Two patients with Knobloch syndrome due to mutation in COL8A1 gene: case report and review of the literature

BACKGROUND

Knobloch syndrome (KNO, OMIM # 267,750) is a rare ciliopathy group sydrome characterized by a collagen synthesis disorder. It represents an uncommon cause of pediatric retinal detachment. This report presents two cases with different COL18A1 gene mutations, complicated by retinal detachment.

CASE PRESENTATION

Both cases exhibited high myopia and various degrees of occipital skull defect. The first case, a female, had bilateral congenital retinal detachment, posterior embryotoxon, and strabismus. The second case, a male, had unilateral congenital retinal detachment and neuromotor developmental delay. The first case, diagnosed in the early months of life, underwent successful retinal reattachment surgery. However, surgery was not performed on the second case, who presented with late-stage unilateral retinal detachment and pre-phthisis.

CONCLUSIONS

The report describes two patients with Knobloch syndrome, one of whom responded favorably to surgery for retinal detachment in both eyes. Successful anatomical results were achieved with early surgical interventions. It is essential to recognize the phenotypic and genetic heterogeneity within KNO.

Efficacy of 5-fluorouracil (5-FU) and low molecular weight heparin (LMWH) in high-risk pediatric retinal detachment; randomized clinical trial

BACKGROUND

Pediatric rhegmatogenous retinal detachments (PRRDs) are complex, rare occurrences and are often related to trauma or congenital abnormalities. Children often do not recognize or report symptoms of retinal detachment. Thus at presentation, PRRD is typically advanced often with macular involvement, proliferative vitreoretinopathy (PVR), chronic duration, and poor visual acuity. Because 5-FU and LMWH are effective in different aspects in the PVR process, it was believed that a syngergistic approach to the prevention of PVR would be advantageous.

METHODS

After informed consent, children under 14 years of age with high-risk PRRD underwent pars plana vitrectomy and silicone oil injection with scleral buckle divided into 2 groups in prospective randomized trial. Group A received intraoperative infusion of 5-FU (200 µg/ml) and LMWH (5 IU/ml), group B received infusion of normal saline. Primary outcome was occurrence of recurrent PRRD within 12 weeks, secondary outcomes were occurrence of PVR, best corrected visual acuity (BCVA), number and timing of secondary procedures within 12 weeks.

RESULTS

The study included 42 eyes of 41 patients, 21 in group A and 21 in group B, the duration of PRRD ranged from 0.5 to 7 months in group A and 0.25-5 months in group B.The rate of recurrent PRRD was higher in group B 33% compared to 19% in group A (p = 0.292). The mean timing of occurrence of recurrent PRRD was 9.5 ± 5 weeks in group A compared to 2.86 ± 2.41 weeks in group B (p = 0.042), more patients in group B ended up with more advanced PVR (p = 0.038), BCVA was hand movement (HM) only in all cases preoperatively and improved to HM-0.3 Snellen in group A compared to light perception (PL)-0.1Snellen in group B (p = 0.035), there was no difference in any of secondary procedures but with later timing in group A 9.71 ± 3.73 weeks than in group B 4.0 ± 2.83 weeks (p = 0.042).

CONCLUSION

This study concluded that the use of the 5-FU and LMWH combination in high risk PRRD resulted in lower rate of postoperative PVR, later recurrence of PRRD and better final BCVA.

TRIAL REGISTRATION NUMBER

Registry: clinicaltrials.gov PRS NCT06166914 date of initial release 4/12/2023. Unique Protocol ID: 9,163,209 date 21/10/2021. Retrospectively registered.

Vitreoretinopathy-Associated Pediatric Retinal Detachment Treatment Outcomes: IRIS® Registry (Intelligent Research in Sight) Analysis

Purpose

To determine the treatment patterns and outcomes of pediatric retinal detachments (RDs) associated with hereditary vitreoretinopathies.

Design

Retrospective cohort analysis using IRIS® Registry (Intelligent Research in Sight) database.

Participants

Patients < 18 years old with a rhegmatogenous RD and a systemic disorder associated with vitreoretinal degeneration (e.g., Stickler syndrome) or other malformation of the vitreous from 2013-2019.

Methods

Cases were identified using International Classification of Diseases, Ninth and Tenth Revisions (ICD-9, ICD-10) diagnostic codes from the IRIS® Registry cohort. Other hereditary vitreoretinopathies that are not encoded by specific ICD code(s) were captured by text search. Nonspecific vitreous abnormality ICD codes were also included. Exclusion criteria included traumatic retinal detachments using ICD codes for ocular trauma and serous or exudative retinal detachment. Surgical procedures were identified using Current Procedural Terminology (CPT) codes for repair of retinal detachment. Baseline demographic information collected included age, gender, race/ethnicity, geographic region of the provider location, and health insurance status.

Main Outcome Measures

Main outcomes measured in this study were average time to first surgery, number of eyes presenting with bilateral detachments, and choice of initial surgical procedure.

Results

A total of 2115 eyes of 1722 patients were identified (mean age, 10.4 years; 58% male). The median time to first surgery was 7 days (interquartile range, 40 days). One thousand four hundred seven eyes of 1134 patients had ≥ 1 year of follow-up, with 506 eyes (36%) developing a fellow eye RD. Thirty-three percent of patients presenting with bilateral detachments, and 349 eyes had initial RD surgery within 1 year of the index date documented by CPT code. Fellow eye detachment occurred a mean of 32 days after initial presentation. The mean number of surgeries per eye within 1 year was 1.68. Best-corrected visual acuity did not improve from a baseline 20/54 to 20/62. The initial procedure was most commonly complex RD repair (n = 176), followed by scleral buckle (n = 102), pars plana vitrectomy (n = 89), laser (n = 59), cryotherapy (n = 5), and pneumatic retinopexy (n = 5). There were 51 new diagnoses of glaucoma and 37 new diagnoses of aphakia within 1 year after the surgical procedure.

Conclusions

IRIS Registry data provide insight into rare pediatric vitreoretinopathy-associated RDs, which have a high rate of reoperation and fellow eye involvement.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Pediatric rhegmatogenous retinal detachment: predictors of anatomic and functional success

PURPOSE

This study describes presenting clinical features and surgical techniques associated with successful repair of pediatric rhegmatogenous retinal detachment (RRD).

METHODS

This is a retrospective case series which involved 242 cases younger than 18 years with new-onset RRD with descriptive statistics for the full group. Further exclusion established 168 cases that underwent surgery with minimum 3-month follow-up. Comparison of features associated with successful outcomes was analyzed using Chi-squared tests, logistic regression and univariate generalized equation models.

RESULTS

We measured proportion of patients with BCVA ≤ 1.0 logMAR and/or an increase in final BCVA of 0.3 logMAR with respect to baseline and complete reattachment at final visit; 104 eyes (62%) achieved total reattachment, and 91 eyes (54%) achieved visual success. Absence of macular involvement, subtotal RRD and older age group (13-18) were associated with both success measures. There were higher visual and anatomic success rates with primary scleral buckling (SB, 66% and 79%; OR 9.26 and 11.09) and combined SB plus pars plana vitrectomy (PPV, 54% and 58%; OR 5.67 and 3.94) compared with PPV alone (26% and 17%).

CONCLUSION

A majority of patients achieved anatomical success with repair. Trauma and myopia were the most common etiologic associations, with myopic cases having better outcomes. Success was more likely in patients with subtotal RRD or uninvolved macula at presentation; previous intraocular surgery was a risk factor for failure. Younger patients had a higher likelihood of worse outcomes. Initial PPV showed a lower rate of success than either SB or combined SB/PPV.