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A 17-year-old girl with a few years' history of declining vision, photophobia, and dry eye symptoms was referred to our clinic. She noted that the vision in the right eye declined significantly over the past several months. On her last year examination, her uncorrected distance visual acuity (UDVA) was recorded as 20/25 in both eyes with a corrected distance visual acuity (CDVA) of 20/20 in both eyes with minimal refractive error, with a diagnosis of bilateral Salzmann nodular degeneration. The patient was given artificial tears and was encouraged to wear sunglasses. On examination now, UDVA was 20/70 in the right eye and 20/40 in the left eye. The manifest refraction was -2.00 + 1.25 × 96 in the right eye and -1.00 + 2.00× 34 in the left eye, with a CDVA of 20/50 and 20/30, respectively. Slitlamp examination revealed superficial reticular stromal scar with clear intervening spaces involving the anterior 75 μm of the stromal cornea in the central 6.0 mm optical zone (Figure 1).JOURNAL/jcrs/04.03/02158034-202104000-00021/figure1/v/2021-04-19T183640Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202104000-00021/figure2/v/2021-04-19T183640Z/r/image-tiff The rest of the anterior and posterior segment examination was completely normal and noncontributory. Anterior segment optical coherence tomography (AS-OCT) revealed subepithelial lesion involving the central aspect of the cornea in the right eye more than that in the left eye (Figure 2). Family history was significant for an older sister with a similar problem who never required medical attention. She also has mild photophobia and dry eye symptoms. What is your differential diagnosis? What diagnostic test will help you in your diagnosis and clinical decision-making? What is the most likely diagnosis in this case? Do you recommend medical and/or surgical intervention in the right eye, realizing that there has been exacerbation of her ocular condition in the most recent year? What is the long-term prognosis and future plan for a patient with this potential condition?

Purpose: To compare proportion of glaucoma and the associated factors among self-reported relatives and non-relatives of predominantly Igbo glaucoma patients Methods: An analytical cross-sectional survey of participants attending a free eye screening dedicated to relatives of glaucoma relatives in Enugu, Nigeria was carried out in July 2017. Non-relatives of glaucoma patients were expected to present for the free screening hence they were allowed to participate to prevent false claims. All participants were interviewed and underwent ophthalmic examinations. Glaucoma diagnosis was based on the ISGEO classification criteria adapted for Nigeria. Participants were subsequently grouped as glaucoma relatives and general population. Results: Forty-two and 56 participants were included in the relatives and general population groups respectively. The proportion of glaucoma in the relatives and general population groups was 43% and 20% respectively. The odds of having glaucoma was three times higher in relatives of patients than in general population (OR= 3.07, 95% CI; 1.25 – 7.5 p=0.013). About 52% of first-degree relatives were diagnosed with glaucoma. In the relatives’ group, 100% of siblings, 40% of children and 0% of parents had glaucoma. Proportion increased with age. Relatives were significantly younger than their probands at diagnosis (16years, p= 0.000). Only 5.6% of the relatives’ group were previously aware of diagnosis. Intraocular pressure and central cornea thickness were similar in both relatives and general population groups. Conclusions: In this screened Igbo population, over one-third of the relatives’ group and about one fifth of general population had glaucoma. Relatives were diagnosed at an earlier age. These findings will aid the advocacy for routine glaucoma family screening services.

Microwave thermokeratoplasty (MTK) is a surgical procedure for the correction of pathologic corneal steepening. The purpose of this study was to examine the postoperative outcomes of eyes with advanced keratoconus that underwent femtosecond-laser zig-zag penetrating keratoplasty (z-PK) following MTK for reshaping of the central cornea. This study involved 32 eyes of 32 consecutive advanced keratoconus patients; i.e., 25 eyes of 25 patients who underwent MTK prior to z-PK (MTK + z-PK group), and 7 eyes of 7 patients who underwent z-PK alone (z-PK group). In all treated eyes, visual acuity (VA) and corneal topography were measured before surgery and at 6-months postoperative. At 6-months postoperative, the mean uncorrected distance VA (logarithm of the minimum angle of resolution) and surface regularity index (SRI) of the MTK + z-PK group was 0.62 ± 0.39 (mean ± standard deviation) and 1.26 ± 0.45, respectively, while that in the z-PK group was 1.02 ± 0.18 and 7.64 ± 3.22, respectively. Both variables were significantly better in the MTK + z-PK group than in the z-PK group (P

Infrared (IR) thermographic assessment of ocular surface temperature (OST) is gaining interest as an adjuvant method to evaluate the ocular surface. It is a quick, non-invasive test that causes minimal, if any, discomfort to patients. The purpose of this article was to summarize research on how OST relates to tear film parameters and dry eye disease (DED). PubMed, Google Scholar, and Scopus searches for specific terms were carried out and eligible articles reviewed. OST of the central cornea is ~34-35°C when measured as a single time-point (typically right after a blink). Dynamically, OST values decrease over time at a rate of ~ −0.01 °C/s in healthy eyes. Single time-point OST values are impacted by temperature, with positive correlations noted with both ambient (1°C↓ results in ~0.16°C↓ in OST) and body (1°C↑ results in ~0.98°C↑ in OST) temperature. Single time-point OST values are also impacted by tear parameters, with negative correlations noted with tear break-up time (TBUT; r=−0.61) and positive correlations with lipid layer thickness (~r=0.50). Dynamically, the rate of OST cooling over the interblink period correlates with various tear parameters including Schirmer’s test scores (r=−0.39), tear meniscus height (r=−0.52) and the rate of tear film break-up (r=−0.74). These data imply that OST decreases more rapidly in individuals with greater tear production, larger tear volumes, and shorter tear break-up times (faster rates of tear film break-up). There are discrepancies in relationships between OST and DED across studies, which is not surprising given that DED encompasses a number of different phenotypic presentations. However, most studies found that OST decreases at a more rapid rate in DED vs. control groups. As such, cooling rate may have utility as a screening tool in DED in combination with established point-of-care tests.

PURPOSE: To evaluate corneal immune dendritiform cell (DC) changes in dry eye disease (DED) using in vivo confocal microscopy (IVCM) and to correlate IVCM parameters with clinical severity. METHODS: This was a retrospective, cross-sectional study including 300 eyes of 150 DED patients and 49 eyes of 49 age-matched controls. Severity of DED was based on the Dry Eye Workshop (DEWS) classification. IVCM images of subbasal layer of the central cornea were analyzed for DC density and morphology (including number of dendrites per DC, DC size and DC field). RESULTS: DC density was significantly higher in DED compared to controls (93.4 ± 6.3 vs. 25.9 ± 3.9 cells/ mm(2); P < 0.001). Morphologically, number of dendrites, DC size and field were significantly larger in DED (3.3 ± 0.1, 106.9 ± 4.7 μm(2), 403.8 ± 20.1 μm(2) than controls (2.3 ± 0.1, 62.5 ± 5.7 μm(2), 241.4 ± 24.4 μm(2), P < 0.001). Significantly higher DC density compared to controls was observed as early as Level 1 DED severity (87 ± 10 cells/mm(2), p < 0.001. Significant morphological changes in DC were detected for Levels 2 to 4 (p= < 0.001, and p = < 0.05) for dendrites and DC field, respectively. Similarly, DC size showed significant increase at DED level 3–4. (p < 0.05). Linear regression analysis showed that both conjunctival and corneal staining were independently associated with DC density, while corneal staining was independently associated with DC morphology. CONCLUSION: DC density and morphology correlated with clinical severity of DED. While, DC density is increased in mild DED, morphological changes are seen only in severe cases. IVCM may be a powerful tool to detect early immune changes and may complement clinical examination in DED.

ObjectiveUsing anterior segment optical coherence tomography (AS-OCT), we investigated the epithelial thickness (ET) of the central cornea and limbal regions in patients with limbal stem cell deficiency (LSCD) as a diagnostic and staging parameter.DesignProspective, cross-sectional study.MethodsThe central corneal epithelium thickness (CET) and maximum limbal epithelium thickness (mLET) were measured in the superior, inferior, nasal, and temporal limbus on AS-OCT images of the normal and eyes with LSCD. CET was obtained by 1-point (OCT-CET1) and 3-point measurement (OCT-CET3). The values of OCT-CET1 and OCT-CET3 were compared to the CET obtained with invivo confocal microscopy (IVCM-CET).ResultsSixty-eight eyes of 50 patients with LSCD and 52 eyes of 34 normal subjects were included. The mean (±standard deviation) OCT-CET3 was 55.0 ± 3.0μm (range, 50.6-62.0μm) in the control group and 41.6 ± 10.8μm (range, 0-56.3μm) in the LSCD group (P < .001). OCT-CET3 had a better correlation with IVCM-CET (r= 0.91) than did OCT-CET1 (r= 0.87, P= .001). The degree of reduction in OCT-CET3 increased in more advanced clinical stages of LSCD (all P < .001). The OCT-CET3 cutoff value that suggests LSCD was 46.6μm. Compared with the control group, the LSCD group had decreases in mLET in all 4 limbal regions (all P < .001). The sensitivity and specificity of OCT-CET3 is the highest among all mLET in detecting LSCD.ConclusionsBoth CET and mLET were thinner in patients with LSCD than in normal subjects. OCT-CET3 appears to be a reliable parameter to confirm LSCD when there is clinical suspicion.

Purpose. The purpose of this study was to confirm the presence of specific patterns of epithelial response in corneal buttons from keratoconus patients. Methods. This was a retrospective and descriptive study. 90 penetrating keratoplasty specimens obtained from patients diagnosed with keratoconus were evaluated using bright-field microscopy. Morphologically identifiable characteristics including epithelial cell density and epithelial thickness were analyzed on hematoxylin and eosin- (H&E-) and periodic acid of Schiff- (PAS-) stained slides. Results. Three distinctive patterns of epithelial alteration of the central cornea were established. Pattern 3, in which the central epithelium was as thick as peripheral epithelium, was the commonest (44.4%), followed by the pattern 2, defined as central epithelium thinner than periphery epithelium (38.9%), and the uncommonest pattern was number 1, with central epithelium thicker than the periphery (16.7%). Conclusions. Three distinctive histologic patterns that could potentially have a diagnostic and prognostic value in keratoconus patients were found.

PURPOSE To ascertain whether offsetting the Descemet membrane endothelial keratoplasty (DMEK) punch can expand the donor pool in conjunction with prepunched and preloaded services by recapturing the corneas otherwise excluded by the conventional central clear zone criteria. METHODS In this retrospective review of corneas recovered and processed for DMEK by a single eye bank between March 2017 and October 2018, corneas failing to meet the conventional central clear zone requirement during initial evaluation (defined as an area in the central cornea where an 7.5- to 8.0-mm diameter graft can be obtained free of previous surgical scars, Descemet tears, or confined areas of endothelial defects) were further evaluated for offset punching. Corneas with a central endothelial cell density of at least 2000 cells/mm at the initial screening (average of 3 specular images assessed with the center dot method) that had a clear zone of 7.5- to 8.0-mm diameter where a graft could be obtained were designated as eligible for offset punching for either prepunched or preloaded DMEK. RESULTS A total of 2607 corneas were found to be suitable for DMEK using the conventional central clear zone criteria. An additional 62 corneas were deemed DMEK suitable by offsetting the punch, yielding a 2.4% increase in the availability of DMEK suitable corneas. CONCLUSIONS Offsetting the DMEK punch can recapture corneas otherwise excluded from the DMEK donor pool because of a failure to meet the conventional central clear zone criteria, and by our estimation may help eye banks meet the growing demand for DMEK tissue while maximizing the transplant potential of every cornea.

Aim To report the outcomes of patients undergoing anterior segment optical coherence tomography-guided transepithelial phototherapeutic keratectomy (ASOCT T-PTK) for central corneal scarring after pterygium excision. Methods The charts of 11 eyes of 10 patients that underwent ASOCT T-PTK following excision of visual axis-involving pterygia were retrospectively reviewed from a single private practice institution. The visual outcomes and corneal topographic findings were evaluated 4±1mo after pterygium excision and 6±2mo after transepithelial phototherapeutic keratectomy (T-PTK). Results All 11 eyes tolerated both the pterygium excision and T-PTK procedure well without any significant intraoperative or postoperative complications. Uncorrected distance visual acuity (UDVA) and manifest refraction corrected distance visual acuity (CDVA) improved after pterygium excision (P=0.03 and P=0.05, respectively). The UDVA and CDVA improved further after T-PTK (P=0.004 and P=0.002, respectively). The topographic surface asymmetry index, topographic surface regularity index, and topographic projected visual acuity significantly improved after T-PTK (P=0.0092, P=0.0022, and P=0.0002, respectively). None of the subjects lost any lines of CDVA, developed recurrence of pterygia or required keratoplasty during the postoperative period. Conclusion ASOCT T-PTK can provide excellent visual and anatomic outcomes in patients with central corneal scarring after excision of visual axis-involving pterygia.

Background. Ophthalmic hypertension is one of the most important diagnostic criteria for congenital glaucoma. The «gold standard» for measuring intraocular pressure (IOP) is the applanation tonometry (Maklakov and Goldmann methods). However, the thickness of the central corneal zone has a significant effect on the value of IOP measured by these methods. The aim of this study was to compare the central corneal thickness (CCT) in children with congenital glaucoma and in healthy children. Material and methods. We examined 15 children aged from 7 months to 14 years (22 eyes) with congenital glaucoma. In the healthy children group, 26 subjects from 7 to 17 years old (51 eyes) were examined. CCT was measured in all subjects using the optical coherence tomograph Carl Zeiss Cirrus HD-OCT 5000 with an external lens for cornea scanning. The examination was carried out in pachymetry mode; the average thickness of the central ring having a diameter of 2 mm was evaluated. Results. Central corneal thickness in children with glaucoma ranged from 471 to 771 microns, the average value was 561.5±72.26 microns. In the group of healthy children, CCT was in the range of 480-597 microns with an average value of 529.88±29.33 microns. Thus, we noted a higher average value of the central corneal thickness and its higher variability in children with glaucoma in comparison with the group of healthy children. Conclusion. All children with glaucoma and suspected glaucoma should routinely perform pachymetry prior to applanation tonometry. One should consider the central corneal thickness when assessing intraocular pressure. Key words: congenital glaucoma, pachymetry, optical coherence tomography, central corneal thickness, applanation tonometry, intraocular pressure.

Significance The well-accepted proposition that central corneal epithelia have limited self-renewal and therefore poor regenerative capacity has recently been challenged. However, methods for real-time monitoring to identify which cells take part in this process are scant. In this study, we visualized and quantified the contribution of central versus peripheral/limbal epithelia during annular wound healing by intravital imaging, through an organ culture system, and via computational modeling. Our results verify the contribution of K14+ limbal-derived stem cells and their early progeny in playing a vital role in this process, while central corneal epithelia contribute minimally to wound closure., Corneal epithelia have limited self-renewal and therefore reparative capacity. They are continuously replaced by transient amplifying cells which spawn from stem cells and migrate from the periphery. Because this view has recently been challenged, our goal was to resolve the conflict by giving mice annular injuries in different locations within the corneolimbal epithelium, then spatiotemporally fate-mapping cell behavior during healing. Under these conditions, elevated proliferation was observed in the periphery but not the center, and wounds predominantly resolved by centripetally migrating limbal epithelia. After wound closure, the central corneal epithelium was completely replaced by K14+ limbal-derived clones, an observation supported by high-resolution fluorescence imaging of genetically marked cells in organ-cultured corneas and via computational modeling. These results solidify the essential role of K14+ limbal epithelial stem cells for wound healing and refute the notion that stem cells exist within the central cornea and that their progeny have the capacity to migrate centrifugally.

PURPOSE To explore the relationship between the degree of iris pigmentation and corneal sensitivity threshold (CST) on a variety of different ethnicities, using the air-jet noncontact corneal aesthesiometer and by applying a consistent method of subject iris pigmentation classification. METHODS A total of 200 subjects (mean age 23.7 ± 3.1 years, 127 women) participated in this clinical cross-sectional study: 100 whites, 40 Asians, 40 Chinese, and 20 Afro-Caribbeans. CST was assessed within the central cornea using a noncontact corneal aesthesiometer, and the degree of iris pigmentation of each subject was noted according to the Seddon method using a set of graded photographs of iris pigmentation (grades 1-5). Inclusion criteria were absence of ocular disease including dry eye, no contact lens wear, and no use of artificial tears. Statistical testing between ethnicities was made by the pairwise t test with Holm adjustment, and a linear model was set up to analyze the effects of ethnicity and iris grade. RESULTS A moderate trend for increasing CST with increasing iris pigmentation grade for all ethnicities was observed (R = 0.46; P < 0.0001), with CST changing from 0.66 ± 0.16 mbars for grade 1, 0.74 ± 0.18 mbars for grade 2, 0.86 ± 0.31 mbars for grade 3, 0.85 ± 0.32 mbars for grade 4, and 1.08 ± 0.40 mbars for grade 5. This correlation was stronger within the white group, representing the only ethnicity with all iris pigmentation grades (R = 0.50; P < 0.0001). CONCLUSIONS There is a moderate relationship between corneal sensitivity and the degree of iris pigmentation, with sensitivity increasing as iris pigmentation decreases. This relationship is stronger within whites.

Purpose: to evaluate subfoveal choroidal thickness (SFCT) and other anatomical parameters of the eye in the early stages after orthokeratological correction of myopia. Material and Methods. The study was conducted on 20 myopic Caucasian patients (40 eyes) with moderate myopia. The main group consisted of 10 children with myopia -4.5 ± 1.03 D aged 11 ± 2.26 years, who were examined before the correction with orthokeratological lenses (OK-lenses) ESA-DL (Dr Lens Tehno, Russia) and 3 weeks after it. The control group comprised 10 patients (20 eyes) with myopia -3.84 ± 1.12 D aged 11.6 ± 1.17 years, who wore monofocal glasses as a correction. SFCT was measured with RS-3000 Advance optical coherent tomograph (OCT) (Nidek, Japan), while axial length (AL), peripheral eye length (PEL), and anterior chamber depth (ACD) was measured with IOL Master 500 optical biometer (Carl Zeiss, Germany), and central cornea thickness (CCT), epithelial thickness (ET) and corneal stroma (ST) thickness, with OCT Avanti Rtvue XR (Optovue, USA). All patients were tested before and 3 weeks after the start of wearing lenses or glasses. Results. SFCF increased by 24.25 ± 19 μm as compared with changes in the control group (p < 0.001) after 3 weeks of wearing OK-lenses. A notable negative correlation of changes in AL and SFCT was revealed in the main group (r = -0.48). CCT decreased by 14.6 ± 2.54 μm in the group wearing OKlenses. The main OK-lens contribution to the statistically significant change in the CCT concerned the epithelium, whose thickness showed a 12.7 ± 1.58 μm (22.6 %) change as compared with the initial data (p < 0.001) and with the change in the control group (p < 0.001). The decrease in AL showed an insignificant correlation with the decrease in the CCT: r = 0.16. ACD, PEL and ST did not change significantly (p > 0.05). Conclusion. SFCT shows an increase in the early stages after OK correction. When controlling the growth of the eye in patients with OK lenses, we need to take into account the impact of the choroid on the results of AL measurement.

This case series examines the magnitude and regional variation in scleral lens-induced corneal edema in postradial keratotomy (RK) eyes. Scheimpflug imaging was used to measure corneal thickness across the central 6 mm before and after scleral lens wear in nine post-RK eyes (median age 64 years). Variations in corneal edema were examined as a function of distance from the corneal center (six 0.5-mm annuli) and from 0° to 360°. The median central corneal edema was 2.19% (interquartile range 1.03%-3.18%; P=0.02) and increased in magnitude and variability further from the central cornea (from 1.30% in the central 0-0.5 mm to 3.12% in the 2.5-3.0 mm midperiphery) (P=0.02). Scleral lens-induced corneal edema in post-RK eyes was greater in magnitude further from the corneal center and at the approximate location of corneal incisions.

Background: Presbyopia treatment in pseudophakic patients with a monofocal IOL is challenging. This study investigates the refractive results of femto-PresbyLASIK and analyzes presbyopia treatment in pseudophakic eyes. Methods: 14 patients with 28 pseudophakic eyes were treated with femto-PresbyLASIK. The dominant eye was targeted at a distance and the non-dominant eye at −0.5 D. The presbyopic algorithm creates a steepness in the cornea center by using an excimer laser that leads to corneal multifocality. Results: 6 months after surgery a refraction of −0.11 ± 0.13 D (p = 0.001), an uncorrected distance visual acuity of 0.05 ± 1.0 logMAR (p &lt, 0.001) and an uncorrected near visual acuity of 0.15 ± 0.89 logMAR (p = 0.001) were achieved in the dominant eye. For the non-dominant eye, the refraction was −0.28 ± 0.22 D (p = 0.002), the uncorrected distance of visual acuity was 0.1 ± 1.49 logMAR, and the uncorrected near visual acuity was 0.11 ± 0.80 logMAR (p &lt, 0.001). Spherical aberrations (Z400) were reduced by 0.21–0.3 µm in 32% of eyes, and by 0.31–0.4 µm in 26% of eyes. Conclusion: By steepening the central cornea while maintaining spherical aberrations within acceptable limits, PresbyLASIK created a corneal multifocality that safely improved near vision in both eyes. Thus, femto-PresbyLASIK can be used to treat presbyopia in pseudophakic eyes without performing intraocular surgery.

Purpose This prospective study assessed the influence of wearing and then discontinuing orthokeratology (OK) lenses on retinal shape and peripheral refraction in myopic children. Methods Fifty-eight myopic children (age 8–12 years) were equally divided into an OK group and a single vision spectacles (SVS) group. After 12 months of OK, it was discontinued for 1 month. Peripheral eye length (PEL), relative peripheral refraction (RPR), and corneal parameters were measured in the right eye on the nasal and temporal retinal sides at baseline, 6 months, and 12 months (13 months in OK group) visits. Results In the SVS group, faster elongation of the temporal side PEL made the eyes more asymmetric and prolate, developing a temporal pointed shape. In the OK group, the nasal retinal side PEL grew faster, the nasal RPR developed less hyperopic defocus, and the eye shape became more symmetric and less prolate. The central cornea became thinner and flattened, while the peripheral cornea became steeper. Changes in corneal thickness, relative peripheral corneal power, and K-values were no significant differences for the OK and SVS groups at 12 months. Conclusions The cornea reverted to be no difference with myopic children with SVS after 1 month discontinuation of OK. The retinal shape of SVS eyes became more asymmetric and prolate with myopia progression. OK remodelled retinal shape to be less asymmetric and less prolate.

Background The tortuosity of nerve fibers has been shown to be important for identifying and monitoring clinically relevant manifestations resulting from of a variety of ocular and systemic disease pathologies and disorders. However, quantifying tortuosity in dense neurite networks can prove challenging, as existing methods require manual scoring and/or complete segmentation of the neurite network. New method We measured neurite tortuosity by quantifying the degree of directional coherence in the Fourier transform of segmented neurite masks. This allowed for the analysis of neurite tortuosity without requiring complete segmentation of the neurite network. We were also able to adapt this method to measure tortuosity at different length and size scales. Results With this novel method, neurite tortuosity was accurately quantified in simulated data sets at multiple length scales and scale variant and scale invariant tortuosity was accurately distinguished. Use of this method on images of murine corneal neurites correctly distinguished known differences between neurite tortuosity in the peripheral and central cornea. Comparison with existing method(s) Other methods require complete segmentation of neurites, which can be prohibitive in dense and/or sparsely labeled neurite networks such as in the cornea. Additionally, other methods require manual curation, manual scoring, or generation of a curated training set, while our novel method directly measures tortuosity as an intrinsic property of the image. Conclusions We report the use of Fourier transforms for quantification of neurite tortuosity at multiple length scales, and with an image input that contains incompletely segmented neurites. This new method does not require manual training or curation, allowing a direct and rapid measurement of neurite tortuosity, thereby enhancing the accuracy and utility of neurite tortuosity measurements for evaluation of ocular and systemic disease pathology.

Purpose The success of Descemet stripping only (DSO) is optimized by performing a well-centered, accurately sized diameter of descemetorhexis with a smooth curvilinear border. To achieve this success, we describe a repeatable and relatively straightforward technique to optimize this descemetorhexis for DSO. Methods The "two-flaps" technique uses the Gorovoy DSO forceps. The technique takes advantage of the flat and smooth surface of the forceps to create the desired 4-mm Descemet stripping with minimal stromal trauma along with a continuous curvilinear descemetorhexis, minimizing the risk of postoperative stromal scarring and extension of the rhexis beyond 4 mm. Results This technique has been used successfully in 11 cases performed by 1 surgeon or directly supervised by him. All cases achieved the desired 4-mm circumference without any residual tags or visually significant stromal scarring, with successful clearing of the central cornea and endothelial cells repopulating the central stripped area. Conclusions This technique described provides a consistent, reproducible, and relatively trauma-free peeling of Descemet membrane and associated endothelial cells/guttae to optimize the success of DSO.

Purpose To report a new severity grading system for Fuchs endothelial corneal dystrophy (FECD) using anterior segment optical coherence tomography (AS-OCT). Methods This observational case series included 75 eyes of 43 patients with FECD and 33 eyes of 33 healthy subjects. Pachymetry and posterior elevation maps were used to determine the AS-OCT-based grading scores. FECD severity was graded from 0-3 as follows: 0, normal; 1, guttae only; 2, stromal oedema; and 3, epithelial and stromal oedema. We further investigated the central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior and posterior best-fit spheres (BFS), and the distance between the central cornea and the thinnest point. Results Thirty-three eyes were graded as 0, four as 1, thirteen as 2, fourteen as 3, twenty-nine as 4, eleven as 5 and four as 6 by the modified Krachmer grade. Thirty-three, 41, 30 and 4 eyes were graded as 0, 1, 2 and 3, respectively, by the AS-OCT-based grading system. The inter-observer agreement was 100% for the AS-OCT-based grading system. The CCT, TCT, posterior BFS, and distance between the central cornea and thinnest point were significantly different between AS-OCT-based grades (p = 0.0001, 0.0001, 0.0036 and 0.0001, respectively). Anterior BFS was not significantly different with the AS-OCT-based grades (p = 0.1184). Conclusion We devised a new severity grading using only objective evaluation and quantitatively demonstrated corneal thickening, predominant flattening of the posterior corneal surface compared with the anterior surface, and displacement of the thinnest point away from the central cornea with FECD progression.

Purpose To investigate corneal sublayer alterations during the postoperative period after small-incision lenticule extraction (SMILE). Setting Synslaser clinic, Oslo, Norway. Study design Retrospective. Methods Patients who underwent SMILE for treating myopia were included. The thicknesses of the corneal epithelium, cap, stromal part of the cap (StromaCap), residual stromal bed (StromaRes), and total stroma (StromaTot) were measured using spectral-domain optical coherence tomography at 1 day, 1 week, 1 month, 3 months, and 6 months postoperatively. Postoperative changes in the corneal sublayer thicknesses were analyzed and correlated with changes in spherical equivalence and anterior and posterior keratometry (K). Results The study was based on analyses of the right eyes of 51 patients. From 1 day to 6 months postoperatively, the corneal epithelium, cap, StromaCap, StromaRes, and StromaTot thicknesses increased from 54.4 ± 4.0 µm to 57.3 ± 5.2 µm; 137.1 ± 5.5 µm to 140.3 ± 5.1 µm; 82.7 ± 5.9 µm to 82.8 ± 6.3 µm; 375.0 ± 40.8 µm to 381.4 ± 30.6 µm; and 457.6 ± 41.1 µm to 462.1 ± 36.7 µm, respectively. Between 1 month and 6 months postoperatively, the increase in anterior K correlated significantly with the thickening of the cap (r = 0.37, P = .03) and the stromal component of the cap (r = 0.36, P = .04) within the central cornea. Conclusions The post-SMILE remodeling behavior between the anterior (StromaCap) and posterior (StromaRes) stroma were dissimilar. There was a significant correlation between changes in anterior K and the central cap and the stromal component of the cap. This might be because of biomechanical changes, tissue remodeling, and wound healing or a combination of some or all of the aforementioned processes.

Aim: To assess the central corneal thickness (CCT) and endothelial cell loss after manual small-incision cataract surgery and phacoemulsification in patients with white cataract. Material and methods: This is a comparative, prospective, non-randomized study on 42 patients with white cataract, who underwent cataract surgery. The patients were divided into manual small-incision cataract surgery (21 eyes, MSICS group) and phacoemulsification cataract surgery group (21 eyes, phaco group). The endothelial cell density (ECD), central cornea thickness (CCT), and corrected distance visual acuity (CDVA) were evaluated at 1 day, 1 week, 4 weeks, and 3 months postoperatively. The results of 20 cases of nuclear sclerosis grade II-III (LOCS III) who underwent phacoemulsification by the same surgeon were also compared. Propensity scoring was used to adjust for confounding by selection bias. Results: The CCT increased after surgery in both groups. The thickness was greater in the phaco group on first day postoperatively (73 µ increase in MSICS group and 138 µ in phaco group, p=0.008) and it returned to preoperative levels 1 month postoperatively. The endothelial cell loss was lower in the MSICS group at 3 months postoperatively (11.8% in MSICS group and 15.8% in phaco group, p=0.111). The CDVA was not different in both groups at 1 week and 4 weeks postoperatively (p>0.05). Conclusions: Manual small-incision cataract surgery for white cataract provided less central corneal thickness changes compared to conventional phacoemulsification. Abbreviations: CCT = central corneal thickness; ECD = endothelial cell density; CDVA = corrected distance visual acuity; APT = absolute phacoemulsification time; EPT = effective phacoemulsification time; MSICS = Manual small-incision cataract surgery in white cataract; Phaco II = Phacoemulsification in white cataract; Phaco I = phacoemulsification in NS 2 + Cataract; Phaco = Phacoemulsification in white cataract; APACRS = Asia-Pacific Association of Cataract and Refractive Surgeons.

Purpose. A combined comparative study of the impact of antiglaucomatous surgeries on the anatomical and optical parameters of the cornea.Materials and methods. The study involved 38 patients (38 eyes) aged 43 to 75 with primary open-angle glaucoma (POAG), which were divided into 2 groups. Patients of group I (15 eyes) underwent classical deep sclerectomy (DSE), while those of group II (23 eyes), had non-penetrating deep sclerectomy (NDSE). All patients underwent a comprehensive examination before and after surgery, including precision visometry, corneal topography, OCT pachymetry.Results. Group I revealed a significant change in the parameters on the 3rd day after the surgery; in particular, the average value of corneal astigmatism increased from -0.93 D to -3.62 D, the curvature radius of the cornea in the vertical meridian increased from 7.56 ± 0.07 mm to 8.34 ± 0.04 mm, the thickness of the central cornea changed from 514.5 ± 0.04 μm to 520.6 ± 0.06 μm. In group II, the corneal astigmatism increased from -0.86 D to -2.75 D, and the curvature radius of the cornea in the vertical meridian changed from 7.72 ± 0.05 mm to 8.12 ± 0.03 mm, the central thickness of the cornea increased from 515.4 ± 0.04 to 516.8 ± 0.12 μm.Conclusion. The degree of surgically induced changes of anatomic and optical parameters of the cornea in POAG patients depended on the amount of intervention: NDSE has a lesser effect on these parameters than classical DSE.

Purpose To evaluate the effect of a single rebubbling procedure after Descemet membrane endothelial keratoplasty (DMEK) on corneal backscatter and endothelial cell loss (ECL). Methods Medical records of 130 consecutive DMEK cases (118 patients) were reviewed and 3 groups were formed: group 1 (n = 32), consisting of DMEK cases followed by 1 rebubbling; group 2a (n = 55), including uneventful DMEK cases with complete graft attachment; and group 2b (n = 25), including uneventful DMEK cases with minor peripheral detachment, not requiring rebubbling. Scheimpflug corneal densitometry (CD) of the central (0-2 mm), paracentral (2-6 mm), and mid-peripheral (6-10 mm) zones, endothelial cell density, central corneal thickness, and corneal volume were measured preoperatively and at 3, 6, 12, and 24 months. Results Central CD in group 1 decreased from 32.3 ± 8.3 grayscale units preoperatively, to 21.2 ± 3.5 at 24 months. In group 2a, CD decreased from 37.0 ± 11.9 to 19.4 ± 3.0 and in group 2b from 32.5 ± 8.8 to 19.8 ± 3.1. No significant differences were observed among the 3 groups at any examination time point (P ≥ 0.12). At 3 months, paracentral CD of group 2a was significantly lower than that of group 1 (P = 0.047). Endothelial cell density at 3 months was higher in group 2a (1613 ± 503 cells/mm) than in group 1 (1350 ± 557 cells/mm; P = 0.033). ECL at 24 months was 56%, 43%, and 53% in groups 1, 2a, and 2b, respectively. Group 2a showed the lowest ECL, central corneal thickness, and corneal volume throughout the study period. Conclusions A single rebubbling procedure does not increase the CD of the central cornea and but results in significantly higher ECL compared with uneventful DMEK with complete graft attachment.

A 13-year-old Japanese female diagnosed with spondyloepiphyseal dysplasia congenita (SEDC) was referred for ophthalmologic evaluation. Examination with slit-lamp and optical coherence tomography revealed bilateral thin cornea with diffuse corneal opacity which was localised at the posterior stromal depth in the central cornea. Unlike the two previously reported cases of diffuse and nodular patterns of corneal opacity in SEDC, the current case exhibited a rare form of corneal opacity. SEDC is one of the type II collagenopathies, characterised by dwarfism because the mutations in COL2A1 prevent bone growth. Although the existence of type II collagen has not been reported in the human corneal stroma, the aetiology of the opacity in the corneal stroma in SEDC type II collagenopathy is of interest.

Humans depend on the coordinated activity of their lower extremities for mobility, an essential feature of Homo sapiens. In addition, they use vision to use this mobility to successfully navigate through their environment. During development, mobility appears to mature first, and then it is coordinated with navigation. Thus, the two, mobility and navigation are likely interdependent in function. Recent studies have indicated that compromising the integrity of the knee, a central element of the lower extremity motion segment, can lead to molecular alterations in both the cornea including the central cornea where light passes, as well as the interior of the eye (the vitreous humor). Not all insults to the knee lead to reproducible alterations in the eye, indicating some specificity in the response. In addition, it was recently reported that alterations to the cells in the vitreous humor occur following dietary induction of obesity in a rat model. As humans with obesity, as well as arthritis of the knee are at risk for ocular involvement and exhibit altered gait characteristics, the clinical and preclinical data raise the possibility of a “knee-eye-brain axis” to control or regulate mobility and navigation. Better delineation of such an axis could have implications for variations in control during maturation, and well as during aging when vision and mobility can be compromised, with increased risk for serious falls and failure to successfully navigate the environment.

Fifty-two guinea pigs ( Cavia porcellus ) with normal ophthalmic examinations were included in this study to determine whether there are differences in the intraocular pressure (IOP) according to age, while assessing the clinical usefulness of 2 different tonometry methods for this species. The animals were divided into 2 groups according to age: young (4 weeks old, 29 animals) and adult (3 to 36 months, 23 animals). Tonometry was performed oculus utro (OU) in the central cornea according to the manufacturer's recommendations. Only measurements with low standard deviation (SD 0.05) nor between sexes (p > 0.05). TonoVet readings were obtained faster than Tono-Pen VET readings (less than 1min vs 3.38 ± 1.27min, respectively [p

To compare changes in the shape and astigmatism of the total, anterior, and posterior cornea between eyes with long-length clear corneal incisions (CCIs) and eyes with short-length CCIs in cataract surgery.Hayashi Eye Hospital, Fukuoka, Japan.Prospective case series.Both eyes of patients having phacoemulsification with temporal CCIs were randomized to have a long-length (≥1.75 mm) or short-length (1.75 mm) CCI. Corneal astigmatic changes were decomposed to vertical/horizontal (Jackson cross-cylinder, axes at 180 degrees and 90 degrees [J0]) and oblique changes (Jackson cross-cylinder, axes at 45 degrees and 135 degrees [J45]) using power vector analysis. Corneal shape changes were assessed using the average of the difference map on videokeratography 2 days and 2, 4, and 8 weeks postoperatively.The mean J0 and J45 values of the total cornea in the 120 eyes evaluated were significantly greater in the long CCI group than in the short CCI group at all follow-ups (P ≤ .0290). The videokeratography showed a wedge-shaped flattening in the total and anterior cornea and a steepening in the posterior cornea around the CCI 2 days postoperatively in both groups. This wound-related flattening of the total and anterior cornea rapidly reduced but persisted until 8 weeks, whereas the steepening of the posterior cornea disappeared within 4 weeks. These changes extended closer to the central cornea in the long CCI group than in the short CCI group.Corneal astigmatic changes were significantly greater after long CCI than after short CCI. The wound-related shape changes occurred immediately postoperatively but rapidly diminished.

Factors governing the steady-state IOP have been extensively studied; however, the dynamic aspects of IOP are less understood. Clinical studies have suggested that intraocular pressure (IOP) fluctuation may be associated with glaucoma risk. This study aims to investigate how stiffening of corneoscleral biomechanical properties affects IOP spikes induced by rapid microvolumetric change. Porcine eyes (n = 25 in total) were subjected to volumetric infusions before and after external treatment of a circular area (11 mm diameter) in either the central cornea or posterior sclera. The treated area in the control group was immersed in phosphate-buffered saline (PBS) for 40 min, while the treated area of the chemical crosslinking group was immersed in 4% glutaraldehyde/PBS for 40 min. A subset of the sham-treated eyes was also subjected to volumetric infusions at a raised steady-state IOP. The magnitude of IOP spikes increased after localized chemical crosslinking of either the cornea (27.5% increase, p < 0.001) or the sclera (14.3% increase, p < 0.001) with corneal crosslinking having a stronger effect than scleral crosslinking (p = 0.018). We also observed that raising the steady-state IOP from 15 to 25 mmHg resulted in marked increase in IOP spike magnitudes by 63.9% (p < 0.001). These results suggested that an increased corneoscleral stiffness could significantly increase IOP spike magnitudes at the same volumetric change. Corneal stiffness appeared to have a strong impact on the IOP spike magnitude and may play a major role in regulating rapid volume-pressure dynamics. An increase in steady-state IOP also resulted in larger IOP fluctuations due to the increased “apparent” stiffness of the ocular shell, suggesting a potential interaction between the magnitude of IOP and its fluctuations. Corneoscleral properties may represent additional pathways for understanding and managing glaucoma risk and warrant future investigation.