Search for a Correlation between Telomere Length and Severity of Retinitis Pigmentosa due to the Dominant Rhodopsin Pro23His Mutation

Purpose: Great variation exists in the age of onset of symptoms and the severity of disease at a given age in patients with retinitis pigmentosa (RP). The final pathway for this disease may involve apoptotic photoreceptor cell death. Telomere length is associated with biologic aging, senescence, and apoptosis. We evaluated whether the length of telomeres in leukocytes correlated with the severity of RP in patients with the Pro23His rhodopsin mutation who have shown marked heterogeneity in disease severity.Methods We evaluated 122 patients with the Pro23His rhodopsin mutation. The patients’ retinal function was stratified according to their 30-Hz cone electroretinogram (ERG). The length of telomeres in leukocytes was measured by the quantitative real time polymerase chain reaction (qRT–PCR) method in the 15 patients with the highest age-adjusted 30-Hz ERG amplitudes and in the 15 patients with the lowest amplitudes. Results: Mean leukocyte telomere length was similar in the 15 patients with the highest cone ERG amplitudes (median: 0.40 units; interquartile range 0.36–0.56) and the 15 patients with the lowest cone amplitudes (median: 0.41 units; inter quartile range 0.34 −0.64; p=0.95). Conclusions: We found no evidence for an association between telomere length and the severity of RP as monitored by the cone ERG in patients with the Pro23His rhodopsin mutation

Search for a correlation between telomere length and severity of retinitis pigmentosa due to the dominant rhodopsin Pro23His mutation

Purpose: Great variation exists in the age of onset of symptoms and the severity of disease at a given age in patients with retinitis pigmentosa ( RP). The final pathway for this disease may involve apoptotic photoreceptor cell death. Telomere length is associated with biologic aging, senescence, and apoptosis. We evaluated whether the length of telomeres in leukocytes correlated with the severity of RP in patients with the Pro23His rhodopsin mutation who have shown marked heterogeneity in disease severity. Methods: We evaluated 122 patients with the Pro23His rhodopsin mutation. The patients' retinal function was stratified according to their 30-Hz cone electroretinogram (ERG). The length of telomeres in leukocytes was measured by the quantitative real time polymerase chain reaction (qRT-PCR) method in the 15 patients with the highest age-adjusted 30Hz ERG amplitudes and in the 15 patients with the lowest amplitudes. Results: Mean leukocyte telomere length was similar in the 15 patients with the highest cone ERG amplitudes (median: 0.40 units; interquartile range 0.36-0.56) and the 15 patients with the lowest cone amplitudes (median: 0.41 units; inter quartile range 0.34-0.64; p=0.95). Conclusions: We found no evidence for an association between telomere length and the severity of RP as monitored by the cone ERG in patients with the Pro23His rhodopsin mutation

Three-Dimensional Computer-Aided Design of a Full-Color Ocular Prosthesis with Textured Iris and Sclera Manufactured in One Single Print Job

Three-dimensional (3D) printing of ocular prosthesis has been scarcely described in medical literature. Although ocular prostheses have been 3D printed successfully, iris colors are often manually added to the final product afterward. The objective was to produce a 3D-printed ocular prosthesis with textured iris and sclera in one single print job. We designed an average 3D model of an ocular prosthesis in 3D software, and took a high-resolution digital photograph of a human eye, which was processed in graphical software. By using functions called "displacement mapping"and "UV mapping"on the 3D model, the extent of height displacement was used to digitally produce a textured and colored iris and sclera on the 3D model. By using a polyjet 3D printer, different colors and materials could be used for different prosthesis components. We were able to design and 3D print a lifelike ocular prosthesis with realistic iris and sclera texture. The process took less than 4 h, of which 2.5 h are "printing time,"reducing labor time compared with conventional methods. This proof-of-concept adds valuable knowledge to the future manufacture of 3D-printed ocular prostheses, which has several benefits over the conventional production method: 3D printing is much faster, reproducible, and prostheses can easily be digitally adjusted and reprinted. This study is an important step in the development of a full-fledged 3D workflow to produce lifelike custom eye prostheses

Three-Dimensional Computer-Aided Design of a Full-Color Ocular Prosthesis with Textured Iris and Sclera Manufactured in One Single Print Job

Three-dimensional (3D) printing of ocular prosthesis has been scarcely described in medical literature. Although ocular prostheses have been 3D printed successfully, iris colors are often manually added to the final product afterward. The objective was to produce a 3D-printed ocular prosthesis with textured iris and sclera in one single print job. We designed an average 3D model of an ocular prosthesis in 3D software, and took a high-resolution digital photograph of a human eye, which was processed in graphical software. By using functions called "displacement mapping"and "UV mapping"on the 3D model, the extent of height displacement was used to digitally produce a textured and colored iris and sclera on the 3D model. By using a polyjet 3D printer, different colors and materials could be used for different prosthesis components. We were able to design and 3D print a lifelike ocular prosthesis with realistic iris and sclera texture. The process took less than 4 h, of which 2.5 h are "printing time,"reducing labor time compared with conventional methods. This proof-of-concept adds valuable knowledge to the future manufacture of 3D-printed ocular prostheses, which has several benefits over the conventional production method: 3D printing is much faster, reproducible, and prostheses can easily be digitally adjusted and reprinted. This study is an important step in the development of a full-fledged 3D workflow to produce lifelike custom eye prostheses

Retinitis pigmentosa

Hereditary degenerations of the human retina are genetically heterogeneous, with well over 100 genes implicated so far. This Seminar focuses on the subset of diseases called retinitis pigmentosa, in which patients typically lose night vision in adolescence, side vision in young adulthood, and central vision in later life because of progressive loss of rod and cone photoreceptor cells. Measures of retinal function, such as the electroretinogram, show that photoreceptor function is diminished generally many years before symptomic night blindness, visual-field scotomas, or decreased visual acuity arise. More than 45 genes for retinitis pigmentosa have been identified. These genes account for only about 60% of all patients; the remainder have defects in as yet unidentified genes. Findings of controlled trials indicate that nutritional interventions, including vitamin A palmitate and omega-3-rich fish, slow progression of disease in many patients. Imminent treatments for retinitis pigmentosa are greatly anticipated, especially for genetically defined subsets of patients, because of newly identified genes, growing knowledge of affected biochemical pathways, and development of animal models

Six Patients with Bradyopsia (Slow Vision). Clinical Features and Course of the Disease

Objective: Recently, it was discovered that subjects who showed a prolonged response suppression on their electroretinogram (ERG) and had symptoms of photophobia, problems adjusting to bright light, and difficulties seeing moving objects shared a mutation in the RGS9 (regulator of G-protein signaling 9) gene that is involved in the deactivation of photoreceptor responses. The disorder was termed bradyopsia (slow vision). This paper reports the clinical presentation and long-term follow-up of 6 bradyopsia patients. Design: Retrospective observational case series with a follow-up ranging from 6 to 30 years. Participants: Six patients with a homozygous mutation in the RGS9 gene. Methods: Clinical symptoms and signs were compared between the subjects and between their visits over time. Main Outcome Measures: Symptoms, visual acuity (VA), ocular findings, visual fields, dark-adaptation tests, color tests, fluorescein angiography, and ERG findings. Results: Data showed a consistency in the individual symptoms and ERG recordings, but an extreme variation in VA between visits. Beside some irregularities in the macula in some patients, no other related eye abnormalities were seen. The low-to-subnormal VA varied with background luminance and typically increased by 2 to 3 lines when pinholes were used. Dark-adaptation tests, color tests, and fluorescein angiography were normal. Visual field tests showed a minor diffuse sensitivity loss. No progressive changes were seen over time. Conclusions: No signs of progression were noted in the 6 bradyopsia patients. Photophobia, impaired movement perception, variable reduced VA that improved with the use of pinholes and ERG abnormalities were typical for the disease

Six patients with bradyopsia (slow vision) - Clinical features and course of the disease

Objective: Recently, it was discovered that subjects who showed a prolonged response suppression on their electroretinogram (ERG) and had symptoms of photophobia, problems adjusting to bright light, and difficulties seeing moving objects shared a mutation in the RGS9 (regulator of G-protein signaling 9) gene that is involved in the deactivation of photoreceptor responses. The disorder was termed bradyopsia (slow vision). This paper reports the clinical presentation and long-term follow-up of 6 bradyopsia patients. Design: Retrospective observational case series with a follow-up ranging from 6 to 30 years. Participants: Six patients with a homozygous mutation in the RGS9 gene. Methods: Clinical symptoms and signs were compared between the subjects and between their visits over time. Main Outcome Measures: Symptoms, visual acuity (VA), ocular findings, visual fields, dark-adaptation tests, color tests, fluorescein angiography, and ERG findings. Results: Data showed a consistency in the individual symptoms and ERG recordings, but an extreme variation in VA between visits. Beside some irregularities in the macula in some patients, no other related eye abnormalities were seen. The low-to-subnormal VA varied with background luminance and typically increased by 2 to 3 lines when pinholes were used. Dark-adaptation tests, color tests, and fluorescein angiography were normal. Visual field tests showed a minor diffuse sensitivity loss. No progressive changes were seen over time. Conclusions: No signs of progression were noted in the 6 bradyopsia patients. Photophobia, impaired movement perception, variable reduced VA that improved with the use of pinholes and ERG abnormalities were typical for the disease

Recurrent contracted sockets treated with personalized, three-dimensionally printed conformers and buccal grafts

Purpose: Recurrent contracted sockets are complex situations where previous surgeries have failed, disabling the wear of an ocular prosthesis. A combined method of surgery and long-term fixation using custom-made, three-dimensional (3D) printed conformers is evaluated. Methods: Retrospective case series of nine patients with recurrent excessive socket contraction and inability to wear a prosthesis, caused by chemical burns (n = 3), fireworks (n = 3), trauma (n = 2) and enucleation and radiotherapy at childhood due to optic nerve glioma (n = 1) with three average previous socket surgeries (range 2–6). Treatment consisted of a buccal mucosal graft and personalized 3D-printed conformer designed to be fixated to the periosteum and tarsal plates for minimal 2 months. Primary outcome was the retention of an ocular prosthesis. Secondary outcome was the need for additional surgeries. Results: Outcomes were measured at final follow-up between 7 and 36 months postoperatively (mean 20 months). Eight cases were able to wear an ocular prosthesis after 2 months. Three cases initially treated for only the upper or only the lower fornix needed subsequent surgery for the opposite fornix for functional reasons. Two cases had later surgery for cosmetic improvement of upper eyelid position. Despite pre-existing lid abnormalities (scar, entropion, lash deficiency), cosmetic outcome was judged highly acceptable in six cases because of symmetric contour and volume, and reasonably acceptable in the remaining two. Conclusions: Buccal mucosal transplant fixated with a personalized 3D-designed conformer enables retention of a well-fitted ocular prosthesis in previously failed socket surgeries. Initial treatment of both upper and lower fornices is recommended to avoid subsequent surgeries for functional reasons

Meta-analysis of ocular axial length in newborns and infants up to 3 years of age

In pediatric ophthalmology it is often necessary to obtain axial length in young children. For children older than 3 years, noncontact biometry can be used. For younger children this is usually not an option, and the clinician needs to rely on other imaging modalities. Depicted data curves in textbooks elaborate on few studies and limited number of subjects. The existing literature regarding normal axial length for preterm infants and term newborns is summarized and critically appraised for number of subjects, relevance, measurement method and error, gender and retinopathy of prematurity. We obtained axial length measurements for a total number of 6,575 eyes in 27 papers published from 1964 to 2018 (9 papers with 2,272 eyes for preterm children, 24 papers with 4,303 eyes for term children). Initially, axial length increases rapidly: from a mean 5.1–16.2 mm in week 12 to week 37 gestational age. From 38 weeks, growth rate decreases from 16.2 mm to a mean of 21.8 mm at 3 years old. Male infants have a larger average axial length than females at birth; the difference is 0.24 mm (95%CI: 0.15–0.33, P < 0.001). We present a useful growth curve and formula that may serve as a reference for diagnosing abnormal growth