Frugal retinal laser training simulation eyes.
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ABSTRACT:
SUBMITTER: Kousha O
PROVIDER: S-EPMC8193028 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:PurposeTo conduct high-resolution imaging of the retinal nerve fiber layer (RNFL) in normal eyes using adaptive optics scanning laser ophthalmoscopy (AO-SLO).MethodsAO-SLO images were obtained in 20 normal eyes at multiple locations in the posterior polar area and a circular path with a 3-4-mm diameter around the optic disc. For each eye, images focused on the RNFL were recorded and a montage of AO-SLO images was created.ResultsAO-SLO images for all eyes showed many hyperreflective bundles in the RNFL. Hyperreflective bundles above or below the fovea were seen in an arch from the temporal periphery on either side of a horizontal dividing line to the optic disc. The dark lines among the hyperreflective bundles were narrower around the optic disc compared with those in the temporal raphe. The hyperreflective bundles corresponded with the direction of the striations on SLO red-free images. The resolution and contrast of the bundles were much higher in AO-SLO images than in red-free fundus photography or SLO red-free images. The mean hyperreflective bundle width around the optic disc had a double-humped shape; the bundles at the temporal and nasal sides of the optic disc were narrower than those above and below the optic disc (P<0.001). RNFL thickness obtained by optical coherence tomography correlated with the hyperreflective bundle widths on AO-SLO (P<0.001)ConclusionsAO-SLO revealed hyperreflective bundles and dark lines in the RNFL, believed to be retinal nerve fiber bundles and Müller cell septa. The widths of the nerve fiber bundles appear to be proportional to the RNFL thickness at equivalent distances from the optic disc.
| S-EPMC3299751 | biostudies-literature
Project description:The incidence of myopia is increasing worldwide, and the investigation on pathophysiology of myopia is becoming more important. This retrospective study aimed to compare the thicknesses of individual retinal layers between high-myopic and control eyes, and to evaluate the effects of age and sex on each retinal layer thickness. We assessed 164 subjects and divided them into two groups based on axial length (AL) (i.e., high-myopic group (AL ≥ 26 mm) and control group (AL < 26 mm)). Individual retinal layer thicknesses of five subfields in the macula were measured using automated retinal segmentation software packaged with the spectral-domain optical coherence tomography and were compared. In high-myopia group, the thicknesses of total retina and all individual retinal layers in central and entire perifoveal subfields were significantly thicker than the corresponding layers in control group after adjustment for ocular magnification (all P < 0.05). There were no significant effects of sex on individual retinal thicknesses, and age had less negative effects on the thicknesses of retina layers in high-myopic eyes than normal eyes. Axially elongated, non-pathologic highly myopic eyes had different structural features than control eyes, with significantly greater individual macular layer thicknesses independent of sex or age.
| S-EPMC6769047 | biostudies-literature
Project description:IntroductionRetinal detachment is a sight-threatening emergency, with more than half of those affected suffering permanent visual impairment. A diagnostic test to identify eyes at risk before vision is threatened would enable exploration of prophylactic treatment. This report presents the use of irregularities in retinal shape, quantified from optical coherence tomography (OCT) images, as a biomarker for retinal detachment.MethodsOCT images were taken from posterior and mid-peripheral retina of 264 individuals [97 after a posterior vitreous detachment (PVD), 99 after vitrectomy for retinal detachment and 68 after laser for a retinal tear]. Diagnoses were taken from history, examination and OCT. Retinal irregularity was quantified in the frequency domain, and the distribution of irregularity across the regions of the eye was explored to identify features exhibiting the greatest difference between retinal detachment and PVD eyes. Two of these features plus axial length were used to train a quadratic discriminant analysis classifier. Classifier performance was assessed by its sensitivity and specificity in identifying retinal detachment eyes and visualised with a receiver operating characteristic (ROC) curve.ResultsValidation set specificity was 84% (44/52 PVD eyes correctly labelled) and sensitivity 35% (23/64 retinal detachment eyes identified, p = 0.02). Area under the ROC curve was 0.75 (95% confidence intervals 0.58-0.85). Retinal detachment eyes were significantly more irregular than PVD eyes in the superior retina (0.70 mm versus 0.49 mm, p < 0.05) and supero-temporal retina (1.12 mm versus 0.80 mm, p < 0.05). Lower sensitivity (16/68, 24%) was seen for eyes with a retinal tear without detachment, that were intermediate in size between retinal detachment and PVD eyes. Axial length on its own was a poor classifier. Neither irregularity nor classification were affected by surgery for retinal detachment or the development of PVD.ConclusionsThe classifier identified 1/3 of retinal detachment eyes in this sample. In future work, these features can be evaluated as a test for retinal detachment prior to PVD.
| S-EPMC9834476 | biostudies-literature
Project description:Laser refractive surgery for myopia increases the eye's higher-order wavefront aberrations (HOA's). However, little is known about the impact of such optical degradation on post-operative image quality (IQ) of these eyes. This study determined the relation between HOA's and IQ parameters (peak IQ, dioptric focus that maximized IQ and depth of focus) derived from psychophysical (logMAR acuity) and computational (logVSOTF) through-focus curves in 45 subjects (18 to 31 yrs) before and 1-month after refractive surgery and in 40 age-matched emmetropic controls. Computationally derived peak IQ and its best focus were negatively correlated with the RMS deviation of all HOA's (HORMS) (r?-0.5; p<0.001 for all). Computational depth of focus was positively correlated with HORMS (r?0.55; p<0.001 for all) and negatively correlated with peak IQ (r?-0.8; p<0.001 for all). All IQ parameters related to logMAR acuity were poorly correlated with HORMS (r?|0.16|; p>0.16 for all). Increase in HOA's after refractive surgery is therefore associated with a decline in peak IQ and a persistence of this sub-standard IQ over a larger dioptric range, vis-à-vis, before surgery and in age-matched controls. This optical deterioration however does not appear to significantly alter psychophysical IQ, suggesting minimal impact of refractive surgery on the subject's ability to resolve spatial details and their tolerance to blur.
| S-EPMC4747534 | biostudies-literature
Project description:IntroductionThough patients with nanophthalmos frequently endure decreased quality of vision with contact lenses or spectacles, refractive surgery is generally an inadequate alternative due to the associated high refractive error. A refractive lens exchange (RLE) is an alternative option but is technically challenging, requiring accuracy in biometry measurements and procedures.Case presentationThis case discusses a 27-year-old female with nanophthalmos (axial lengths 17.6 mm and 17.4 mm, right and left eyes, respectively) who underwent a femtosecond laser-assisted (FLA) RLE with simultaneous implantation of a monofocal and a Sulcoflex trifocal (Rayner, Britain) lens in each eye. Preoperative cycloplegic refraction was +11.50/-0.75 × 145 and +12.00/-1.00 × 35 in the RE and LE, respectively. Best-corrected visual acuity (BCVA) at distance and near in the RE and LE was 6/7.5 and J1, 6/8.5 and J2, respectively. Uncorrected visual acuity (UCVA) was >6/120 and >J14 for each eye. FLA RLE was performed in the RE, then in the LE 2 weeks later. In each eye, a monofocal (44.0 D, RE, and LE) and a Sulcoflex trifocal lens (both implants, Rayner, Britain) were implanted in one procedure. Distance and near UCVA measured 6 weeks post-op RE and 1-month post-op LE at 6/8.5 and J1 in the RE, 6/10 and J1 in the LE. The RE and LE refraction and BCVA were +0.50/-1.00 × 115, 6/7.5, and plano/-1.00 × 55, 6/8.5, respectively. The post-op outcomes were uneventful.ConclusionA single procedure concurrently implanting a monofocal and Sulcoflex trifocal intraocular lens in nanophthalmic eyes resulted in an excellent UCVA. This procedure can be considered esthetic and reconstructive as it significantly improves patient appearance and function.
| S-EPMC10861217 | biostudies-literature
Project description:PurposeTo compare the anatomic and functional outcomes of pars plana vitrectomy (PPV) for treating rhegmatogenous retinal detachments (RRDs) between two groups with and without postoperative prone positioning.MethodsThis retrospective cohort study included 142 eyes of 142 patients with a primary RRD. All patients underwent PPV with 20% sulfur hexafluoride gas tamponade and were divided into two groups: the groups that did and did not maintain a prone position postoperatively. All patients were followed for more than 3 months. The main outcome measures were the best-corrected visual acuity (BCVA), retinal reattachment rate, and postoperative complications.ResultsSixty-five eyes were included in the prone position group and 77 eyes in the group without prone positioning; the respective initial reattachment rates were 83.1% and 96.1%, a difference that reach significance (p = 0.011). In the eyes with inferior breaks, the initial reattachment rate was 94.7% (18 eyes) without prone positioning, which was significantly (p = 0.036) better than the 60% (6 eyes) initial reattachment rate in the group with prone positioning. In the eyes without inferior breaks, there was no significant difference in the initial reattachment rates between the two groups. The BCVAs at the 3-month postoperative visit did not differ significantly between the two groups. An epiretinal membrane (ERM) was observed postoperatively in 10 (13.0%) eyes in the group without prone positioning; no ERMs were seen postoperatively in eyes in which the internal limiting membrane (ILM) was peeled during PPV.ConclusionsPPV without postoperative prone positioning is associated with a higher reattachment rate in eyes with a RRD, especially those with inferior retinal breaks. PPV with postoperative supine and lateral positioning might be beneficial to manage RRDs associated with inferior retinal breaks if ILM peeling is performed intraoperatively.
| S-EPMC5786309 | biostudies-literature
Project description:We evaluated the retinal function of retinal dragging (Rdrag) and radial retinal folds (Rfolds) in eyes with familial exudative vitreoretinopathy (FEVR) using full-field electroretinography (ERG). Seventeen eyes of nine patients with FEVR who had Rdrag or Rfolds were retrospectively studied. Eyes were classified into four groups according to the severity of the retinal alterations: Group 1, without Rdrag or Rfolds (5 eyes); Group 2, with Rdrag (4 eyes); Group 3, with Rfolds (6 eyes); and Group 4, with Rfolds in which all major retinal vessels were involved (2 eyes). The amplitudes of all ERG components and the implicit times of the photopic a- and b-waves and 30-Hz flicker responses were decreased or prolonged as the severity of the retinal alterations increased (P?<?0.01). The photopic negative response was most severely affected and nearly undetectable in all eyes in Groups 3 and 4, although the other ERG components were detectable in all eyes in Group 3 and one eye in Group 4. These results suggest the decrease of retinal functions was correlated with the degree of severity of Rdrag and Rfolds in eyes with FEVR. In addition, the function of the retinal ganglion cells appears to be more severely affected compared with the others.
| S-EPMC4960584 | biostudies-literature
Project description:To determine deep optic nerve head structure changes after transient intraocular pressure elevation during laser in situ keratomileusis (LASIK) for myopia.Enhanced depth imaging-optical coherence tomography was performed in each myopic eye that underwent LASIK surgery. Enhanced depth imaging-optical coherence tomography images were created at postoperative 1 day, 1 week, 2 weeks, and 1 month. Lamina cribrosa (LC) thickness, LC depth and prelaminar thickness at the superior, middle and inferior portions of the optic nerve head were measured by two investigators.Forty eyes in 40 patients were included in the present study. During follow-up, there were no significant differences in prelaminar thickness or LC depth. The LC demonstrated increased thickness at postoperative 1 day at all three locations (superior, middle, and inferior) (p < 0.001, p < 0.001, p < 0.001, respectively). However, no significant changes were observed at postoperative 1 week, 2 weeks, and 1 month.The LC thickness could increase at 1 day after LASIK surgery. However, the thickness will gradually return to baseline morphology. Temporary intraocular pressure increase during LASIK does not appear to induce irreversible LC thickness changes.
| S-EPMC5906408 | biostudies-literature
Project description:PurposeTo estimate retinal ganglion cell (RGC) losses associated with visible glaucomatous localized retinal nerve fiber layer (RNFL) defects.DesignObservational cross-sectional study.MethodsA multicenter study of 198 normal eyes (138 subjects) and 66 glaucomatous eyes (55 subjects) recruited from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. All eyes underwent standard automated perimetry (SAP), spectral-domain optical coherence tomography, and fundus stereophotography within 6 months. Glaucomatous eyes were included if localized RNFL defects were detected by masked grading of stereophotographs. The number of RGCs in each sector of a structure-function map was estimated using a previously published model combining RGC estimates from SAP and spectral-domain optical coherence tomography. The estimated percentage loss of RGCs (combined structure-function index) was calculated.ResultsIn glaucomatous eyes, there were 136 sectors with visible RNFL defects and 524 sectors without visible RNFL defects. The most common sectors with visible RNFL defects were inferior and inferotemporal sectors, followed by superior and supertemporal sectors. Eyes with visible RNFL defects had a mean estimated RGC count of 657,172 cells versus 968 883 cells in healthy eyes (P < .001). The average combined structure-function index in sectors with a visible RNFL defect (59 ± 21%) was significantly higher than in sectors without a visible RNFL defect in glaucomatous eyes (15 ± 29%; P < .001) and higher than in healthy eyes (1 ± 13%; P < .001).ConclusionsAlthough visible localized RNFL defects often are considered an early sign of glaucoma, this study indicates that they are likely to be associated with large neuronal losses.
| S-EPMC3764310 | biostudies-literature