Crosslinking for post-laser-assisted in situ keratomileusis corneal ectasia: Transepithelial flap-on 30 minute and flap-lift 4 minute protocol

Purpose: To evaluate the outcomes of transepithelial corneal collagen crosslinking (CXL) for management of corneal ectasia after laser?assisted in situ keratomileusis (LASIK). Methods: CXL was performed on 18 eyes of 16 patients either with LASIK flap lift (n = 9; 365 nm, 30 mW/cm2, 4 minutes, pulse) or with transepithelial flap?on (n = 9 eyes; 365 nm, 3 mW/cm2, 30 minutes) technique. Postoperative change in maximum keratometry (Kmax), anterior elevation, posterior elevation, spherical equivalent (SE), logMAR uncorrected distance visual acuity (UDVA), aberrations, and central corneal thickness (CCT) were evaluated at 12 months postoperatively. Results: A total of 18 eyes of 16 patients (11 males, 5 females) were included. Overall, Kmax flattened more after flap?on CXL (P = 0.014) compared to flap?lift CXL. The endothelial cell density and posterior elevation were stable throughout the follow?up period. Index of vertical asymmetry (IVA), keratoconus index (KI), and central keratoconus index (CKI) decreased after flap?on CXL at 12 months, postoperatively (P < 0.05), whereas there were no statistically significant changes in these parameters after flap?off CXL group. The spherical aberrations and total root mean square decreased after flap?lift CXL at 12 months, postoperatively (P < 0.05). Conclusion: In our study, transepithelial collagen crosslinking was successfully used to halt disease progression in post?LASIK keratectasia. We recommend flap?on surgical technique for these cases

Elliptical deep anterior lamellar keratoplasty in severe Acanthamoeba keratitis

Acanthamoeba keratitis (AK) is an intractable infection of the cornea. Penetrating keratoplasty is widely used for the management of severe AK but suffers from complications like graft rejection, endophthalmitis, and glaucoma. Herein, we aimed to describe the surgical technique and the results of elliptical deep anterior lamellar keratoplasty (eDALK) for the management of severe AK. In this retrospective case series, records of consecutive patients with AK poorly responsive to medical treatment who underwent eDALK from January 2012 to May 2020 were reviewed. The largest diameter of infiltration was ?8 mm and did not involve the endothelium. The recipient bed was made by an elliptical trephine, and big bubble or wet-peeling technique was performed. Postoperative best spectacle-corrected visual acuity, endothelial cell density, corneal topographic data, and complications were evaluated. Thirteen eyes of thirteen patients (eight men and five women, 45.54 ± 11.78 years old) were included in this study. The mean follow-up interval was 21.31 ± 19.59 months (range, 12–82 months). At the last follow-up, the mean best spectacle-corrected visual acuity was 0.35 ± 0.27 logarithm of the minimum angle of resolution. The mean refractive and topographic astigmatism were ? 3.21 ± 1.77 and 3.08 ± 1.14 D, respectively. Intraoperative perforation was encountered in one case and double anterior chambers occurred in two cases. One graft developed stromal rejection and one eye developed amoebic recurrence. eDALK can serve as the first-line surgical management of severe AK poorly responsive to medical treatment.

Vector analysis of astigmatic correction after single-step transepithelial photorefractive keratectomy and femtosecond-assisted laser in-situ keratomileusis for low to moderate myopic astigmatism

Purpose: This study aimed to evaluate the outcomes of astigmatic correction by single?step transepithelial photorefractive keratectomy (TransPRK) and femtosecond?assisted laser in?situ keratomileusis (Femto?LASIK) surgeries. Methods: A total of 218 subjects received TransPRK or Femto?LASIK surgery for the treatment of myopia and astigmatism (?2.25 to ?0.25 D). Refraction errors and uncorrected (UDVA) and corrected distance visual acuity (CDVA) were examined before and at 3 months after surgery. Astigmatism changes were assessed by vector analysis. Results: Preoperative parameters of the TransPRK group were similar to the Femto?LASIK group. UDVA and CDVA at 3 months were similar between both groups. Manifest refraction (MR) spherical equivalent in the TransPRK group (0 ± 0.20 D) was slightly lower compared with the Femto?LASIK group at 3 months (0.11 ± 0.25 D, P = 0.001). MR cylinder was ?0.06 ± 0.19 D in the TransPRK group and ?0.02 ± 0.15 D in the Femto?LASIK group at 3 months (P = 0.135). The index of success (IS) was 0.15 ± 0.36 in the TransPRK group and 0.06 ± 0.17 in the Femto?LASIK group (P = 0.125). The correction index (CI) was 1.03 ± 0.19 in the TransPRK group and 1.01 ± 0.11 in the Femto?LASIK group (P = 0.815). Conclusion: For low to moderate myopic astigmatism, TransPRK provided a comparable astigmatic treatment effect as Femto?LASIK. Myopic astigmatism was both slightly overcorrected after TransPRK and Femto?LASIK surgeries

Transepithelial phototherapeutic keratectomy for post-traumatic recurrent corneal erosions

Purpose: To evaluate the outcomes of transepithelial phototherapeutic keratectomy (transepithelial PTK) for treatment of posttraumatic recurrent corneal erosions. Methods: Twenty?four eyes of 22 patients with posttraumatic recurrent corneal erosions who were treated with transepithelial PTK from April 2018 to July 2020 were included in this retrospective study. The rates of recurrent erosions and complications were evaluated during the follow?up after surgery. Visual acuity and refraction were recorded preoperatively and 1 year after surgery. Total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations were recorded using corneal tomography preoperatively and 1 year after surgery. Results: Mean postoperative follow?up was 13 months (range: 12� months). None of the patients suffered from any complications or further erosions. Uncorrected distance visual acuity, best?corrected distance visual acuity, spherical equivalent, and cylinder remained stable at 1?year postoperatively compared with the baseline (P = 0.214, P = 0.461, P = 0.084, and P = 0.879, respectively). Moreover, there was no significant difference in total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations between baseline and 1?year postoperative visit (P = 0.938, P = 0.136, and P = 0.981, respectively). Conclusion: Transepithelial PTK was an effective treatment for patients with posttraumatic recurrent corneal erosions.

Recent advances in diagnosis and management of Mycotic Keratitis.

Mycotic keratitis is a major cause of corneal blindness, especially in tropical and subtropical countries. The prognosis is markedly worse compared to bacterial keratitis. Delayed diagnosis and scarcity of effective antifungal agents are the major factors for poor outcome. Over the last decade, considerable progress has been made to rapidly diagnose cases with mycotic keratitis and increase the efficacy of treatment. This review article discusses the recent advances in diagnosis and management of mycotic keratitis with a brief discussion on rare and emerging organisms. A MEDLINE search was carried out for articles in English language, with the keywords, mycotic keratitis, fungal keratitis, emerging or atypical fungal pathogens in mycotic keratitis, investigations in mycotic keratitis, polymerase chain reaction in mycotic keratitis, confocal microscopy, treatment of mycotic keratitis, newer therapy for mycotic keratitis. All relevant articles were included in this review. Considering the limited studies available on newer diagnostic and therapeutic modalities in mycotic keratitis, case series as well as case reports were also included if felt important.

Effect of refractive correction on ocular optical quality measurement using double-pass system / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Optical Quality Analysis System II (OQAS, Visiometrics, Terrassa, Spain) that uses double-pass (DP) technique is the only commercially available device that allows objective measurement of ocular retinal image quality. This study aimed to evaluate the impact of spectacle lenses on the ocular optical quality parameters and the validity of the optometer within OQAS.</p><p><b>METHODS</b>Seventy eyes of healthy volunteers were enrolled. Optical quality measurements were performed using OQAS with an artificial pupil diameter of 4.0 mm. Three consecutive measurements were obtained from spectacle correction corresponding to subjective refraction and from the OQAS built-in optometer separately. The modulation transfer function cutoff frequency, the Strehl ratio, the width of the point spread function (PSF) at 10% of its maximal height (PSF10), and the width of the PSF at 50% of its maximal height (PSF50) were analyzed.</p><p><b>RESULTS</b>There was no significant difference in any of the parameters between the spectacle correction and the optometer correction (all P > 0.05, paired t-test). A good agreement was found between both the methods and a good intraobserver repeatability in both the correction methods. Difference in best focus between two methods was the only parameter associated significantly with optical quality parameter differences. Best focus difference, built-in optometer correction with or without external cylindrical lens, and age were associated significantly with PSF10 difference. No linear correlation between refractive status and optical quality measurement difference was observed. A hyperopic bias (best focus difference of (0.50 ± 0.44) D) and a relatively better optical quality using spectacle correction in high myopia group were found.</p><p><b>CONCLUSIONS</b>OQAS based on DP system is a clinically reliable instrument. In patients with high myopia, measurements using built-in optometer correction should be considered and interpreted with caution.</p>