A New Classification for Retinitis Pigmentosa Including Multifocal Electroretinography to Evaluate the Disease Severity

Aim: To establish a useful and objective classification for retinitis pigmentosa (RP) to evaluate the disease severity. Methods: This is a retrospective cross-sectional study. Visual acuity (VA), visual field (VF) width, ellipsoid zone width on optic cohorence tomography (OCT) and multifocal electroretinography (mf ERG) values were obtained from medical records of patients with RP. A scoring criterion was developed wherein each variable was assigned a score from 0 to 5 depending on its distribution. The cumulative score (from 0 to 20) was used to classify disease severity from grade 0 to 5. The scores were correlated with each other and the final grade. Results: Data of 152 eyes of 92 patients who had the results of all tests were reviewed. The mean age was 41.2 years. The mean VA of the patients was 0.13 ± 0.16 Snellen lines. The majority of patients had a VA less than 20/40 (88.6%), a visual field smaller than 20˚ (78%), and an ellipsoid zone width smaller than 7˚ (84.4%). The majority of the patients (85.4%) were in advanced stage of the disease (Grade 4 and 5). Conclusions: We present a simple, objective and easy to use disease severity classification for RP which can be used to categorize patients and to evaluate and compare treatment results.

Umbilical cord derived mesenchymal stem cell implantation in retinitis pigmentosa: a 6-month follow-up results of a phase 3 trial

AIM:To investigate the efficacy and the safety of umbilical cord derived mesenchymal stem cell(UC-MSC)implantation in patients with retinitis pigmentosa(RP).METHODS:This prospective,single-center,phase 3 clinical study enrolled 124 eyes of 82 RP patients.The patients received 5 million UC-MSCs to the suprachoroidal area with a surgical procedure.Patients were evaluated on the 1st day,1st,and 6th months postoperatively.Best corrected visual acuity(BCVA),anterior segment and fundus examinations,color photography,optical coherence tomography(OCT),and visual field(VF)tests were carried out at each visit.Fundus fluorescein angiography(FFA)and multifocal electroretinography(mfERG)recordings were performed at the end of the 6th month.Ocular and systemic adverse events of the surgical procedure were also noted.RESULTS:All of the 82 patients completed the 6-month follow-up period.None of them had any serious systemic or ocular complications.There were statistically significant improvements in BCVA and VF during the study(all P<0.05).The amplitudes of the P1 waves in the central areas showed significant improvements in mfERG recordings.There were also significant increases in implicit times of P1 waves in the central areas.CONCLUSION:Suprachoroidal administration of UC-MSCs has beneficial effect on BCVA,VF,and mfERG measurements during the 6-month follow-up period.Cell mediated therapy based on the secretion of growth factors(GFs)seems to be an effective and safe option for degenerative retinal diseases.

Subtenon Injection of Autologous Platelet-Rich Plasma in Retinitis Pigmentosa: Is It a New Therapeutic Option?

Purpose: Growth factors (GFs) and neurotrophins can decelerate retinal degeneration. This study aimed to investigate the safety, efficacy and durability of subtenon injections of autologous platelet-rich plasma (aPRP) which is a rich source of GFs in retinitis pigmentosa (RP) patients. Methods: 154 eyes of 77 RP patients with various degrees of narrowed visual field were investigated in this study. Each patient received three injections with 4-week intervals and followed for at least 12 months. The examinations and the tests were obtained before the injection, 1 month after the third injection and every 3 months during the study. The primary aim was to evaluate the effects of aPRP on visual acuity (VA) and visual functions, the second aim was to estimate the duration of the therapy effect and the need for additional aPRP injection. Results: Median age of the 77 RP patients was 35.2 ± 13.9 years. All of the eyes received 3 monthly bilateral subtenon aPRP injections. Of these patients 26 received an additional one, 12 received additional two and 1 patient received additional 3 injections with 3-month interval. There were no significant ocular or systemic side effects. The mean baseline VA was 0.22 ± 0.18 Snellen lines. It improved to 0.31 ± 0.19 following three aPRP injections, which was statistically significant. At the end of the study period, the mean VA was 0.27 ± 0.22 Snellen lines. Conclusion: The subtenon injection of aPRP might be an effective therapy and might have a positive influence in the preservation of visual functions and visual acuity of RP patients.

Changes in retinal vessel diameters in migraine patients during attack-free period

AIM：To evaluate the retinal vessel diameters in patients with migraine by optical coherence tomography（OCT）.METHODS：In this cross-sectional study,124 eyes of 62 patients with a diagnosis of unilateral migraine during attack-free period and 42 age-and sex-matched control subjects were included. Migraine patients were divided into the ≤2 migraine attacks per month group and the ≥5 migraine attacks per month group. All subjects underwent complete ophthalmological and neurological examinations before measurements. Retinal vessel diameters and choroidal thickness were examined with the Spectralis OCT.RESULTS：The mean diameters of the arteries in the eyes on the headache side of control group,≥5 migraine attacks per month and ≤2 migraine attacks per month group at 480 μm from the optic disk（Raster 3）were 119.54±46.69,136.68±25.93 and 119.34±31.75 μm respectively with a steady decline to 105.57±32.15,118.18±31.87 and 108.05±38.77 μm at 1440 μm（Raster 7）,the last measurement point,respectively. The retinal artery diameter measurements were significantly increased in ≥5 migraine attacks per month patients at four out of five measured points compared to control group（P〈0.05）. There were no statistical differences at any of the points of vein measurements. The choroidal thickness measurements were significantly decreased in ≥5 migraine attacks per month patients at all measured points compared to control group（P〈0.05）.CONCLUSION：The retinal artery diameter is found to increase significantly and the choroidal thickness is found to decrease in the eyes on the headache side in ≥5 migraine attacks per month patients compared to control group.

Cross-Validation of the Turkish Version of the 28-Item Impact of Vision Impairment Profile Test

Purpose: To translate the original 28-item Impact of Vision Impairment Profile into Turkish and to investigate its validity and reliability. Methods: Patients with no limitations to respond and affected by a chronic eye disease including retinitis pigmentosa (RP), age-related macular degeneration (ARMD) and diabetic macular edema which cause low vision were enrolled. The Turkish version of the IVI test was administered to all participants. The linguistic translation followed the international guidelines of forward and backward translation. 256 subjects who had a Snellen visual acuity of 6/12 or worse in the eye with best corrected visual acuity (BCVA) completed the Turkish version of the IVI-28 item. Psychometric evaluation of the Turkish IVI test involved the assessment of internal consistency, test-retest reliability, convergent and known-groups validity. Results: The mean (±SD) age of the participants was 53.67 ± 17.22 years. There were 256 patients with one of the following conditions: 105 RP (41%), 77 ARMD (30%), 74 DME (29%). Patients with lower visual acuity (VA) had lower index scores than those with higher VA (p = 0.001), which showed a sufficient responsiveness. Conclusion: Statistical analysis showed that Turkish version of the IVI-28 item is a valid and reliable instrument to measure vision-related quality of life (VRQoL) in patients with low vision.

Effects of chronic smoking on color vision in young subjects

AIM: To evaluate the effects of chronic smoking on color vision in young subjects.METHODS: This study included 91 smokers and 88non-smokers(a total of 179 volunteers) without any ophthalmologic and systemical disorders. The subjects were between 18-40 years of age with a best corrected visual acuity(BCVA) of 20/20, normal anterior and posterior segment examinations and normal intraocular pressure. The color vision of the subjects were evaluated with Farnsworth-Munsell 100 Hue test(FMHT). The total error scores and axis calculation were performed for each subject and the results correlated.RESULTS: Mean age and the standard deviation was28±5y in the smokers group, and 26.7±5.5y in the control group(P =0.101). Sex distribution was similar in the two groups(P =0.365). There was no significant correlation between age and FMHT total error scores(P =0.069).Median of FMHT total error scores of smokers and non-smokers were 65 and 50.50, respectively. FMHT total error scores was found significantly higher in smokers than non-smokers(P =0.004). There was no statisticaly significant difference between smoker and non-smoker groups with respect to axis ratio calculation(P =0.611).There was no significant correlation with FMHT total error scores with neither smoking duration nor number of cigarettes smoked per day(P =0.405, P =0.454,respectively).· CONCLUSION: This study suggested that chronic smoking affects the color vision of young smokers but this may not be sector selective.

Comparison of the effects of intravitreal bevacizumab and dexamethasone in experimental posterior penetrating eye injury

AIM： To compare the effects of intravitreal anti-vascular endothelial growth factor（VEGF） and dexamethasone in an experimental rabbit model of posterior penetrating ocular injury.METHODS： Thirty white New Zealand rabbits were included in the study. A posterior penetrating ocular injury was performed at the superotemporal quadrant. They were randomly divided into three groups. The rabbits in group 1 received intravitreal dexamethasone, in group 2 they received intravitreal bevacizumab and those in group 3 received intravitreal physiological saline solution in both eyes. All eyes were examined ophthalmologically on the 1^st, 3^rd, 7^th, 14^th and 28^th days following the injury and the clinical findings were scored. On the day 28, the eyes were enucleated, evaluated and scored macroscopically, histopathologically and scanning electron microscopically.RESULTS： The median clinical score on the 14 th and 28 th days and the median macroscopic score of the dexamethasone group was significantly better than that of control（P=0.004, 0.018）. Dexamethasone group was also better than that of bevacizumab group but the differences did not reach statistical significance. Retinal detachment rate was 8.3%, 16.6% and 12.5% in the dexamethasone group, bevacizumab group and control group, respectively（P=0.476）. More extensive fibrocelluler proliferations were observed in controls compared with dexamethasone and bevacizumab groups. But these differences did not reach the statistical significance（P=0.538）. In scanning electron microscopy all groups showed fibreous stalk and dense collagen fibrils in vitreous. CONCLUSION： This study shows that intravitreal injection of both dexamethasone and bevacizumab may reduce the intraocular fibrous proliferation after an experimental posterior penetrating ocular injury in rabbits.

The Evaluation of Vision Related Quality of Life in Patients with Retinitis Pigmentosa after Suprachoroidal Umbilical Cord Derived Mesenchymal Stem Cell Treatment

Background: The aim of this study was to evaluate vision related quality of life (VRQoL) in patients with retinitis pigmentosa (RP) after suprachoroidal umbilical cord derived mesenchymal stem cell (UC-MSC) treatment. Methods: The patients were evaluated regarding to the VRQoL before the treatment and at the end of the first year. The study was performed in an affiliated hospital of a university between 2018 and 2020. The patients were operated by a single surgeon and evaluated at baseline and at first, sixth and twelfth month after stem cell implantation. To assess patients’ subjective visual situation, we used Impact of Vision Impairment (IVI) Profile 28-item questionnaire. It basically evaluated vision-related activities in three subscales: “reading and accessing information”, “mobility and independence” and “emotional well-being”. This test is established to assess VRQoL in low vision patients. Results: A total of 123 people, ranging in age from 18 to 48 years, participated in the study and 43.9% (n = 54) were women. The study patients were followed up for one year and the questionnaire was filled by patients at baseline and one year after surgery. In all groups, no difficulty was observed in understanding the questionnaire. The results showed significant improvements in VRQoL after stem cell treatment (p < 0.05). The analysis of each subscale score including “reading and accessing information”, “mobility and independence” and “emotional well-being” before and after treatment showed significant improvements in all subscale scores (p < 0.05). Conclusions: IVI 28 item questionnaire seems to be an effective test for the assessment of VRQoL in low vision patients. The suprachoroidal implantation of UC-MSC for the treatment of RP can improve the quality of life of these patients.