Bruch membrane opening-minimum rim width and retinal nerve fiber layer thickness in myopic children.

BACKGROUND/OBJECTIVES: It is debatable whether the decrease of retinal nerve fiber layer (RNFL) thickness in myopic people under 18 years of age is due to insufficient measurement techniques or to real physical loss of retinal ganglion cells and axons. Hence, to better understand the relationship between the degree of myopia and the neuroretinal rim (NR), we aim to investigate the NR in the eyes of healthy myopic children using the novel measurement algorithms of spectral-domain optical coherence tomography (SD-OCT). SUBJECTS/METHODS: This prospective, cross-sectional study includes 378 left eyes of 378 (301 female) participants divided into three groups according to their spherical equivalent (SE) refractive error (RE) [Group-1(G1), -1.00 ≤ SE ≤ 1.00 diopters (D); Group-2 (G2), -4.00 ≤ SE < -1.00 D; Group-3 (G3), SE<-4.00 D]. All participants underwent a full ophthalmic examination, including biometric and pachymetric measurements. Standard peripapillary RNFL, as well as the novel algorithms, Bruch's membrane opening-minimum rim width (BMO-MRW), and RNFL acquired using the anatomic positioning system (APS-RNFL) were obtained by SD-OCT. Nasal, temporal, temporal-inferior, temporal-superior, nasal-inferior, nasal-superior sectors' and their general (global) averages were recorded. Rim areas and disc sizes were measured via confocal scanning laser ophthalmoscopy. Global and the six sectors' averages were recorded. RESULTS: G1 consisted of 141 subjects, G2 consisted of 89, and G3 consisted of 48. The sex distribution (p = 0.112) and mean age (p = 0.129) of the groups were similar. The mean global averages of the standard RNFLs were 96 ± 14.4 µ in G1, 93.8 ± 12.9 µ in G2, and 86 ± 11.8 µ in G3. The mean global averages of the APS-RNFLs were 103.9 ± 97 µ in G1, 103.3 ± 10.6 µ in G2, and 102 ± 10.6 µ in G3. The mean global averages of the BMO-MRW were 374.4 ± 57.7 µ in G1, 373.2 ± 62.2 µ in G2, and 351.9 ± 63.9 µ in G3. For the global averages, APS-RNFL and BMO-MRW did not detect any difference between the three groups (p = 0.563, p = 0.089, respectively), but the standard RNFL did (p < 0.001). Standard RNFL and APS-RNFL were found to be well correlated; however, the correlations between BMO-MRW and standard RNFL or APS-RNFL were either absent or very weak. All three methods showed weak but significant negative correlations with high myopic spherical RE, especially those in the standard RNFL. Moderately negative correlations were found between BMO-MRW and disc size in all sectors (highest in the nasal sector; r = -0.387, p < 0.001). However, there was almost no significant relationship between disc size and standard RNFL or APS-RNFL. Moderately significant negative correlations were observed between the groups categorically and standard RNFL in almost all sectors, while this was much less with APS-RNFL and was not observed in almost any sector with BMO-MRW. CONCLUSIONS: When evaluating the NR in healthy myopic children, it was found that, in particular, BMO-MRW and APS-RNFL are less effected by RE degree compared to standard RNFL. BMO-MRW and APS-RNFL should be used on these children to avoid the possible misdiagnosis of glaucoma.

Bruch's membrane opening-minimum rim width: An alternative OCT biomarker study for multiple sclerosis.

PURPOSE: Bruch's membrane opening-minimum rim width (BMO-MRW) and RNFL measured using anatomic positioning system (APS-RNFL) are novel OCT methods and remained unexplored in MS patients.To investigate the novel parameters of spectral-domain OCT as an alternative biomarker in patients with multiple sclerosis (MS). METHODS: Retrospective cohort study; participants consisted of relapsing-remitting MS (RRMS) patients and healthy controls (HC). Eyes were classified according to the presence of MS and previous optic neuritis (ON). Measurements of standard peripapillary RNFL (S-RNFL), BMO-MRW, and APS-RNFL were performed. RESULT: A total of 244 eyes of 122 participants (MS-patients: 63, HC: 59) were included in the study. Fifty-one eyes had a history of previous ON. In almost all measured parameters, neuroretinal rim thicknesses were observed the thinnest in eyes with ON history between all subgroups. S-RNFL and APS-RNFL techniques showed the difference in neuroretinal rim thickness in all three subjects (ON+, ON-, and HC). However, BMO-MRW, on the other hand, could not distinguish between ON(-) patients and HC. The relationship between OCT parameters and EDSS were observed only in eyes with an ON history in all three techniques. A meaningful model with 78% accuracy was obtained by using only the OCT parameters as risk factors. In the ROC analysis, no parameters were found to have acceptable high sensitivity and specificity. BMO-MRW was statistically weaker in every aspect than other RNFL techniques. CONCLUSION: The novel APS-RNFL technique appears to be a bit more reliable alternative to S-RNFL technique to support therapeutic decision-making in MS. BMO-MRW has not been found as a successful alternative to S-RNFL.

The Surgical Outcomes of Limbal Allograft Transplantation in Eyes Having Limbal Stem Cell Deficiency.

PURPOSE: To report the limbal allograft transplantation and penetrating keratoplasty (PK) results in limbal stem cell deficiency (LSCD)-developed eyes because of chemical or thermal injury. METHODS: Medical records of 18 eyes of 14 patients who had undergone keratolimbal allograft (KLAL) or living-related conjunctival limbal allograft (lr-CLAL) with or without PK and followed up at least 1 year postoperatively were evaluated retrospectively. The preoperative LSCD grade was noted in all patients. Rejection incidents, recurrence of LSCD, and corneal graft clarity along with a visual improvement during the follow-up were noted. The complications rate due to surgery or injury itself, for instance, glaucoma and cataract, were evaluated. The limbal allograft tissue survival analysis and corneal allograft survival analysis were done to reveal the differences in both the procedures. The existence of normal corneal epithelium and improvement in visual acuity were accepted as the surgical success criteria. RESULTS: In the limbal allograft transplantation group, the survival rates of the allograft tissue were 65 ± 10.7% at 1 year and 36.6 ± 11.4% at 3 years in lr-CLAL and 66.7 ± 15.7% at 12 months and 53.3 ± 17.3% at 18 months in KLAL-transplanted eyes. The survival rate of corneal allograft at the 5th postoperative year was lower in the simultaneous procedure compared to the staged procedure, but it was not statistically significant (25.7 ± 25.8% vs. 62.5 ± 17.1%, P = 0.75). The ambulatory vision was achieved in 10 eyes (56%) after a mean follow-up time of 93.8 ± 37.8 months. The visual acuity level has increased in 12 eyes (67%) in which the limbal allograft transplantation was applied. The ambulatory visual acuity level was achieved (≤1.0 logMar [20/200]) in 10 eyes (56%). In addition, two or more Snellen lines' gain in the best corrected visual acuity was observed in 12 eyes of 18 (67%) at the last follow-up, and there was not any significant difference between the KLAL and lr-CLAL. CONCLUSIONS: Ocular surface integrity was longer in KLAL than in lr-CLAL transplantation, but it was not statistically significant. The staged procedure was more convenient than the simultaneous procedure in terms of corneal allograft clarity maintenance in limbal allograft-employed eyes.