Contralateral Eye Study Research Articles

Comparison between 80-microns versus 100-microns flap femtosecond LASIK for correction of myopia and myopic astigmatism.

This study aimed to compare the safety, efficacy, and visual outcomes of 80-microns LASIK versus 100-microns LASIK in managing myopia and myopic astigmatism. The study was conducted at a tertiary care hospital in North India. This was a prospective contralateral eye study that included patients with myopia and myopic astigmatism seeking refractive correction. The eligibility criteria included normal corneal topography, an epithelial thickness less than 60 microns, a calculated percentage tissue ablation (with 100-microns flap) less than 40%, a calculated residual stromal bed thickness (with 100-microns flap) more than 300 microns, and willingness to participate and follow up. Patients with glaucoma, cataracts, other visually disabling ocular pathologies, and a history of past ocular surgery were excluded. All patients underwent LASIK with 80-microns LASIK in one eye and 100-microns LASIK in the other eye. The patients were followed up for 6 months, and the results were analyzed. The study included 216 eyes of 108 patients. The mean preoperative spherical equivalent in the 80-microns group and the 100-microns group was -3.53 ± 1.81 and -3.69 ± 1.32 diopters, respectively (P = 0.78). The mean 6 months decimal postoperative UCVA was 0.98 ± 0.13 in the 80-microns group and 0.97 ± 0.14 in the 100-microns group (P = 0.99). The postoperative change in the higher-order aberration profile was comparable in both groups (P = 0.78). The percentage tissue ablation was significantly lower in the 80-microns group (P = 0.002). The incidence of flap micro striae and OBL was higher in the 80-microns group, while neither of these had any visual implications. The study concluded that 80-microns LASIK is an efficacious and safe alternative to 100-micron LASIK, especially useful in patients with higher myopia.

Comparative outcomes of mechanical and transepithelial PRK on the same excimer laser: A contralateral eye study.

Compare refractive results between mechanical PRK (mPRK) and transepithelial PRK (tPRK) with WaveLight Allegretto EX500 excimer laser system (Alcon Laboratories, Fort Worth, TX, USA). Department of Ophthalmology of the Federal University of Sao Paulo, Brazil. Prospective and randomized study. In 151 eyes of 73 patients with astigmatism and myopia, both eyes had similar refraction before surgery, with a maximum of 15-µm difference in ablation who underwent mPRK in one eye and tPRK in the contralateral eye. The mean age of the patients in this study was 31.45 ± 6.97 years (range, 22 to 54 years). A comparison was made with all variables between the two groups, and we found that UDVA and SE were worse in the tPRK group at six months than in the mPRK group. In the mPRK group, there was a higher frequency in the +/- 0.50 range and a lower frequency in the +/- 1.50 range. In the tPRK group, however, there was a lower frequency in the +/- 0.50 range and a higher frequency in the +/- 1.50 range. Concerning gain or loss of lines of sight, there was no association between the two groups (chi-square test, p = 0.887). Both mPRK and tPRK appear to have similar safety. However, mPRK was associated with significantly better UDVA and SE six months post-operatively.

Retinal and choroidal thickness in fuchs uveitis syndrome: a contralateral eye study

BackgroundTo investigate the subfoveal retinal and choroidal thickness in patients with unilateral Fuchs Uveitis Syndrome (FUS).MethodsThis comparative contralateral study was performed in affected eyes with FUS versus fellow eyes. For each eye parameters such as subfoveal choroidal thickness (SCT), subfoveal choriocapillary thickness (SCCT), central macular thickness (CMT), and central macular volume (CMV) were measured; then the measured values of affected and fellow unaffected eye were compared.ResultsThirty-seven patients (74 eyes) including 19 females (51.4%) with a mean age of 36.9 ± 7.6 years were enrolled. The mean SCT was lower in the affected eyes (344.51 ± 91.67) than in the fellow (375.59 ± 87.33) with adjusting for duration of disease and axial lengths (P < 0.001). The mean SCCT, CMT, and CMV were higher in eyes with FUS than in fellow eyes (P < 0.05).ConclusionsThe result of our study demonstrated that affected eyes in patients with FUS tend to have thinner SCT and thicker SCCT and CMT compared to uninvolved fellow eyes.

Topical Dorzolamide as Adjunctive Treatment With Intravitreal Bevacizumab in Bilateral Diabetic Macular Edema.

Intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents is accepted as the gold standard treatment for center-involving diabetic macular edema (CI-DME). Adjunctive administration of topical dorzolamide may enhance the therapeutic effects of anti-VEGF agents. In this study, we compared the efficacy of topical dorzolamide plus intravitreal injection of bevacizumab (IVB) versus IVB alone in patients with bilateral DME. This prospective, randomized contralateral eye study was carried out in a tertiary referral ophthalmology center, Al-Zahra Eye Hospital, Zahedan, Iran, between April 2021 and April 2022. Thisstudy included 50 eyes of 25 patients with bilateral DME. All eyes received three consecutive monthly injections of IVB. For each patient, one eye was randomized to instill dorzolamide eye drops three times a day as an intervention, and the other received artificial tear drops as a placebo. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) were evaluated before starting treatment and then monthly for the first three months. Among 25 included patients, the average age was 56.64 ± 7.97 years, and 48% were female. BCVA did not improve significantly in any groups (P > 0.05). No significant difference was observed in terms of BCVA between the intervention and control groups (P > 0.05). The present study showed a decrease in CMT in both study groups (P < 0.05). At month 3, the decrease in mean CMT from baseline was significantly higher in eyes receiving topical dorzolamide compared to the control group (-88.92 ± 82.90 vs. -37.64 ± 86.16 µM, respectively; P = 0.037). IOP decreased significantly only in eyes receiving dorzolamide (P < 0.001). The results of the present study indicate that adjunctive administration of topical dorzolamide has a beneficial effect on CMT reduction from baseline, but it did not have an additive effect on BCVA improvement compared to IVB monotherapy.

Ultrasound biomicroscopic findings in Fuchs uveitis syndrome: A contralateral eye study

Abstract: PURPOSE: The aim of this study was to determine ultrasound biomicroscopic findings in patients with Fuchs uveitis syndrome (FUS). METHODS: This cross-sectional, contralateral comparative eye study was conducted on patients with unilateral FUS. Both eyes of each patient underwent ultrasound biomicroscopy (UBM) imaging at the 12, 3, 6, and 9-o’clock radial meridians. Ultrasonographic data were collected, including the thickness (mm) of the ciliary body (CB), CB with ciliary processes, and iris thickness at 0.8 mm from the iris root, mid-iris, and iris tip. RESULTS: We enrolled 36 eyes from 18 patients with unilateral FUS, including 10 (55.6%) females, with a mean age of 38.44 ± 9.2 years. The average thickness of CB (P &lt; 0.001), 0.8 mm from the iris root (P = 0.003), mid-iris (P &lt; 0.001), and the iris tip (P &lt; 0.001) was thinner in the affected eyes compared to the fellow eyes of the patients. Analysis of variance analysis showed that differences among all quadrants were not significant in both groups (P &gt; 0.05). CONCLUSION: This study showed that CB and iris thickness were significantly thinner in the affected eyes compared to the fellow eyes of patients with FUS, as assessed using the UBM technique.

Topical Medroxyprogesterone Acetate and Corneal Epithelium Healing after Photorefractive Keratectomy: A Randomized, Double-masked Contralateral Eye Study.

The objective of the study was to evaluate the efficacy and safety of topical 1% medroxyprogesterone in corneal epithelial healing after photorefractive keratectomy (PRK). In this placebo-controlled double-masked randomized contralateral eye study, 66 eyes of 33 patients with myopia and myopia-astigmatism were assigned into two groups to receive either 1% topical medroxyprogesterone (intervention) or artificial tear (placebo) at the end of PRK surgery. The patients were followed up daily for 5 days until epithelial healing was achieved. The time taken for epithelial healing was the main outcome measure. The mean age of the subjects was 32.97 ± 7.6 years and 46 individuals were female (69.7%). All baseline refractive characteristics were comparable between the groups. There was no significant difference between the two groups in terms of epithelial defect size on Day 1 (P: 0.67). Both groups exhibited a consistent pattern of decreasing epithelial defect size from Day 1 to Day 5, with the control group having slightly worse initial values. There were no significant differences between the groups in the following days. Both groups showed substantial reductions in the epithelial defect size, but the intervention group showed a more prominent decrease on Day 2. The intervention did not show a significant statistical difference compared to the control group, and both groups ended up with a similar outcome. These findings suggest that the topical 1% medroxyprogesterone does not significantly affect the healing of corneal epithelium after PRK.

Preservative-Free Topical Anesthetic Unit-Dose Eye Drops for the Management of Postoperative Pain Following Photorefractive Keratectomy.

Ocular pain is a common complication following photorefractive keratectomy (PRK). The level of patient satisfaction with current pain control strategies is not high. This study aims to assess the efficacy and safety of a novel regimen of preservative-free oxybuprocaine hydrochloride 0.4% unit-dose eye drops for post-PRK pain control. In a contralateral eye study, 144 eyes of 72 patients who underwent bilateral transepithelial PRK (TransPRK) were stratified into experimental and control groups. The experimental group received preservative-free oxybuprocaine hydrochloride 0.4% unit-dose eye drops five times daily postoperatively until complete epithelial healing, while the control group received sodium hyaluronate 0.2% instead. The main outcome measures were pain scores assessed by the verbal rating scale and visual analogue scale (VRS, VAS), the corneal epithelial defect (CED) area, epithelial healing duration evaluated by slit-lamp biomicroscopy and anterior segment optical coherence tomography (AS-OCT), and endothelial cell density (ECD) measured before and 1 month after surgery. Pain scores assessed by VRS and VAS were significantly lower in the experimental group 8h after surgery, and 1, 2, and 3days postoperatively (P < 0.001). The mean CED area showed no significant differences between the two groups at different follow-ups (P value > 0.05). The corneal epithelial healing had a mean duration of 3.32 ± 0.47 days in both studied groups and was parallel in both eyes of each patient. In each group, 49 eyes (68%) and 72 eyes (100%) had a fully epithelialized surface on the third and fourth postoperative days, respectively. No significant changes were observed in the mean ECD 1 month following surgery in both groups (P value > 0.05). Preservative-free oxybuprocaine hydrochloride 0.4% unit-dose eye drops are effective and safe in controlling early postoperative pain following TransPRK. The availability of the single-dose unit preparation can overcome the problem of topical anesthetic abuse. ClinicalTrials.gov Identifier: NCT05733741.

Effects of artificial tears on keratocyte cell density after femtosecond laser in situ keratomileusis: a prospective, comparative, interventional, contralateral eye study

Background: Flap creation during laser refractive surgery restructures the anterior cornea, particularly the stroma, reducing the keratocyte cell density (KCD). This reduced density makes it challenging to completely regenerate to the presurgical phase. The aim of the present study was to investigate the effects of two types of artificial tear (AT) interventions on KCD up to 3 months after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery. Methods: This prospective, double-blind, comparative, interventional, contralateral eye study recruited patients with myopia scheduled for FS-LASIK. Inclusion criteria were healthy individuals aged 19 – 25 years with moderate or high myopia, a maximum cylindrical error of - 1.25 diopters, and a maximum pupil size of 6.5 mm who had undergone FS-LASIK and completed 3 months of follow-up. Complete optometric and ophthalmologic examinations were performed. Bilateral simultaneous FS-LASIK surgery was performed using the same femtosecond laser platform as in the standard procedure. The Research Randomizer was used to determine the eye to be treated with Systane® Hydration (Alcon Laboratories, Inc., Fort Worth, TX, USA) or Systane® ULTRA (Alcon Laboratories, Inc., Fort Worth, TX, USA) AT. KCD was examined using real-time images obtained from in vivo confocal microscopy (Heidelberg Retina Tomograph 3 with the Rostock Cornea Module, HRT III RCM); Heidelberg Engineering GmbH, Heidelberg, Germany) at baseline and 1- and 3-month postoperative visits. Results: We included 60 eyes of 30 participants with a mean (standard deviation) age of 21.34 (1.85) years and a male-to-female ratio of 1:1 who completed 3-month post-FS-LASIK surgery follow-up. KCD did not differ significantly between the two groups at any visit (all P &gt; 0.05); nevertheless, mean KCD was initially reduced up to 1 month postoperatively and then revealed a slight increase up to 3 months postoperatively in Systane® Hydration-treated eyes and continued to reduce in Systane® ULTRA-treated eyes. Intragroup comparisons revealed that the eyes treated with ATs experienced a significant reduction in KCD between the preoperative and 1-month postoperative visits and between the preoperative and 3-month postoperative visits (all P &lt; 0.05). Treatment-related complications were not observed. Conclusions: Overall, KCD reduced up to 3 months post-FS-LASIK surgery. Both AT types exerted a comparable effect on postoperative KCD up to 3 months. Future studies with a more frequent administration of ATs, longer follow-up periods, and a control group are required before preliminary outcomes of the present study can be generalized.

Choroidal thickness measurements of subjects with pseudoexfoliative syndrome and pseudoexfoliative glaucoma: A contralateral eye study.

In this study, we aimed to investigate the peripapillary choroidal thickness (PPCT) and macular choroidal thickness (MCT) in pseudoexfoliation (PEX) syndrome and compare the data of the contralateral eyes according to the presence of biomicroscopic eye involvement and glaucoma. In this cross-sectional case-control study, PPCT and MCT measurements were analyzed in 162 eyes of 81 subjects with PEX syndrome, diagnosed biomicroscopically with the detection of PEX material. The sample included 63 eyes with pseudoexfoliation glaucoma (PG), 49 eyes with visible PEX material alone without glaucoma (PM), 50 fellow eyes without biomicroscopically visible PEX material (F), and 48 eyes of 24 healthy individuals (controls) without any sign of PEX in the detailed ophthalmologic examination. The PEX syndrome group consisted of 25 PM-F, 25 PG-F, 19 PG-PG, and 12 PM-PM eye pairs. The PPCT and MCT values were compared between the eye-pairs of the subjects with the PEX syndrome. The mean PPCT measurements were 183.3 ± 8.1 µm, 158.5 ± 5.4 µm, 167.8 ± 5.9 µm, and 149.9 ± 5.5 µm for the eyes in the control, F, PM, and PG groups, respectively. The eyes in the PG group had statistically significantly lower measurements than those in the control group (p < 0.01). In the contralateral eye comparison of the subjects with PEX syndrome, no significant difference was found in relation to the mean PPCT and MCT measurements between the PM-F, PG-F, and PG-PG eye pairs (p > 0.05 for all). Although the eye groups with PEX syndrome had lower mean PPCT measurements than the controls, the contralateral eye analysis of the asymmetrically involved eye pairs showed no significant differences.

Effectiveness of ketorolac-soaked bandage contact lens for pain management after photorefractive keratectomy

Objective To evaluate the effect of ketorolac-soaked contact lenses (CLs) on postoperative pain after photorefractive keratectomy (PRK) and their potential side effects including conjunctival hyperaemia and delayed epithelial healing. Methods This is a prospective, randomised, double-blind, contralateral eye study. A total of 310 eyes of 155 patients who underwent PRK in both eyes were included in the study. After photoablation, a 0.4% ketorolac-soaked bandage CL was placed over the cornea in Group 1, while a drug-free soft bandage CL was placed over the cornea in Group 2. The postoperative pain was evaluated using a verbal numerical rating scale. The ocular redness was compared using the black pixels (veins, and areas of redness) and white pixels (remaining areas) of the images. The complications and time to corneal wound healing were also recorded. Results The mean pain score was significantly lower in Group 1 (2.7 ± 1.3) than in Group 2 (7.4 ± 1.4) on postoperative day 1 (p < 0.001). However, on the 3rd postoperative day, there was no significant difference between the groups in terms of pain scores (p = 0.42). Preoperative eye redness was 199.2 ± 16.0 pixels in Group 1 and 200.1 ± 17.6 pixels in Group 2 (p = 0.65). There was no statistically significant difference between the two groups in terms of eye redness at the postoperative 24th and 72nd hours (p = 0.43 and p = 0.39, respectively). Conclusion Soaking the bandage CL in a solution containing ketorolac 0.4% for 15 minutes could significantly lower pain scores on the first postoperative day after PRK, with no serious complications.

Safety and Precision of Two Different Flap-morphologies Created During Low Energy Femtosecond Laser-assisted LASIK.

Currently, two major principles exist to create LASIK flaps: firstly, a strictly horizontal (2D) cut similar to the microkeratome-cut and secondly an angled cut with a "step-like" edge (3D). The strictly horizontal (2D) cut method can be performed using apparatus such as the low-energy FEMTO LDV Z8 laser and its predecessors which are specific to this type. Alternatively, the low-energy FEMTO LDV Z8 laser's 3D flap design creates an interlocking flap-interface surface which potentially contributes toward flap stability. In addition, the FEMTO LDV Z8 offers flap-position adjustments after docking (before flap-creation). The current study analyzed precision, safety, efficacy, as well as patient self-reported pain and comfort levels after applying two different types of LASIK flap morphologies which were created with a low-energy, high-frequency femtosecond (fs) laser device. A prospective, interventional, randomized, contralateral eye, single-center comparison study was conducted from November 2019 to March 2020 at the Hamburg vision clinic/ zentrumsehstärke, Hamburg, Germany. Eleven patients and 22 eyes received low-energy fs LASIK treatment for myopia or myopic astigmatism in both eyes. Before the treatment, the eyes were randomized (one eye was treated with the 2D, the other eye with the 3D method). The mean central flap thickness one month after surgery was 110.7 1.6 μm (2D) and 111.2 1.7 μm (3D); P = 0.365 (2D vs 3D). Flap thickness measured at 13 different points resulted in no statistically significant differences between any of the measurement points within/between both groups; demonstrating good planarity of the flap was achieved using both methods. Despite not being statistically significant, the surgeons recognized an increase in the presence of an opaque bubble layer in the 3D flap eyes during surgery and some patients reported higher, yet not statistically significant, pain scores in the 3D flap eyes during the first hours after the treatment. Overall, safety- and efficacy indices were 1.03 and 1.03, respectively. In this prospective, randomized, contralateral eye study, the low-energy fs laser yielded predictable lamellar flap thicknesses and geometry at one-month follow-up. Based on these results, efficacy and safety of the corresponding laser application, that is, 2D vs 3D, are equivalent.

Does Adjunctive Under-flap CXL Reduce Regression for Hyperopic LASIK?

To investigate whether adding accelerated under-flap corneal cross-linking to hyperopic laser in situ keratomileusis (LASIK-ufCXL) affects postoperative stability and regression, visual and refractive outcomes, and subjective quality of vision. This prospective comparative contralateral eye study included 51 patients with hyperopia (102 eyes) who received LASIK-ufCXL in the eye with highest defocus equivalent (DEQ) or randomized when DEQ equal, with the contralateral control eye receiving LASIK alone. After excimer ablation, 0.25% riboflavin was instilled on the stromal bed for 3 minutes. The flap was repositioned, followed by a total irradiation dose of 3.24 J ultraviolet A (UV-A) light administered to the corneal surface, using 18 mW/cm2 UV-A for 3 minutes. Postoperative hyperopic regression (stability) was the primary outcome measure, defined by the difference in spherical equivalent (SEQ) at 1 week and 24 months postoperatively. Secondary measures reported uncorrected distance visual acuity, corrected distance visual acuity, cylinder vector analysis, subjective quality of vision, subjective night vision disturbances, and corneal haze. At 24 months, the SEQ stability (P = .4273) and the magnitude of hyperopic regression (P = .5613) did not significantly differ between groups, with a small trend showing hyper-opic regression of 0.50 diopters or greater being less frequent in LASIK-ufCXL eyes. There were no significant differences in accuracy, efficacy, and safety (P > .05), with a small trend of more residual refractive astigmatism in the LASIK-ufCXL group (P = .3216, Cohen's d: -0.29). Subjective quality of vision trended inferior in LASIK-ufCXL eyes (P = .2237, Cohen's d: -0.25), with a greater haze grading (P = .0466, Cohen's d: 0.41). Postoperative regression and stability were statistically equivalent between hyperopic LASIK vs LASIK-ufCXL, with identical safety. There were small clinical trends of lower efficacy, accuracy, and subjective quality of vision in LASIK-ufCXL eyes. [J Refract Surg. 2022;38(12):770-779.].

Comparison Between the Wavefront-Optimized and Custom-Q Aspheric Ablation Profiles in Myopic Eyes With Two Different Q-targets: A Contralateral Eye Study.

To compare two aspheric ablation profiles in myopic refractive surgery using different asphericity targets. Patients underwent laser in situ keratomileusis (LASIK) with the WaveLight EX500 laser platform (Alcon, WaveLight Laser Technologie). Asymmetric surgery was performed, programming the wavefront-optimized (WFO) ablation profile in one eye and the custom-Q (CQ) profile in the contralateral eye. The patients were divided into two groups following a systematic randomization method. The Q-target programmed for the preoperative Q group was equal to the preoperative asphericity of the CQ profile, and for the -0.6 Q-target group, the Q-target was set to -0.6. The study included 100 patients (200 eyes). Both groups had comparable safety and efficacy indexes greater than 1. A similar oblate shift in postoperative asphericity was seen in both groups regardless of the ablation profile and programmed Q-target. Asphericity was 0.33 ± 0.34 and 0.35 ± 0.29 (P = .18) in the preoperative Q group and 0.26 ± 0.28 and 0.26 ± 0.27 (P = .89) in the -0.6 Q-target group for WFO and CQ, respectively. A lower spherical aberration was found with CQ compared to WFO when the Q-target was set to -0.6: 0.211 ± 0.121 versus 0.144 ± 0.114 (P < .01). However, no statistically significant differences were found when the preoperative Q-target was used. WFO and CQ treatments are similar in terms of refractive and visual outcomes. CQ offers greater control over the increase in positive spherical aberration after myopic refractive surgery, but it does not represent an advantage over WFO in the oblate shift in postoperative asphericity regardless of the Q-target programmed. [J Refract Surg. 2022;38(11):698-707.].

Role of Corneal Collagen Cross Linking in Halting the Progression of Keratoconus: A Contralateral Eye Study

Objective: To assess the efficacy of Corneal Collagen Cross-Linking in preventing the progression of Keratoconus by comparing changes in Maximum Simulated Keratometry (K-max) in treated and untreated eye of the same patient. Methodology: All the cases, that met the inclusion/exclusion criteria (with complete pre-operative examinations), were enrolled in the study. Patients gave informed permission. In each patient, a computerized random number table was used to pick one eye for treatment and the other as a control. Patients were told to stop wearing hard contact lenses 3 weeks before the treatment and soft lenses 1 week before. After pre-op assessment, the selected eye underwent CXL. To control bias, only one experienced surgeon carried out the procedure and a thorough examination was done at 1st post-op day, 01 week, 01, 03 and 4 months after CXL. Main outcome measure during follow up was K-max as measured by Corneal Topography using Galilei G4. One experienced person performed corneal topography for all eyes to control bias. Results: In our study, mean age was 20.55+6.27 years, 60.61%(n=20) were male while 39.39%(n=13) were females. Comparison of the efficacy of corneal collagen cross-linking in preventing the progression of keratoconus by comparing changes in maximum simulated keratometry (K-max) in treated and untreated eyes of the same patient shows that 96.97%(n=32) in CXL and 3.03%(n=1) in control group showed efficacy whereas remaining 3.03%(n=1) in CXL and 96.97%(n=32) in control group had no efficacy, p value was 0.000. Conclusion: We concluded that Corneal Collagen Cross Linking is significantly effective in preventing increase in K-max when compared with the control group. Keywords: Keratoconus, Maximum Simulated Keratometry, Corneal Collagen Cross-Linking, Efficacy

Corneal densitometry in bilateral keratoconus patients with unilateral corneal Vogt's striae: a contralateral eye study.

To investigate corneal densitometry and correlations with corneal morphological parameters in patients with bilateral keratoconus (KC) with unilateral Vogt's striae. This prospective contralateral study enrolled 112 patients (224 eyes) with evident KC characteristics (corneal topography with asymmetric bow-tie pattern, inferior steepening), and at least one KC sign (conical protrusion of the cornea at the apex, corneal stromal thinning, Fleischer ring, Vogt's striae) on slit-lamp examination. Corneal densitometry and morphological parameters were measured using Pentacam HR. The mean age was 23.93 ± 6.81years. Fifty-two (23.22%), 111 (49.55%), and 61 (27.23%) eyes were in mild, moderate, and severe groups, respectively. Corneal densitometry values of the anterior 0-2mm and 2-6mm, intermediate 0-2mm and 2-6mm, posterior 2-6mm, and total cornea 2-6mm were significantly higher in eyes with Vogt's striae (P < 0.05), whereas those of the anterior 6-10mm, posterior 0-2mm, and total cornea 6-10mm were significantly lower in eyes with Vogt's striae (P < 0.05). Anterior 0-2mm and total cornea 2-6mm corneal densitometry values were positively correlated with anterior K1 (A-K1), K2 (A-K2), Km (A-Km), Kmax (A-Kmax), anterior corneal elevation, and posterior corneal elevation (P < 0.05), and negatively correlated with central corneal thickness and thinnest corneal thickness in eyes with Vogt's striae (P < 0.05). A-K2, A-Km, and A-Kmax were significantly correlated with the densitometry values of the anterior 0-2mm and intermediate 0-2mm in eyes without Vogt's striae (P < 0.05). Vogt's striae mainly occur on the anterior and intermediate layers during KC progression.

Long-Term Changes in Corneal Endothelial Cell Density after Ex-PRESS Implantation: A Contralateral Eye Study.

Our purpose is to evaluate long-term changes in corneal endothelial cells after Ex-PRESS shunt implantation for the treatment of glaucoma in Chinese patients by comparison with the contralateral eye. In this retrospective observational study, glaucoma patients with a single eye undergoing Ex-PRESS shunt implantation surgery were consecutively enrolled. For each patient, the clinical assessment, including corneal endothelial cell density (CECD) before surgery and at 6, 12 months, and at last follow-up (2.43 ± 0.63 years) after surgery was reviewed. The operated eyes were in the study group and the unoperated contralateral eyes were used as the control group to compare the CECD change. A total of 48 subjects (age, 51.02 ± 17.96 years) were included. The follow-up period was 2.08~3.17 years, with an average of 2.43 ± 0.63 years. At the last follow-up after the surgery, the CECD decrease in the operated eyes (5.0%) was similar to that in the contralateral eyes (3.2%) (p = 0.130). There were no significant differences in CECD reduction between the two groups at baseline and each postoperative follow-up (6 months, 12 months and at the last follow-up) (all p > 0.05). The average IOP reduction after the surgery was 50.8%, and the number of IOP-lowering medications was significantly reduced (p < 0.05). In addition, visual acuity showed no significant differences during follow-up (p > 0.05). In this study, we found that the CECD reduction of Ex-PRESS shunt-implanted Chinese eyes was similar to that of contralateral eyes without surgery.

Alterations in the ocular surface and tear film following keratoplasty

The purpose of this study was to evaluate any alterations in the tear film and ocular surface beyond the early postoperative period following penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). This cross-sectional, contralateral-eye study compared ocular surface and tear film parameters of eyes with a previous PK or DALK in one eye and no prior surgery in the contralateral eye. Overall, 14 (87.5%) participants underwent PK, and 2 (12.5%) underwent DALK using a mechanical dissection. The median time from surgery was 3.4 years (range 1.5 to 38.7 years). The indication for unilateral keratoplasty was keratoconus in 15 (94%) participants, and corneal scarring in 1 (6%) eye, secondary to microbial keratitis. Operated eyes exhibited poorer non-invasive tear film breakup time, lower corneal sensitivity, lower sub-basal nerve density and more severe fluorescein staining scores than unoperated fellow eyes (all Q < 0.05). There were no significant differences in tear film lipid layer quality, tear meniscus height, conjunctival hyperaemia, lissamine green staining score, or meibography grade between operated and fellow eyes (all Q ≥ 0.20). Higher corneal esthesiometry threshold (lower corneal sensitivity) was correlated with shorter non-invasive tear film breakup time (Spearman’s rho = − 0.361, p = 0.04) and increased fluorescein staining score (Spearman’s rho = 0.417, p = 0.02). Keratoplasty can induce persistent changes in the ocular surface and tear film, including: increased fluorescein staining, decreased tear film breakup time, decreased corneal sub-basal nerve plexus density, and reduced corneal sensitivity.

Femtosecond laser-assisted in situ keratomileusis with topography-guided or asphericity-adjusted derived data: a comparative contralateral eye study

BackgroundWavefront-optimized laser-assisted in situ keratomileusis (LASIK) ablation is the most commonly performed procedure in refractive surgery, but new technologies have become available. Our goal was to compare topography-guided (Contoura) and asphericity-guided (Custom-Q) customized ablation treatments for the correction of myopia with or without astigmatism.MethodsThis prospective, randomized, double-blind, contralateral eye study included 60 eyes of 30 patients with myopia or myopic astigmatism requiring femtosecond LASIK (FemtoLASIK) treatment. For each patient, one eye was randomized to undergo Contoura treatment, and the other underwent Custom-Q abaltion. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractive spherical equivalent (MRSE), sphere (SPH), cylinder (CYL), 6.0-mm total corneal aberration root mean square (RMS), coma (COMA), trefoil (TREF), and spherical aberration (SA) were measured and analysed after a 1-year follow-up.ResultsThe UDVA was − 0.08 ± 0.06 logMAR in Contoura eyes and − 0.08 ± 0.05 logMAR in Custom-Q eyes (p = 0.309) after 12 months. Twenty-five eyes (83%) in the Contoura group and twenty-six eyes (87%) in the Custom-Q group had a UDVA of 20/16 at the end of 12 months, and 100% of eyes in both groups reached a UDVA of 20/25 or better. Ninety and 100% of eyes in the Contoura and Custom-Q groups, respectively, achieved a residual CYL ≤0.50 D (p = 0.237). No statistically significant difference was observed between the surgical techniques in the preoperative to 1-year postoperative changes for any of the parameters evaluated (MRSE, CYL, RMS, DEF, COMA, TREF, and SA).ConclusionsThe Contoura and Custom-Q techniques yielded excellent visual and refractive results, but the evidence did not reveal any clear differences between these two methods after 1 year of follow-up.Trial registrationReBEC - Registro Brasileiro de Ensaios Clínicos [Internet]: Rio de Janeiro (RJ): Instituto de Informação Científica e Tecnológica em Saúde (Brazil); 2010 -. Identifier RBR-8rs5kt Myopia and Astigmatism Topography-guided Refractive Surgery by Contoura Method Versus Customized by Asphericity in Contralateral Eyes: A prospective Double blind Randomized Study. Available from https://ensaiosclinicos.gov.br/rg/RBR-8rs5ktDate of registration: 02/03/2020 (dd/mm/yyyy).CAAE:96778718.9.0000.5192.Issuing authority: Plataforma Brasil.CEP:2.979.279.Issuing authority: HUOC.

Predictability of Central Corneal Stromal Reduction After SMILE and FS-LASIK for High Myopia Correction: A Prospective Randomized Contralateral Eye Study.

To compare small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) in terms of the predictability of central stromal thickness reduction in eyes with high myopia. In this prospective, randomized contralateral eye trial, 42 patients received SMILE in one eye and FS-LASIK (using the Amaris 750S excimer laser [SCHWIND eye-tech-solutions]) in the fellow eye for the correction of high myopia (manifest refraction spherical equivalent: < -6.00 diopters). Spectral-domain optical coherence tomography was used to measure the central corneal and epithelial thickness. Pre-operative and postoperative values were compared to determine the amount of central stromal reduction achieved. At the 6-month follow-up visit, the amount of central stromal reduction was overestimated by 20.05 ± 5.92 µm in the SMILE group (P < .0001) and underestimated by 8.21 ± 8.14 µm in the FS-LASIK group (P < .0001). The mean actual central stromal reduction achieved with SMILE was significantly less than that achieved with FS-LASIK (10.10 ± 18.01 µm, range: 1.90 to 18.29 µm, P < .001). The discrepancy between the planned and achieved central corneal stromal reduction was not associated with refractive overcorrection or undercorrection in either the SMILE group or the FS-LASIK group (P = .9743 vs P = .0777). In patients with high myopia, the laser software platform may underestimate and overestimate the amount of actual corneal reduction in eyes treated with FS-LASIK and SMILE, respectively. SMILE required less corneal stroma compared to FS-LASIK in the studied cohort using the Amaris 750S excimer laser when correcting a similar spherical equivalent refraction. [J Refract Surg. 2022;38(2):90-97.].

Intracameral dexamethasone 9% vs prednisolone acetate 1% in controlling postoperative pain and inflammation in patients undergoing cataract surgery.

To compare patient preferences of postoperative cataract surgery topical medication use between a 1-drop and a 3-drop regimen. Two private cataract surgery centers. Open-label randomized self-controlled prospective study. This study included 30 patients (60 eyes) undergoing routine cataract surgery in both eyes. In this contralateral eye study, 1 eye of each patient was randomized to the 1-drop regimen of intracameral delivery of moxifloxacin and dexamethasone suspension and topical bromfenac for 30 days. The other eye, randomized to the 3-drop regimen, received topical moxifloxacin 0.5% 4 times a day for 7 days and bromfenac 0.07% daily for 30 days postoperatively, along with prednisolone acetate 1% 4 times a day for 30 days. Patients reported their preferred regimen 2 weeks after the second surgery with a validated questionnaire. Secondary outcomes included subjective ocular pain, inflammation score, and out-of-pocket cost. Intraocular pressure (IOP) and macular thickness were also measured. Of the 29 patients, 28 (96.6%) significantly more preferred the eye treated with a 1-drop regimen. Self-reported pain, activity interference, and out-of-pocket cost were significantly less in the 1-drop group. Inflammation and 1-day uncorrected distance visual acuity were also significantly better in the 1-drop group. Macular thickness and mean IOP were similar between groups. Intracameral delivery of steroid and antibiotics was preferred by most of the patients undergoing cataract surgery. These eyes had significantly less pain, inflammation, activity interference, and out-of-pocket cost and significantly better uncorrected distance visual acuity at 1 day postoperatively. IOP and macular thickness were similar between groups.