Tuck-in deep anterior lamellar keratoplasty for the management of post-radial keratotomy keratectasia.

PURPOSE: To evaluate the outcomes of tuck-in deep anterior lamellar keratoplasty (DALK) for the management of post-radial keratotomy (RK) keratectasia. SETTING: Institution. DESIGN: Retrospective. METHODS: Medical records of all cases presenting with post-RK keratectasia from January 2012 to December 2019 were included. Data on corrected distance visual acuity (CDVA), refraction, keratometry, ultrasonic pachymetry, corneal topography, endothelial cell count, applanation tonometry, and dilated fundus examination recorded at all follow-up visits were included. Details of surgical steps, including intraoperative and postoperative complications and any secondary procedures performed subsequently, were also recorded. RESULTS: 7 eyes of 5 patients that developed corneal ectasia after a previous RK procedure underwent DALK with peripheral tuck-in. All eyes had CDVA ≤6/24, preoperatively. The surgical procedure was successfully performed in all eyes without any intraoperative complications. CDVA at the final follow-up ranged between 6/9 and 6/60, with 6 eyes achieving CDVA of 6/18 or better. The median keratometric cylinder reduced from a preoperative value of 7.2 ± 9.27 diopters (D) to 2 ± 1.83 D at the final follow-up. The median central corneal thickness at the final follow-up was 598 ± 40.01 µm, and spherical equivalent ranged between -1.75 D and -3.5 D (median -2 ± 0.57). The percentage of endothelial cell loss ranged between 2.1% and 8.4%. All eyes retained graft clarity, and none showed any evidence of significant interface haze or corneal vascularization. CONCLUSIONS: Tuck-in DALK could successfully address corneal ectasia developing after RK, achieving visual gains. Moreover, it was able to restore the peripheral corneal thickness with a minimal risk for dehiscence of RK incisions.

Evaluation of Autograft Characteristics After Pterygium Excision Surgery: Autologous Blood Coagulum Versus Fibrin Glue.

PURPOSE: To compare graft outcomes following pterygium excision and conjunctival autograft fixation using patient's in situ autologous blood or standard fibrin glue-assisted conjunctival autograft adhesion. METHODS: Outcomes of 23 consecutive eyes which underwent pterygium excision and conjunctival autograft with autologous in situ blood coagulum (group I) were compared with historical case controls (20 eyes) that had undergone fibrin glue-assisted conjunctival autograft (group II). Primary outcome measure was graft stability. Secondary outcome measure was severity of graft inflammation at day 1, day 7, 3 months, and 6 months. RESULTS: The two groups were similar regarding age, gender, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refractive error, tear function tests, and pterygium size. Mean surgical time was similar for the two groups (14.2±2.74 min, group I; 12.25±1.88 min, group II; P=0.1); with the mean difference in operative time being 1.95 min (95% CI, 0.48-3.42 min). Postoperatively, there was a statistically significant reduction in astigmatism and improvement in UCVA, BCVA, and spherical equivalent in all eyes. No difference was found in mean epithelial defect healing time, UCVA, BCVA, astigmatism, tear film break-up time, and Schirmer I and II at 6 months between the two groups. Initial graft stability was better for group II at 1 month (P=0.001) but was similar for both groups at 6 months. Median score of graft inflammation was significantly more for group II during the first week (P<0.05; Wilcoxon rank-sum test). CONCLUSION: Autologous blood may be used as an effective alternative with lesser postoperative inflammation in comparison to glue-assisted autograft fixation.

Development of novel in silico model to predict corneal permeability for congeneric drugs: a QSPR approach.

This study was undertaken to determine in vivo permeability coefficients for fluoroquinolones and to assess its correlation with the permeability derived using reported models in the literature. Further, the aim was to develop novel QSPR model to predict corneal permeability for fluoroquinolones and test its suitability on other training sets. The in vivo permeability coefficient was determined using cassette dosing (N-in-One) approach for nine fluoroquinolones (norfloxacin, ciprofloxacin, lomefloxacin, ofloxacin, levofloxacin, sparfloxacin, pefloxacin, gatifloxacin, and moxifloxacin) in rabbits. The correlation between corneal permeability derived using in vivo studies with that derived from reported models was determined. Novel QSPR-based model was developed using in vivo corneal permeability along with other molecular descriptors. The suitability of developed model was tested on ß-blockers (n = 15). The model showed better prediction of corneal permeability for fluoroquinolones (r(2) > 0.9) as well as ß-blockers (r(2) > 0.6). The newly developed QSPR model based upon in vivo generated data was found suitable to predict corneal permeability for fluoroquinolones as well as other sets of compounds.

Induction of posterior vitreous separation using LASIK suction ring may have a potential role in the management of diabetic macular edema.

A significant percentage of patients with diabetic macular edema respond poorly to conventional laser photocoagulation. One associated factor in such patients with refractory diabetic macular edema is the absence of posterior vitreous detachment (PVD). Several invasive methods, such as surgical induction of PVD result in resolution of macular edema and improvement in visual acuity. Being invasive such modalities may have important surgical risks, such as retinal detachment and endophthalmitis. Recently, laser in situ keratomeilusis (LASIK), a well-accepted refractive procedure, has been reported to produce posterior vitreous detachment in patients with myopia. We herein hypothesize that application of LASIK suction ring, an external procedure, may be useful in the induction of PVD in patients with refractory diabetic macular edema and may have a better safety profile.