Reduction In Central Corneal Thickness Research Articles

EndoArt®: results in patients with glaucoma drainage devices

EndoArt® (Eye Yon Medical, Ness Ziona, Israel) is anovel artificial corneal inner layer transplant and an innovative treatment alternative for patients at high risk for graft failure after posterior lamellar corneal transplantation (EK). We present the initial results of the EndoArt® implantation in patients with glaucoma drainage devices (GDD). In this study 12eyes with GDD were retrospectively evaluated. All had ahigh risk of transplant rejection in cases of EK (previous other glaucoma surgery in addition to GDD, n = 8, condition following Descemet membrane endothelial keratoplasty, DMEK, n = 9, uveitis, n = 2, or synechiae, n = 2). The EndoArt® was secured with agas bubble and one to three holding sutures. The preoperative and postoperative best spectacle-corrected visual acuity (BSCVA) and central corneal thickness (CCT) were determined. The need for additional gas injections (rebubbling) was analyzed. Octafluoropropane (C3F8) 12% was used in nine patients and sulfur hexafluoride (SF6) 20% in three patients as anterior chamber tamponade to ensure adhesion of the EndoArt®. At least one rebubbling was necessary in four eyes. The preoperative BSCVA was 1.6 (± 0.5) logMAR and significantly improved to 1.1 (± 0.6) logMAR after 12weeks (p = 0.028). The preoperative CCT was 719 µm ± 145.7, which significantly decreased to 622.4 µm ± 174.9 after six weeks (p = 0.004) and to 591.7 µm ± 190.8 after 12weeks (p = 0.096). In one eye, the prosthesis was explanted due to a suspected fibrotic remodelling of the cornea following multiple previous DMEKs. EndoArt® led to asignificant improvement in BSCVA and reduction in CCT; however, there was ahigh rebubbling rate in patients with GDD. In high-risk patients, the use of EndoArt® may be advantageous in avoiding graft failure after EK.

Clinical, Anatomical, and Densitometric Changes following Dresden vs. Accelerated Corneal Cross-Linking in Progressive Keratoconus.

To compare clinical, anatomical, and densitometric changes following Dresden (DCXL) vs. accelerated (ACXL) corneal UVA cross-linking (CXL; Avedro KXL, Geuder, Heidelberg, Germany) in progressive keratoconus (KC). In this retrospective study, we analyzed 20 patients following DCXL (3 mW/cm², 30 min, 5.4 J/cm²) and 44 patients following ACXL (9 mW/cm², 10 min, 5.4 J/cm²) between January 2016 and February 2020. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), central corneal thickness (CCT), steepest keratometry (Kmax), keratoconus index (KI), thinnest pachymetry (Pthin), and corneal densitometry (CD) were measured before and 3, 6, 12, and 24 months after CXL. During the follow-up period, no changes in UCVA, BSCVA, Kmax, KI, or Pthin occurred. CCT significantly decreased 3 months after DCXL (p = 0.032) and ACXL (p = 0.006). At the 12- and 24-month follow-up, CCT remained decreased in the DCXL (p = 0.035, 0.036, respectively) but not in the ACXL group. At the 12-month follow-up, the reduction in CCT was significantly greater in DCXL compared to ACXL (p = 0.012). At the 3-, 6-, 12-, and 24-month follow-ups, we found a significant increase in the anterior stroma CD following DCXL (p = 0.019, 0.026, 0.049, 0.047, respectively) but not ACXL. The CD changes were localized in the central concentric zones (0.0 to 6.0 mm). No intra- or postoperative complications occurred. ACXL and DCXL effectively halted KC progression. ACXL proved to be a safe time-saving alternative to conventional DCXL. DCXL led to a reduction in CCT and an increment in the CD of the central anterior stroma during 24 months of follow-up.

Predictability of the Achieved Lenticule Thickness in Keratorefractive Lenticule Extraction for Myopia Correction

Purpose: To assess the predictability between the SCHWIND ATOS femtosecond laser (SCHWIND eye-tech-solutions) read-out and achieved lenticule thickness measured using MS-39 anterior segment optical coherence tomography (ASOCT; CSO) at the corneal vertex at postoperative 1 day and 1 and 3 months of follow-up. Methods: This retrospective case series included 130 eyes of 65 consecutive patients who were treated with SmartSight (SCHWIND eye-tech-solutions) lenticule extraction. Sixty-four percent of patients were women with a mean spherical refraction of −4.98 ± 1.19 diopters (D) and mean astigmatism of 0.53 ± 0.64 D. The measurements were performed using AS-OCT with the Phoenix Software v 4.1.1.5. Lenticule thickness was obtained by the subtraction method between preoperative and postoperative total corneal thickness. Results: A lower reduction in central corneal thickness (CCT) compared to the laser read-out for all three follow-up visits can be observed. Essentially, the reduction in CCT was identical at 3 months versus 1 month. The reduction in CCT was lowest at postoperative 1 day. Examining the 1- and 3-month data (essentially equivalent), one can see a best fit of y = 0.94 x −7 µm. Conclusions: The reduction in CCT was stable from 1 month of follow-up. The stable reduction in CCT was −6% (−1.5% after accounting for design decisions) and −7 µm lower than the respective laser read-out. The findings are predictable, showing a certain level of the lenticules becoming slightly thinner than their respective laser read-outs. [ J Refract Surg . 2023;39(11):728–735.]

A comparative study of divide and conquer, stop and chop and direct chop techniques of nucleotomy in topical phacoemulsification: an interventional study

Based on population research, it has been found that more than 74% of elderly individuals in India have either undergone cataract surgery or have cataracts, and women are more likely than males to acquire cataracts. A cataract is one of the primary causes of blindness in India and around the world, but it's also the leading cause of avoidable blindness. There have been many advances in cataract surgery including advancements in surgical techniques and the availability of various intra-ocular lenses for better visual rehabilitation of the patient. Phacoemulsification is now one of the most commonly used surgical techniques for cataract extraction, it is done under local anesthesia or under topical anesthesia. As with all cataract surgeries, there is corneal decompensation even with phacoemulsification. Our study aims to compare three different nucleotomy approaches used for topical phacoemulsification: Divide & Conquer, Stop & Chop, and Direct Chop. We will assess which technique yields the best visual prognosis postoperatively, causes less corneal decompensation and has fewer complications. Specular microscopy will be used in patients who are to be operated for cataract extraction. Before the operation, we can use specular microscopy to determine the number of Corneal Endothelial cells and Central Corneal Thickness of the patient. Then, after the surgery, we can conduct another specular microscopy test to compare the techniques used for nucleotomy. This will help us determine which technique results in less loss of corneal endothelial cells and less reduction in central corneal thickness. Thus, we will use specular microscopy as a diagnostic tool and also a prognostic indicator in our study. Visual acuity of the patient will be measured preoperatively and again post operatively to compare which surgical technique achieves best visual rehabilitation for the patient.

Comparison of central corneal thickness treated with small incision lenticule extraction, femtosecond laser-assisted in situ keratomileusis, or laser-assisted subepithelial keratomileusis for myopia.

To compare the central corneal thickness (CCT) treated with small incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), or laser-assisted subepithelial keratomileusis (LASEK) for myopia correction. This was a retrospective case series study. Patients who had completed 1-year follow-up after receiving SMILE, FS-LASIK, or LASEK at our hospital from January 2019 to July 2021 were included. Pentacam pachymetry was performed to measure the CCT. The predicted CCT reduction was obtained through laser platform. The measured CCT reduction was defined as the difference between the preoperative and postoperative CCT using Pentacam pachymetry. There were 100 eyes treated by SMILE, 100 eyes by FS-LASIK, and 100 eyes by LASEK. There was a significant difference in predicted CCT reduction among the three surgeries (P < 0.001), but no significant difference in measured CCT reduction postoperatively (PGroup = 0.373). At 1year postoperatively, the CCT reduction was overestimated by 17.85 ± 5.36µm in the SMILE group, underestimated by 4.31 ± 7.08µm in the FS-LASIK group, and underestimated by 7.60 ± 8.28µm in the LASEK group (PGroup < 0.001, PTime < 0.001). In the FS-LASIK group, the difference between predicted and measured CCT reduction was not related to the predicted CCT reduction (P = 0.095). The laser platform may overestimate the CCT reduction for SMILE and underestimate it for FS-LASIK and LASEK. FS-LASIK has a much higher level of accuracy in CCT reduction, which is not influenced by refractive correction.

Assessment of corneal sublayer thickness changes in glaucoma patients using optical coherence tomography and correlation of epithelial layer thinning with dry eye monitoring

In this study, we aimed to assess the central corneal epithelial thickness (CET), central corneal stromal thickness (CST), and total central corneal thickness (CCT) thinning relationships with dry eye development monitoring and underestimated measurement of intraocular pressure (IOP) in primary open-angle glaucoma (POAG) patients treated with timolol, dorzolamide, and brimonidine. This longitudinal cohort study included 106 patients with POAG. All patients underwent a detailed ophthalmic examination. In addition, CET, CST, and CCT were measured using anterior segment optical coherence tomography (AS-OCT). Subsequently, the cohort was divided into three groups based on the therapy administered. The Tomec group received monotherapy with benzalkonium chloride (BAK)-preserved timolol+dorzolamide fixed combination. The Alphagan group received monotherapy with purite-preserved brimonidine, and the Combigan group received monotherapy with BAK-preserved timolol+brimonidine fixed combination. CET, CST, and CCT did not show a statistically significant decrease in the Alphagan group (p>0.05). However, the Tomec and Combigan groups showed significantly reduced measurements, except for stromal thickness (p<0.05). Finally, a significant positive correlation was found between changes in tear break-up time (TBUT) and CET during the follow-up period (r=0.637, p=0.001). CET and CCT thinning were higher in the Tomec and Combigan groups than in the Alphagan group. Furthermore, although CCT reduction was significant in the Tomec and Combigan groups, its effect on IOP underestimation was approximately 1%. Furthermore, the positive correlation between CET and TBUT suggests that CET measurement with AS-OCT may also be useful in dry eye monitoring.

Effects of topical prostaglandin therapy on corneal layers thickness in primary open-angle glaucoma patients using anterior segment optical coherence tomography.

To evaluate the effects of latanoprost, bimatoprost, and travoprost eye drops and their preservatives on each corneal layer thickness in patients with primary open-angle glaucoma (POAG). We retrospectively analyzed 79 eyes of 79 patients with POAG who were receiving prostaglandin therapy. Patients were divided into three subgroups according to monotherapy with latanoprost, bimatoprost, and travoprost during a mean of 43.14 ± 19.12months follow-up period. In addition, the central corneal epithelial thickness (CET), central corneal stromal thickness (CST), and total central corneal thickness (CCT) were measured by anterior segment optical coherence tomography (AS-OCT) at baseline and every six months after treatment initiation at each visit between 9 and 12 o'clock in the morning. Furthermore, intraocular pressure (IOP) was measured with Goldmann applanation tonometry (GAT) after AS-OCT measurements at each visit. All three groups were not significantly different in age, gender, follow-up period, and mean intraocular pressure values (p > 0.05 for all). The reduction of CCT in the latanoprost, bimatoprost, and travoprost groups was 6.53 ± 3.17, 18.59 ± 8.42, and 10.1 ± 1.13µm, respectively. The decrease in CST values was 4.65 ± 1.54, 15.84 ± 7.47, 9.69 ± 1.45µm, and CET values were 1.88 ± 1.66, 2.75 ± 0.73, 0.41 ± 0.54µm in all groups, respectively. A statistically significant thinning was observed in all corneal layers (p < 0.05) except the CST values in the latanoprost group and CET values in the travoprost group. However, no significant difference was found in the average reduction of CET, CST, and CCT values among the three groups (p > 0.05). Topical treatment with latanoprost, bimatoprost, and travoprost affects each layer of the cornea separately according to the active and protective substances contained in these eye drops. On the other hand, the thinning effect on the corneal layers was similar in these three drugs because there was no significant difference between the three groups in the total amount of thinning of the corneal layers during the follow-up period.

Effect of Topical Prostaglandin Analogue Therapy on Central Corneal Thickness: A Systematic Review.

To investigate whether prostaglandin analogue (PGA) eyedrops have a significant effect on central corneal thickness (CCT), we conducted a systematic search of literature published from 2000 to 2021. Among the studies conducted on topical PGA therapy in open-angle glaucoma or ocular hypertension patients over 18 years old, prospective studies with CCT change as an outcome were included. A single-arm meta-analysis was conducted to assess the overall effect on CCT, and subgroup analysis according to exposure time of PGA eyedrops was also performed. We counted the number of articles that reported on severe events (CCT reduction of 25 μm or more) and obtained their proportion. The methodological quality was assessed by the McHarm tool. Twenty-two reports of prospective studies were selected. The results of the single-arm meta-analysis showed very high heterogeneity. Still, in subgroup analysis, when PGA was used for more than 6 months, heterogeneity was low, and a significant decrease in CCT was observed. Severe events were reported in two reports and occurred in 3.8% to 14.8% of participants. PGA eyedrop use may cause a clinically significant CCT decrease, requiring CCT follow-up.

Comparison of Predictability in Central Corneal Thickness Reduction After SMILE and FS-LASIK for High Myopia Correction.

To compare central corneal thickness (CCT) reduction after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) in eyes with high myopia. In this prospective, consecutive study, 70 eyes with high myopia undergoing SMILE (n = 35) or FS-LASIK (n = 35) were recruited. Corneal topography images were acquired using the Pentacam HR imaging system preoperatively and at 1day, 1month, and 6months postoperatively. Predicted CCT reduction was extracted directly from the VisuMax femtosecond laser system or MEL80 excimer laser platform. The achieved CCT reduction was determined using corneal thickness difference maps from the Pentacam. Comparative statistics and linear regression analyses were performed to evaluate the predictability in stromal thickness reduction. The mean predicted CCT reductions were 152.9 ± 6.7μm and 150.9 ± 7.3μm in the FS-LASIK and SMILE groups, respectively, with no statistical difference. For each follow-up time, no significant difference was noted in the two groups in the achieved CCT reduction. At 6-month follow-up, the CCT reductions were overestimated to be 23.06 ± 6.97µm and 28.29 ± 13.92µm in the SMILE and FS-LASIK groups, respectively (P = 0.003), showing statistical difference. Regression analysis revealed that the positive correlation between achieved and predicted CCT reductions was stronger in SMILE (R2 = 0.5065, P < 0.001) than in FS-LASIK (R2 = 0.2237, P = 0.004). Overestimated CCT reduction was not correlated with predicted CCT reduction in either group. Systematically overestimated CCT reduction is found after SMILE and FS-LASIK in high myopia correction. Deviations between planned and achieved CCT reductions are more pronounced in FS-LASIK than in SMILE.

Efficacy of hypertonic saline in treatment of corneal edema: A randomized crossover trial

BackgroundTo determine the efficacy of sodium chloride (NaCl) 5% drops in comparison to 6% ointment and study tear Osmolarity as an objective measure correlating with clinical findings in the treatment of corneal edema. MethodsThis is a prospective, randomized, interventional, open-label, crossover study of 40 eyes of 40 patients with corneal edema due to Bullous keratopathy and Fuchs endothelial dystrophy. Subjects were divided into 2 groups by simple randomization: group A received NaCl 5% drops and group B received NaCl 6% ointment. Both treatments were administered four times daily for seven days. Subsequently, after a 1-week wash-out period, switch over of treatment was done. Central corneal thickness (CCT) and tear osmolarity were primarily efficacy variables. ResultsBaseline parameters were comparable. The median reduction in CCT from baseline (706.7 ± 58.41 μm), at 6 hours with NaCl 5% drops was 23 μm (-27, 74) and that with NaCl6% ointment was 37.5 μm (-7, 85). The reduction in CCT was more with 6% ointment (p = 0.013). The difference in reduction in CCT between two treatments at one week was not statistically significant, although there was a substantial reduction in thickness with each treatment individually. The change in tear osmolarity from the baseline at 2 Hours with both NaCl5% drops and 6% ointment was significant, and it remained so till 6 h. Side-effects such as stickiness, stinginess, blurring, and foreign body sensation were more with 6% eye ointment. ConclusionTopical NaCl 6% eye ointment in QID dosage is more effective than NaCl 5% drops in the medical management of corneal edema. In patients symptomatically intolerant to ointment, NaCl 5% eye drops may be prescribed as an effective option.

Evaluation of central corneal thickness in patients with dry eye disease in a tertiary eye hospital in Kancheepuram

Background: Dry eye disorder is a disease mainly due to the tear insufficiency which results in eye discomfort and disturbances in vision. Dry eye also affects the ocular dimensions, especially corneal thickness. Central corneal thickness (CCT) assessment plays an important role in refractive surgeries and in the pre-operative assessment of other ocular surgeries. Aims and Objectives: This study aims to assess the effect of dry eye disease (DED) on CCT with age- and gender-matched controls. Materials and Methods: One hundred and four subjects (52 cases and 52 controls) who attended SRM Medical College and Hospital ophthalmology outpatient department were included in the study. DED was diagnosed with DEQS questionnaire, slit-lamp examination, TFBUT, and Schirmer’s test. Pachymetry was used for measuring the CCT of all subjects. Student “t”-test was used to determine the significance of difference between two means. P&lt;0.05 was considered statistically significant. Results: In our study, there were 60 female patients and 44 male patients. The ratio of male-to-female was 1:1.3. The CCT among cases was very low (533.19 μm±30.05) compared to controls (569.27 μm±45.56) and this difference was statistically significant (P&lt;0.05). When subgrouped under gender, the difference in CCT among males between the two groups was statistically significant and it was highly significant among females. When the reduction in CCT among the cases was studied under different age groups, the subjects in the 41–60 years age group had a statistically highly significant difference in CCT between the two groups while it was also significant in other age groups. Conclusion: There is a significant decrease in CCT due to DED. Pachymetry for central corneal estimation shall be included in the routine management of dry eye patients so that corneal thinning could be identified earlier and treated with artificial tears or other substitutes.

Management of Late Descemet's Membrane Detachment After Penetrating Keratoplasty in Keratoconus.

The purpose of this study was to describe the feasibility of Descemet membrane endothelial keratoplasty (DMEK) as a treatment modality for spontaneous detachment of DM (DMD) decades after penetrating keratoplasty (PK) for keratoconus. We describe the clinical characteristics and therapeutic surgical approach in 6 eyes of 5 patients with DMD. Clinical images, anterior segment optical coherence tomography scans, and histological findings are presented. Mean age of patients at time of diagnosis was 60 years (range 56-66 years). Mean interval between PK and occurrence of DM detachment was 36 years (range 29-45 years). In 4 of 6 eyes, air injections into the anterior chamber were initially attempted to reattach DM to the stroma but without long-lasting effect. Two eyes underwent repeat PK because of pronounced ectasia after long-standing DMD and stromal scars. DMEK was performed successfully in 4 eyes leading to an increase in visual acuity and a reduction in central corneal thickness. Electron microscopy showed abnormal vacuolar inclusions and collagenous material in the posterior nonbanded layer and a separation of the anterior banded layer from the posterior nonbanded layer. This case series provides evidence that DMEK is a viable option in eyes with spontaneous DM detachment after PK. Visual outcome is limited by the persisting high astigmatism in the ectatic cornea. Illustrated by a small series of patients, the results of DMEK in this condition are presented and new findings about the pathophysiology are given.

English

BACKGROUND Dry eye disease is one of the most common presentation in hospital with varied presenting complaints and which can lead to various complications. Study is done on 200 eyes diagnosed with dry eyes in a tertiary centre in South India using Schirmer; and tear break up time test. Their central corneal thickness is measured using specular microscopy. The correlation of dry eye disease and central corneal thickness is assessed. Dry eye disease diagnosed using Schirmer test showed a strong correlation with the central corneal thickness. A significant reduction in central corneal thickness was observed in dry eyes disease diagnosed with Schirmer disease. The factors affecting dryness includes inflammatory component and evaporating component. Based on my study the results of dry eyes due to inflammation of eye can be considered to have more association to the pathogenesis in relation to central corneal thickness. Inflammation decreases the eyes’ ability to produce normal tear. METHODS 200 eyes of 100 patients who presented in hospitals diagnosed with dry eye disease were included in the study. The central corneal thickness of these patients was measured and corelated with the degree of dryness using Shermer’s test and tear film break up time. RESULTS A statistical significance was observed between the inflammatory component causing dry eyes and the CCT values. CONCLUSIONS There is a significant association between the central corneal thickness and dry eye diseases. KEY WORDS Central Corneal Thickness, Schirmer’s Test, TBUT.

Evaluation of a novel combination of TRAM-34 and ascorbic acid for the treatment of corneal fibrosis in vivo.

Corneal injury and aberrant wound healing commonly result in corneal fibrosis and subsequent vision loss. Intermediate-conductance calmodulin/calcium-activated K+ channels (KCa3.1) have been shown to promote fibrosis in non-ocular and ocular tissues via upregulation of transforming growth factor beta (TGFβ). TRAM-34 is a selective inhibitor of KCa3.1 and reduces fibrosis by downregulation of TGFβ-induced transdifferentiation of stromal fibroblasts to myofibroblasts. Ascorbic acid has been demonstrated to be effective in promoting corneal re-epithelialization and reduction of neovascularization via anti-VEGF and anti-MMP mechanisms. This study evaluates tolerability and efficacy of a novel combination of TRAM-34 (25μM) and ascorbic acid (10%) topical treatment for corneal fibrosis using an established in vivo rabbit model and conducting clinical eye examinations. Markers of corneal fibrosis were evaluated in all corneas at study endpoint via histopathology, immunofluorescence, and quantitative real-time PCR. The eyedrop treated eyes showed significantly improved clinical outcomes based on modified McDonald Shadduck scores, reduction of clinical haze on Fantes scores, and reduction of central corneal thickness (CCT). At cellular and molecular levels, eyedrop treatment also significantly reduced expression of alpha smooth muscle actin (α-SMA) mRNA and protein, collagen III mRNA, and fibronectin mRNA compared to non-treated eyes. Our study suggests that a tested new bimodal eyedrop is well tolerated and effectively reduces corneal fibrosis/haze in rabbits in vivo.

Changes in Corneal Parameters after DMEK Surgery: A Swept-Source Imaging Analysis at 12-Month Follow-Up Time.

Purpose To assess the time course changes in corneal topographic parameters during the one-year follow-up after Descemet membrane endothelial keratoplasty (DMEK) surgery. Materials and Methods Twenty-one patients (24 eyes) who underwent DMEK surgery were evaluated. Best corrected visual acuity (BCVA), endothelial cell count (ECC), central corneal thickness (CCT), mean keratometry (MK), mean astigmatism (MA), astigmatism asymmetry (AA), and higher-order aberration (HOA) were assessed at baseline and 1, 3, 6 and 12 months after the surgery using CASIA2 anterior segment swept-source OCT (Tomey, Japan). Results In patients who underwent DMEK surgery, BCVA improved gradually at the subsequent visits during the 12-month follow-up. A significant reduction in ECC and CCT at the 1st month was noted, which remained stable until the 6th month postoperatively. Anterior and total MK values remained unchanged, whereas changes in posterior keratometry were noticeable until the 6th month after surgery. A significant reduction in the anterior, posterior, and total astigmatism magnitude as well as astigmatism asymmetry was observed during the first 6 months after surgery. A gradual anterior, posterior, and total HOA decrease was documented until the 12th month after surgery. Negative correlations between baseline values of CCT, MK, MA, AA, and HOA and postoperative variations in those parameters at consecutive follow-up time points were observed. Accordingly, negative correlations between baseline CCT and postoperative changes in corneal topographic parameters after surgery were found. Conclusion The stabilization of most corneal topographic parameters takes place within 6 months after the procedure, whereas HOA reduction and BCVA improvement gradually occur during the first year after surgery. Preoperative values of corneal topographic parameters strongly determine their changes detected after DMEK surgery, which may suggest that early therapeutic intervention results in better visual outcomes.

Randomized, Double-Masked, Pilot Study of Netarsudil 0.02% Ophthalmic Solution for Treatment of Corneal Edema in Fuchs Dystrophy

To evaluate off-label use of netarsudil 0.02% for treatment of corneal edema associated with Fuchs dystrophy. Prospective, randomized clinical trial. Twenty-nine subjects with symptomatic Fuchs dystrophy were enrolled and randomized to use netarsudil or placebo eye drops once daily for 3 months. The primary outcomes were the change in central corneal thickness between baseline and 1 month and between baseline and 3 months. Secondary outcomes included change in scotopic corrected distance visual acuity (CDVA) at 3 months and change in scores on a visual disability questionnaire validated for use with Fuchs dystrophy. Compared with use of placebo, use of netarsudil produced significant reduction in central corneal thickness at 1 month (mean difference, -20 µm; 95% confidence interval, -32 to -9 µm) and 3 months (mean difference, -26 µm; 95% confidence interval, -39 to -12 µm) and significant improvement in scotopic CDVA at 3 months (mean difference +1.6 lines; 95% confidence interval, 0.2-3.0 lines). Scores on the visual disability questionnaire did not change significantly in either arm or differ significantly between arms. One subject assigned to netarsudil had baseline epithelial bullae and withdrew from the study because of disabling glare. Use of netarsudil was associated with reduction of corneal edema and improvement in scotopic CDVA in Fuchs dystrophy patients. Further study is needed to more fully assess patient satisfaction and visual acuity under various lighting conditions and to compare use of netarsudil with other treatment options such as endothelial keratoplasty.

Poor re-epithelialization following corneal collagen crosslinking with riboflavin-uva for advanced bullous keratopathy: Case series

To assess safety and efficacy of corneal collagen crosslinking (CXL) for advanced bullous keratopathy (BK). Eight eyes of eight patients subjected to Dresden CXL protocol. BK history of at least one year, severe pain and no indication for keratoplasty due to poor visual prognosis. best corrected visual acuity (BCVA), pain (decimal visual scale), central corneal thickness (CCT) by tomography (Pentacam®, Oculus Inc, Germany), corneal bullae and complications. Seven women and one man of median age 77.00 (range 58-79) years. The median follow-up was 7 (range 5-7) months. BCVA remained unchanged through follow-up. A significant decrease in pain was observed at the end of the follow-up period (median 6, range 5-6 vs. median 0, range 0-4, P=0.05). Corneal tomography could only be performed in three cases, due to poor vision or image quality. A reduction in mean CCT was observed in the first post procedural month (from 708.33±140.48 to 627±136.89μm). In all eight cases, the absence of corneal bullae only persisted for two months after CXL. In six patients, corneal re-epithelialization after CXL was poor; in four of these eyes, the problem was resolved with topical treatment, but in the remaining two eyes, amniotic membrane transplant and mechanical debridement were required. In this uncontrolled small case series, CXL treatment improved pain in patients with advanced BK. However, the high rate of poor re-epithelialization requiring surgical treatment observed in one third of cases makes this treatment controversial.

Evaluation of the Difference between Predicted and Measured Central Corneal Thickness Reduction after SMILE and Femtosecond Laser-assisted LASIK for Myopia

ABSTRACT Purpose To evaluate the agreement between the predicted and measured central corneal thickness (CCT) reduction after the small incision lenticule extraction (SMILE) surgery and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery. Methods A total 165 patients were enrolled in this prospective study. Eighty patients with a mean spherical equivalent (SE) of −4.72 ± 1.80 Diopters (D) were treated with the FS-LASIK procedure and Eighty-five patients with a mean SE of −4.78 ± 1.63 D were treated with SMILE procedure. One eye for each patient was randomly selected and included for statistical analysis. Ultrasound pachymetry measurement and Scheimpflug camera corneal topography were performed preoperatively and 3 months postoperatively. The measured CCT reduction was calculated by comparing the preoperative examinations with postoperative examinations. Comparative statistics and linear regression analyses were performed. Results The mean predicted CCT reduction was 95.02 ± 21.39 μm in FS-LASIK group and 103.49 ± 22.87 μm in SMILE group (P = .015). The prediction of laser platform was found to overestimate the measured CCT reduction for both FS-LASIK group (ultrasound 13.20 ± 9.34 μm) and SMILE group (ultrasound 13.12 ± 8.68 μm). The prediction of laser platform was found to systematically overestimate the measured CCT reduction in FS-LASIK group. In SMILE group, the difference between predicted and measured CCT reduction were found significantly related with the predicted CCT reduction (P < .001 for ultrasound; and P = .004 for Pentacam). Conclusion A systematic overestimation of measured CCT reduction in FS-LASIK group did not influence the refractive precision of FS-LASIK. Due to the different biomechanical distributions in post-SMILE cornea, the measured CCT reduction was influenced as the changes in refractive correction. Nomogram adjustment for high myopic correction needs further research.

Evaluation of the Effect of Fasting on Glaucoma Patients.

Objectives:The aim of this research was to evaluate the effect of daytime Ramadan fasting and dehydration on intraocular pressure (IOP) and biometric parameters in primary open-angle glaucoma (POAG) patients.Methods:This prospective study included 30 eyes of 30 POAG patients who were fasting during Ramadan (Group 1), 40 healthy participants who were fasting (Group 2), and 40 healthy individuals who were not fasting (Group 3). The eyes were evaluated twice a day at approximately 8 am and 4 pm during Ramadan and 1 month after Ramadan.Results:IOP values at 4 pm were higher in Group 1 than Groups 2 and 3 in Ramadan (p=0.029 and 0.007, respectively). The diurnal reduction in IOP was significantly smaller during fasting in the glaucoma patients compared with Groups 2 and 3 (p=0.012 and 0.007, respectively). Comparisons of biometric parameters revealed less reduction in central corneal thickness (CCT) values from 8 am to 4 pm in glaucoma patients than in Groups 2 and 3 (p<0.05 for all comparisons) during Ramadan and after Ramadan.Conclusion:POAG patients had a higher IOP at 4 pm during the fasting period than was seen following Ramadan. In addition, the diurnal reduction of IOP and CCT was smaller in patients with POAG compared with healthy subjects.

Reference Values of the Central Corneal Thickness with Different Refractive Errors for the Adult Egyptian Population.

AimTo generate reference values of the central corneal thickness (CCT) with different refractive errors for the adult eastern Egyptian population.Subjects and MethodsThis study was a retrospective, observational, and cross-sectional study. It included 1166 eyes (1166 subjects) scheduled for LASIK, who came to private refractive eye centre, Ismailia, Egypt. The study period was from January 2018 to January 2020. The subjects were divided into a broad range of myopia with spherical equivalent (SE) ≤-0.5D and hyperopia (SE) ≥+0.5D. Then, the myopic eyes divided into low (SE>-3.0D), moderate (SE-3.0D to >-6.0D), and high (SE≤-6.0D). Similarly, the hyperopic eyes were divided into low (SE<+3.0D) and moderate (SE+3.0D to <+6.0D) and high ≥+6.0D. The refractive error was measured by an auto-refractometer, and CCT was measured using ultrasonic pachymetry.ResultsThe data of 556 myopic eyes in 556 subjects (31.1% males and 68.9% females) and 610 hyperopic subjects (34.4% males and 65.6% females) were included in this study. The mean±SD of CCT for the total myopic subjects was 532.8±32.6μm, range (470 to 627μm). The mean±SD of SE was -4.06±2.50D, range (−0.50 to −14.00D). The mean±SD of CCT for the total hyperopic subjects was 530.8±37.2μm, range (471 to 616μm). The mean±SD of SE was +3.57±1.98D, range (+0.50 to +8.50D). About 16.2% of the myopic eyes and 12.7% of the hyperopic eyes have CCT less than 500μm.ConclusionThe mean of the central corneal thickness of the eastern Egyptian population was 532.8μm for myopic and 530.8μm for hyperopic subjects, respectively. The myopic and hyperopic subjects show a reduction in CCT with age. Females have a thinner cornea than males, 16.2% of the myopic eyes and 12.7% of the hyperopic eyes have CCT less than 500μm.