Significant Corneal Research Articles

Importance of monitoring the ocular surface of patients with Kearns‐Sayre syndrome: a case report

AbstractPurposeKearns‐Sayre Syndrome (KSS) is a congenital mitochondrial myopathy initially described by the triad: Progressive external ophthalmoplegia, pigmentary retinopathy, heart block. Surgical procedures to alleviate ptosis can cause corneal injury from exposure. The lack of blinking can lead to a difficult contraction of the muscles responsible for squeezing the meibomian glands causing their dysfunction (MGD). Therefore, the follow‐up is of special interest in those cases where we suspect KSS due to the probable appearance of complications.MethodsWe present the case of a male of 9 years old who presented a sudden‐onset ptosis and bilateral internuclear ophthalmoplegia. Initially, he was diagnosed with Myasthenia. At the age of 12, resection of the elevator upper eyelid was performed in both eyes (BE). In the successive visits: negative Bell's sign, a progressive MGD and significant corneal thinning in the lower half of the BE were observed, and the right eye (RE) was affected with an infiltrated ulcer.ResultsTreatment with high hydration in BE and RE was treated with antibiotics eye drops and antibiotic ophthalmic ointment. After reviewing the history and given the high suspicion of KSS, genetic tests were requested to confirm it. Maintenance treatment was settled in BE with high hydration, 20% autologous serum and therapeutic contact lens. After a year of exhaustive monthly follow‐up, the patient remains stable and there is no progression of the corneal thinning.ConclusionsIt is important to take care of the ocular surface in these cases of KSS due to the corneal exposure after ptosis surgery. We must achieve stability in terms of symptoms and visual acuity without incurring other complications such as infections or perforation.

A case of double hypopyon secondary to Serratia keratitis after penetrating keratoplasty

We report a case of a 39-year-old male who underwent therapeutic penetrating keratoplasty in his left eye. Three weeks after the procedure, he presented with complaints of blurred vision, redness in the eye, and ocular pain after trauma by insect bite four days back. Slit-lamp examination revealed central epithelial defect with deep stromal infiltrate accompanied by a double hypopyon. Serratia sp. was isolated on cultures. Serratia marcescens was confirmed on the VITEK 2 system. Isolated organism was sensitive to imipenem. Fortified imipenem 1% eye drop was started on a half-hourly basis. At six weeks follow-up, resolving infiltrate with significant corneal scarring and vascularization was seen.

RNA sequencing uncovers alterations in corneal endothelial metabolism, pump and barrier functions of Slc4a11 KO mice

Slc4a11 KO mice show significant corneal edema, altered endothelial morphology, and mitochondrial ROS at an early age without a decrease in endothelial cell density. We examined the differential gene expression profile between wild type (WT) and KO with the goal of finding pathways related to corneal endothelial metabolic, pump and barrier function that can explain the corneal edema. Freshly dissected Corneal Endothelium-Descemet's Membrane (CEDM) and cultured Mouse Corneal Endothelial Cells (MCEC) were obtained from WT and Slc4a11 KO mice. RNA sequencing Ingenuity Pathway Analysis (IPA) predicted activation, inhibition or differential regulation of several pathways. QPCR and Western analysis validated downregulation of Glycolytic enzymes, Mitochondrial complex components and Ion transporters. Functional testing revealed decreases in endothelial lactate production, Extracellular Acidification Rate (ECAR), glutaminolysis, and Oxygen Consumption Rate (OCR) of KO CEDM in the presence of Glutamine (Gln) that was not compensated by fatty acid oxidation. Stromal lactate was significantly elevated in KO along with decreased expression of MCT1 and MCT4 lactate transporters in endothelial cells. ATP levels were 2x higher in KO CEDM, concomitant with a 3-fold decrease in Na-K-ATPase activity and reduced basolateral membrane localization. Genes for cholesterol biosynthesis, glutathione metabolism and tight and adherens junctions were elevated. Alteration of tight junction structure and cortical cytoskeleton is evident in KO corneal endothelium with a significant increase in trans-endothelial fluorescein permeability. We conclude that Slc4a11 KO induces a coordinated decrease in glycolysis, glutaminolysis, lactate transport and Na-K-ATPase activity. These changes together with an altered barrier function cause an accumulation of stromal lactate in Slc4a11 KO mice leading to chronic corneal edema.

Twelve-Month Outcomes of the Wavefront-Optimized Photorefractive Keratectomy for High Myopic Correction Compared with Low-to-Moderate Myopia.

PurposeTo evaluate the 12-months outcomes of photorefractive keratectomy (PRK) in patients with high myopia (≥ 6.0 diopters, D) compared with low-to-moderate myopia (< 6.0 D).Patients and MethodsRecords of 46 patients (69 eyes) who underwent PRK for myopic and astigmatic correction between October 2015 and December 2018 were reviewed. High myopic eyes (29 eyes) were compared with low-to-moderate myopic eyes (40 eyes). All surgeries were adjunct with 0.02% mitomycin C intraoperatively. Measured outcomes included postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, corneal haze rate, and any complications.ResultsAt 12 months post-PRK, 26 eyes (89.7%) in the high myopia and 39 eyes (97.5%) in the low-to-moderate myopia group had UDVA ≥ 20/20, (p=0.30). Average postoperative logMAR UDVA at 12 months was −0.04 (20/18) and −0.11 (20/15) for the high myopia and low-to-moderate myopia groups, respectively. No eyes in either group had residual refractive errors >1 D. No eyes in both groups developed significant corneal haze at month 12. No eyes had a loss of greater than two Snellen lines of CDVA at 12 months post-surgery. The efficacy and safety indices at 12 months post-surgery were not significantly different between groups (1.06±0.26 vs.1.14±0.27, p =0.25 and 1.14±0.27 vs 1.17±0.26, p=0.60 for low-to-moderate myopia vs high myopia groups, respectively).ConclusionPRK with high myopic correction provides excellent refractive outcomes and is safe, compared to those of low-to-moderate myopic correction.

In vivo biocompatibility evaluation of in situ-forming polyethylene glycol-collagen hydrogels in corneal defects

The available treatment options include corneal transplantation for significant corneal defects and opacity. However, shortage of donor corneas and safety issues in performing corneal transplantation are the main limitations. Accordingly, we adopted the injectable in situ-forming hydrogels of collagen type I crosslinked via multifunctional polyethylene glycol (PEG)-N-hydroxysuccinimide (NHS) for treatment and evaluated in vivo biocompatibility. The New Zealand White rabbits (N = 20) were randomly grouped into the keratectomy-only and keratectomy with PEG-collagen hydrogel-treated groups. Samples were processed for immunohistochemical evaluation. In both clinical and histologic observations, epithelial cells were able to migrate and form multilayers over the PEG-collagen hydrogels at the site of the corneal stromal defect. There was no evidence of inflammatory or immunological reactions or increased IOP for PEG-collagen hydrogel-treated corneas during the four weeks of observation. Immunohistochemistry revealed the presence of α-smooth muscle actin (α-SMA) in the superior corneal stroma of the keratectomy-only group (indicative of fibrotic healing), whereas low stromal α-SMA expression was detected in the keratectomy with PEG-collagen hydrogel-treated group. Taken together, we suggest that PEG-collagen may be used as a safe and effective alternative in treating corneal defect in clinical setting.

Small fiber neuropathy in the cornea of Covid-19 patients associated with the generation of ocular surface disease

PurposeTo describe the association between Sars-CoV-2 infection and small fiber neuropathy in the cornea identified by in vivo corneal confocal microscopy. MethodsTwenty-three patients who had overcome COVID-19 were recruited to this observational retrospective study. Forty-six uninfected volunteers were also recruited and studied as a control group. All subjects were examined under in vivo confocal microscopy to obtain images of corneal subbasal nerve fibers in order to study the presence of neuroma-like structures, axonal beadings and dendritic cells. The Ocular Surface Disease Index (OSDI) questionnaire and Schirmer tear test were used as indicators of Dry Eye Disease (DED) and ocular surface pathology. ResultsTwenty-one patients (91.31%) presented alterations of the corneal subbasal plexus and corneal tissue consistent with small fiber neuropathy. Images from healthy subjects did not indicate significant nerve fiber or corneal tissue damage. Eight patients reported increased sensations of ocular dryness after COVID-19 infection and had positive DED indicators. Beaded axons were found in 82.60% of cases, mainly in patients reporting ocular irritation symptoms. Neuroma-like images were found in 65.22% patients, more frequently in those with OSDI scores >13. Dendritic cells were found in 69.56% of patients and were more frequent in younger asymptomatic patients. The presence of morphological alterations in patients up to 10 months after recovering from Sars-CoV-2 infection points to the chronic nature of the neuropathy. ConclusionsSars-CoV-2 infection may be inducing small fiber neuropathy in the ocular surface, sharing symptomatology and morphological landmarks with DED and diabetic neuropathy.

Femtosecond laser-assisted anterior lamellar keratoplasty with suboptimal outcomes: a case series

ABSTRACT Objective To identify preoperative clinical characteristics of patients undergoing femtosecond laser-assisted anterior lamellar keratoplasty who failed to achieve optimal postoperative visual outcomes. Methods In this single-center, retrospective case series, patients who underwent femtosecond laser-assisted anterior lamellar keratoplasty between 2013 and 2018 were included if they required graft revision, subsequent corneal procedure, or additional postoperative visits for a femtosecond laser-assisted anterior lamellar keratoplasty-related issue. Visual outcomes assessed included best-corrected visual acuities and postoperative corneal astigmatism. Results Eight eyes of eight patients meeting the above criteria were included. Mean patient age was 64.5 years (range, 21 to 89 years). Mean included preoperative best-corrected visual acuities was one logarithm of the minimum angle of resolution (range, 0.3 logarithm of the minimum angle of resolution to counting fingers). Indications for femtosecond laser-assisted anterior lamellar keratoplasty included anterior stromal scarring due to viral keratitis (two cases), bacterial keratitis (one case), chronic epithelial defect (one case), Avellino dystrophy (one case), trauma (one case), and chronic endothelial failure (two cases). Six patients had history of prior intraocular surgeries including phacoemulsification (four cases), pars plana vitrectomy (one case), endothelial keratoplasty (two cases), and trabeculectomy (one case). Mean included best-corrected visual acuities at most recent follow-up was one logarithm of the minimum angle of resolution (range zero logarithm of the minimum angle of resolution to hand movements) representing improvement or stability in six of eight patients. Visually significant corneal astigmatism was present in four of eight patients. Post-femtosecond laser-assisted anterior lamellar keratoplasty procedures included graft repositioning, arcuate keratotomy, phacoemulsification, and regraft. Conclusion While femtosecond laser-assisted anterior lamellar keratoplasty offers a less-invasive treatment option compared to penetrating keratoplasty, intraoperative and postoperative management can be complex. Femtosecond laser-assisted anterior lamellar keratoplasty in patients with history of prior endothelial keratoplasty or ongoing ocular comorbidities should be pursued with caution.

Corneal confocal microscopy demonstrates axonal loss in different courses of multiple sclerosis

Axonal loss is the main determinant of disease progression in multiple sclerosis (MS). This study aimed to assess the utility of corneal confocal microscopy (CCM) in detecting corneal axonal loss in different courses of MS. The results were confirmed by two independent segmentation methods. 72 subjects (144 eyes) [(clinically isolated syndrome (n = 9); relapsing–remitting MS (n = 20); secondary-progressive MS (n = 22); and age-matched, healthy controls (n = 21)] underwent CCM and assessment of their disability status. Two independent algorithms (ACCMetrics; and Voxeleron deepNerve) were used to quantify corneal nerve fiber density (CNFD) (ACCMetrics only), corneal nerve fiber length (CNFL) and corneal nerve fractal dimension (CNFrD). Data are expressed as mean ± standard deviation with 95% confidence interval (CI). Compared to controls, patients with MS had significantly lower CNFD (34.76 ± 5.57 vs. 19.85 ± 6.75 fibers/mm2, 95% CI − 18.24 to − 11.59, P < .0001), CNFL [for ACCMetrics: 19.75 ± 2.39 vs. 12.40 ± 3.30 mm/mm2, 95% CI − 8.94 to − 5.77, P < .0001; for deepNerve: 21.98 ± 2.76 vs. 14.40 ± 4.17 mm/mm2, 95% CI − 9.55 to − 5.6, P < .0001] and CNFrD [for ACCMetrics: 1.52 ± 0.02 vs. 1.45 ± 0.04, 95% CI − 0.09 to − 0.05, P < .0001; for deepNerve: 1.29 ± 0.03 vs. 1.19 ± 0.07, 95% − 0.13 to − 0.07, P < .0001]. Corneal nerve parameters were comparably reduced in different courses of MS. There was excellent reproducibility between the algorithms. Significant corneal axonal loss is detected in different courses of MS including patients with clinically isolated syndrome.

Correlation between long-term use of rigid gas permeable contact lenses and endothelial morphometric changes in keratoconus patients

PurposeThis study was conducted to evaluate the effects of long-term use of rigid gas-permeable (RGP) contact lenses on corneal endothelium in keratoconus (KC) patients using non-contact specular microscopy. In addition, the correlation between wearing duration of RGP lenses (years & hours /d) and endothelial morphometric changes in KC patients was performed. This may provide more useful data for clinical application of RGP contact lens. Study designThis study was a prospective, observational, comparative, hospital based, nonrandomized, cross-sectional, and quantitative study. Subjects and methodsThe study included 40 eyes of non-wearer contact lens KC patients (group 1) and 38 KC eyes with a long history of Rose K2 RGP contact lens wearing (group 2). The corneal endothelial morphology such as endothelial cell density (ECD); coefficient of variation of cell area (CV); percentage of hexagonal cells (HEX); and central corneal thickness (CCT) were evaluated in all patients using SP3000P Specular Microscope. ResultsThe study included 40 eyes of non-wearer contact lens KC patients (20 mild KC eyes and 20 moderate KC eyes) and 38 KC eyes with a long history of RGP contact lens wearing (18 mild KC eyes and 20 moderate KC eyes). The mean duration of RGP lenses wearing was 5.67 ± 3.481 years & 12.11 ± 2.698 h/d in mild KC eyes and 7.15 ± 5.294 years &13.65 ± 2.889 h/d in moderate KC eyes. Wearing duration in hours in mild KC eyes showed a significant moderate negative correlation with ECD (r = −0.529, p = 0.024) and a moderate positive correlation with CV (r = 0.565, p = 0.015). In addition, wearing duration in years in moderate KC eyes showed a significant moderate negative correlation with ECD (r = −0.465, p = 0.039) and moderate positive correlation with CV (r = 0.627, p = 0.003). However, wearing duration in hours in moderate KC eyes showed a significant moderate negative correlation with HEX only (r = −0.490, p = 0.028). This study reported significant corneal thinning in contact lens wearer KC eyes in contrast to non-wearer KC eyes. ConclusionThis study documented a significant correlation between a long-term use of Rose K2 RGP using the three-point touch and corneal endothelial morphometric changes in KC patients. In addition, the current study confirmed a significant corneal thinning in RGP contact lens wearer compared to non-contact lens wearer KC patients. Further studies are recommended to evaluate the association between different RGP lens materials with different oxygen permeability transmissibility; different lens design types; different fitting methods; the duration of contact lens wear and the endothelial morphometric changes in KC patients.

Unilateral Traumatic Posterior Corneal Ectasia: Clinical Manifestations, Findings of Advanced Imaging, and Long-term Follow-up

PURPOSE: To describe a case of unilateral isolated traumatic posterior corneal ectasia characterized by advanced multi-modal diagnostic tests. METHODS: Case report and literature review. RESULTS: Following blunt trauma to the left eye, a 34-year-old woman presented with persistently blurry vision. Central corneal thickness was 300 µm, compared to 519 µm in the right eye. Scheimpflug tomography revealed significant corneal thinning in a defined inferotemporal region with corresponding elevation of the posterior corneal surface. Posterior corneal ectasia was confirmed with anterior segment optical coherence tomography. Wavefront aberrometry demonstrated increased higher order aberrations in the affected eye. Vision remained stable during 4.5 years of follow-up with a final visual acuity of 20/50 maintained with spectacle correction only. CONCLUSIONS: A unique case of unilateral post-traumatic posterior corneal ectasia was presented. The multi-modal imaging provided a detailed characterization of the structural characteristics of the cornea, guided management, and allowed for differentiation from other corneal pathologies at an early stage. [ Journal of Refractive Surgery Case Reports . 2021;1(2):e31–e35.]

Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus.

To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data. This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients (age 18-62y) with keratoconus diagnosis from two Spanish centers. Ferrara ring segment (AJL Ophthalmic) implantation was performed in all cases, using the mechanical procedure in 25 eyes (28.4%) and a femtosecond laser-assisted procedure in 63 eyes (71.6%). The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asphericity and astigmatism or the discrepancy among astigmatism and coma orientations. Visual, refractive, corneal topographic, aberrometric, and pachymetric changes after surgery were evaluated during a 3-month follow-up. The implants induced a significant refractive change as well as an improvement in uncorrected (UDVA) and corrected distance visual acuity (CDVA; P<0.001). Postoperative CDVA of 0.10 logMAR or better was achieved in 28.4% and 46.5% of eyes, respectively. Two eyes (2.3%) lost two or more lines of CDVA whereas a total of 53.5% of eyes gained lines of CDVA. A significant central anterior and posterior corneal flattening was induced (P≤0.003), with a significant reduction of anterior (P<0.001) and posterior corneal astigmatisms (P=0.048), and a change in anterior asphericity (P<0.001). Total primary coma (6 mm pupil) change was also statistically significant (preoperative 3.66±3.04 µm vs postoperative 2.33±2.26 µm, P<0.001). No significant differences were found in the effect of ring segments between cases implanted using the mechanical and femtosecond techniques (P≥0.101). The implantation of Ferrara rings based on the nomogram evaluated is safe and effective for promoting a visual rehabilitation in keratoconus, with a relevant control of primary coma aberration.

A mouse model of brittle cornea syndrome caused by mutation in Zfp469

ABSTRACTBrittle cornea syndrome (BCS) is a rare recessive condition characterised by extreme thinning of the cornea and sclera. BCS results from loss-of-function mutations in the poorly understood genes ZNF469 or PRDM5. In order to determine the function of ZNF469 and to elucidate pathogenic mechanisms, we used genome editing to recapitulate a human ZNF469 BCS mutation in the orthologous mouse gene Zfp469. Ophthalmic phenotyping showed that homozygous Zfp469 mutation causes significant central and peripheral corneal thinning arising from reduced stromal thickness. Expression of key components of the corneal stroma in primary keratocytes from Zfp469BCS/BCS mice is affected, including decreased Col1a1 and Col1a2 expression. This alters the collagen type I/collagen type V ratio and results in collagen fibrils with smaller diameter and increased fibril density in homozygous mutant corneas, correlating with decreased biomechanical strength in the cornea. Cell-derived matrices generated by primary keratocytes show reduced deposition of collagen type I, offering an in vitro model for stromal dysfunction. Work remains to determine whether modulating ZNF469 activity will have therapeutic benefit in BCS or in conditions such as keratoconus in which the cornea thins progressively. This article has an associated First Person interview with the first author of the paper.

Evaluation of Corneal Endothelial Changes and Corneal Tomographic Parameters in Eyes with Keratoconus

Purpose: To evaluate changes in corneal endothelium and its correlation with tomographic parameters in different stages of keratoconus (KC).Methods: This study was conducted on 95 eyes of 70 patients with KC attending to Mansoura ophthalmic center and 40 normal controls with matching age and sex in the period from April 2018 till May 2019. All individuals were subjected to full history and ocular examination. In addition Oculus pentacam was performed to diagnose KC, grades and assessment of Keratometry, thickness at the apex, thinnest corneal thickness and Anterior and Back elevation, while Specular microscopy was performed to assess the endothelial cell counting, Coefficient of variation (C/V) and Hexagonal cell ratio.Results: There were highly statistically significant differences among KC cases and the control group as regards endothelial count, C/V and hexagonal cell ratio. In addition such changes had a positive correlation with the degree of KC. Conclusion: There were significant corneal endothelial changes as well as Corneal Tomographic alterations among eyes with KC compared to normal ones and these changes have a positive correlation with the severity of KC. Specular microscopic examinations in patients with KC provide important data in addition to topography.

Factors influencing haze formation and corneal flattening, and the impact of haze on visual acuity after conventional collagen cross-linking: a 12-month retrospective study

BackgroundOur aim was to determine associations of pachymetry, keratometry, and their changes with haze formation and corneal flattening after collagen cross-linking, and to analyse the relationship between postoperative haze and visual outcome.MethodsRetrospective analysis was performed on 47 eyes of 47 patients with keratoconus using the Pentacam HR Scheimpflug camera before and 1, 3, 6 and 12 months after cross-linking. Corneal backscattered light values in grey scale unit were recorded in the anterior, center and posterior corneal layers and in four concentric rings. Surface area- and thickness-corrected grey scale unit values were assessed with an additional calculation. Friedman test with post hoc Wilcoxon signed-rank test was used to analyse changes in visual acuity, pachymetry, keratometry and densitometry. Spearman’s rank correlation test was used to detect correlations of haze formation and corneal flattening with pachymetry, keratometry and their postoperative change. Generalized estimating equations analysis was used to investigate the influence of densitometry values on postoperative visual acuity after controlling for the effect of preoperative keratometry.ResultsOne year after treatment, significant flattening was observed in maximum and mean keratometry readings (p < 0.001). Significantly increased densitometry values were observed in three central rings compared to baseline (post hoc p < 0.0125). According to receiver operating characteristic curve, densitometry value of the anterior layer of 0–2 mm ring was the most characteristic parameter of densitometry changes after cross-linking (area under the curve = 0.936). Changes in haze significantly correlated with preoperative maximum keratometry (R = 0.303, p = 0.038) and with the changes in maximum keratometry (R = -0.412, p = 0.004). Changes in maximum keratometry correlated with preoperative maximum keratometry (R = -0.302, p = 0.038). Postoperative haze had a significant impact on uncorrected and best corrected distance visual acuity (β coefficient = 0.006, p = 0.041 and β coefficient = 0.003, p = 0.039, respectively).ConclusionsOur findings indicate that in more advanced keratoconus more significant corneal flattening effect parallel with haze formation can be observed after cross-linking. Despite significant reduction of keratometry, postoperative corneal haze may limit final visual acuity.

The effects of trypan blue use on the corneal endothelium during cataract surgery in patients with pseudoexfoliation syndrome (PEX)

Purpose In the present clinical study, it was aimed to investigate the possible effects of Trypan blue (TB) use on the corneal endothelium during cataract surgery in eyes with pseudoexfoliation syndrome (PEX) during a three-month follow-up period using the contralateral eye control design. Methods This prospective, randomised controlled, individual cohort study included 92 eyes of 46 patients with bilateral PEX and cataracts. While 1% TB was applied to one eye of the patients before capsulorhexis (study group), it was not applied to the other eye (control group). Both groups were compared preoperatively and postoperatively in terms of endothelial cell density (ECD), endothelial cell loss (%), pleomorphism, polymegathism and central corneal thickness (CCT) using specular microscopy. Results Preoperative corneal ECD was measured as 2362.56 ± 253.27 in the study group, 2380.84 ± 220.54 in the control group, and 2145.58 ± 221.71 in the study group and 2184.97 ± 200.94 cells/mm2 in the control group in the postoperative 3rd-month follow-up (p = 0.71 and = 0.37, respectively). In addition, there were no significant differences between the two groups in terms of the percentage of hexagonal cells, coefficient of variation (CV), and CCT both preoperatively and postoperatively 3 months later (p = 0.78, =0.39, =0.95 preoperatively and p = 0.31, =0.26, =0.83 postoperatively, respectively). Conclusion This study demonstrated that the injection of 1% TB into the anterior chamber for staining the anterior capsule during cataract surgery did not cause significant corneal endothelial changes at postoperative 3rd months, despite the increased fragility of corneal endothelial cells in patients with PEX.

Long-term Results of Palpebral Fissure Transfer With No Lower Eyelid Spacer in Chronic Progressive External Ophthalmoplegia

To evaluate the long-term outcomes of the palpebral fissure transfer (PFT) technique without lower eyelid spacer in patients with chronic progressive external ophthalmoplegia (CPEO). Retrospective interventional case series. Consecutive patients with CPEO with PFT surgery (2006-2017) and a minimum follow-up of 24 months were included. The PFT included simultaneous levator resection or frontalis sling (based on the levator function and Bell's phenomenon) and lower eyelid retractor recession without spacer. Primary outcome measures included the change in margin reflex distance 1 (MRD-1), MRD-2, and palpebral fissure height (PFH) in the course of time. Potential predictors of keratopathy were also explored. There were 32 patients (64 eyelids) with the mean age and follow-up of 34.1 years (range 15-56 years) and 37.9 months (range 24-72 months), respectively. Mean MRD-1 significantly increased from -0.9 mm to 3.4 mm in postoperative weeks 1 and 2 and 1.8 mm at the last follow-up. Mean MRD-2 significantly decreased from 5.6 mm to 3.7 mm in postoperative weeks 1 and 2 and 5 mm at the last follow-up. Eyes with frank lower eyelid retraction (MRD-2 >5 mm) gained more reduction in MRD-2 compared with those with no sclera show (-0.9 mm vs -0.3 mm, P< .001). Reoperation was performed in 9 eyelids for under- (n=5) and overcorrection (n=4). Persistent keratopathy was observed in 3 eyes (4.5%). Lower eyelid retractor recession without spacer yields significant protective corneal coverage at the critical early postoperative period when the risk of keratopathy is highest.

Outcomes of toric IOL implantation guided by iris-registered femtosecond laser capsulotomy markings

To assess the accuracy and stability of iris-registered femtosecond laser-assisted anterior capsule axis markings (compensating cyclotorsion) along with refractive and visual outcomes after toric IOL implantation. This prospective case series included eyes with visually significant cataracts and regular corneal astigmatism ranging from 1.25D to 4.0D, which received FLACS and toric IOL implantation, at The Eye Institute of West Florida, Largo, Florida, USA. Preoperative iris registration was used in conjunction with a femtosecond laser platform to create cyclotorsion corrected axis marks at the capsulotomy edge to facilitate toric IOL axial alignment. Patients were examined one, seven and thirty days after surgery to assess capsulotomy marks axis, toric IOL axis along with visual and refractive outcomes. Eighteen eyes of 13 patients aged 74.35 ± 8.65years were included. Mean pre-op CDVA was 0.24 ± 0.16 LogMAR, while mean post-op UDVA was 0.09 ± 0.09 LogMAR. Mean pre-op corneal astigmatism was 1.85 ± 0.41 D, decreasing to 0.24 ± 0.41 D of refractive astigmatism postoperatively (p < 0.001). The capsular toric axis markings were visible in 100% of eyes throughout the follow-up; the mean difference between intended capsulotomy mark axis and measured capsulotomy mark axis was 1.6°, 1.7° and 1.3 o at the 1, 7 and 30 day intervals (p > 0.05), respectively. No capsule-related or any other type of complications was noted. Iris-registered femtosecond laser-assisted anterior capsule axis markings are safe and may be considered as an alternative option to the known axis marking techniques for toric IOL axial alignment at the time of cataract surgery.

Comparison of long-term surgical outcomes for scleral-fixated versus retropupillary iris-claw intraocular lens.

To compare the clinical features and long-term treatment outcomes of patients undergoing secondary intraocular lens (IOL) surgery with scleral-fixated (SFIOL) versus retropupillary iris-claw IOL (RPICIOL). Consecutive patients treated between June 2014 and December 2019 at two tertiary centres were retrospectively reviewed. The primary outcome was the best-corrected visual acuity (BCVA). Secondary outcomes included factors associated with significant corneal endothelial injury and postoperative redislocation. This study included 395 eyes undergoing surgery with SFIOL (237 eyes, 60%) or RPICIOL (158 eyes, 40%), with no differences in baseline BCVA (p=0.76) or endothelial cell density (ECD) (p=0.39). Compared with the SFIOL group, the RPICIOL group had faster visual recovery (postoperative month 1, 20/37 vs. 20/46, p=0.005) sustained to over 36 months (p=0.034), favourable absolute prediction errors (within 0.5D, 67.3% vs. 54.9%, p=0.027), and shorter operation times (52.7 vs. 60.9 min, p=0.015). There was no difference in ECD after 12 months (P=0.282). Over a mean follow-up duration of 33 months (152 cases >3 years, 38.5%), the SFIOL group experienced more cases of tilted/decentred IOLs (14 vs. 1, p=0.006), suture exposure (7 vs. 0, p=0.045), and redislocation (17.7% vs. 10.1%, p < 0.001). Multivariable regression showed that a final BCVA below 20/40 was associated with SFIOL (P=0.007), older age (p=0.001), intraoperative complications (p=0.002), past history of vitrectomy/glaucoma surgery or uveitis (p=0.046), and surgically induced astigmatism >1D (p=0.029). RPICIOL appears to be a safe and effective surgical option for secondary IOL surgery over a long-term follow-up, comparing favourably against conventional SFIOL.

Inducible Slc4a11 Knockout Triggers Corneal Edema Through Perturbation of Corneal Endothelial Pump.

PurposeThe conventional Slc4a11 knockout (KO) shows significant corneal edema at eye opening, a fact that complicates the study of the initial events leading to edema. An inducible KO would provide opportunities to examine early events following loss of Slc4a11 activity.Methods Slc4a11 Flox (SF) mice were crossed with mice expressing the estrogen receptor Cre Recombinase fusion protein and fed tamoxifen (Tm) for two weeks. Corneal thickness (CT) was measured by OCT. At eight weeks endpoint, oxidative damage, tight junction integrity, stromal lactate concentration, endothelial permeability, differentially expressed transporters, and junction proteins were determined. Separately, a keratocyte only inducible Slc4a11 KO was also examined.ResultsAt four weeks post-Tm induction Slc4a11 transcript levels were 2% of control. Corneal thickness increased gradually and was 50% greater than Wild Type (WT) after eight weeks with significantly altered endothelial morphology, increased nitrotyrosine staining, significantly higher stromal lactate, decreased expression of lactate transporters and Na-K ATPase activity, higher ATP, altered expression of tight and adherens junctions, and increased fluorescein permeability. No significant differences in CT were found between WT and keratocyte only Slc4a11 KO.ConclusionsThe Slc4a11 inducible KO shows development of a similar phenotype as the conventional KO, thereby validating the model and providing a tool for further use in examining the sequence of cellular events by use of noninvasive in vivo physiological probes.

Corneal Thickness and Anterior Chamber Flare After Cataract Surgery: A Randomized Controlled Trial Comparing Five Regimens for Anti-Inflammatory Prophylaxis.

PurposeTo investigate the relationship between early post-operative anterior chamber inflammation (aqueous flare) and central corneal thickness (CCT) after cataract surgery and to evaluate the effect of anti-inflammatory prophylaxis on CCT.SettingDepartment of Ophthalmology, Rigshospitalet-Glostrup, University Hospital Copenhagen, Denmark.DesignPost-hoc analysis of a prospective randomized controlled trial.Patients and MethodsA total of 470 participants who underwent standard cataract surgery were randomly allocated to prophylactic treatment with nonsteroidal anti-inflammatory drug (NSAID, groups C and D) or a combination of NSAID and steroid eye drops (groups A and B), commenced either pre-operatively (A and C) or post-operatively on the day of surgery (B and D), or “drop-less surgery” (peri-operative subtenon depot of dexamethasone, group E). Aqueous flare was measured before and three days after surgery. CCT was measured before surgery, three days, three weeks, and three months after surgery. Data were analyzed according to the intention-to-treat method.ResultsDoubling of aqueous flare increased mean CCT by 15.6 microns (95% CI 9.8; 21.3, P<0.001) three days after surgery. Mean CCT increased from 549 microns (95% CI 545; 552) at baseline to 594 microns (95% CI 585; 602) three days after surgery and returned to 551 microns (95% CI 545; 557) three months after surgery. Mean CCT was thinner in group C compared to group A three days after surgery. No difference was found for any other groups or time points.ConclusionIncreased anterior chamber inflammation was associated with significant corneal thickening three days after cataract surgery. Choice of anti-inflammatory regimen seemed to be of no or minimal importance on CCT when the effect of inflammation was accounted for. Corneal thickening is possibly mediated by underlying deterioration of the blood-aqueous barrier and corneal endothelium pump function caused by a post-operative inflammatory response.