Ocular manifestations and surgical results in patients with Alport syndrome

Continuous Curvilinear Capsulorhexis - A Practical Review

BACKGROUND

Continuous curvilinear capsulorhexis (CCC) has become the gold standard technique for anterior capsulotomy, a cardinal development in modern cataract surgery. CCC enables safer and relatively convenient access to the crystalline lens, however it is more challenging to master than older methods. Understanding the physics underlying this procedure is key to achieving the desired results and avoiding complications.

PURPOSE

To review and present the established information about CCC, and to create a practical guide to this important step in cataract surgery.

METHODS

A literature review was conducted using PubMed, Embase, Cochrane and Scopus databases, with emphasis on up-to-date information. The first part of this review describes the evolution of CCC and discusses the different approaches, the various instruments available, tips and pearls and the general setup for best results. The second half covers more recent innovations and common complications, and strategies to prevent or manage them. This paper provides a practical review of all aspects of CCC.

Femtosecond laser-assisted cataract surgery for bilateral anterior lenticonus

Anterior lenticonus is a characteristic ocular feature of Alport syndrome, leading to progressive vision deterioration. Surgical lens removal may be an option in such cases, and the role of femtosecond laser-assisted cataract surgery (FLACS) has been recently described. Herein, we report the third described case, to our knowledge, of bilateral anterior lenticonus surgically approached through FLACS. A 25-year-old man with X-linked Alport syndrome complained of bilateral progressive vision loss. Ophthalmological evaluation revealed a corrected distance visual acuity of 20/63 in both eyes and bilateral anterior lenticonus associated with anterior polar cataract. FLACS was performed, followed by IOL placement on the capsular bag, without any intraoperative complications. One month postoperatively, uncorrected distance visual acuity was 20/20 in both eyes. Considering these results and the information published so far, this technology might be a good option for these patients.

Alport Syndrome and Femtosecond Laser-assisted Cataract Surgery

We report the surgical management of a patient with bilateral anterior lenticonus due to Alport syndrome using femtosecond laser-assisted cataract surgery (FLACS) and the Optiwave Refractive Analysis (ORA) system. A 38-year-old man with Alport syndrome presented to our department with visual loss due to anterior lenticonus in both eyes. Adjustments during bilateral FLACS were performed with the software's calipers to manually delineate the anterior capsulotomy. Multifocal toric intraocular lenses (IOLs) were selected and placed in the posterior chamber with the aid of intraoperative aberrometry. The intended postoperative positioning parameters for the IOL as well as the planned visual acuity and refraction were achieved. The implementation of FLACS and intraoperative wavefront aberrometry is a safe and useful surgical approach for the management of cataract in challenging cases such as patients with anterior lenticonus due to Alport syndrome.

Phacoemulsification in bilateral anterior lenticonus in Alport syndrome: A case report

RATIONALE

To report the visual status and results of phacoemulsification cataract surgery in a young patient with Alport syndrome associated with bilateral anterior lenticonus. The milestone of this report is the use of anterior segment optical coherence tomography (AS-OCT) to confirm the central protrusion of the anterior surface of the crystalline lens.

PATIENT CONCERNS

A 23-year-old young woman presented with severe progressive visual loss in both eyes, which started several years ago.

DIAGNOSES

Refractive status was indicative of high myopia with astigmatism and vision was not improved with optimal correction to better than 0.1 in the right eye and 0.2 in the left eye (visual acuities given in decimal notation). Slit-lamp examination showed transparent cornea, anterior lenticonus and posterior sub-capsular cataract in both eyes. The classical appearance of oil droplet was evident using retro-illumination on the slit lamp.

INTERVENTIONS

The natural lenses were replaced with intraocular lens (IOL).

OUTCOMES

An excellent refractive status achieved associated with an uncorrected distance visual acuity 0.9 and 0.8 in the right and left eye, respectively.

LESSONS

AS-OCT is a valuable device for confirming the budging of the anterior crystalline lens surface.

Bilateral giant macular holes: A rare manifestation of Alport syndrome

PURPOSE:

Alport syndrome is a rare condition characterized by the clinical triad of nephritic syndrome, sensorineural deafness, and ophthalmological alterations. Herein, we present a rare case of a patient diagnosed with Alport syndrome and bilateral giant macular holes.

CASE DESCRIPTION:

A 40-year-old woman with a previously unreported mutation in the COL4A4 gene suggestive of autosomal-recessive Alport syndrome presented at our department. The patient exhibited bilateral full-thickness macular holes measuring >1500 µm at their smallest diameters. The very large dimensions of both macular holes were indicative of a bad prognosis regarding hole closure, and a conservative approach was adopted. The patient was maintained on renal substitution therapy, and genetic counseling was offered to other family members.

CONCLUSION:

Ophthalmological findings associated to Alport syndrome commonly include anterior lenticonus and dot-and-fleck retinopathy, although giant macular holes can also be associated with this condition. A multidisciplinary approach is crucial in the management of these patients, as Alport syndrome is an inherited systemic basement membrane disease.

Toric multifocal intraocular lens implantation in a case of bilateral anterior and posterior lenticonus in Alport syndrome

We report the first case of toric multifocal intraocular lens (IOL) implantation in both the eyes of a young patient of Alport syndrome with anterior and posterior lenticonus with a successful outcome. An 18-year-old female patient presented with progressively blurred vision in both eyes since 4–5 years not improving with glasses. Refraction showed high myopia with astigmatism; however, the vision did not improve beyond 6/60 with glasses correction. Clinical examination on slit lamp showed anterior and posterior lenticonus bilaterally with a classical oil droplet appearance. We performed clear lens extraction by phacoemulsification with toric multifocal IOL implantation in both eyes. Postoperatively, the patient achieved an excellent refractive outcome with the unaided vision of 6/9, N6 in both eyes.

Femtosecond laser-assisted cataract surgery in anterior lenticonus due to Alport syndrome

Purpose

We describe a case of bilateral anterior lenticonus in a patient with Alport syndrome treated with femtosecond laser-assisted cataract surgery (FLACS).

Observations

FLACS was performed without complication, and a desirable postoperative visual acuity was achieved.

Conclusions and importance

Femtosecond laser-assisted cataract surgery is an effective approach for managing patients with anterior lenticonus secondary to Alport syndrome.

Femtosecond Laser-Assisted Cataract Surgery in Alport Syndrome with Anterior Lenticonus

Purpose

To report the surgical treatment of 3 eyes of 2 patients with bilateral anterior lenticonus due to Alport syndrome using femtosecond laser-assisted cataract surgery (FLACS).

Methods

Two patients with Alport syndrome presented to our department due to anterior lenticonus in both eyes. We performed FLACS with posterior chamber lens implantation in both eyes of one patient and in one eye of the other patient. Anterior segment morphologic changes were visualized with a Scheimpflug camera, and anterior segment optical coherence tomography preoperatively and 3 months after surgery. Ultrastructure of the cut capsule edges was observed with scanning electron microscopy and compared to the edge of femtosecond laser capsulotomy performed on an otherwise healthy patient with cataract (control).

Results

The intraocular lens (IOL) postoperative positioning parameters met the international requirements of aspherical and wavefront customized IOLs (tilt <10 degree, decentration <800 μm). Scanning electron microscopy revealed the same characteristics of the cut capsule edges in the Alport and in the control eyes.

Conclusions

Femtosecond laser cataract surgery can be a safe and successful method for optical rehabilitation of anterior lenticonus in patients with Alport syndrome.

Bilateral anterior lenticonus in a case of Alport syndrome: a clinical and histopathological correlation after successful clear lens extraction

A 29-year-old woman presented with symptoms of gradual, progressive, painless diminution of vision in both eyes for past 8-10 years. On examination, uncorrected visual acuity was 20/60 in the right eye and 20/126 in the left eye. Anterior segment examination was essentially normal except for a conical protrusion in the pupillary axis of the anterior lens capsule with a clear underlying lens. During surgery, central protruded fragile lens capsule was meticulously handled to create well-centered continuous curvilinear capsulorhexis by using paediatric rhexis forceps. Histopathology of excised capsule showed markedly thinned lens capsule with normal epithelium. Electron microscopy of the anterior lens capsule showed multiple linear and irregular zones of dehiscence. Few of these had fibrillar, irregular electron-dense material and vacuoles; and adjacent cells were irregular suggestive of Alport syndrome. Postoperative course was uneventful and visual acuity improved to 20/20 unaided. Clear lens extraction is an effective means of rehabilitating visually symptomatic anterior lenticonus of Alport syndrome.

Clear lens phacoemulsification in Alport syndrome: refractive results and electron microscopic analysis of the anterior lens capsule

PURPOSE

To report the ocular findings of patients with Alport syndrome and the results of clear lens extraction in this patient group.

METHODS

Twenty-three eyes of 15 patients with a diagnosis of Alport syndrome were included in this study. Clear corneal phacoemulsification and intraocular foldable lens implantation was performed in eyes with indeterminate refractive errors and/or poor visual acuity and anterior capsule samples were analyzed with electron microscopy.

RESULTS

All patients had a history of hereditary nephritis and/or deafness as systemic involvement. Ophthalmologic examination revealed anterior lenticonus with high myopia and/or irregular astigmatism in all patients. The mean best-corrected visual acuity (BCVA) was 0.67 ± 0.17 logMAR (range 1.0-0.4) preoperatively and 0.17 ± 0.08 logMAR (range 0.3-0.0) postoperatively. Postoperative refractive lenticular astigmatism dramatically decreased and no ocular complications arose during the follow-up period. Transmission electron microscopic analysis of the lens capsules supported the diagnosis of Alport syndrome.

CONCLUSIONS

Clear lens phacoemulsification and foldable intraocular lens implantation is a safe and effective therapeutic choice for the management of uncorrectable refractive errors and low visual acuity due to anterior lenticonus in patients with Alport syndrome.

Mechanical response of wild-type and Alport murine lens capsules during osmotic swelling

The mechanical support of basement membranes, such as the lens capsule, is believed to arise from one of their main constituents - collagen IV. The basement membranes of the lens, kidney, and ear normally contain two different types of collagen IV networks, referred to as the major and minor chain networks. In Alport syndrome, a mutation in one of the minor chain COL4 genes leads to the absence of the minor chain network, causing life-threatening disturbances. We hypothesized that the absence of the minor chain network increases basement membrane distensibility, as measured in wild-type (n = 25) and Alport syndrome (n = 21) mice using the lens capsule as a model. Osmotic swelling experiments revealed direction-dependent changes. As a reflection of lens capsule properties, Alport lenses strained significantly more than wild-type lenses in the anterior-posterior direction, i.e. along their thickness, but not in the equatorial direction (p = 0.03 and p = 0.08, respectively). This is consistent with clinical data: Alport patients develop conical protrusions on the anterior and posterior lenticular poles. There was no evidence of significant change in total amount of collagen between Alport and wild-type lenses (p = 0.6). The observed differences in distensibility could indicate that the major chain network alone cannot fully compensate for the absence of the more highly cross-linked minor chain network, which is believed to be stronger, more stable, and resistant to deformation. The addition of mechanical information on Alport syndrome to the currently available biological data provides a fuller picture into the progression of the disease.

Challenge in pathologic diagnosis of Alport syndrome: evidence from correction of previous misdiagnosis

Background

Pathologic studies play an important role in evaluating patients with Alport syndrome besides genotyping. Difficulties still exist in diagnosing Alport syndrome (AS), and misdiagnosis is a not-so-rare event, even in adult patient evaluated with renal biopsy.

Methods

We used nested case–control study to investigate 52 patients previously misdiagnosed and 52 patients initially diagnosed in the China Alport Syndrome Treatments and Outcomes Registry e-system.

Results

We found mesangial proliferative glomerulonephritis (MsPGN, 26.9%) and focal and segmental glomerulosclerosis (FSGS, 19.2%) were the most common misdiagnosis. FSGS was the most frequent misdiagnosis in female X-linked AS (fXLAS) patients (34.8%), and MsPGN in male X-linked AS (mXLAS) patients (41.2%). Previous misdiagnosed mXLAS patients (13/17, 76.5%) and autosomal recessive AS (ARAS) patients (8/12, 66.7%) were corrected after a second renal biopsy. While misdiagnosed fXLAS patients (18/23, 78.3%) were corrected after a family member diagnosed (34.8%) or after rechecking electronic microscopy and/or collagen-IV alpha-chains immunofluresence study (COL-IF) (43.5%) during follow-up. With COL-IF as an additional criterion for AS diagnosis, we found that patients with less than 3 criteria reached have increased risk of misdiagnosis (3.29-fold for all misdiagnosed AS patients and 3.90-fold for fXLAS patients).

Conclusion

We emphasize timely and careful study of electronic microscopy and COL-IF in pathologic evaluation of AS patients. With renal and/or skin COL-IF as additional criterion, 3 diagnosis criteria reached are the cutoff for diagnosing AS pathologically.

Clear lens extraction in Alport syndrome with combined anterior and posterior lenticonus or ruptured anterior lens capsule

We describe the results of clear lens extraction in 7 eyes of 4 Alport-syndrome patients. Three patients (6 eyes) had both anterior and posterior lenticonus; the fourth patient had spontaneous rupture of the anterior lens capsule, resulting in an acute drop in vision. Clear lens extraction was an effective method for visual rehabilitation in Alport syndrome patients.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.