Phacoemulsification and intraocular lens implantation in Alport syndrome with anterior lenticonus

CASE REPORT

Phacoemulsification and intraocular lens implantation in Alport syndrome with anterior lenticonus Mohammad Ali Zare, MD, Mohammad Taher Rajabi, MD, Mehdi Nili-Ahmadabadi, MD, Syed Jafar Oskouee, MD, Sasan Moghimi, MD

Eleven eyes of 6 patients with Alport syndrome had phacoemulsification with implantation of a single-piece acrylic hydrophobic intraocular lens (IOL) (AcrySof SA6OAT, Alcon) because of anterior lenticonus. All patients had excellent visual acuity after surgery. We recommend phacoemulsification with IOL implantation as a safe and effective procedure in patients with anterior lenticonus secondary to Alport syndrome. J Cataract Refract Surg 2007; 33:1127–1130 Q 2007 ASCRS and ESCRS

Alport syndrome consists of a clinical triad: hereditary nephritis, sensorineural deafness, and ocular abnormalities that may involve the cornea, lens (lenticonus), and retina (superficial perimacular white flecks).1–6 The main abnormality in Alport syndrome is deficient synthesis of type IV collagen, which is the main component of basement membranes.7 Anterior lenticonus is one of the most common ocular findings in Alport syndrome and is found in 90% of patients, more commonly in men than in women.8 We present 11 eyes of 6 patients with anterior lenticonus owing to Alport syndrome who had continuous curvilinear capsulorhexis (CCC) and phacoemulsification with intraocular lens (IOL) implantation. All patients achieved excellent visual results (Table 1). CASE REPORTS Case 1 A 32-year-old woman was admitted to the Farabi Eye Hospital with a complaint of decreased visual acuity due

to anterior lenticonus. Her history included deafness since childhood and renal disease with proteinuria and hematuria. On ocular examination, the best corrected visual acuity (BCVA) was 20/160 in the right eye and 20/80 in the left eye. Slitlamp examination revealed anterior lenticonus in both eyes as well as perimacular flecks. Phacoemulsification and implantation of a single-piece acrylic hydrophobic IOL (AcrySof SA60AT, Alcon) was performed in the right eye and left eye 2 weeks apart. One week postoperatively, the BCVA was 20/30 and 20/25 in the right eye and left eye, respectively. Two months later, the BCVA was 20/20 in both eyes.

Case 2 A 36-year-old woman with a history of renal transplantation following chronic renal failure (CRF) was admitted to the eye hospital because of loss of visual acuity in both eyes. The visual acuity was 20/80 and 20/40 in the right eye and left eye, respectively. Slitlamp examination revealed anterior lenticonus in both eyes as the only positive finding. The fundus examination was normal. Phacoemulsification and implantation of an AcrySof IOL were performed in both eyes 2 weeks apart. After surgery, the BCVA was 20/20 and 20/25 in the right eye and left eye, respectively.

Accepted for publication February 6, 2007.

Case 3

From the Tehran University Eye Research Center, Farabi Eye Hospital, Tehran, Iran.

A 45-year-old man with a history of renal transplantation following CRF presented with a loss of visual acuity. He had been deaf since childhood. The BCVA was 20/30 in the right eye and 20/160 in the left eye. Slitlamp examination revealed anterior lenticonus in both eyes; the left eye also had an anterior capsular cataract due to rupture of the anterior capsule. Phaocemulsification and implantation of an AcrySof IOL were performed in the left eye. Two weeks postoperatively, the BCVA was 20/25.

No author has a financial or proprietary interest in any material or method mentioned. Corresponding author: Mohammad Taher Rajabi, MD, Tehran University Eye Research Center, Farabi Eye Hospital, Tehran, Iran. E-mail: [email protected]. Q 2007 ASCRS and ESCRS Published by Elsevier Inc.

0886-3350/07/$dsee front matter doi:10.1016/j.jcrs.2007.02.019

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Table 1. Demographic and clinical data of patients with Alport syndrome. Age

Sex

Systemic disorders

Ocular finding

Case I

32

F

Deafness, renal disease

ALC, premacular flecks

Case II

36

F

Renal transplantation

ALC

Case III Case IV

45 29

M M

Renal transplantation, deafness Renal disease

ALC, anterior capsular cataract ALC, PPMD

Case V

21

M

Deafness, renal disease

ALC

Case VI

24

M

Deafness, renal disease

ALC

Preoperative VA

Postoperative VA

20/160(OD), 20/80(OS) 20/80(OD), 20/400(OS) 20/160(OS) 20/200(OD), 20/50(OS) 20/40(OD), 20/40(OS) 20/160(OD), 20/80(OS)

20/20(OD), 20/20(OS) 20/20(OD), 20/25(OS) 20/25(OS) 20/25(OD), 20/20(OS) 20/25(OD), 20/25(OS) 20/30(OD), 20/25(OS)

VA; visual acuity, F; female, M; male, ALC; anterior lenticonus, PPMD; posterior polymorphous corneal dystrophy

Case 4 A 29-year-old man was referred to the eye hospital for refractive surgery. On ocular examination, the BCVA was 20/200 in the right eye and 20/50 in the left eye. The refractive error was 4.50 1.50  160 and 2.75 2.00  180, respectively. Slitlamp examination revealed a vesicular appearance of the cornea, compatible with posterior polymorphic dystrophy (PPMD). Both crystalline lenses had anterior lenticonus. The fundus examination was normal. Phacoemulsification and implantation of an AcrySof IOL were performed. After surgery, the BCVA was 20/25 and 20/20 in the right eye and left eye, respectively. The anterior capsule of the lens with lenticonus, removed for capsular thickness measurement, was 4 mm.

Cases 5 and 6 Two brothers, 21 and 24 years old, were referred to our center because of a loss of visual acuity. Both had hearing loss from childhood and renal failure. The BCVA was 20/40 in both eyes in one brother and 20/160 in the right eye and 20/80 in the left eye in the other brother. On ocular examination, both had anterior lenticonus. Phacoemulsification and implantation of an AcrySof IOL were performed in both eyes of both patients 2 weeks apart. One month after surgery, the BCVA was 20/25 in both eyes of one patient and 20/30 in the right eye and 20/25 in the left eye of the other patient.

DISCUSSION Alport syndrome has a prevalence of 1/5000.9 Eightyfive percent of patients have the X-linked form. Affected men develop renal failure and a high-tone sensorineural deafness by the age of 20.9 The reported incidence of ocular manifestation in Alport syndrome is 11% to 92%.9 The typical ocular associations are dot-and-fleck retinopathy, which occurs in about 85% of affected adult men; anterior lenticonus, which

occurs in about 25%; and the rare posterior polymorphous corneal dystrophy.1,2,5,6,9,10 The retinopathy and anterior lenticonus are not evident in childhood but become worse with time.9 A retinal lesion is often present at the onset of renal failure, but signs of anterior lenticonus appear later. The demonstration of a dot-and-fleck retinopathy in any individual with a family history of Alport syndrome or with end-stage renal disease is diagnostic of the syndrome.9,11 Additional ocular features described in the X-linked form include other corneal dystrophies, microcornea, arcus, iris atrophy, cataract, spontaneous lens rupture, spherophakia, posterior lenticonus,8 poor macular reflex,4 and macular hole.6 Telangiectasia of the conjunctiva,12 fluorescein angiogram hyperfluorescence, electrooculogram and electroretinogram abnormalities, and retinal pigmentation9 have also been reported. In this syndrome, the main problem is defective synthesis of type IV collagen.7 As the major component of basement membranes in the human body, collagen type IV is composed of 6 genetically distinct chains; namely, alpha 1 to alpha 6.2 These 6 chains are encoded by genes COL4A1 to COL4A6, respectively.2 Genes COL4A1 and COL4A2 are located on chromosome 13, genes COL4A3 and COL4A4 are located on chromosome 2, and genes COL4A5 and COL4A6 are mapped to the long arm of chromosome X.2,5 All mutations demonstrated to date in X-linked Alport syndrome have affected the COL4A5 gene, which encodes the alpha-5 chain of type IV collagen.2 This protein is probably common to the basement membranes of the glomerulus, cochlea, retina, lens capsule, and cornea. However, the alpha-3 (IV), -4 (IV), and -5 (IV) collagen chains are usually absent from the affected basement membranes because the abnormal

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CASE REPORT: ALPORT SYNDROME AND IOL IMPLANTATION

alpha-5 (IV) molecule interferes with the stability of all 3. The loss of these collagen molecules from the affected basement membranes results in an abnormal ultrastructural appearance.2,13 The ocular and other clinical features of autosomal recessive Alport syndrome are identical to those seen in the X-linked disease, while retinopathy and cataracts are the only ocular abnormalities described in the rare autosomal dominant form. Hearing problems usually start in childhood in male patients and around 40 years of age in female patients.5 Ocular problems are seen in X-linked and autosomal recessive but not in the autosomal dominant form,5 which is the most important cause of anterior lenticonus.8 Anterior lenticonus is considered pathognomonic for Alport syndrome with the exception of traumatic lenticonus.5 Combined anterior and posterior lenticonus is a rare finding in Alport syndrome. Anterior lenticonus is a progressive developmental anomaly that is bilateral in 75% of patients. Anterior lenticonus does not exist at birth but usually manifests during the second or third decade.5 Anterior lenticonus may lead to visual loss, but cataract extraction and IOL implantation can improve the patient’s visual acuity, as demonstrated in our patients. In this report, we described 11 eyes of 6 patients with Alport syndrome, one of whom had PPMD (Case 4) and another had midperipheral retinal flecks (Case 1). All patients had CCC and phacoemulsification with implantation of a foldable posterior chamber IOL and achieved acceptable BCVA. Our findings are comparable to those in the reports by John et al.7 and Sukhija et al.8 In two of the earlier studies, a CCC was performed after the cortical lens matter was aspirated, as in a 2-stage CCC.10,14 We performed a CCC starting in the midperiphery rather than a conventional CCC, which is initiated in the center of the capsule. This step is important because it avoids inadvertent spontaneous rupture of the lens capsule, which is thin and fragile in Alport syndrome.1 The anterior capsule is more fragile at the poles than at the periphery.15 We cannot comment on the fragility of the posterior capsule, but stripping the posterior cortex during bimanual irrigation/aspiration (I/A) was carefully done, keeping the vacuum limit at 150 mm Hg, as Sukhija et al.8 suggest. Electron microscopy of the anterior capsule in patients with Alport syndrome has demonstrated thinning and dehiscence that contain vacuoles and fibrillar material,1,16–19 explaining the observed fragility during capsulorhexis and anecdotal reports of spontaneous capsule rupture in the natural course of anterior lenticonus.14

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To our knowledge, no electron microscopy studies of the posterior capsule of the crystalline lens in Alport syndrome or posterior lenticonus are available, although Khalil and Saheb20 demonstrate thinning of the posterior capsule on histopathology. We did not experience any difficulty performing phacoemulsification and I/A. We recommend phacoemulsification with foldable posterior chamber IOL implantation as a safe and effective procedure in anterior lenticonus. Continuous curvilinear capsulorhexis without peripheral extension is possible in patients with Alport syndrome, starting slightly away from the center of the anterior capsule to avoid radial tears.

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16. Takei K, Furuya A, Hommura S, Yamaguchi N. Ultrastructural fragility and type IV collagen abnormality of the anterior lens capsules in a patient with Alport syndrome. Jpn J Ophthalmol 2001; 45:103–104 17. Streeten BW, Robinson MR, Wallace R, Jones DB. Lens capsule abnormalities in Alport’s syndrome. Arch Ophthalmol 1987; 105: 1693–1697 18. Choi J, Na K, Bae S, Roh G. Anterior lens capsule abnormalities in Alport syndrome. Korean J Ophthalmol 2005; 19:84–89 19. Kato T, Watanabe Y, Nakayasu K, et al. The ultrastructure of the lens capsule abnormalities in Alport’s syndrome. Jpn J Ophthalmol 1998; 42:401–405

20. Khalil M, Saheb N. Posterior lenticonus. Ophthalmology 1984; 91:1429–1430; 43A

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First author: Mohammad Ali Zare, MD Tehran University Eye Research Center, Farabi Eye Hospital, Tehran, Iran