Clinical and genetic investigation of isolated microspherophakia in a consanguineous Tunisian family

Congenital anomalies of lens shape

The crystalline lens is an important structure in the eye that starts to develop as early as the 22nd day of gestation, with further differentiation that continues after the induction. Congenital anomalies of the lens may involve the size, shape, and position of the lens. They may sometimes be associated with anterior segment dysgenesis or persistence of the tunica vasculosa lentis and hyperplastic vitreous and hyaloid system. Manifestations of anomalies of the lens shape are usually seen in early or late childhood however may sometimes be delayed into adulthood based on the level of visual impairment or the presence or absence of any syndromic associations. While lens coloboma has more often been reported in isolation, the more commonly implicated genes include the PAX6 gene, lenticonus in particular anterior is often part of Alport syndrome with extra-ocular manifestations in the kidneys and hearing abnormalities due to mutations in the alpha 5 chain of the Type IV collagen gene. Recognition of these manifestations and obtaining a genetic diagnosis is an important step in the management. The level of visual impairment and amblyopia dictates the outcomes in patients managed either conservatively with optical correction as well as surgically where deemed necessary. This review discusses the various anomalies of the lens shape with its related genetics and the management involved in these conditions.

An innovative alternative for spherophakia

Objective: The aim of this case report is to report a new aphakic intraocular lens (IOL) that can be used for spherophakia. Methods: This is a single case report wherein the authors elaborate the technique of inserting the new IOL design in patients with spherophakia. Results: This new IOL design is very stable and is very promising in our follow-up of 6 months. Conclusion: The CM T-flex IOL can be a simple and alternate option for correcting aphakia.

Sutureless Scleral-Fixated Intraocular Lens Implantation for Refractive Rehabilitation in Eyes With Spherophakia

PURPOSE

Spherophakia is a rare, debilitating congenital ocular disorder.

METHODS

This institution-based, retrospective, interventional study evaluated medical records of 16 patients with spherophakia with a median age of 19.5 years. Twenty-six eyes underwent scleral-fixated intraocular lens implantation. The technique involved 2 parallel-to-limbus scleral tunnels fashioned using a microincision vitrectomy blade, followed by lensectomy, core vitrectomy, externalization of haptics through 2 separate diametrically opposite sclerotomies, and tucking in of the haptics into the tunnels. Anterior and posterior segment examination, visual acuity, and intraocular pressure (IOP) were noted at baseline and final follow-up.

RESULTS

Baseline best-corrected visual acuity (BCVA) of all eyes was 0.49 ± 0.51 logarithm of the minimum angle of resolution (logMAR) (Snellen equivalent, 6/18). BCVA of more than 6/60 was present in 28 of 32 (87.5%) eyes, and 13 of 26 (50%) eyes that were operated on had a baseline BCVA of more than 6/18. Postoperative BCVA in 26 eyes improved from 0.43 ± 0.32 logMAR to 0.19 ± 0.21 logMAR (Snellen equivalent, 6/9) (P = .002). Postoperative BCVA was more than 6/18 in 20 of 26 (76.9%) operated-on eyes (P = .046), and all eyes had a final BCVA of more than 6/60. In 20 of 26 (76.9%) eyes, BCVA improved from preoperative status. Postoperatively, spherical equivalent improved from -9.55 ± 5.17 diopters to -0.29 ± 1.45 diopters (P < .001). Apart from 2 patients with Marfan syndrome, 1 with Weill-Marchesani syndrome, and 1 with homocystinuria, the remaining patients had isolated spherophakia. Six eyes presented with an IOP greater than 21 mm Hg, and 50% of these eyes had a final IOP that decreased to less than 15 mm Hg after lensectomy.

CONCLUSIONS

Lensectomy with pars plana vitrectomy and scleral-fixated intraocular lens is an effective method of refractive rehabilitation for patients with spherophakia presenting with visual disability.

Zinn's zonule

The Zonule of Zinn, or ciliary zonule, is the elaborate system of extracellular fibers that centers the lens in the eye. In humans, the fibers transmit forces that flatten the lens during the process of disaccommodation, thereby bringing distant objects into focus. Zonular fibers are composed almost entirely of 10-12 nm-wide microfibrils, of which polymerized fibrillin is the most abundant component. The thickest fibers have a fascicular organization, where hundreds or thousands of microfibrils are gathered into micrometer-wide bundles. Many such bundles are aggregated to form a fiber. Dozens of proteins comprise the zonule. Most are derived from cells of the non-pigmented ciliary epithelium in the pars plana region, although some are probably contributed by the lens and perhaps other tissues of the anterior segment. Zonular fibers are viscoelastic cables but their component microfibrils are rather stiff structures. Thus, the elastic properties of the fibers likely stem from lateral interactions between microfibrils. Rupture of zonular fibers and subsequent lens dislocation (ectopia lentis) can result from blunt force trauma or be a sequela of other eye diseases, notably exfoliation syndrome. Ectopia lentis is also a feature of syndromic conditions caused typically by mutations in microfibril-associated genes. The resulting ocular phenotypes raise the possibility that the zonule regulates lens size and shape, globe size, and even corneal topology, in addition to its well-recognized role in accommodation.

Spherophakia and Ectopia Lentis in a Sturge-Weber Patient: A Case Report

Sturge-Weber syndrome (SWS) is a rare, sporadic neurocutaneous disorder, primarily characterized by port-wine stain (PWS) over the ophthalmic division of the trigeminal nerve (V1) territory (hallmark feature) and glaucoma (in 30-60% of cases). Other ocular manifestations include episcleral involvement of the PWS, choroidal vascular malformations, and iris heterochromia. Two previous reports also associated ectopia lentis concomitantly among these cases. However, here we report spherophakia as a novel ophthalmological finding in SWS. A 56-year-old female previously diagnosed with SWS presented to the outpatient clinic complaining of right-sided decreased visual acuity and pain after a fall. Phenotypically, the patient had a PWS around V1 territory and involvement of both eyelids. Previous relevant ocular history included retinal detachment without macular involvement, ocular hypertension, and phacodonesis. The slit-lamp examination showed anterior lens luxation and elevated intraocular pressure (IOP) of 40 mm Hg by tonometry. Prior to the surgical approach, the patient received hypotensive treatment for elevated IOP. After intracapsular lens extraction, measurements were consistent with spherophakia. Postoperatively, the patient underwent optical coherence tomography (OCT). There was cystic macular edema (CME) by OCT and a detached posterior hyaloid membrane. The patient fully recovered with topical treatment of bromfenac for CME. To the best of our knowledge, this is the first report of concomitant anterior lens luxation and spherophakia (novel association) in a SWS patient. Our findings supplement the differential ocular diagnoses in SWS and should be considered in the routine ocular exam, specifically of the anterior segment. CME occurred similar to otherwise healthy eyes. However, in this case, topical anti-inflammatory medications had a good response and were well-tolerated.

Femtosecond laser-assisted cataract surgery in a spherophakic lens: An unusual case report

RATIONALE

Spherophakia is a rare diagnosis which is often associated with a shallow anterior chamber, angle-closure glaucoma, lens subluxation, and lenticular myopia. When cataracts occur with subluxation of the lens, vision is often markedly affected. This often presents surgeons with a unique challenge of maintaining good visual outcomes while minimizing potential complications.

PATIENT CONCERNS

A 48-year-old female was referred for ophthalmological assessment due to decreased vision in the left eye. In the left eye, the best-corrected visual acuity at distance was 20/125 with manifest refraction of -6.5D + (-0.75) D × 118°. The slit lamp examination showed iridodonesis and a significant nuclear cataract (C3N3) with tremor in the left eye. After pupil dilation, a subluxated lens, weak zonules, and "fake golden ring" within the lens was noted.

DIAGNOSIS

Due to the patient's symptoms, examination results, she was diagnosed with cataract, subluxation of the lens and spherophakia in left eye.

INTERVENTIONS

The patient underwent an uneventful femtosecond laser-assisted cataract surgery (Alcon Fort Worth, TX). The laser was able to perform a circular free-floating anterior capsulotomy and easy lens fragmentation.

OUTCOMES

There were no postoperative complications. At 3 months postoperatively, the uncorrected visual acuity was 20/25, and the manifest refraction was -0.25 D - 0.75 D × 148° with the corrected distance visual acuity of 20/16.

LESSONS

Femtosecond laser-assisted cataract surgery is an effective approach for cataract surgery in patients with subluxated and spherophakic lenses, with the benefits of causing minimal further zonular damage and easy lens fragmentation.

Clinical spectrum and surgical outcomes in spherophakia: a prospective interventional study

PurposeTo study the varied clinical presentations of patients with spherophakia, their management using surgical methods, and the clinical outcomes.Patients and methodsA prospective interventional study of 13 patients of spherophakia who presented to us from January 2014 and were followed up over the course of their treatment, and the data were documented for analysis.ResultsIn all, 26 eyes of 13 patients were reviewed and the median age of presentation was 12±12.05 years. All patients had a bilateral presentation with 22 eyes having lenticular myopia with a mean refractive error of -11.5±12.945 DS. Ten eyes presented with glaucoma of which six had raised intraocular pressure (IOP) >21 mm Hg. A total of 23 eyes underwent lens extraction for dislocation/subluxation. Lens extraction helped lower overall IOP. Refractive rehabilitation was done with ACIOL, posterior chamber intraocular lens (PCIOL) with capsular tension ring, and scleral-fixated intraocular lens (SFIOL) in respective cases with ACIOLs being the most commonly used option.ConclusionsSpherophakia is a rare condition, which exhibits a varying degree of lenticular myopia, glaucoma, and subluxation of the crystalline lens. Lensectomy with proper rehabilitation using ACIOL, PCIOL, or SFIOL is a method of managing subluxation and unacceptable myopia. Lensectomy may also be a viable option of controlling glaucoma alongside medications and glaucoma surgery for the management of glaucoma in such cases.

Retropupillary iris-claw intraocular lens for the surgical correction of aphakia in cases with microspherophakia

PURPOSE

This study aimed to evaluate the safety and efficacy of retropupillary fixation of an iris-claw intraocular lens (IOL; Verisyse polymethyl methacrylate IOL, Abbott Medical Optics [AMO], Netherlands) for the surgical correction of aphakia in microspherophakic eyes without sufficient capsular support.

DESIGN

This was a prospective, interventional, noncomparative case series.

METHODS

This interventional case series comprised 17 eyes of 9 microspherophakic patients. Retropupillary fixation of the Verisyse iris-claw IOL (AMO) was performed in all cases. The surgical time was measured. Corrected distance visual acuity, astigmatism, intraocular pressure (IOP), tissue reaction, pigment dispersion, and stability of the IOL were studied 1 day, 3 days, 1 week, 2 weeks, 1 month, and 6 months postoperatively.

RESULTS

Eight patients had familial microspherophakia and one patient had Marfan's syndrome. Eighty-two percent of the cases achieved a visual acuity of 0.3 or better. There was no significant postoperative inflammatory reaction. Transient elevation of IOP was recorded in two cases in the 1st week only. One IOL developed disengagement of one of the haptics from the iris and was successfully re-engaged. All the other IOLs were well centered and stable. The mean surgical time was 18.0 ± 4.5 min.

CONCLUSIONS

Retropupillary fixation of an iris-claw IOL is a safe and effective procedure that provides early visual recovery. It is also a time-saving method for correcting aphakia in microspherophakic eyes without sufficient capsular support.

[Isolated microspherophakia in a Senegalese family]

PURPOSE

To report the clinical investigation of isolated microspherophakia involving a Senegalese family in order to appreciate its functional impact.

OBSERVATIONS

This is a rural family comprised of 7 members. The sibship included three girls and two boys. One of the girls, who lived in a distant zone, was unable to be examined. Of all the examined members of the family, only the father was unaffected by the illness. There was no consanguinity. The general medical examination was normal. The best-corrected visual acuity (VA) for the girls was 2/10. For one of the boys, BCVA was 8/10 for both eyes, and for the other, BCVA was 10/10 for the right eye and 8/10 for the left eye. The mother's VA was 10/10 and P2 without correction. Myopia and astigmatism were present in the 4 children of the sibship. During the examination, we noted the presence of small crystalline lenses, which were very round and presented an abnormal visibility of the lens equator and zonular fibers. The diagnosis of microspherophakia was confirmed by measurement of the lens diameters by ultrasound biomicroscopy. Complications were present in the girls, including pupillary block glaucoma and amblyopia for the elder, and retinal degeneration and amblyopia for the younger daughter. The elder daughter was managed medically with glaucoma drops. The younger daughter received optical correction and a prophylactic Argon LASER treatment. The two boys received optical correction. No treatment was recommended for the mother.

CONCLUSION

Microspherophakia is a rare condition. Some serious complications can lead to amblyopia. A better multidisciplinary evaluation would allow for early detection and a better prognosis.