The use of in vivo confocal microscopy to track treatment success in fungal keratitis and to differentiate between Fusarium and Aspergillus keratitis.

PURPOSE: To evaluate the usefulness of serial in vivo confocal microscopy (IVCM) examinations to measure hyphal density for monitoring the treatment success among patients with fungal keratitis, and to compare the hyphal diameter as well as branching angle as a way of differentiation between Aspergillus and Fusarium species observed in IVCM. STUDY DESIGN: Prospective nonrandomized study. PATIENTS AND METHODS: The study was conducted from February 2015 to September 2016. Hyphal diameter, density and branching angle measurements were performed using IVCM at admission and on a weekly basis for at least 2 weeks after the start of treatment. RESULTS: During the period of study, 65 patients with culture-confirmed fungal keratitis were recruited. Of them, 40 were culture-positive for Fusarium spp. and 25 patients for Aspergillus spp. Before the start of treatment, the mean branching angle did not differ between the two species and the mean hyphal diameter was statistically higher for Aspergillus spp. (p = 0.029). Two weeks after the start of treatment, the mean hyphal diameter was statistically lower (p < 0.001) in the treatment failure group. Also the hyphal density significantly decreased with successful treatment (p < 0.05). CONCLUSION: Decreasing hyphal density in serial IVCMs might be used as an indicator to predict the successful response of fungal ulcers to treatment. Branching angle is not different between Aspergillus and Fusarium keratitis. The mean hyphal diameter is significantly lower in the treatment failure group.

Topographic typology in a consecutive series of refractive surgery candidates.

PURPOSE: The term 'keratoconus (KC) suspect' is used as a blanket term to refer to any deviation of virgin cornea shape toward KC features. We intend to subclassify such topographies in meaningful and informative designations. METHODS: Pentacam corneal topographies of 199 consecutive refractive surgery candidates (398 eyes) are examined. Features of steepness, inferior-superior asymmetry, focal steepening, thinning, and bounded anterior or posterior elevations are observed in the quad map. Scissoring on retinoscopy, loss of best spectacle-corrected visual acuity, and iron ring deposition were looked for. Through iterative observation and refinement of classification criteria-partly taken from the literature-all eyes were designated a specific topographic diagnosis, i.e., circumventing the usage of the expression KC 'suspect'. RESULTS: Topographies of 308, 48, 21, 13, 6, 1, and 1 (collectively 398 eyes) were designated: normal, 'atypical normal,' forme fruste KC, posterior KC, subclinical/mild KC, superior KC, and pseudo-KC, respectively. CONCLUSION: Current imaging modalities of the cornea and our accumulated experience in refractive science allow assignment of distinctive designations for abnormal corneal shapes along the topography spectrum. We devised and used the expressions: normal, atypical normal, forme fruste (arrested-incomplete) KC, posterior KC, subclinical (active latent) KC, superior KC, and pseudo-keratoconus. Identification of 1.5% (mild) KC highlights the importance of screening for ultraviolet cross-linkage candidacy in refractive surgery referrals.

A comparison between Goldmann applanation tonometry and dynamic contour tonometry after photorefractive keratectomy.

BACKGROUND: The intraocular pressure (IOP) could be measured by both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT). Although these two methods have been discussed widely after laser-assisted sub-epithelial keratectomy (LASIK), there is little data in the cases undergoing photorefractive keratectomy (PRK). We aimed to compare the changes of IOP measurements obtained by GAT and DCT after PRK for myopia/myopic astigmatism. METHODS: This prospective study enrolled 77 candidates (154 eyes) for PRK to correct myopia or myopic astigmatism and 30 matched patients (30 eyes) with myopia or myopic astigmatism who served as controls. Changes of the IOP measurements (ΔIOP) obtained by GAT and DCT before and at 6 months after PRK in the operated eyes, and at baseline and 6 months later in the controls, were documented. Changes of the central corneal thickness (ΔCCT) were determined in the same fashion. RESULTS: The mean IOP readings obtained by DCT were comparable before and at 6 months after procedure (18.34 ± 3.03 mmHg and 17.87 ± 2.61 mmHg respectively, p = 0.41); whereas the mean IOP reading obtained by GAT decreased significantly 6 months postoperatively (17.92 ± 3.63 mmHg and 16.25 ± 2.66 mmHg, p < 0.001). A significant correlation was present between the ΔIOP obtained by GAT and ΔCCT (r = 0.61, p < 0.001). Similar correlation was not significant between the DCT-obtained ΔIOP and the ΔCCT (r = 0.07, p = 0.44). The mean ΔIOP obtained by GAT was significantly higher in the operated eyes than in the controls (-1.54 ± 1.45 vs 0.07 ± 0.44 mmHg, p = 0.02). The mean DCT-obtained ΔIOP was just marginally insignificant between the operated and nonoperated eyes (-0.63 ± 0.59 vs 0.02 ± 0.38 mmHg respectively; p = 0.09). CONCLUSIONS: The authors recommend DCT after PRK in the cases with myopia or myopic astigmatism.

Application of polycaprolactone nanofibers as patch graft in ophthalmology.

PURPOSE: The purpose of the study was to evaluate tissue reaction to polycaprolactone (PCL) nanofiber patches in the cornea, conjunctiva, and anterior chamber (AC) in rabbit eyes and to assess their biocompatibility for use as patch grafts. METHODS: Two 100 µ PCL patches were implanted under the conjunctiva and in the corneal stroma of one albino New Zealand rabbit, and pathologic evaluation was done after 3 weeks. In the next step, two PCL patches were implanted; one in the corneal stroma and the other in the AC of two rabbits followed by pathologic evaluation after 3 months. RESULTS: On slit-lamp examination, there was minimum inflammation in all cases. Pathologic examination showed that the contact and probably merging between the host tissue and PCL fibers were achieved with minimal tissue reaction. CONCLUSION: As a biocompatible material, PCL nanofibers seem to be a promising modality for the repair of different tissue defects including melting, thinning, and perforation. They may also be a suitable material for manufacturing keratoprostheses.

Erratum.

[This corrects the article DOI: 10.1159/000454979.].

Recurrent Corneal Perforation due to Chronic Graft versus Host Disease; a Clinicopathologic Report.

PURPOSE: To describe a case of chronic graft versus host disease (GVHD) leading to severe dry eye and recurrent corneal perforation in both eyes, its stepwise management and histopathological reports. CASE REPORT: A 22-year-old woman with a history of thalassemia and subsequent high-dose chemotherapy followed by allogeneic bone marrow transplant (BMT) was referred to Farabi Eye Hospital. Despite aggressive medical and surgical intervention, corneal vascularization in her right eye progressed and led to corneal perforation. Cyanoacrylate glue was applied to seal the perforation, however it recurred. Multilayer amniotic membrane transplantation (AMT) was performed to seal the corneal perforation, which was effective for a short period. Subsequently, the corneal perforation recurred and penetrating keratoplasty was performed. After a few months deep vascularization and descemetocele occurred in the fellow left eye and the patient finally underwent therapeutic lamellar keratoplasty. CONCLUSION: Patients with GVHD are at risk of severe dry eye and subsequent corneal vascularization. Recurrent and recalcitrant corneal perforation resistant to cyanoacrylate glue and multilayer AMT may occur. Proper systemic and ocular management alongside close collaboration with the hematologist is strongly recommended to control the condition.

Amniotic Membrane Extract Preparation: What is the Best Method?

PURPOSE: To compare different preparation methods for a suitable amniotic membrane (AM) extract containing a given amount of growth factors. METHODS: In this interventional case series, we dissected the AM from eight placentas within 24 hours after delivery, under clean conditions. After washing and mixing, AM extracts (AMEs) were prepared using pulverization and homogenization methods, and different processing and storing conditions. Main outcome measures were the amount of added protease inhibitor (PI), the relative centrifugal force (g), in-process temperature, repeated extraction times, drying percentage, repeated pulverization times, and the effect of filtering with 0.2 µm filters. Extract samples were preserved at different temperature and time parameters, and analyzed for hepatic growth factor (HGF) and total protein using ELISA and calorimetric methods, respectively. RESULTS: The extracted HGF was 20% higher with pulverization as compared to homogenization, and increased by increasing the PI to 5.0 µl/g of dried AM. Repeating centrifugation up to 3 times almost doubled the extracted HGF and protein. Storing the AME at -170° for 6 months caused a 50% drop in the level of HGF and protein. Other studied parameters showed no significant effect on the extracted amount of HGF or total protein. CONCLUSION: Appropriate extraction methods with an adequate amount of PI increases the level of extractable components from harvested AMs. To achieve the maximal therapeutic effects of AMEs, it is necessary to consider the half-life of its bioactive components.

Preoperative anterior segment optical coherence tomography as a predictor of postoperative phakic intraocular lens position.

PURPOSE: To evaluate anterior segment optical coherence tomography (AS-OCT) in the preoperative simulation of postoperative iris-fixated phakic intraocular lens (pIOL) position in the anterior chamber. SETTING: Farabi Eye Research Center, Department of Ophthalmology, Tehran University of Medical Sciences, Tehran, Iran. DESIGN: Case series. METHODS: Using AS-OCT, the pIOL position was simulated preoperatively in 2 ways and compared with the actual postoperative pIOL position. For preoperative evaluations, the simulator was placed on the posterior pigmented epithelium of the iris. Then, the simulation was performed with the simulator placed in the middle of the iris tissue. The following distances were measured: from the center of the pIOL to the endothelium, from the edge of the pIOL to the endothelium, and from the posterior surface of the pIOL to the crystalline lens. RESULTS: The study examined 26 eyes (16 patients). Although all distances in both simulation methods (except the lens vault in the first method of simulation) were highly correlated (all P<.009), only the results with the simulator placed in the middle of the iris tissue were not statistically different from the corresponding postoperative measurements (P=.209 and P=.564 for distance from endothelium to the center and the pIOL edge, respectively). CONCLUSIONS: Using the pIOL template of the AS-OCT system for preoperative simulation of iris-fixated pIOLs improved the criteria for patient selection for implantation of these pIOLs. The simulator should be placed in the middle of the iris tissue for preoperative simulation. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Comparison of postoperative higher-order aberrations and contrast sensitivity: tissue-saving versus conventional photorefractive keratectomy for low to moderate myopia.

PURPOSE: To assess the efficacy, predictability, safety, contrast sensitivity, higher-order aberrations (HOAs), and patient satisfaction after tissue-saving photorefractive keratectomy (PRK) and conventional PRK. SETTING: Department of Ophthalmology, Farabi Eye Hospital, Tehran Medical University, Tehran, Iran. DESIGN: Comparative case series. METHODS: This prospective study evaluated eyes with low to moderate myopia that had PRK with a Technolas 217z excimer laser. Patients were randomly assigned to have surgery using a conventional algorithm (PlanoScan) or a tissue-saving algorithm (Zyoptix). Contrast sensitivity, HOAs, and patient satisfaction were analyzed preoperatively and 1, 3, and 6 months postoperatively. RESULTS: The conventional group comprised 42 eyes (21 patients) and the tissue-saving group, 62 eyes (31 patients). At 6 months, all eyes in both groups were within ±0.50 diopter of the attempted correction and had an uncorrected distance visual acuity of 20/25 or better. However, the tissue-saving group had a statistically significantly greater increase in the mean root mean square of total HOAs and more induced spherical aberration than the conventional group (P<.05). There was no significant difference between the 2 groups in mesopic or photopic contrast sensitivity. The level of satisfaction after surgery was the same in the 2 groups. CONCLUSIONS: Although the conventional and tissue-saving algorithms for PRK were both safe and effective in treating low to moderate myopia, tissue-saving PRK induced a greater increase in HOAs than conventional PRK; this may be because of the smaller blend zone of the tissue-saving algorithm. Contrast sensitivity and patient satisfaction were comparable between the 2 methods.