RESUMO
Purpose: To analyze the effect of various macular hole indices and postoperative microstructural changes of all retinal layers on postoperative functional outcomes in patients with idiopathic full?thickness macular hole (FTMH). Methods: In this prospective study, pre and post?operative optical coherence tomography (OCT) scans of 36 eyes with idiopathic FTMH were analyzed. Hole indices and microstructural changes of all retinal layers such as ellipsoid zone (EZ), external limiting membrane (ELM) integrity, outer and inner retinal defects, and cystoid resolution were studied on follow?up visits. Results: Out of 36 eyes, type?1 closure was achieved in 23 eyes (65.7%) and type?2 closure in 11 eyes (31.42%), one eye showed persistent hole, and one eye was lost to follow?up. The mean minimum diameter of hole (P = 0.026), mean MHI (P = 0.001), DHI (P = 0.158), THI (P = 0.001), and HFF (P < 0.001) showed statistical significance with the type of hole closure. Postoperatively, eyes with intact ELM and EZ had better BCVA at the final visit. The BCVA was better by logMAR 0.73 ± 0.38 (P < 0.001) in patients with absent outer retinal defects. There was a significant difference in BCVA of 0.52 ± 0.35 at 1 month and 0.64 ± 0.34 at 6 months in eyes without inner retinal defects (P < 0.001). At 6 months, cystoid resolution was observed in 28 (80%) eyes. BCVA was significantly better at 1 month (P < 0.001) and at 6 months (P = 0.001) in eyes with no DONFL. Conclusion: Macular hole indices determine the closure type. Postoperative regeneration of outer retinal layers and resolution of retinal defects significantly influence the final visual outcomes. ELM recovery is seen as a prerequisite for EZ regeneration with no new IRD after a period of 3 months
RESUMO
Objectives: The objective of this study is to evaluate and to compare the tensile weld strengths and microstructural changes in four archwires namely beta titanium, stainless steel (SS), blue elgiloy and timolium before and after immersion in 1.23% acidulated phosphate fluoride (APF) solution. Materials and Methods: The mean tensile weld strength of a weld joint of four arch wires were compared pre‑fluoride (Group 1) with post fluoride (Group 2) and the microstructural characteristics of weld joints were evaluated under an optical microscope. Results: The mean tensile weld strength for beta titanium was 445.64 N/mm2, blue elgiloy was 363.26 N/mm2, SS was 358.30 N/mm2 and timolium was 308.62 N/mm2. After immersion in fluoride the mean tensile strength for beta titanium was 427.16 N/mm2, blue elgiloy was 359.86 N/mm2, SS is 349.44 N/mm2 and timolium is 294.86 N/mm2. After immersion in fluoride, the beta titanium and SS had a smooth fusion at the center of weld assembly with characteristic nugget formation. The beta titanium weld assembly had greater tensile weld strength than other welded assemblies. Blue elgiloy ranked second, whereas SS and timolium were third and fourth respectively. Conclusion: The wires in descending order of their mean tensile weld strength, on evaluation of their weld joints were found to be: Beta titanium > blue elgiloy > SS > timolium. The reduction in tensile weld strength was statistically insignificant for all the archwires after exposure to 1.23% APF at 37°C for 90 min.