silicone SI30NB 21.5 diopter (D) IOL (Allergan Medical Optics, Inc.) were performed in August 1995. The postoperative course was unremarkable, and the CDVA was 20/20. In January 1997, the patient developed a posterior subcapsular cataract in his left eye with a CDVA of 20/40. Uneventful phacoemulsification with use of sodium hyaluronate and implantation of a 3-piece silicone SI30NB 22.0 D IOL were performed. The postoperative course was again unremarkable, with a return to 20/20 CDVA. The patient was followed yearly until 2002 and maintained 20/20 CDVA bilaterally with clear IOLs and a 0886-3350/$ - see front matter http://dx.doi.org/10.1016/j.jcrs.2014.04.022
CASE REPORT: PARS PLANA VITRECTOMY FOR IOL DYSTROPHIC CALCIFICATION
normal fundoscopic examination with no asteroid hyalosis or diabetic retinopathy noted. The patient was lost to follow-up until October 2008, at which time he was seen in consultation for a Nd:YAG laser capsulotomy evaluation of the right eye. Ophthalmic examination revealed a CDVA of 20/20 bilaterally with a mild opacity of the posterior capsules, greater in the right eye than in the left. Dilated fundoscopic examination revealed mild epiretinal membranes, partial posterior vitreous detachments bilaterally, and no asteroid hyalosis. It was decided not to perform an Nd:YAG capsulotomy, and the patient was referred back to his referring eye doctor. The patient was reevaluated in November 2011 with a new visual complaint of “floaters for a while” and decreased vision. Pertinent ophthalmic evaluation revealed a CDVA of 20/20 and 20/25 in the right eye and left eye, respectively; posterior capsule opacities were greater in the left eye than in the right and progressed from the previous evaluation in October 2008. On fundoscopic examination, asteroid hyalosis was noted bilaterally for the first time and the epiretinal membranes had clinically progressed. In November 2011, an Nd:YAG capsulotomy was done in the left eye for a presumed significant capsule opacity. Immediately on opening the posterior capsule, a white fleck-like opacity limited to the posterior surface of the IOL consistent with dystrophic calcification of the posterior surface of the IOL was noted. Despite the CDVA remaining 20/25 after the procedure, the patient subjectively noted an improvement in his vision. In July 2012, the patient was referred back for consideration of an Nd:YAG capsulotomy in the right eye. On examination, the CDVA had decreased to 20/25 in the right eye and the opacity of the posterior surface of the IOL had progressed. The patient was symptomatic with complaints of deteriorating vision (Figure 1). On fundoscopic examination,
1229
persistent epiretinal membranes and asteroid hyalosis were noted; the latter had become more prominent bilaterally. Dystrophic calcification of the silicone IOL in association with asteroid hyalosis bilaterally was diagnosed, and an IOL exchange was considered for the right eye instead of an Nd:YAG capsulotomy. However, because of the unique situation of relatively retained good visual acuity in association with documented progressive dystrophic calcification of the IOL and an epiretinal membrane, a PPV was also considered. A sutureless 23-gauge PPV and epiretinal removal were performed in the right eye in September 2012. At the time of the PPV, the posterior capsule was opened and an unsuccessful attempt was made to remove the dystrophic calcification on the posterior optic. The CDVA remained unchanged at 20/25 postoperatively, but the patient subjectively noted significant improvement in his visual symptoms with resolution of the symptomatic floaters in the right eye. In April 2013, the patient noted decreasing vision the left eye; the CDVA was 20/30. Slitlamp examination revealed progressive dystrophic calcification of the IOL on the left side. A central Nd:YAG opening was present, and repeat optical coherence tomography revealed worsening of the epiretinal membrane. The right eye remained symptom free with retained visual acuity of 20/25. The dystrophic calcification of the posterior capsule in the right eye that had a PPV was unchanged. In April 2013, the patient had an uneventful sutureless 23-gauge PPV with removal of the asteroid hyalosis and a membrane peel in the left eye. At the time of the PPV, an unsuccessful attempt was again made to remove the calcification on the posterior optic. When the patient was last evaluated in January 2014, the uncorrected distance acuity was 20/20 in the right eye and 20/25 in the left eye. The dystrophic calcifications of the silicone optics were unchanged in severity since the PPVs, and the patient had no evidence of recurrent asteroid hyalosis.
DISCUSSION
Figure 1. Slitlamp photograph of white fleck-like opacities on the posterior surface of the silicone IOL.
The exact origin and method of formation of dystrophic calcification on silicone IOLs in eyes with asteroid hyalosis is not known.5 Most experts agree that the material opacifying the IOL (calcium apatite crystals) is derived from the asteroid bodies or, more likely, from a similar process that resulted in the vitreous condition itself.3 Asteroid hyalosis is an acquired, degenerative, age-related condition, and age-related changes in the vitreous composition and/or matrix may serve as a substrate on which calcium apatite crystals form.6 Clinical and pathological studies have shown a lower prevalence of asteroid hyalosis in patients with a complete posterior vitreous detachment (PVD).7 It is not known whether asteroid hyalosis is less likely to form in the presence of a PVD or whether the composition of the vitreous in patients with asteroid hyalosis prevents the PVD. Our patient was noted to have partial PVDs bilaterally. The only successful therapeutic surgical option reported for an opacified silicone IOL secondary to dystrophic calcification in association with asteroid hyalosis has been IOL explantation and exchange.8 Neodymium:YAG laser dusting of the opacities from
J CATARACT REFRACT SURG - VOL 40, JULY 2014
1230
CASE REPORT: PARS PLANA VITRECTOMY FOR IOL DYSTROPHIC CALCIFICATION
the posterior surface of the optic with temporary improvement in vision has been reported.9 However, the Nd:YAG laser capsulotomy opening promotes direct contact between the vitreous and posterior surface of the optic, leading to an acceleration of the dystrophic calcification and ultimate clinical worsening.3 The recent study of the perioperative complications of an IOL exchange for a visually significant IOL opacification by Fern andez-Buenaga et al.10 revealed that approximately one-third of the patients required an anterior vitrectomy and the new IOL had to be implanted in the ciliary sulcus in the majority of patients. In addition, multiple studies have confirmed the increased complication rate of an IOL exchange if a Nd:YAG capsulotomy opening was present.11 Leysen et al.4 reported an anterior vitrectomy rate of 48% (18 of 37 cases) when an Nd:YAG capsulotomy had been performed. Since our patient had a previous Nd:YAG capsulotomy in 1 eye and had had a 3-piece silicone IOL in the capsular bag for approximately 17 years, it was thought that an IOL explantation and exchange would carry significant perioperative surgical risks and the likely need for an anterior vitrectomy. It was hypothesized that a PPV in our patient might remove the source of the abnormal calcification and/ or the matrix on which the calcium apatite crystals form and halt the progressive opacification of the IOL, preventing the need for IOL explantation and exchange. Our patient had an additional surgical indication for a PPV with his epiretinal membranes. Other potential benefits of a PPV in our patient included improved visualization of the fundus and possible improvement of visual function with resolution of his symptomatic floaters by removal of the asteroid hyalosis itself.12 The surgical risks of a PPV in an eye with asteroid hyalosis and no other ocular comorbidities should ideally be assessed versus the risk of a late IOL exchange before this intervention is considered. However, no large series of PPV for asteroid hyalosis have been reported, and the risks of a PPV in this setting are not known. A PPV for primary symptomatic floaters has been reported by Tan et al.13 and may give a reasonable estimate of the complications of a PPV in patients with asteroid hyalosis. In this study, a 16.4% incidence of iatrogenic retinal breaks and a 2.5% incidence of a rhegmatogenous retinal detachment were reported. The study confirmed that even with contemporary techniques, significant potential complications of a PPV must be considered. With a limited follow-up (16 months in the right eye and 9 months in the left eye), our patient has done well, with total resolution of the visual symptoms, stabilization of the IOL opacification, and retained
excellent visual acuity. The authors appreciate that a significant component of the improved visual function would be attributable to the epiretinal membrane removal bilaterally and the opening of the posterior capsule in 1 eye. In addition, there have been rare reports of decreased vision secondary to asteroid hyalosis alone with improved visual acuity after PPV,1 and this may have played a role in the patient's improved visual function. Therefore, we accessed the stabilization of the clinical appearance of the opacities on the posterior surface primarily as an indicator of the success of the PPV procedure. During the PPV, efforts to clean the posterior optic of the opacification were not successful. We want to emphasize the limitations of this procedure and that it should not be performed if the patient has visually significant dystrophic calcification of the IOL. In the unique clinical situation of a documented progressive opacification of a silicone IOL secondary to asteroid hyalosis in which the vision is still well maintained, we think it is reasonable to consider a PPV to avoid the inherent risks of a late IOL exchange. Obviously, the risks/benefits of a PPV have to be weighed against the risk of a late IOL exchange in this setting. Other instances in which a PPV could be considered would be the clinical situation of an Nd:YAG capsulotomy performed for a presumed primary capsule opacity and a diagnosis of dystrophic calcification secondary to asteroid hyalosis. If the patient's visual symptoms are temporally alleviated by dusting the posterior capsule, a PPV may prevent progressive reaccumulation of the opacity and the subsequent need for an IOL exchange. Further studies and longer follow-up will be necessary to better assess the potential role of PPV in patients with asteroid hyalosis and dystrophic calcification of their silicone IOLs. REFERENCES 1. Wackernagel W, Ettinger K, Weitgasser U, Bakir BG, Schmut O, Goessler W, Faschinger C. Opacification of a silicone intraocular lens caused by calcium deposits on the optic. J Cataract Refract Surg 2004; 30:517–520 2. Foot L, Werner L, Gills JP, Shoemaker DW, Phillips PS, Mamalis N, Olson RJ, Apple DJ. Surface calcification of silicone plate intraocular lenses in patients with asteroid hyalosis. Am J Ophthalmol 2004; 137:979–987 3. Stringham J, Werner L, Monson B, Theodosis R, Mamalis N. Calcification of different designs of silicone intraocular lenses in eyes with asteroid hyalosis. Ophthalmology 2010; 117:1486–1492 4. Leysen I, Bartholomeeusen E, Coeckelbergh T, Tassignon MJ. Surgical outcomes of intraocular lens exchange: five-year study. J Cataract Refract Surg 2009; 35:1013–1018 5. Topilow HW, Kenyon KR, Takahashi M, Freeman HM, Tolentino FI, Hanninen LA. Asteroid hyalosis, biomicroscopy, ultrastructure, and composition. Arch Ophthalmol 1982; 100:964–968
J CATARACT REFRACT SURG - VOL 40, JULY 2014
CASE REPORT: PARS PLANA VITRECTOMY FOR IOL DYSTROPHIC CALCIFICATION
6. Mitchell P, Wang MY, Wang JJ. Asteroid hyalosis in an older population: the Blue Mountains Eye Study. Ophthalmic Epidemiol 2003; 10:331–335 7. Fawzi AA, Vo B, Kriwanek R, Ramkumar HL, Cha C, Carts A, Heckenlively JR, Foos RY, Glasgow BJ. Asteroid hyalosis in an autopsy population; the University of California at Los Angeles (UCLA) experience. Arch Ophthalmol 2005; 123:486–490. Available at: http://archopht.jamanetwork.com/ data/Journals/OPHTH/9938/ecs40033.pdf. Accessed February 20, 2014 8. Jones JJ, Jones YJ, Jin GJ. Indications and outcomes of intraocular lens exchange during a recent 5-year period. Am J Ophthalmol 2014; 157:154–162 9. Werner L, Kollarits CR, Mamalis N, Olson RJ. Surface calcification of a 3-piece silicone intraocular lens in a patient with asteroid hyalosis; a clinicopathologic case report. Ophthalmology 2005; 112:447–452 ndez-Buenga R, Alio JL, Pinilla-Corte s L, Barraquer RI. 10. Ferna Perioperative complications and clinical outcomes of intraocular lens exchange in patients with opacified lenses. Graefes Arch Clin Exp Ophthalmol 2013; 251:2141–2146
1231
€rk Y. 11. Kubaloglu A, Sari ES, Koytak A, Cinar Y, Erol K, Ozertu Intraocular lens exchange through a 3.2-mm corneal incision for opacified intraocular lenses. Indian J Ophthalmol 2011; 59:17–21. Available at: http://www.ncbi.nlm.nih.gov/pmc/ articles/PMC3032237/?reportZprintable. Accessed February 20, 2014 12. Parnes RE, Zakov ZN, Novak MA, Rice TA. Vitrectomy in patients with decreased visual acuity secondary to asteroid hyalosis. Am J Ophthalmol 1998; 125:703–704 13. Tan HS, Mura M, Lesnik Oberstein SY, Bijl HM. Safety of vitrectomy for floaters. Am J Ophthalmol 2011; 151:995–998
J CATARACT REFRACT SURG - VOL 40, JULY 2014
First author: David I. Ullman, BSc Retina Specialists of Pensacola, Pensacola, Florida, USA
Pars plana vitrectomy for dystrophic calcification of a silicone intraocular lens in association with asteroid hyalosis David I. Ullman, BSc, Sunil Gupta, MD
We present a case in which a pars plana vitrectomy (PPV) was performed to halt the progressive dystrophic calcification of an intraocular lens (IOL) and the need for an IOL exchange. With limited follow-up, the patient’s visual complaints have resolved, the dystrophic calcification of the IOL has stabilized, and good visual acuity has been retained. To our knowledge, this is the first report of a patient with progressive dystrophic calcification of silicone IOLs in association with asteroid hyalosis treated primarily with a PPV. In certain cases, PPV may be considered in patients with dystrophic calcification in association with asteroid hyalosis and may prevent the need for a late IOL exchange. Financial Disclosure: Neither author has a financial or proprietary interest in any material or method mentioned. J Cataract Refract Surg 2014; 40:1228–1231 Q 2014 ASCRS and ESCRS
The association of dystrophic calcification of silicone intraocular lenses (IOLs) in eyes with asteroid hyalosis requiring intraocular exchange was first reported in 2004.1,2 Clinically, progressive white fleck-like deposits are localized to the posterior optic surface of the silicone IOL and occur years after initial implantation. Previous attempts to remove the dystrophic calcification with a neodymium:YAG (Nd:YAG) laser capsulotomy and “dusting” of the posterior surface of a silicone IOL have had limited success.3 The reports of successful treatment with Nd:YAG dusting of the opacity have been temporary, with a progressive reaccumulation of the deposits requiring explantation and IOL exchange. Since IOL explantation and exchange are more difficult and entail more risk after an Nd:YAG capsulotomy, the definitive primary surgical treatment for this phenomenon has been IOL explantation and exchange prior to Nd:YAG capsulotomy.4
Submitted: January 25, 2014. Final revision submitted: February 19, 2014. Accepted: February 20, 2014. From the Retina Specialists of Pensacola, Pensacola, Florida, USA. Corresponding author: Sunil Gupta, MD, Retina Specialists, 5150 North Davis Highway, Pensacola, Florida 32503, USA. E-mail: [email protected].
1228
Q 2014 ASCRS and ESCRS Published by Elsevier Inc.
To our knowledge, this is the first report of treatment of late opacification of a silicone IOL in association with asteroid hyalosis with a pars plana vitrectomy (PPV). Our patient was unique in that we had documented progressive opacification of the silicone optic with retained good visual acuity. In addition, the patient had progressive bilateral epiretinal membranes. A PPV was performed in the hopes of stabilizing the opacification of the silicone optic by removing the asteroid bodies and vitreous and simultaneously surgically repairing the epiretinal membrane. CASE REPORT A 45-year-old white man was first evaluated for cataract evaluation in July 1995. The medical history was pertinent for adult-onset diabetes. The ophthalmic examination was remarkable for a visually significant cataract in the right eye with a corrected distance visual acuity (CDVA) of 20/40. On dilated fundoscopic examination, no asteroid hyalosis or diabetic retinopathy was noted. Uneventful phacoemulsification with use of sodium hyaluronate (Vitrax) and implantation of a 3-piece silicone SI30NB 21.5 diopter (D) IOL (Allergan Medical Optics, Inc.) were performed in August 1995. The postoperative course was unremarkable, and the CDVA was 20/20. In January 1997, the patient developed a posterior subcapsular cataract in his left eye with a CDVA of 20/40. Uneventful phacoemulsification with use of sodium hyaluronate and implantation of a 3-piece silicone SI30NB 22.0 D IOL were performed. The postoperative course was again unremarkable, with a return to 20/20 CDVA. The patient was followed yearly until 2002 and maintained 20/20 CDVA bilaterally with clear IOLs and a 0886-3350/$ - see front matter http://dx.doi.org/10.1016/j.jcrs.2014.04.022
CASE REPORT: PARS PLANA VITRECTOMY FOR IOL DYSTROPHIC CALCIFICATION
normal fundoscopic examination with no asteroid hyalosis or diabetic retinopathy noted. The patient was lost to follow-up until October 2008, at which time he was seen in consultation for a Nd:YAG laser capsulotomy evaluation of the right eye. Ophthalmic examination revealed a CDVA of 20/20 bilaterally with a mild opacity of the posterior capsules, greater in the right eye than in the left. Dilated fundoscopic examination revealed mild epiretinal membranes, partial posterior vitreous detachments bilaterally, and no asteroid hyalosis. It was decided not to perform an Nd:YAG capsulotomy, and the patient was referred back to his referring eye doctor. The patient was reevaluated in November 2011 with a new visual complaint of “floaters for a while” and decreased vision. Pertinent ophthalmic evaluation revealed a CDVA of 20/20 and 20/25 in the right eye and left eye, respectively; posterior capsule opacities were greater in the left eye than in the right and progressed from the previous evaluation in October 2008. On fundoscopic examination, asteroid hyalosis was noted bilaterally for the first time and the epiretinal membranes had clinically progressed. In November 2011, an Nd:YAG capsulotomy was done in the left eye for a presumed significant capsule opacity. Immediately on opening the posterior capsule, a white fleck-like opacity limited to the posterior surface of the IOL consistent with dystrophic calcification of the posterior surface of the IOL was noted. Despite the CDVA remaining 20/25 after the procedure, the patient subjectively noted an improvement in his vision. In July 2012, the patient was referred back for consideration of an Nd:YAG capsulotomy in the right eye. On examination, the CDVA had decreased to 20/25 in the right eye and the opacity of the posterior surface of the IOL had progressed. The patient was symptomatic with complaints of deteriorating vision (Figure 1). On fundoscopic examination,
1229
persistent epiretinal membranes and asteroid hyalosis were noted; the latter had become more prominent bilaterally. Dystrophic calcification of the silicone IOL in association with asteroid hyalosis bilaterally was diagnosed, and an IOL exchange was considered for the right eye instead of an Nd:YAG capsulotomy. However, because of the unique situation of relatively retained good visual acuity in association with documented progressive dystrophic calcification of the IOL and an epiretinal membrane, a PPV was also considered. A sutureless 23-gauge PPV and epiretinal removal were performed in the right eye in September 2012. At the time of the PPV, the posterior capsule was opened and an unsuccessful attempt was made to remove the dystrophic calcification on the posterior optic. The CDVA remained unchanged at 20/25 postoperatively, but the patient subjectively noted significant improvement in his visual symptoms with resolution of the symptomatic floaters in the right eye. In April 2013, the patient noted decreasing vision the left eye; the CDVA was 20/30. Slitlamp examination revealed progressive dystrophic calcification of the IOL on the left side. A central Nd:YAG opening was present, and repeat optical coherence tomography revealed worsening of the epiretinal membrane. The right eye remained symptom free with retained visual acuity of 20/25. The dystrophic calcification of the posterior capsule in the right eye that had a PPV was unchanged. In April 2013, the patient had an uneventful sutureless 23-gauge PPV with removal of the asteroid hyalosis and a membrane peel in the left eye. At the time of the PPV, an unsuccessful attempt was again made to remove the calcification on the posterior optic. When the patient was last evaluated in January 2014, the uncorrected distance acuity was 20/20 in the right eye and 20/25 in the left eye. The dystrophic calcifications of the silicone optics were unchanged in severity since the PPVs, and the patient had no evidence of recurrent asteroid hyalosis.
DISCUSSION
Figure 1. Slitlamp photograph of white fleck-like opacities on the posterior surface of the silicone IOL.
The exact origin and method of formation of dystrophic calcification on silicone IOLs in eyes with asteroid hyalosis is not known.5 Most experts agree that the material opacifying the IOL (calcium apatite crystals) is derived from the asteroid bodies or, more likely, from a similar process that resulted in the vitreous condition itself.3 Asteroid hyalosis is an acquired, degenerative, age-related condition, and age-related changes in the vitreous composition and/or matrix may serve as a substrate on which calcium apatite crystals form.6 Clinical and pathological studies have shown a lower prevalence of asteroid hyalosis in patients with a complete posterior vitreous detachment (PVD).7 It is not known whether asteroid hyalosis is less likely to form in the presence of a PVD or whether the composition of the vitreous in patients with asteroid hyalosis prevents the PVD. Our patient was noted to have partial PVDs bilaterally. The only successful therapeutic surgical option reported for an opacified silicone IOL secondary to dystrophic calcification in association with asteroid hyalosis has been IOL explantation and exchange.8 Neodymium:YAG laser dusting of the opacities from
J CATARACT REFRACT SURG - VOL 40, JULY 2014
1230
CASE REPORT: PARS PLANA VITRECTOMY FOR IOL DYSTROPHIC CALCIFICATION
the posterior surface of the optic with temporary improvement in vision has been reported.9 However, the Nd:YAG laser capsulotomy opening promotes direct contact between the vitreous and posterior surface of the optic, leading to an acceleration of the dystrophic calcification and ultimate clinical worsening.3 The recent study of the perioperative complications of an IOL exchange for a visually significant IOL opacification by Fern andez-Buenaga et al.10 revealed that approximately one-third of the patients required an anterior vitrectomy and the new IOL had to be implanted in the ciliary sulcus in the majority of patients. In addition, multiple studies have confirmed the increased complication rate of an IOL exchange if a Nd:YAG capsulotomy opening was present.11 Leysen et al.4 reported an anterior vitrectomy rate of 48% (18 of 37 cases) when an Nd:YAG capsulotomy had been performed. Since our patient had a previous Nd:YAG capsulotomy in 1 eye and had had a 3-piece silicone IOL in the capsular bag for approximately 17 years, it was thought that an IOL explantation and exchange would carry significant perioperative surgical risks and the likely need for an anterior vitrectomy. It was hypothesized that a PPV in our patient might remove the source of the abnormal calcification and/ or the matrix on which the calcium apatite crystals form and halt the progressive opacification of the IOL, preventing the need for IOL explantation and exchange. Our patient had an additional surgical indication for a PPV with his epiretinal membranes. Other potential benefits of a PPV in our patient included improved visualization of the fundus and possible improvement of visual function with resolution of his symptomatic floaters by removal of the asteroid hyalosis itself.12 The surgical risks of a PPV in an eye with asteroid hyalosis and no other ocular comorbidities should ideally be assessed versus the risk of a late IOL exchange before this intervention is considered. However, no large series of PPV for asteroid hyalosis have been reported, and the risks of a PPV in this setting are not known. A PPV for primary symptomatic floaters has been reported by Tan et al.13 and may give a reasonable estimate of the complications of a PPV in patients with asteroid hyalosis. In this study, a 16.4% incidence of iatrogenic retinal breaks and a 2.5% incidence of a rhegmatogenous retinal detachment were reported. The study confirmed that even with contemporary techniques, significant potential complications of a PPV must be considered. With a limited follow-up (16 months in the right eye and 9 months in the left eye), our patient has done well, with total resolution of the visual symptoms, stabilization of the IOL opacification, and retained
excellent visual acuity. The authors appreciate that a significant component of the improved visual function would be attributable to the epiretinal membrane removal bilaterally and the opening of the posterior capsule in 1 eye. In addition, there have been rare reports of decreased vision secondary to asteroid hyalosis alone with improved visual acuity after PPV,1 and this may have played a role in the patient's improved visual function. Therefore, we accessed the stabilization of the clinical appearance of the opacities on the posterior surface primarily as an indicator of the success of the PPV procedure. During the PPV, efforts to clean the posterior optic of the opacification were not successful. We want to emphasize the limitations of this procedure and that it should not be performed if the patient has visually significant dystrophic calcification of the IOL. In the unique clinical situation of a documented progressive opacification of a silicone IOL secondary to asteroid hyalosis in which the vision is still well maintained, we think it is reasonable to consider a PPV to avoid the inherent risks of a late IOL exchange. Obviously, the risks/benefits of a PPV have to be weighed against the risk of a late IOL exchange in this setting. Other instances in which a PPV could be considered would be the clinical situation of an Nd:YAG capsulotomy performed for a presumed primary capsule opacity and a diagnosis of dystrophic calcification secondary to asteroid hyalosis. If the patient's visual symptoms are temporally alleviated by dusting the posterior capsule, a PPV may prevent progressive reaccumulation of the opacity and the subsequent need for an IOL exchange. Further studies and longer follow-up will be necessary to better assess the potential role of PPV in patients with asteroid hyalosis and dystrophic calcification of their silicone IOLs. REFERENCES 1. Wackernagel W, Ettinger K, Weitgasser U, Bakir BG, Schmut O, Goessler W, Faschinger C. Opacification of a silicone intraocular lens caused by calcium deposits on the optic. J Cataract Refract Surg 2004; 30:517–520 2. Foot L, Werner L, Gills JP, Shoemaker DW, Phillips PS, Mamalis N, Olson RJ, Apple DJ. Surface calcification of silicone plate intraocular lenses in patients with asteroid hyalosis. Am J Ophthalmol 2004; 137:979–987 3. Stringham J, Werner L, Monson B, Theodosis R, Mamalis N. Calcification of different designs of silicone intraocular lenses in eyes with asteroid hyalosis. Ophthalmology 2010; 117:1486–1492 4. Leysen I, Bartholomeeusen E, Coeckelbergh T, Tassignon MJ. Surgical outcomes of intraocular lens exchange: five-year study. J Cataract Refract Surg 2009; 35:1013–1018 5. Topilow HW, Kenyon KR, Takahashi M, Freeman HM, Tolentino FI, Hanninen LA. Asteroid hyalosis, biomicroscopy, ultrastructure, and composition. Arch Ophthalmol 1982; 100:964–968
J CATARACT REFRACT SURG - VOL 40, JULY 2014
CASE REPORT: PARS PLANA VITRECTOMY FOR IOL DYSTROPHIC CALCIFICATION
6. Mitchell P, Wang MY, Wang JJ. Asteroid hyalosis in an older population: the Blue Mountains Eye Study. Ophthalmic Epidemiol 2003; 10:331–335 7. Fawzi AA, Vo B, Kriwanek R, Ramkumar HL, Cha C, Carts A, Heckenlively JR, Foos RY, Glasgow BJ. Asteroid hyalosis in an autopsy population; the University of California at Los Angeles (UCLA) experience. Arch Ophthalmol 2005; 123:486–490. Available at: http://archopht.jamanetwork.com/ data/Journals/OPHTH/9938/ecs40033.pdf. Accessed February 20, 2014 8. Jones JJ, Jones YJ, Jin GJ. Indications and outcomes of intraocular lens exchange during a recent 5-year period. Am J Ophthalmol 2014; 157:154–162 9. Werner L, Kollarits CR, Mamalis N, Olson RJ. Surface calcification of a 3-piece silicone intraocular lens in a patient with asteroid hyalosis; a clinicopathologic case report. Ophthalmology 2005; 112:447–452 ndez-Buenga R, Alio JL, Pinilla-Corte s L, Barraquer RI. 10. Ferna Perioperative complications and clinical outcomes of intraocular lens exchange in patients with opacified lenses. Graefes Arch Clin Exp Ophthalmol 2013; 251:2141–2146
1231
€rk Y. 11. Kubaloglu A, Sari ES, Koytak A, Cinar Y, Erol K, Ozertu Intraocular lens exchange through a 3.2-mm corneal incision for opacified intraocular lenses. Indian J Ophthalmol 2011; 59:17–21. Available at: http://www.ncbi.nlm.nih.gov/pmc/ articles/PMC3032237/?reportZprintable. Accessed February 20, 2014 12. Parnes RE, Zakov ZN, Novak MA, Rice TA. Vitrectomy in patients with decreased visual acuity secondary to asteroid hyalosis. Am J Ophthalmol 1998; 125:703–704 13. Tan HS, Mura M, Lesnik Oberstein SY, Bijl HM. Safety of vitrectomy for floaters. Am J Ophthalmol 2011; 151:995–998
J CATARACT REFRACT SURG - VOL 40, JULY 2014
First author: David I. Ullman, BSc Retina Specialists of Pensacola, Pensacola, Florida, USA
