Ocular complications and prophylactic strategies in Stickler syndrome: a systematic literature review

The genetics and disease mechanisms of rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) is a sight threatening condition that warrants immediate surgical intervention. To date, 29 genes have been associated with monogenic disorders involving RRD. In addition, RRD can occur as a multifactorial disease through a combined effect of multiple genetic variants and non-genetic risk factors. In this review, we provide a comprehensive overview of the spectrum of hereditary disorders involving RRD. We discuss genotype-phenotype correlations of these monogenic disorders, and describe genetic variants associated with RRD through multifactorial inheritance. Furthermore, we evaluate our current understanding of the molecular disease mechanisms of RRD-associated genetic variants on collagen proteins, proteoglycan versican, and the TGF-β pathway. Finally, we review the role of genetics in patient management and prevention of RRD. We provide recommendations for genetic testing and prophylaxis of at-risk patients, and hypothesize on novel therapeutic approaches beyond surgical intervention.

Outcomes in Retinal Detachment Repair and Laser Prophylaxis for Syndromes with Optically Empty Vitreous

PURPOSE

To evaluate and compare surgical outcomes for syndromes with optically empty vitreous (SOEV)-associated rhegmatogenous retinal detachments.

DESIGN

A retrospective, cross-sectional, 2-arm study of a single pediatric vitreoretinal surgeon's patients from a quaternary referral center with SOEV was performed to examine visual and anatomical outcomes of rhegmatogenous retinal detachment and laser prophylaxis.

SUBJECTS

Patients identified either through slit-lamp examination (presence of an optically empty or void space in the vitreous gel structure) or genetic testing. Fifty-six eyes of 49 patients were identified in the retinal detachment arm. Sixty eyes of 48 patients were identified in the laser prophylaxis arm.

METHODS

Comparison of initial retinal detachment (RD) surgical repair via pars plana vitrectomy (PPV), scleral buckle (SB), or PPV-SB with final anatomical success, best-corrected visual acuity (BCVA), and number of surgical procedures. Secondary analysis was performed looking at eyes failing their initial SB, eyes with a giant retinal tear at presentation, eyes failing RD repair within specific time intervals, and eyes where hyaloid was elevated during initial vitrectomy. An additional study arm examined the outcomes of final BCVA and the presence and timing of developing a retinal tear or RD in eyes who received laser prophylaxis.

MAIN OUTCOME MEASURES

Visual acuity, surgical repair techniques (PPV, SB, PPV-SB), number of surgeries, anatomical retinal reattachment success.

RESULTS

Initial SB had statistically significant better final BCVA (P < 0.01) and better final anatomical success (P < 0.01). No statistical difference in the number of surgeries needed to achieve anatomical success between the initial SB versus initial PPV-SB/PPV. Hyaloidal elevation during the initial vitrectomy was associated with improved final BCVA and higher final anatomical success without the use of silicone oil (P < 0.01 and 0.04 respectively). Lastly, eyes that developed RDs after laser prophylaxis had better final BCVA than untreated eyes (P < 0.05).

CONCLUSION

Initial SB yields better overall outcomes in SOEV presenting with rhegmatogenous retinal detachment. Stickler Type-1 patients had similar outcomes compared with other SOEV, suggesting both populations should be treated with similar approaches.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Inherited causes of combined vision and hearing loss: clinical features and molecular genetics

Combined vision and hearing loss, also known as dual sensory impairment, can occur in several genetic conditions, including ciliopathies such as Usher and Bardet-Biedl syndrome, mitochondrial DNA disorders and systemic diseases, such as CHARGE, Stickler, Waardenburg, Alport and Alstrom syndrome. The retinal phenotype may point to the diagnosis of such disorders. Herein, we aim to provide a comprehensive review of the molecular genetics and clinical features of the most common non-chromosomal inherited disorders to cause dual sensory impairment.

Connective tissue disorders and eye: A review and recent updates

Collagen vascular disorders (CVDs), also known as connective tissue diseases (CTDs), are a heterogeneous group of entities that affect the connective tissues and are capable of causing end-organ damage to multiple systems, primarily cardiopulmonary and musculoskeletal. However, the occurrence and severity are highly variable among patients. Ocular involvement occurs in a significant number of these disorders and may precede the onset of other extraocular features, thereby serving as an important marker in the diagnosis of these diseases. A timely and accurate diagnosis enables the management of complications. CTDs are primarily immune-mediated inflammatory diseases; however, classifications have encompassed heritable disorders affecting collagen-containing structures and disorders of vascular development. A review of literature published until 25 January 2022 and collected from various databases using the relevant keywords was conducted. All publications (original articles, review articles, as well as case reports) describing the ocular features in CTDs were studied in detail. The objective of this review is to recognize the common ophthalmic presentations of various autoimmune and heritable CTDs, distinguish them from overlapping diseases, elaborate on the prognosis and management of these varied eye presentations, and deliberate on their impact on other ophthalmic surgeries.

Retinal Detachment Prophylaxis for Patients With Stickler Syndrome: A Survey of Pediatric Retinal Specialist Treatment Preferences

BACKGROUND AND OBJECTIVE

Stickler syndrome is the most common inherited cause of pediatric rhegmatogenous retinal detachment. The purpose of this study was to survey pediatric retinal surgeon preferences for prophylactic treatment of Stickler syndrome patients.

STUDY DESIGN

A voluntary, anonymous 27-question survey was developed by RedCap and distributed to the Association of Pediatric Retinal Surgeons. The survey was distributed on March 17, 2021. Results were tabulated on April 12, 2021 in Microsoft Excel. All surveys returned were included.

RESULTS

Thirty-four (76% response rate) respondents completed the survey. Twenty-six (76%) reported primarily using prophylactic laser retinopexy, four (12%) preferred use of cryotherapy, and 12% reported using prophylactic scleral buckle.

CONCLUSIONS

The majority of the United States. and international pediatric retinal surgeons use laser retinopexy as the primary method of prophylactic treatment. These results may serve as a benchmark for retinal surgeons less familiar with prophylactic treatment approaches. [Ophthalmic Surg Lasers Imaging Retina 2023;54:102-107.].

Risk and Prevention of Retinal Detachments in Patients with Stickler Syndrome

BACKGROUND AND OBJECTIVE

To report the impact of prophylactic laser retinopexy in the prevention of retinal detachments (RDs) in patients with Stickler syndrome.

PATIENTS AND METHODS

This was a retrospective, comparative case series of patients with Stickler syndrome from the year 2000 to 2019. We compared the rate of RDs between individuals who did and did not receive prophylactic laser therapy. In patients with an RD, we compared the rate of RD in the fellow eye with and without prophylactic laser treatment.

RESULTS

A total of 95 eyes were identified. Fifty-four percent of the overall population was female. The RD rate was 26.7% among eyes without previous prophylactic laser retinopexy and 4.6% among eyes with previous prophylactic laser retinopexy. A Cox proportional model revealed that laser prophylaxis treatment had a statistically significant effect on the risk of RD or retinal tear during the 25-year survival period from birth (P = .034). Eyes receiving treatment were 70% less likely to experience RD or retinal tear (hazard ratio, 0.297; 95% CI, 0.097 to 0.913).

CONCLUSIONS

This study's results suggest a potential role for prophylactic laser retinopexy in the prevention of rhegmatogenous RD among patients with a clinical diagnosis of Stickler syndrome. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:7-11.].

Genetic Characteristics and Phenotype of Korean Patients with Stickler Syndrome: A Korean Multicenter Analysis Report No. 1

Stickler syndrome is an inherited connective tissue disorder of collagen. There are relatively few reports of East Asian patients, and no large-scale studies have been conducted in Korean patients yet. In this study, we retrospectively analyzed the genetic characteristics and clinical features of Korean Stickler syndrome patients. Among 37 genetically confirmed Stickler syndrome patients, 21 types of gene variants were identified, of which 12 were novel variants. A total of 30 people had variants in the COL2A1 gene and 7 had variants in the COL11A1 gene. Among the types of pathogenic variants, missense variants were found in 11, nonsense variants in 8, and splice site variants in 7. Splicing variants were frequently associated with retinal detachment (71%) followed by missense variants. This is the first large-scale study of Koreans with Stickler syndrome, which will expand the spectrum of genetic variations of Stickler syndrome.

Controversy and Consideration of Refractive Surgery in Patients with Heritable Disorders of Connective Tissue

Heritable Disorders of Connective Tissue (HDCTs) are syndromes that disrupt connective tissue integrity. They include Osteogenesis Imperfecta (OI), Ehlers Danlos Syndrome (EDS), Marfan Syndrome (MFS), Loeys-Dietz Syndrome (LDS), Epidermolysis Bullosa (EB), Stickler Syndrome (STL), Wagner Syndrome, and Pseudoxanthoma Elasticum (PXE). Because many patients with HDCTs have ocular symptoms, commonly myopia, they will often present to the clinic seeking refractive surgery. Currently, corrective measures are limited, as the FDA contraindicates laser-assisted in-situ keratomileusis (LASIK) in EDS and discourages the procedure in OI and MFS due to a theoretically increased risk of post-LASIK ectasia, poor wound healing, poor refractive predictability, underlying keratoconus, and globe rupture. While these disorders present with a wide range of ocular manifestations that are associated with an increased risk of post-LASIK complications (e.g., thinned corneas, ocular fragility, keratoconus, glaucoma, ectopia lentis, retinal detachment, angioid streaks, and ocular surface disease), their occurrence and severity are highly variable among patients. Therefore, an HDCT diagnosis should not warrant an immediate disqualification for refractive surgery. Patients with minimal ocular manifestations can consider LASIK. In contrast, those with preoperative signs of corneal thinning and ocular fragility may find the combination of collagen cross-linking (CXL) with either photorefractive keratotomy (PRK), small incision lenticule extraction (SMILE) or a phakic intraocular lens (pIOL) implant to be more suitable options. However, evidence of refractive surgery performed on patients with HDCTs is limited, and surgeons must fully inform patients of the unknown risks and complications before proceeding. This paper serves as a guideline for future studies to evaluate refractive surgery outcomes in patients with HDCTs.

Proline metabolism and transport in retinal health and disease

The retina is one of the most energy-demanding tissues in the human body. Photoreceptors in the outer retina rely on nutrient support from the neighboring retinal pigment epithelium (RPE), a monolayer of epithelial cells that separate the retina and choroidal blood supply. RPE dysfunction or cell death can result in photoreceptor degeneration, leading to blindness in retinal degenerative diseases including some inherited retinal degenerations and age-related macular degeneration (AMD). In addition to having ready access to rich nutrients from blood, the RPE is also supplied with lactate from adjacent photoreceptors. Moreover, RPE can phagocytose lipid-rich outer segments for degradation and recycling on a daily basis. Recent studies show RPE cells prefer proline as a major metabolic substrate, and they are highly enriched for the proline transporter, SLC6A20. In contrast, dysfunctional or poorly differentiated RPE fails to utilize proline. RPE uses proline to fuel mitochondrial metabolism, synthesize amino acids, build the extracellular matrix, fight against oxidative stress, and sustain differentiation. Remarkably, the neural retina rarely imports proline directly, but it uptakes and utilizes intermediates and amino acids derived from proline catabolism in the RPE. Mutations of genes in proline metabolism are associated with retinal degenerative diseases, and proline supplementation is reported to improve RPE-initiated vision loss. This review will cover proline metabolism in RPE and highlight the importance of proline transport and utilization in maintaining retinal metabolism and health.

Stickler Syndrome (SS): Laser Prophylaxis for Retinal Detachment (Modified Ora Secunda Cerclage, OSC/SS)

Purpose

To introduce a novel technique of encircling laser prophylaxis (ora secunda cerclage Stickler syndrome, OSC/SS) to prevent rhegmatogenous retinal detachment (RRD) in Stickler syndrome eyes.

Patients and Methods

After first eye RRD at age 50 and at age 18, respectively, a 53-year-old father and his 22-year-old son with type 2 SS (STL2) gave informed consent and underwent OSC/SS prophylaxis, performed in each fellow eye. A 26-year-old STL2 daughter then suffered first eye retinal detachment and similarly chose fellow eye OSC/SS prophylaxis. A second son, 28 years of age with STL2, chose OSC/SS prophylaxis in both eyes.

Results

The three OSC/SS treated fellow eyes have gone 12 years, 11 years, and 8 years without RRD. STL1 and less common STL2 eyes are known to have a similar rate of RRD, and 80% of STL1 fellow eyes develop RRD at a median of 4 years in the absence of prophylaxis. Moreover, five of six (83%) known STL2 family members suffered RRD, only the STL2 son with bilateral OSC/SS remaining bilaterally attached. All five OSC/SS treated eyes (average 8.7 years post-prophylaxis) retained preoperative visual acuity of 20/20 to 20/30, with an average, asymptomatic reduction of meridional field in each eye to 50 degrees. In contrast, in the three eyes having suffered RRD prior to presentation, visual acuity ranged from 20/125 to 8/200 and average meridional field was 29 degrees.

Conclusion

Encircling grid laser (OSC) modified in Stickler eyes to encompass the ora serrata and extend posteriorly to and between the vortex vein ampullae (OSC/SS) is a reasonable RRD prophylaxis option to offer STL1 and STL2 patients as an alternative to no treatment or less effective prophylaxis. Because of rarity and severity, the ultimate proof of safety and efficacy will likely come not from randomized trials, but from a non-randomized, prospective, cohort comparison study of such individual efforts.

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