Preoperative Central Corneal Thickness Research Articles

Analysis of the changes in corneal optical density following small incision lenticule extraction for myopia and related influencing factors

Purpose: To examine changes in corneal optical density (COD) following small incision lenticule extraction (SMILE) for myopia and the associated factors affecting COD. Methods: One hundred and ten eyes of 110 subjects who underwent SMILE were included in this study. COD and influencing factors were evaluated before and three months after SMILE. The changes in COD were compared and analysed with those of other influencing factors. Representative positive outcomes were chosen to investigate the influence in various ways. Results: This study found significant reductions in most anterior, central, and posterior CODs following SMILE (P<0.05), but the anterior 2-6 mm COD exhibited a significant increase (P<0.001). Lenticule thickness (LT), refractive sphere, preoperative Km, and Δcorneal volume (CV) were related to some of the whole ΔCODs (P<0.05). Age, gender, intraocular pressure (IOP), refractive cylinder, corrected distance visual acuity (CDVA), preoperative central corneal thickness (CCT), and preoperative CV were not correlated with the whole ΔCODs. Further exploration revealed that an increase in LT leads to a pattern of increasing and then decreasing changes in the whole ΔCODs. Most of the ΔCODs values were significantly lower in the high central corneal stromal ablation thickness group than in the high anterior corneal stromal ablation thickness group (P<0.05). Conclusions: Changes in COD were mainly caused by LT and its associated factors. However, the relationship between LT and ΔCOD might not be linear. Deeper corneal stromal ablation may reduce the COD. Changes in COD following SMILE are a multifaceted process influenced by various circumstances.

Corneal Endothelial Keratoprosthesis EndoArt in Patients with Glaucoma at High Risk of Graft Failure After Keratoplasty.

The novel endothelial keratoprosthesis EndoArt improves corneal edema by reducing the inflow of aqueous humor into the cornea. We assessed the early outcome after EndoArt implantation in patients at a high risk of graft failure after keratoplasty. This retrospective study included 14 patients with high-risk eyes owing to at least one of the following risk factors for graft failure after keratoplasty: multiple previous surgeries (glaucoma surgery, keratoplasty) and recurrent intraocular inflammation because of uveitis, aniridia, or anterior synechia. After descemetorhexis, the EndoArt keratoprosthesis was placed on the posterior stroma, secured with a gas bubble and 1 to 3 transcorneal holding sutures. Best spectacle-corrected visual acuity and central corneal thickness were calculated preoperatively and postoperatively. In addition, detachment of the keratoprosthesis and the need for additional gas injections (rebubbling) were analyzed. Octafluoropropane (C3F8) 12% in 11 patients and sulfur hexafluoride 20% in 3 patients were used to attach EndoArt. Detachments requiring at least 1 rebubbling occurred in 8 eyes. Preoperative best spectacle-corrected visual acuity was 1.6 (±0.6) logarithm of the minimal angle of resolution and improved to 1.3 (±0.6) after 12 weeks. Preoperative central corneal thickness (771.8 μm ± 157) significantly decreased postoperatively in all patients (622.1 μm ± 184.7 [P = 0.025] and 562.8 μm ± 183.6 [P = 0.012] after 6 and 12 weeks, respectively). EndoArt improved visual acuity and significantly reduced corneal thickness within 3 months postoperatively, subjectively, but not statistically significantly. The rebubbling rates in this cohort with an altered anterior segment anatomy were relatively high. Patients at a high risk of graft failure may benefit from this novel endothelial keratoprosthesis.

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.

The Influence of Corneal Thickness on Surgically Induced Corneal Astigmatism Derived from Total Keratometry Measured by Anterior Segment Swept-Source OCT.

The purposeof the study was to explore the possible correlations between the anterior segment parameters derived from anterior segment swept-source optical coherence tomography (AS-SS-OCT) with the surgically induced corneal astigmatism (CSIA) calculated from total keratometry (TK) measured by AS-SS-OCT. Seventy-one eyes of 67 patients with age-related cataract who underwent phacoemulsification combined with intraocular lens implantation with 2.2-mm incision were included. The CSIA values were calculated from anterior keratometry (CSIAKant) and TK (CSIATK) measured by AS-SS-OCT, respectively. Hotelling's T2 test was used to evaluate the difference. The correlation of CSIA with various parameters derived from AS-SS-OCT was tested with the Spearman correlation coefficient. The centroid of CSIAKant and of CSIATK were 0.31 ± 0.55 D @ 54° and 0.41 ± 0.59 D @ 51°, with no significant difference (F = 1.283, p = 0.281, Hotelling's T2). The mean absolute CSIAKant and CSIATK were 0.58 ± 0.24 D and 0.65 ± 0.28 D. Spearman test showed that the magnitude of CSIAKant was negatively correlated with preoperative peripheral corneal thickness (PCT, p = 0.045) and the magnitude of anterior keratometry (p = 0.044). The magnitude of CSIATK was negatively correlated with preoperative central corneal thickness (CCT, p = 0.003) and preoperative PCT (p = 0.015). The increased thickness of the peripheral cornea is correlated with the decrease in the magnitude of the CSIA. The correlation we identified between the corneal thickness and the CSIA indicated that certain preoperative parameters should be considered for the prediction of CSIA for a more precise refractive outcome.

Comparison of early visual outcomes after SMILE using VISUMAX 800 and VISUMAX 500 for myopia: a retrospective matched case–control study

VISUMAX 800 was introduced to improve the patient experience and clinical outcomes of small incision lenticule extraction (SMILE). This was a retrospective, matched, and case–control study (1:2) controlled for preoperative central corneal thickness and refractive error that compared early refractive and visual outcomes after SMILE using VISUMAX 800 and VISUMAX 500 to treat myopia. We included 50 eyes that underwent the VISUMAX 800 SMILE and 100 eyes that underwent the VISUMAX 500 SMILE. SMILE using VISUMAX 800 was performed using the CentraLign aid for vertex centration. Cyclotorsion was controlled by an OcuLign assistant in the VISUMAX 800 group after corneal marking. Corneal higher-order aberrations (HOAs) were evaluated using a Pentacam 1 month after surgery. No differences were observed in the pre- and post-operative refractive and visual outcomes at 1 day, 1 month, and 6 months after surgery. VISUMAX 800 induced less total HOAs than VISUMAX 500 (P = 0.036). No statistically significant differences were observed in the amounts of induced spherical aberrations or vertical and horizontal comas. No differences were observed in the 1 month and 6 months refractive and visual outcomes between two SMILE procedures, except for VISUMAX 800, which resulted in lower postoperative total HOAs than VISUMAX 500.

Comparison of Endothelial Cell Loss after Phacoemulsification Surgery between Patients with Diabetes Mellitus and Non-Diabetic Patients at Kariadi Hospital: A Prospective Study

Abstract&#x0D; Introduction &amp; Objectives : To compare the endothelial cell loss after phacoemulsification surgery in patients with DM and non- DM patients&#x0D; Methods : This was a prospective study conducted at Kariadi Hospital, Semarang, Indonesia. A total of 20 eyes of 20 patients (10 DM and 10 non-DM) who underwent phacoemulsification surgery were included in this study. The central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX) were measured preoperatively and on day-7 postoperatively. The percentage of endothelial cell loss (%ECL) was calculated and compared between the two groups.&#x0D; Results : The mean pre-operative and post-operative CCT was similar in both groups (DM =546.6±44.26μm, non-DM=516.7±42.2μm, p=0.949 ;DM=562.8±46.1μm, non-DM=533.7±46.6μm, p=0.997). The mean percentage of endothelial cell loss was slightly higher in the DM group compared to the non- DM group but not significant (6.66±2.36% vs. 2.31±1.72%, p=0.566). There were no significant differences between the CV and HEX on pre-operative and day-7 after surgery&#x0D; Conclusion : Patients with DM have a slightly higher percentage of endothelial cell loss after phacoemulsification surgery compared to non-DM patients. The mean CCT, CV and HEX pre-operation and day-7 were quite similar in both groups. These findings suggest that patients with DM may require more careful monitoring and follow-up after phacoemulsification surgery.

Changes in Central Corneal Thickness and Central Macular Thickness following Uncomplicated Small-incision Cataract Surgery.

Cataract surgery is an invasive procedure that causes mechanical and inflammatory insult to the eye. The objective was to study the changes in central corneal thickness (CCT) which is an indirect indicator of corneal endothelial dysfunction and the changes in macular thickness following uncomplicated small incision cataract surgery (SICS) Materials and methods: This was a prospective observational study with a before-and-after design conducted in Reiyukai Eiko Masunaga eye hospital, Banepa, Kavrepalanchok, Nepal. SICS was performed on 68 eyes of 62 patients. Change in CCT and central macular thickness (CMT) from baseline was observed post-surgery on the first day, one week, and six weeks. There were 27 (43.5%) females and 35 males (56.5%) in the study. Mean age was 58.26 ±10 years. This difference of visual acuity between pre and post-operative state was statistically significant. The first post-operative day (POD) and first week post-operative CCT values when compared with preoperative CCT values were statistically significant. However, post-operative CCT values at six weeks were similar to preoperative values. Also, the differences at day one, first week and six weeks post-operative CMT values when compared with preoperative CMT values were statistically significant. This study revealed that there is a significant rise in CCT after SICS which gradually tends to normalize at six weeks. Similarly there is a gradual rise in CMT after SICS persisting even at six weeks. These changes were subtle and there was a marked improvement of visual acuity at six weeks after SICS.

Corneal epithelial remodeling induced by combined small incision lenticule extraction and accelerated corneal collagen crosslinking for myopia

To evaluate the changes of the corneal epithelial thickness (ET) profile induced by combined small incision lenticule extraction and accelerated corneal collagen crosslinking (SMILE-xtra) for myopia compared with the standard small incision lenticule extraction (SMILE). Nuri Eye Hospital, 61, Dunsan-ro, Seo-gu, Daejeon, 35233, Korea. Retrospective cross-sectional study. Thirty-one myopic eye undergoing SMILE-xtra and control group of 36 myopic eyes undergoing SMILE were retrospectively analyzed. Spectral-domain optical coherence tomography (CIRRUS™ HD-OCT 5000, ZEISS, Dublin, CA) was used to measure corneal ET of 17 zones within the central 7-mm zone at preoperative, postoperative 1 month, 3 months and 6 months. Postoperative ET alterations were analyzed for correlation with treatment parameters. There was no difference in preoperative mean age, postoperative MRSE, visual acuity, and ablation depth between the two groups, and there was a significant difference in preoperative central corneal thickness. Both groups showed the greatest increase in corneal ET in the paracentral area on the inferotemporal area, respectively, for 6 months. The preoperative MRSE and the ablation depth showed significant correlation with the postoperative epithelial thickening in mid-peripheral sectors in both groups, and significant negative correlations in paracentral sectors only in SMILE-xtra group. It is significant as the first study to compare corneal epithelial remodeling between SMILE and SMILE with accelerated corneal collagen crosslinking. The SMILE-xtra with the relatively large corneal ablation did not show a significant difference in the pattern of corneal epithelial remodeling compared to the SMILE group.

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.

Which is More Effective and Safer? Comparison of Propensity Score-Matched Microhook Ab Interno Trabeculotomy and iStent Inject.

The purpose of this study was to compare the surgical outcomes between abinterno trabeculotomy (LOT) and iStent injectW implantation (iStent) both combined with cataract surgery, matching the background factors including age, intraocular pressure (IOP), medication score, central corneal thickness (CCT), and axial length. A total of 100 eyes from 75/79 patients with primary open-angle glaucoma were included in the LOT/iStent groups. The background factors were matched between the two groups using the propensity score. There were no significant differences in age, IOP, medication score, CCT, and axial length, preoperatively. The postoperative medication scores were 1.3 ± 1.2 and 1.2 ± 1.2 in the LOT and iStent groups. The postoperative IOPs were 12.8 ± 2.8 and 13.1 ± 2.4mmHg in the LOT and iStent groups, respectively. The changes in the medication score were - 0.64 ± 1.4 and - 0.44 ± 1.6 in the LOT and iStent groups, respectively. The changes in the IOP were - 2.1 ± 3.3 and - 1.5 ± 3.0mmHg in the LOT and iStent groups, respectively. These values were not significantly different between the two groups. The postoperative IOP and changes in the IOP were significantly associated with preoperative IOP and CCT. There was no significant difference in the occurrence of postoperative complications (hyphema, 11.0% and 6.0%, and transient ocular hypertension, 8.0% and 5.0%, in the LOT and iStent groups, respectively). LOT and iStent have similar surgical outcomes with sufficient safety. Postoperative IOP was significantly associated with preoperative IOP and CCT in both groups.

Comparison of Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty in Keratoconic Eyes With Previous Hydrops-Related Corneal Scar.

This study aimed to compare the outcomes of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) procedures in keratoconic eyes with a previous hydrops-related corneal scar. In this retrospective study, the medical records of patients who had hydrops-related corneal scarring and underwent keratoplasty surgery were reviewed. Patients treated with DALK were classified as group 1, and patients treated with PK as group 2. Preoperative and postoperative best-corrected visual acuity, central corneal thickness, keratometry (K), and refractive error values of each group were recorded and compared. Seventy-eight eyes (41 in group 1 and 37 in group 2) were included in this study. The mean follow-up period of the patients was 37.7 ± 30.0 months in group 1 and 51.2 ± 29.4 months in group 2 ( P = 0.06). The preoperative and postoperative best-corrected visual acuity and central corneal thickness values were statistically similar in both groups (each P value >0.05). Keratometry values (K1 and mean keratometry) were significantly steeper in group 1 ( P1 = 0.02 and P2 = 0.03, respectively). Descemet membrane perforation was experienced in 7 (4 macroperforation and 3 microperforation; 15.6%) of 45 eyes that planned to perform DALK. These 4 eyes with macroperforation underwent PK and were excluded from the study. When all postoperative complications were assessed, although the total complication rate was 21% after DALK, it was 43% after PK ( P = 0.04). DALK with a big-bubble technique is a feasible surgery in eyes with corneal scarring due to previous hydrops and is comparable with PK in terms of visual and refractive outcomes. This study suggests that DALK, which is safer than PK with less postoperative complication rates, should be the primary surgical option to avoid serious complications in keratoconic eyes with hydrops-related corneal scarring.

Changes in corneal endothelial cell density after trabeculectomy.

Glaucoma is a leading cause of blindness worldwide for which trabeculectomy is the most effective surgical intervention for advanced disease. However, trabeculectomy has been associated with alterations to corneal endothelium, including a decrease in corneal endothelial cell density (CECD). The purpose of this study was to investigate changes in CECD after trabeculectomy, and identify factors contributing to cell loss, such as pre-operative biometry and lens status. This retrospective study included 72 eyes of 60 patients who underwent trabeculectomy between January 2018 and June 2021 at two private hospitals. Demographic and clinical data were obtained at baseline. Corneal specular microscopy was performed pre-operatively and at 6 months after surgery. CECD was evaluated and compared between groups to quantify changes to corneal endothelium and identify significant factors affecting decreases in cell density. Mean CECD was 2284.66 ± 375.59 pre-operatively and 2129.52 ± 401.96 after 6 months (p < 0.001). A greater decrease in CECD (p = 0.005) was observed in phakic eyes (235.45 ± 118.32) compared to pseudophakic eyes (137.82 ± 107.30). The amount of cell loss was negatively correlated with pre-operative central corneal thickness (p = 0.009) and anterior chamber (AC) depth (p = 0.033). There were no significant correlations between changes to CECD and patient age, gender, number of pre-operative glaucoma medications and number of post-operative antifibrotic agents. Significant decreases in CECD occurred after trabeculectomy. Less corneal endothelial cell loss occurred in pseudophakic eyes. Hence, if patients need trabeculectomy and cataract surgery, it may be better to perform cataract surgery first. Longer term studies should derive more information.

Preoperative central corneal thickness in eyes with pediatric cataract versus normal fellow eyes

To compare the preoperative central corneal thickness (CCT) in eyes with unilateral cataract with their normal fellow eyes in the pediatric population. A retrospective chart review was conducted using the STORM Kids cataract database. Eyes with traumatic cataract, previous surgery or therapeutic manipulation, or age >18 years were excluded. Only eyes with a normal fellow eye were included. The intraocular pressure, age at time of surgery, race, sex, and type of cataract were also extracted from the record. A total of 70 eyes with unilateral cataract and 70 fellow normal eyes met inclusion criteria. The mean age at the time of surgery was 3.35 years (range, 0.08-15.05). The mean preoperative CCT in the operated eyes was 577 ± 58 μm (range, 464-898 μm). The mean preoperative CCT in fellow eyes was 570 ± 35 μm (range, 485-643 μm). There was no statistically significant difference between the preoperative CCT in cataract eyes versus unaffected fellow eyes (P = 0.183). When stratified by age, the difference in the CCT between cataract and fellow eyes was greatest in the <1 year age group, but was not statistically significant (P = 0.236). The mean preoperative corneal diameter of operative eyes was 11.0 mm (range, 5.5-12.5 mm [n = 68]). The mean preoperative IOP was 15.1 mm Hg (n = 66). In our study cohort, there was no significant difference in mean preoperative CCT between unilateral pediatric cataract eyes and unaffected fellow eyes.

Postoperative, but not preoperative, central corneal thickness correlates with the postoperative visual outcomes of Descemet membrane endothelial keratoplasty.

Descemet membrane endothelial keratoplasty (DMEK) restores visual acuity in patients with progressive corneal endothelial diseases such as Fuchs endothelial corneal dystrophy (FECD). However, patients often prefer to delay the surgery as long as possible, even though outcomes are poorer in advanced FECD. A recent study proposed that preoperative central corneal thickness (CCT) of ≥625 μm associated with worse best spectacle-corrected visual acuity (BSCVA) after DMEK for FECD. Since this threshold could signal to both surgeons and patients when to perform DMEK, we further explored the relationship between CCT and BSCVA with a retrospective cohort study. The cohort consisted of all patients with FECD who underwent DMEK in a tertiary-care hospital in 2015-2020 and were followed for 12 months. Extremely decompensated corneas were not included. Relationships between preoperative CCT and BSCVA on days 8 and 15 and months 1, 3, 6, and 12 were examined with Pearson correlation analyses. Eyes with preoperative CCT <625 or ≥625 μm were also compared in terms of postoperative BSCVA. Relationships between postoperative CCT and final BSCVA were also explored. The cohort consisted of 124 first-operated eyes. Preoperative CCT did not correlate with postoperative BSCVA at any timepoint. Eye subgroups did not differ in postoperative BSCVA. However, postoperative CCT at 1-12 months correlated significantly with 12-month BSCVA (r = 0.29-0.49, p = 0.020-0.001). Thus, postoperative, but not preoperative, CCT correlated with postoperative BSCVA. This phenomenon may reflect factors that distort preoperative CCT measurements but disappear after surgery. This observation and our analysis of the literature suggest that while there is a relationship between CCT and post-DMEK visual acuity, preoperative CCT measurements may not always adequately reflect that relationship and may therefore not be a reliable predictor of DMEK visual outcomes.

Evaluation of Ocular Biometric Parameters Following Cataract Surgery

Background: The aim of this study was to highlight the structural changes in patients with cataract following surgery and the repercussions on the anterior pole. Methods: A total of 83 patients diagnosed with cataract who underwent uneventful phacoemulsification was included. Every patient was examined one week prior to and two weeks after the surgery. Pre- and postoperative assessment included examination of the anterior and posterior segment, keratometry, and optical biometry. Results: The pre- vs. postoperative axial length (AL) mean difference was 0.07 ± 0.18 mm (p &lt; 0.001).The mean difference of the postoperative anterior chamber depth (ACD) vs. preoperative ACD values (1.11 ± 0.50 mm) was also statistically significant (p &lt; 0.001). The linear regression function postoperative central corneal thickness (CCT) = 0.9004 × (preoperative CCT) + 0.0668, where it characterized a reduced positive correlation (R2) of 68.89% between the postoperative CCT and preoperative CCT. The mean pre-/post-operative differences in the K1 values were 0.08 ± 0.38 D, with a statistically significant difference between the two datasets (p = 0.0152). The mean pre/postoperative difference in the K2 values was 0.002 ± 0.58 D (p = 0.4854). Conclusions: ACD deepened significantly postoperatively. Regarding AL, there was a decrease after surgery, and a very good positive correlation between the post and preoperative values. The CCT values decreased with age. The 2.2-mm corneal incision during cataract surgery resulted in a relatively small postoperative residual astigmatism.

Comparison of surgically induced astigmatic changes after cataract surgery in post-Laser in situ keratomileusis corneas versus virgin eyes.

Postoperative refraction in modern mi-croincision cataract surgery gained extra importance in patients with the previous laser-assisted in situ keratomileusis (LASIK) surgery. The surgically induced astigmatic changes in those eyes may differ not only in magnitude but also in direction compared to virgin corneas. This study aimed to compare the surgically induced astigmatic changes after microscopic cataract surgery between post-LASIK corneas and virgin eyes. Cases that underwent microincision cataract surgery in eyes with and without previous LASIK surgery were reviewed. The demographics, the axial length at cataract surgery, the central corneal thickness, spheric and cylindric values, keratometry readings, and postoperative posterior corneal astigmatism were retrospectively evaluated. A modified Alpins method was used for astigmatic vector analysis, and baseline astigmatism, surgically induced astigmatism, difference vector, flattening effect, and torque were assessed. A total of 42 eyes from 24 subjects was evaluated. Group I consisted of 14 eyes with the previous LASIK, and Group II included 28 eyes without any refractive surgery. Preoperative mean central corneal thickness in Group I was significantly thinner (p=0.012). There was no significant difference in baseline astigmatism between the groups regarding magnitude and power vectors. After microincision cataract surgery, there were no significant differences in mean spheric and cylindric values and mean keratometry readings (all p>0.05). However, surgically induced astigmatism and difference vector were significantly higher on J45 vector component in post-LASIK eyes and microincision cataract surgery steepening effect on post-LASIK corneas was significantly higher than those in virgin eyes (p=0.001, p=0.002 and p=0.018, respectively). Cataract surgery has steepened the corneas in both groups with a significantly higher steepening effect in post-LASIK eyes. Certainly, corneal topography cataract surgery is particularly helpful to provide more precise surgically induced astigmatism interpretations.

Comparison of Postoperative Safety, Efficacy, and Visual Quality after SMILE for Myopic Patients with Different Corneal Thicknesses

Purpose To investigate the safety, efficacy, and visual quality of small incision lenticule extraction (SMILE) in different corneal thickness patients with myopia or myopic astigmatism. Methods This prospective cohort study included 191 right eyes of 191 patients. Eyes were divided into three groups according to preoperative central corneal thickness (CCT) (Preoperative central corneal thickness (CCT) was the group indicator.) There were 31 eyes in the thin cornea group (CCT ≤500 um (μm), TC), 94 eyes in the moderate corneal thickness group (CCT ≥501 um (μm) and ≤550 um (μm), MD) and 66 eyes in the thick cornea group (CCT ≥550 um (μm), TK). Comparisons in uncorrected (UDVA) and best-corrected distance visual acuity (BDVA), manifest refractive spherical equivalent (SE), preoperative mesopic/photopic contrast sensitivity (CS), ocular higher-order aberrations (HOAs) at a 6mm analytical pupil diameter, and visual quality questionnaires were made (performed) among the three groups during the postoperative six months. Subgroup analyses were made based on preoperative SE. Results The safety indices at six months were 1.15 ± 0.18, 1.14 ± 0.17, and 1.18 ± 0.17, respectively (p = 0.374), and the efficacy indices at six months were 1.07 ± 0.25, 1.12 ± 0.22, and 1.11 ± 0.21, respectively (p = 0.599). The postoperative SE was −0.07 ± 0.52D, −0.14 ± 0.38D, and −0.05 ± 0.46D after SMILE in the three groups, respectively (p = 0.376). No significant difference was found in mesopic/photopic CS, HOAs, and visual quality among different corneal thickness groups and SE groups. Postoperative SE and efficacy indices were the lowest in thin cornea eyes with ultra-high myopia (over −9.00 D). Conclusions SMILE provides comparable safety, efficacy, and visual quality results in different corneal thickness patients. Those with myopia higher than -9.00 D had less efficacy after surgery, especially in thin cornea patients.

Impact on corneal morphology after cataract surgery with intracameral moxifloxacin in neglected hard cataracts.

To evaluate corneal morphology after use of 0.5% intracameral moxifloxacin (ICM) in cataract surgery in patients who presented late with hard cataracts. Cross-sectional study conducted from June-2021 to December-2021 at a tertiary eye-care center. 90 patients over 60 years with high-risk characteristics for Covid-19, who presented late with higher grades of nuclear-sclerosis (NS), were included. They underwent phacoemulsification and 0.5%moxifloxacin (0.1 ml) was injected intracamerally at the end of surgery. Best-corrected visual acuity (BCVA), intraocular pressures (IOP), endothelial cell density (ECD), coefficient of variation in cell-area (CoV), hexagonality (Hex) and central corneal thickness (CCT) were measured preoperatively and postoperatively on day1, day7 and day30. Statistical analysis was done by Anova test. p-value<0.05 was considered significant. Mean age of presentation was 65.26±8.3 years. Mean preoperative BCVA (1/60-to-6/60), IOP (16.7±2.3 mm of Hg), CCT (523.93±39.6µ), ECD (2547±302.08cells/mm2), Hex (47.04±5.7%) and CoV (37.57±3.9) changed to BCVA (6/9-to-6/6), IOP (17.5±2.1 mm of Hg), CCT (538.42±36.9µ), ECD (2388.40±339.25cells/mm2), Hex (44.44±5.6%) and CoV (39.09±4.5) at day30 postoperative. Average rate of change at day30 was increase in CCT (2.89%), ECD loss (6.4%), decrease in Hex (4.9%) and increase in CoV (4.6%), though clinically insignificant. No case of endophthalmitis or toxic-anterior segment syndrome seen. 0.5% moxifloxacin (0.1 ml) is safe as intracameral antibiotic to prevent postoperative infection in high-risk patients. The reported changes in the corneal parameters were within the range of any routine surgeries of hard senile cataracts. No specific effect could be attributed to ICM.

Ability of routinely collected clinical factors to predict good visual results after primary Descemet membrane endothelial keratoplasty: a cohort study

BackgroundA comprehensive analysis of routinely collected pre/perioperative demographic/clinical factors that could predict final visual acuity after primary Descemet membrane endothelial keratoplasty (DMEK) has not been conducted previously.MethodsA retrospective monocenter cohort study was performed with consecutive patients with Fuchs endothelial corneal dystrophy (FECD) who underwent DMEK or triple-DMEK (DMEK combined with cataract surgery) in 2016–2020 in a French tertiary-care hospital. DMEK-only patients were pseudophakic. Patients were followed for 12 months. Surgery was considered successful when 12-month best-corrected visual acuity (BCVA) was ≤0.1 logMAR (≥0.8). Exploratory multivariate analysis was conducted with the following routinely collected variables to determine their ability to predict 12-month BCVA: patient age and sex; graft donor age; triple DMEK; preoperative values of BCVA, endothelial cell density (ECD), central corneal thickness (CCT), and mean anterior keratometry; and rebubbling.ResultsOf 100 eyes (100 patients; mean age, 72 years; 61% female), 81 achieved a 12-month BCVA of ≤0.1 logMAR. Logistic regression analysis showed that older age was a significant prognosticator for 12-month BCVA > 0.1 logMAR (Odds Ratio = 0.914, 95% confidence intervals = 0.846–0.987; p = 0.02).ConclusionsAn older age associated with worse visual acuity outcomes after DMEK. This was confirmed by our analysis of the literature and supports the notion that DMEK should be conducted without delay once symptoms appear. Patient sex, donor age, triple-DMEK, and anterior keratometry also did not predict final BCVA in the literature. Preoperative CCT, ECD, and BCVA, and rebubbling occasionally appear in the literature as BCVA predictors, possibly reflecting an underlying ECD-BCVA axis.

Use of Scheimpflug Tomography and OCT Tomography to Examine Corneal Dimensional and Anterior Chamber Depth before and after LASIK Surgery

Aims: The aim of this study is to compare corneal parameters in: central corneal thickness (CCT), thinnest corneal thickness (TCT), mean radius of curvature (Rm) and anterior chamber depth (ACD) obtained from Pentacam Schiempflug and OCT Tomography imaging which are checked preoperatively and six months postoperatively after LASIK surgery.&#x0D; Methodology: Our sample consisted of 40 eyes. Changes in corneal dimensions were monitored before and after LASIK surgery using scheimpflug tomography (Pentacam HR) and optical coherence tomography (OCT). The parameters measured were CCT, TCT, Rm and the ACD. The results between the two techniques were compared with the Bland-Altman method.&#x0D; Results: During the analysis of the results, a statistically significant difference was observed between the two techniques in terms of the preoperative CCT as well as the TCT both preoperatively and postoperatively.&#x0D; Scheimpflug tomography gives higher values of the CCT than OCT, up to thickness 530nm, while above this it seems that OCT overestimates the thickness of the cornea. Scheimpflug tomography at the TCT seems to give higher values than OCT tomography, up to thickness 520 nm, while above that it seems that OCT tomography overestimates TCT. We have similar results postoperatively for TCT.&#x0D; The two techniques agree on the ACD and the Rm rating.&#x0D; Conclusion: How converging or different the two imaging devices are because it is important for both clinical practice and research may be a point of reference for starting a new research.