Current Issue : April - June Volume : 2018 Issue Number : 2 Articles : 6 Articles
Background. The changes in corneal biomechanical properties after LASIK remain an unknown but important topic for surgical\ndesign and prognostic evaluation. This study aims to observe the postoperative corneal biomechanical properties one month after\nLASIK with amount of corneal cutting (ACC) greater than 50% of the central corneal thickness (CCT). Methods. FS-LASIK was\nperformed in 10 left rabbit eyes with ACC being 60% (L60) and 65% (L65) of the CCT, while the right eyes (R) were the control.\nAfter 4 weeks, rabbits were executed and corneal strip samples were prepared for uniaxial tensile tests. Results. At the same strain,\nthe stresses of L65 and L60 were larger than those of R. The elastic moduli of L60 and L65 were larger than those of R when the\nstress was 0.02 MPa, while they began to be less than those of R when stress exceeds the low-stress region. After 10 s relaxation, the\nstress of specimens L65, L60, and R increased in turn. Conclusion. The elastic moduli of the cornea after FS-LASIK with ACC\ngreater than 50% of the CCT do not become less under normal rabbit IOP. The limit stress grows with the rise of ACC when\nrelaxation becomes stable....
Purpose. To determine the efficacy, safety, and predictive outcome factors for intravitreal dexamethasone implant (DEX) in\npseudophakic cystoid macular edema (PCME). Methods. Retrospective, interventional, controlled study. Patients included\nhad to have clinically significant PCME and have been treated with the DEX between 2012 and 2015. Charts and oneyear\ndata were selected consecutively, and efficacy and safety were abstracted. Visual acuity (VA) and central foveal\nthickness (CFT) were analysed. Results. Nineteen patient data sets were analysed. After treatment with DEX, mean VA\nincreased significantly by 0.2 logMAR (p = 0 034), while the mean CFT was reduced significantly by 162.79 �¼m (p < 0 001).\nFive patients receiving a combination of DEX/bevacizumab have not experienced a higher mean VA gain or CFT\nreduction compared to fourteen patients receiving DEX alone. Decision rules, when to combine DEX with bevacizumab,\nhave not been defined before the study. Only posttreatment VA gains in the nonhypertensive subgroup (n = 11) were\nsignificantly better (p = 0 026). Analysis of data from diabetes patients (n = 4) versus nondiabetics yielded no significant\ndifferences in efficacy. There have been no adverse events within follow-up time. Conclusion. The use of DEX in\nPCME showed significant improvements in VA and CFT. The VA seems to show greater improvements in patients\nwithout hypertension....
Objectives. To describe the past 20 years� correction modalities for keratoconus and their visual outcomes and possible\ncomplications. Methods. A review of the published literature related to the visual outcomes and possible complications in the\ncontext of keratoconus management using nonsurgical procedures for the last 20 years (glasses and contact lenses) was\nperformed. Original articles that reported the outcome of any correction modalities of keratoconus management were reviewed.\nResults. The most nonsurgical procedure used on keratoconus management is the contact lens fitting. Soft contact lenses and\nsoft toric contact lenses, rigid gas-permeable contact lenses, piggyback contact lens system, hybrid contact lenses, and scleral and\ncorneoscleral contact lenses form the contemporary range of available lens types for keratoconus management with contact\nlenses. All of them try to restore the vision, improve the quality of life, and delay surgical procedures in patients with this\ndisease. Complications are derived from the intolerance of using contact lens, and the use of each depends on keratoconus\nseverity. Conclusions. In the context of nonsurgical procedures, the use of contact lenses for the management of keratoconic\npatients represents a good alternative to restore vision and improve the quality of live in this population...
Background. Retinitis pigmentosa (RP) comprises a group of inherited disorders in which patients typically lose night vision in\nadolescence and then lose peripheral vision in young adulthood before eventually losing central vision later in life. A\nretrospective case-control study was performed to evaluate differences in ocular biometric parameters in primary angle-closure\nglaucoma (PACG) patients with and without concomitant RP to determine whether a relationship exists between PACG and\nRP. Methods. We used ultrasound biomicroscopy (UBM) to measure anterior chamber depth (ACD). A-scan biometry was\ncarried out to measure lens thickness (LT) and axial length (AL). Propensity score matching and mixed linear regression model\nanalysis were conducted. 23 patients with chronic primary angle-closure glaucoma (CPACG) associated with RP, 21 patients\nwith acute primary angle-closure glaucoma (APACG) associated with RP, 270 patients with CPACG, and 269 patients with\nAPACG were recruited for this study. Results. There were no significant differences on ACDs, ALs, and relative lens position\n(RLP) (P > 0 05) between patients with PACG associated with RP and patients with PACG; however, patients with APACG\nassociated with RP had a significantly greater LT than patients with APACG (P < 0 05). Conclusion. Patients with PACG\nassociated with RP had the same biometric parameter characteristic as the patients with CPACG and APACG. This may suggest\nthat RP is a coincidental relationship with angle-closure glaucoma....
Purpose. To evaluate contrast sensitivity (CS) changes in acute central serous chorioretinopathy (CSC). Methods. Visual acuity\n(VA), CS, and subretinal fluid (SRF) were evaluated monthly for 6 months. Treatment was considered at 3 months in case of\npersistent SRF. Results. Twelve of 20 eyes (60%) had spontaneous SRF resolution within 4 months. Five of 8 patients with\ndelayed SRF resolution received either focal laser or photodynamic therapy. The CS was impaired in all spatial frequencies at\nbaseline. There was a negative correlation between the baseline SRF thickness and CS at 3 and 6 cycles per degree (cpd). The CS\nimproved significantly at the time of fluid resolution (p = 0 001) and continued to improve in 3 and 6 cpd. The CS at 6 cpd did\nnot recover if compared to a normal fellow eye at 6 months (p = 0 018). The CS of 12 cpd at 6 months was superior in the\nspontaneous resolution group. Conclusion. The impaired CS gradually improved as the SRF reduced at all spatial frequencies.\nCS at 3 and 12 cpd continued to improve after complete fluid resolution. Despite an excellent final VA, the CS at 6 months did\nnot regain its normal value....
Purpose. To evaluate corneal transparency following accelerated collagen cross-linking (ACXL) in pediatric keratoconus.\nDesign. A prospective interventional case series. Methods. This study included 47 eyes (25 patients), aged 9ââ?¬â??14 years, with\ndocumented progressive keratoconus. After applying 0.1% riboflavin drops, ACXL was performed. Assessment included\ncorrected distance visual acuity (CDVA), uncorrected visual acuity (UCVA), corneal haze, and corneal densitometry in\ngrayscale units (GSU). Result. The mean baseline and corneal densitometry peaked at 3 months post-ACXL while central\nand posterior densitometry showed a statistically significant increase (P < 0 05) and peaked at 8 months postoperatively. By\n12 months, densitometry in all corneal layers (P ââ?°Â¥ 0 99) and concentric zones (P ââ?°Â¥ 0 97) reached near baseline values.\nSlit-lamp graded haze peaked at 1 month to 1.82 Ã?± 0.65 (P < 0 05) and declined to near baseline at 12 months (0.39 Ã?± 0.58).\nThere was a statistically significant increase in the mean UCVA and CDVA at 12 months. Conclusion. Total and\nanterior corneal densitometry peaked after 3 months, while central and posterior densitometry peaked after 8 months.\nMaximum haze was at 1 month post-ACXL. All corneal layers, concentric zone densitometry and haze reached near\nbaseline values after 1 year. Scheimpflug densitometry showed weak correlation with CDVA over the 12-month follow-up\nperiod (r = âË?â??0 193)....
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