Outcomes of lensectomy and risk factors for failure in spherophakic eyes with secondary glaucoma

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.

Outcomes of lensectomy with glued intraocular lens and factors associated with failure in eyes with spherophakia and glaucoma

Purpose

To evaluate the outcomes of lensectomy with a glued intraocular lens (IOL) in spherophakic eyes with secondary glaucoma and assess factors associated with failure.

Methods

We prospectively evaluated outcomes of lensectomy with glued IOL in 19 eyes with spherophakia and secondary glaucoma (intraocular pressure (IOP) ≥22 mm Hg and/or glaucomatous optic disc damage) between 2016 and 2018. The vision, refractive error, IOP, antiglaucoma medications (AGMs), optic disc changes, need for glaucoma surgery, and complications were assessed. Success was defined as complete when IOP was ≥5 and ≤21 mmHg without AGMs; qualified success as similar IOP with up to 3 AGM; the need for >3AGM/additional surgery for IOP control was considered a failure.

Results

Preoperatively, the median (interquartile range: IQR) age was 18 (13.5-30) years. IOP was 16 (14-22.5) mmHg on a median of 3 (2,3) AGMs. Median postoperative follow up was 27.7 months (11.9, 39.7). Postsurgery, most patients achieved emmetropia, with significantly decreased refractive error from a median spherical equivalent of -12.5D to + 0.5D, P < 0.0002. The complete success probability was 47% (95% confidence intervals (CIs): 29-76%) at 3 months and was 21% (8 - 50%) at 1 year and 3 years. The qualified success probability was 93% (82-100%) at 1 year, which reduced to 79% (60-100%) in 3 years. None of the eyes had any retinal complications. The higher number of preoperative AGM was found to be a significant risk factor (p < 0.02) for the failure of complete success.

Conclusion

One-third of the eyes had IOP control without the need for AGM postlensectomy with glued IOL. Surgery resulted in significant improvement in visual acuity. The higher number of preoperative AGM was associated with poor glaucoma control after glued IOL surgery.

A systematic approach to the management of microspherophakia

Microspherophakia is a rare developmental abnormality of the crystalline lens with a myriad of ocular and systemic associations. Glaucoma is a serious complication associated with this disorder. Early identification of the disease, timely visual rehabilitation, and appropriate management of the lens and glaucoma can help us prevent blindness from this condition. Multidisciplinary care with lifelong follow-up is recommended, as this typically affects the younger population. Current treatment protocols for this condition are mainly based on case reports and retrospective studies with shorter follow-up. Due to the rarity of this disease, designing a large randomized controlled trial to identify the merits and demerits of each management strategy is challenging. With cataract, glaucoma, and vitreoretinal specialists, each having their preferred way of managing microspherophakic lenses, we decided to do a comprehensive review of the existing literature to devise an integrated approach toward effective management of these patients. This review will collate all evidence and provide a very practical decision-making tree for its management.

Diagnosis and treatment of microspherophakia

As a rare congenital disease, microspherophakia (MSP) is characterized by small and spherically shaped crystalline lenses. The common complications of MSP include secondary glaucoma and crystalline lens dislocation or subluxation. Patients with MSP often show high lenticular myopia. The special morphological characteristics and complex complications bring challenges to the treatment of patients with MSP. Although there are some studies on MSP, most are case reports. In this article, the morphological characteristics, complications, genetic diagnosis, and treatment of MSP were systematically reviewed, providing valuable insight into the clinical diagnosis and treatment of this disease.

Artesunate induces mitochondria-mediated apoptosis of human retinoblastoma cells by upregulating Kruppel-like factor 6

Retinoblastoma (RB) is the most common primary intraocular malignancy in children. Intravitreal chemotherapy achieves favorable clinical outcomes in controlling RB vitreous seeds, which are a common reason for treatment failure. Thus, a novel, effective and safe intravitreal chemotherapeutic drug is urgently required. The malaria drug artesunate (ART) recently demonstrated remarkable anticancer effects with mild side effects. The purpose of this study is to investigate the anti-RB efficacy, the underlying mechanism and the intraocular safety of ART. Herein, we verified that ART inhibits RB cell viability and induces cell apoptosis in a dose- and time-dependent manner. Microarray analysis revealed that Kruppel-like factor 6 (KLF6) was upregulated after ART treatment, and this was further confirmed by real-time PCR and western blot assays. Silencing of KLF6 expression significantly reversed ART-induced RB cell growth inhibition and apoptosis. Furthermore, ART activated mitochondria-mediated apoptosis of RB cells, while silencing KLF6 expression significantly inhibited this effect. In murine xenotransplantation models of RB, we further confirmed that ART inhibits RB tumor growth, induces tumor cell apoptosis and upregulates KLF6 expression. In addition, KLF6 silencing attenuates ART-mediated inhibition of tumor growth in vivo. Furthermore, we proved that intravitreal injection of ART in Sprague-Dawley (SD) rats is safe, with no obvious retinal function damage or structural disorders observed by electrophysiology (ERG), fundal photographs, fundus fluorescein angiography (FFA) or optical coherence tomography (OCT) examinations. Collectively, our study revealed that ART induces mitochondrial apoptosis of RB cells via upregulating KLF6, and our results may extend the application of ART to the clinic as an effective and safe intravitreal chemotherapeutic drug to treat RB, especially RB with vitreous seeds.

[Scleral-fixated intraocular lenses with Z‑suture technique for lens subluxation associated with spherophakia]

This article reports the case of a 38-year-old woman who presented with spherophakia and bilateral lens subluxation. Spherophakia patients have abnormally weak zonula fibers, whereby the lens can subluxate. The patient was treated by phacoemulsification combined with the placement of a scleral-fixated intraocular lens with the Z‑suture technique. Scleral-fixated intraocular lenses are a treatment option for spherophakia. The knotless Z‑suture technique has a low risk of suture erosion and scleral atrophy.

Femtosecond laser-assisted cataract surgery in patients with zonular weakness

Purpose

To present the clinical value of femtosecond laser assisted cataract surgery (FLACS) in eyes with compromised zonules.

Observations

We present two cases of femtosecond laser assisted cataract surgery (FLACS) in eyes with compromised zonules. Three eyes from two patients with zonular weakness and cataract underwent FLACS (Alcon LenSx Lasers Inc., Aliso Viejo, CA). One patient underwent bilateral FLACS in the setting of spherophakia with zonular weakness. The other patient had Marfan's syndrome with associated ectopia lentis. Laser assisted capsulotomy was achieved in all eyes. One eye had vitreous prolapse during surgery and required an iris-sutured lens. All eyes had a postoperative corrected distance visual acuity of 20/25 or better.

Conclusions and Importance

FLACS is a safe and effective alternative to conventional phacoemulsification cataract surgery in patients with zonular weakness.

A three-dimensional organoid model recapitulates tumorigenic aspects and drug responses of advanced human retinoblastoma

Persistent or recurrent retinoblastoma (RB) is associated with the presence of vitreous or/and subretinal seeds in advanced RB and represents a major cause of therapeutic failure. This necessitates the development of novel therapies and thus requires a model of advanced RB for testing candidate therapeutics. To this aim, we established and characterized a three-dimensional, self-organizing organoid model derived from chemotherapy-naïve tumors. The responses of organoids to drugs were determined and compared to relate organoid model to advanced RB, in terms of drug sensitivities. We found that organoids had histological features resembling retinal tumors and seeds and retained DNA copy-number alterations as well as gene and protein expression of the parental tissue. Cone signal circuitry (M/L⁺ cells) and glial tumor microenvironment (GFAP⁺ cells) were primarily present in organoids. Topotecan alone or the combined drug regimen of topotecan and melphalan effectively targeted proliferative tumor cones (RXRγ⁺ Ki67⁺) in organoids after 24-h drug exposure, blocking mitotic entry. In contrast, methotrexate showed the least efficacy against tumor cells. The drug responses of organoids were consistent with those of tumor cells in advanced disease. Patient-derived organoids enable the creation of a faithful model to use in examining novel therapeutics for RB.