To compare in vivo corneal imaging by scanning slit white light and laser confocal microscopy systems. Twenty healthy individuals and 10 patients with corneal dystrophies including Fuchs, granular, Map-Dot-Fingerprint dystrophies, and amiodarone-induced keratopathy were examined with the ConfoScan 3 (Nidek Technologies) scanning slit white light confocal microscope equipped with x40 front lens (Zeiss) and the Rostock Cornea Module (RCM) for HRT II (Heidelberg Engineering) laser confocal microscopy system equipped with Olympus x60 front lens. The endothelial cell density counts were performed and results were compared. For additional validation of endothelial cells density results, separate counts were carried out using the specular microscope SP-1000 (Topcon). The healthy and pathologically changed corneal structures are imaged in a similar manner by both systems. The differences in quality of acquired images in contrast and brightness between the systems are debatable, although the laser system was more efficient for epithelium imaging and white light scanning slit was better for evaluation of endothelium. Some of the examinations completed with the laser system, which requires applanating its front lens to the cornea, imaged dark striae in posterior stroma and Descemet membrane folds, resembling those observed in corneal pathologies, whereas most were probably induced by the pressure applied to the cornea during examination. All the results of cell density (for patients and for subjects with no ophthalmic disease) counts performed with the RCM (laser system) were higher than those with the ConfoScan 3 (scanning slit system) by 36.7% +/- 11.9% (SD) and 30.2% +/- 11.3% higher than SP-1000 (specular). The difference in cell counts between the RCM and other methods was increasing at higher cell densities. The morphologic findings in examinations performed with the laser confocal microscopy system are generally comparable to white light scanning slit confocal microscopy. Direct applanation of the front lens of the laser system to the cornea may generate certain changes in confocal microscopy outcomes, including imaging of Descemet membrane folds and dark lines in stroma, which should be differentiated from pathologic alterations. Comparison of the endothelium cell density counts obtained with the 2 systems should be made cautiously because significant differences might occur--RCM configured with the Olympus x60 front lens was found to overestimate the results compared with both CS3 and SP-1000 microscopes, with the range of disparity increasing for higher cell densities.

The ocular microbiome composition has only been partially characterized. Here, we used RNA-sequencing (RNA-Seq) data to assess microbial diversity in human corneal tissue. Additionally, conjunctival swab samples were examined to characterize ocular surface microbiota. Short RNA-Seq reads, obtained from a previous transcriptome study of 50 corneal tissues, were mapped to the human reference genome GRCh38 to remove sequences of human origin. The unmapped reads were then used for taxonomic classification by comparing them with known bacterial, archaeal, and viral sequences from public databases. The components of microbial communities were identified and characterized using both conventional microbiology and polymerase chain reaction (PCR) techniques in 36 conjunctival swabs. The majority of ocular samples examined by conventional and molecular techniques showed very similar microbial taxonomic profiles, with most of the microorganisms being classified into Proteobacteria, Firmicutes, and Actinobacteria phyla. Only 50% of conjunctival samples exhibited bacterial growth. The PCR detection provided a broader overview of positive results for conjunctival materials. The RNA-Seq assessment revealed significant variability of the corneal microbial communities, including fastidious bacteria and viruses. The use of the combined techniques allowed for a comprehensive characterization of the eye microbiome’s elements, especially in aspects of microbiota diversity.

Soft contact lenses may be used as a bandage after corneal refractive surgery. Silicone hydrogel contact lenses offer the advantage of increased oxygen permeability over conventional hydrogel lenses for this application. To evaluate a silicone hydrogel contact lens as a continuous wear bandage applied after laser-assisted sub-epithelial keratomileusis (LASEK). We conducted a prospective, open-label, non-randomized clinical trial involving thirty patients treated with unilateral LASEK. Patients were fitted with a lotrafilcon A (Focus NIGHT & DAY; CIBA Vision, Duluth, GA) silicone hydrogel soft contact lens that was worn continuously for 3 to 4 days post-operatively. Lens movement and slitlamp evaluations of conjunctival hyperemia 1, 2, and 3 days after surgery (DAS) were recorded, as was the condition of the corneal epithelium after lens removal. Subjective comfort was rated by the patients along with the presence of symptoms or pain. Post-blink lens movement was evaluated by investigators as "very good" or "good" in 87% of eyes at 1 DAS, in 73% at 2 DAS, and in 60% at 3 DAS. Conjunctival hyperemia was assessed as normal or trace in 96% of eyes at 1 DAS, in 76% at 2 DAS, and in 67% at 3 DAS. An average of 80% of eyes showed normal or trace conjunctival hyperemia during the trial. The condition of the corneal epithelium after contact lens removal was rated as "very good" in 13% or "good" in 73% of eyes. An average of 77% of subjects reported "very good" or "good" comfort during the trial. Symptoms or pain were rated as "absent" or "mild" by all subjects at 1 DAS and 2 DAS and by 96% at 3 DAS. An average of 99% rated symptoms or pain as either "absent" or "mild" during the trial. The lotrafilcon A lens was found to be an effective and well-tolerated bandage lens after LASEK.

Keratoconus (KTCN) is a degenerative disorder of the eye that results in the conical shape and thinning of the cornea and is a leading cause for corneal transplantations. A number of studies suggest that genetic factors play a role in KTCN etiology. Some candidate gene variants have recently been shown to be associated with KTCN. The purpose of our study was to verify the role of VSX1, TGFBI, DOCK9, IPO5, and STK24 sequence variants in Polish KTCN patients. Forty-two Polish patients with sporadic KTCN and 50 control individuals were enrolled into this study. Both affected and unaffected individuals underwent detailed ophthalmic examination. The mutations screening in the candidate genes was performed by the direct sequencing method. Analysis of VSX1, TGFBI, DOCK9, IPO5, and STK24 genes identified numerous sequence variants. Variants c.-264_-255delGGGGTGGGGT, c.627 + 23G > A, c.809-6_809-5insT, and c.*200G > T in the VSX1 gene, and heterozygous c.1598G > A mutation (Arg533Gln) in exon 12 of TGFBI were detected for the first time in KTCN patients. Two known sequence variants of TGFBI c.1620T > C (Phe540Phe) and c.1678 + 23G > A were observed in KTCN patients and control individuals. The newly reported c.717 + 43A > G substitution in intron 7 of DOCK9 was identified in both KTCN patients and healthy individuals. Our investigation showed that KTCN-related sequence variants of analyzed genes were found in a very small proportion of the studied patients indicating that genes other than VSX1, TGFBI, DOCK9, IPO5, and STK24 are involved in the development and progression of KTCN in Polish patients. Our results support the hypothesis about the genetic heterogeneity of KTCN.

Fuchs endothelial corneal dystrophy (FECD) is a common corneal endotheliopathy with a complex and heterogeneous genetic background. Different variants in theTCF4gene have been strongly associated with the development of FECD.TCF4encodes the E2-2 transcription factor but the link between the strong susceptibility locus and disease mechanism remains elusive. Here, we confirm a strong positive association betweenTCF4single nucleotide polymorphism rs613872 and FECD in Polish patients (OR = 12.95, 95% CI: 8.63–19.42,χ2=189.5,p<0.0001). We show thatTCF4expression at the mRNA level in corneal endothelium (n=63) does not differ significantly between individuals with a particularTCF4genotype. It is also not altered in FECD patients as compared to control samples. The data suggest that changes in the transcript level containing constitutiveTCF4exon encoding the amino-terminal part of the protein seem not to contribute to disease pathogenesis. However, considering the strong association ofTCF4allelic variants with FECD, genotyping ofTCF4risk alleles may be important in the clinical practice.