Epithelial and stromal remodeling after corneal collagen cross-linking evaluated by spectral-domain OCT.

PURPOSE: To evaluate changes in corneal epithelial and stromal thickness after corneal collagen cross-linking (CXL) in eyes with keratoconus and postoperative corneal ectasia using spectral-domain optical coherence tomography (SD-OCT). METHODS: Anterior segment SD-OCT (RTVue-100; Optovue, Inc., Fremont, CA) was used to compare regional corneal epithelial and stromal thickness in eyes with keratoconus and ectasia before CXL and 1 and 3 months after CXL. The anterior surface of the cornea, epithelium-Bowman's layer interface, and posterior reflective surface were used as anatomical landmarks to measure epithelial and stromal thickness, respectively. Regional thickness was assessed centrally and at 21 points 0.5 mm apart across the central 6 mm of the corneal vertex in the horizontal and vertical meridians. RESULTS: Thirty-one eyes from 30 patients were evaluated, including 17 eyes (17 patients) with keratoconus and 14 eyes (13 patients) with ectasia. Preoperatively, a highly irregular epithelial thickness profile and distribution was observed in both groups. After CXL, epithelial thickness was significantly thinner 2.5 and 2 mm below and 1.5 mm above the corneal apex (49.26 ± 5.69 µm; range: 43 to 62 µm), and 2.5 and 1 mm nasal and 2 mm temporal to the corneal apex (46.66 ± 4.53 µm; range: 39 to 57 µm) compared to preoperative values (P < .05 for all measurements). Epithelial thickness standard deviations were significantly lower (by 3 to 6 µm) 3 months after CXL, compared to ranges before CXL in both the vertical and horizontal meridians for keratoconus and ectasia (P = .048). No significant differences were found between epithelial remodeling in keratoconus and corneal ectasia (P = .98). No significant or consistent stromal changes were found for either group. CONCLUSIONS: Significant epithelial remodeling occurs after CXL in eyes with keratoconus and corneal ectasia, creating a similar, more regularized thickness profile in all meridians in the early postoperative period. This pattern of remodeling may facilitate interpretation of corneal curvature and thickness changes after CXL and may be related to visual acuity after CXL.

Prediction of the small aperture intraocular lens on visual acuity in patients with keratoconus.

PURPOSE: To investigate the impact of corneal higher-order aberrations (HOAs) on predicted corrected distance visual acuity (CDVA) in patients with keratoconus at varying simulated pupil apertures. SETTING: Ophthalmology clinics, Medical University of South Carolina, USA. DESIGN: Retrospective chart review study. METHODS: 56 eyes with keratoconus were examined using Scheimpflug tomography during routine examinations prior to medical intervention. The severity of keratoconus was graded using the Amsler-Krumeich classification. Zernike analysis was used to obtain corneal aberrations using simulated pupil diameters of 6-, 4-, and 2 mm. These data were extrapolated to obtain the total RMS HOAs for a 1.6 mm simulated pupil to evaluate the potential effect of a small aperture intraocular lens. Correlation analysis was used to study the impact and relative contributions of HOAs on CDVA. Convolution of HOAs from OPD-Scan III (NIDEK) provided a clinical method to predict CDVA with different simulated pupil sizes in corneas with irregular astigmatism. RESULTS: There were statistically significant positive correlations between photopic CDVA and the magnitude of total and individual (coma, spherical aberration and trefoil) HOAs in this cohort of keratoconus subjects. A keratoconus case with the small aperture IOL confirms the improvement in vision due to the pinhole effect. CONCLUSIONS: The small aperture IOL is expected to markedly reduce aberrations in keratoconus patients up to Amsler-Krumeich class 4 severity to levels consistent with the levels seen in healthy patients. Convolution of corneal HO aberrations with the ETDRS chart provides a useful simulation of the impact of pinhole optics in aberrated eyes.

EYELID MARGIN DISEASE (BLEPHARITIS AND MEIBOMIAN GLAND DYSFUNCTION): CLINICAL REVIEW OF EVIDENCE-BASED AND EMERGING TREATMENTS.

ABSTRACT: Blepharitis is a common ophthalmic condition with multiple etiologies and no definitive, universal treatment. The treatment modalities for managing lid margin diseases vary depending on the disease's cause, location, and severity. For anterior blepharitis, management options include eyelid hygiene with warm compresses, eyelid scrubs, baby shampoo, and over-the-counter eyelid cleansers. Topical antibiotics and antibiotic-steroid combination drops/ointments for the eye and eyelid may accompany these. For posterior blepharitis/meibomian gland dysfunction (MGD), at-home warm compress or in-office administration of heat therapy/thermal pulsation treatment that aims to clear obstruction in the meibomian glands and restore meibum secretions to maintain a healthy tear film, are recommended. In addition to the above treatment strategies, various other compounds to manage lid margin diseases are in the late stages of development. This review summarizes the available treatment modalities or those in the pipeline for treating blepharitis and MGD.

The Current State in the Diagnosis of Eyelid Margin Disease: A Clinical Review.

The eyelid margin is vital to ocular surface integrity. Much peer-reviewed literature has been established in eyelid margin inflammation, better known as blepharitis. The purpose is to review and understand the impact of eyelid margin disease. Anterior blepharitis causes inflammation at the eyelash base, ciliary follicles, and the palpebral skin. Posterior blepharitis occurs when there is inflammation with the posterior eyelid margin disease. In common usage, the term "blepharitis" used alone almost always refers to anterior blepharitis. Classification of eyelid margin disease should be based on etiopathogenesis, location, primary vs. secondary, and chronicity. Blepharitis has several etiopathologies (infectious, inflammatory, squamous). MGD can refer to the functional and/or structural problems with the MG. Meibomitis (or meibomianitis) occurs when there is inflammation associated with the MGD. The presence of blepharitis and/or MGD (with or without inflammation) can impact the ocular surface and thereby affect anterior segment and cataract surgeries. This review article evaluates the differential diagnoses of eyelid margin disease, including various forms of blepharitis, MGD, and meibomitis.

SD-OCT analysis of regional epithelial thickness profiles in keratoconus, postoperative corneal ectasia, and normal eyes.

PURPOSE: To assess corneal microarchitecture and regional epithelial thickness profile in eyes with keratoconus, postoperative corneal ectasia (ectasia), and normal unoperated eyes (controls) using spectral-domain optical coherence tomography (SD-OCT). METHODS: Regional corneal epithelial thickness profiles were measured with anterior segment SD-OCT (Optovue RTVue-100, Optovue Inc., Fremont, CA). Epithelial thickness was assessed at 21 points, 0.5 mm apart, across the central 6-mm of the corneal apex in the horizontal and vertical meridians. RESULTS: One hundred twenty eyes were evaluated, including 49 eyes from 29 patients with keratoconus, 32 eyes from 16 patients with ectasia, and 39 eyes from 21 control patients. Average epithelial thickness at the corneal apex was 41.18 ± 6.47 µm (range: 30 to 51 µm) for keratoconus, 46.5 ± 6.72 µm for ectasia (range: 34 to 60 µm), and 50.45 ± 3.92 µm for controls (range: 42 to 55 µm). Apical epithelial thickness was significantly thinner in eyes with keratoconus (P < .0001) and ectasia (P = .0007) than in controls. Epithelial thickness ranges in all other areas varied widely for keratoconus (range: 21 to 101 µm) and ectasia (range: 30 to 82 µm) compared to controls (range: 43 to 64) (P = .0063). CONCLUSION: SD-OCT demonstrated significant central and regional epithelial thickness profile differences between keratoconus, ectasia, and control eyes, with significant variability and unpredictability in ectatic eyes. This regional irregularity may necessitate direct epithelial thickness measurement for treatments where underlying stromal variations may be clinically relevant, including corneal collagen cross-linking or topography-guided ablations.

Tolerance to Induced Astigmatism With a Monofocal Intraocular Lens Designed to Extend the Depth of Focus.

PURPOSE: To determine tolerance to residual astigmatism and visual performance in eyes implanted with a monofocal intraocular lens (IOL) designed to extend the depth of focus (Tecnis Eyhance, DIB00; Johnson & Johnson Vision) compared to eyes implanted with a standard monofocal IOL (Tecnis ZCB00; Johnson & Johnson Vision). METHODS: This prospective, observational study enrolled consecutive patients who underwent routine cataract surgery and implantation of either the DIB00 (n = 20) or ZCB00 (n = 20) IOL. Astigmatic defocus was induced with a plus cylinder from +0.50 to +2.00 diopters (D) in 0.50-D steps for each astigmatic orientation (against-the-rule [ATR], with-the-rule [WTR], and oblique). Outcome measures included the comparison of mean visual acuity at each step of defocus, astigmatic defocus curves, and near and intermediate visual acuity. RESULTS: Eyes implanted with the DIB00 demonstrated greater astigmatic tolerance and were more likely to maintain 20/40 or better visual acuity with up to +2.00 D of induced ATR and oblique astigmatism than the ZCB00 IOLs. The DIB00 group showed 1.3 lines better visual acuity at 2.00 D of ATR astigmatic defocus and 1 line better than the ZCB00 group at 1.50 D of oblique astigmatic defocus. Although the distance visual acuity was comparable, near and intermediate visual acuities (both distance-corrected and uncorrected) were better for the DIB00 IOL than for the standard ZCB00 IOL. CONCLUSIONS: The monofocal IOL designed to extend the depth of focus (DIB00 group) showed greater tolerance to induced astigmatism in ATR and oblique orientations and superior uncorrected and distance-corrected near and intermediate visual acuity than the standard monofocal IOL of the same IOL platform. [J Refract Surg. 2023;39(4):222-228.].

Spectral-Domain OCT Lens Meridian Position as a Metric to Estimate Postoperative Anatomical Lens Position.

PURPOSE: To evaluate the prediction of postoperative anatomical lens position (ALP) using intraoperative spectral-domain optical coherence tomography (SD-OCT) lens anatomy metrics in patients who underwent femtosecond laser-assisted cataract surgery. METHODS: Intraoperative SD-OCT (Catalys; Johnson & Johnson Vision) and postoperative optical biometry (IOLMaster 700; Carl Zeiss Meditec AG) were used to assess anterior segment landmarks, including lens thickness, lens volume, anterior chamber depth, lens meridian position (LMP), and measured ALP. LMP was defined as the distance from the corneal epithelium to the lens equator, and ALP was defined as the distance from the corneal epithelium to the IOL surface. Eyes were divided into groups according to axial length (> 22.5 mm, 22.5 to 24.5 mm, and > 24.5 mm) and IOL type (Tecnis ZCB00 [Johnson & Johnson Vision]; AcrySof SN-60WF [Alcon Laboratories, Inc], or enVista MX60E [Bausch & Lomb]) to further analyze the correlation between LMP and ALP. Theoretical effective lens position was back-calculated using a specific formula. Primary outcome was correlation between postoperative measured ALP and LMP. RESULTS: A total of 97 eyes were included in this study. Linear regression analysis displayed a statistically significant correlation between intraoperative LMP and postoperative ALP (R2 = 0.522; P < .01). No statistically significant correlation was observed between LMP and lens thickness (R2 = 0.039; P = .06) or between ALP and lens thickness (R2 = 0.02; P = .992). The greatest predictor for ALP was LMP (ß = 0.766, P < .001; R2 = 0.523). CONCLUSIONS: Intraoperative SD-OCT-measured LMP correlated better than anterior chamber depth and axial length to postoperative ALP. Further studies are necessary to analyze the impact of preoperative or intraoperative LMP measurements on postoperative refractive outcomes. [J Refract Surg. 2023;39(3):165-170.].

Anterior segment reconstruction due to cosmetic iris implants placed in the anterior chamber.

A 27-year-old woman had BrightOcular iris implants placed for cosmetic purposes that changed eye color from brown to blue bilaterally. Of note, BrightOcular implants are not approved by the U.S. Food and Drug Administration (FDA) for use in the United States and have been associated with severe ocular complications. In keeping with their design, they were placed in the anterior chamber (AC) in both eyes of this patient; surgery was performed outside the United States. As has been described previously and tragically in other cases, she developed chronic inflammation, intolerable glare, angle-closure glaucoma, corneal edema, and cataracts in both eyes. For medically unmanageable elevated intraocular pressure (IOP), she underwent diode laser cyclophotocoagulation (CPC) in both eyes, and eventually, an Ahmed tube shunt (New World Medical, Inc.) was placed in the right eye. Although she was advised and urged to have the iris implants removed, despite her ocular issues, she refused removal until intolerable glare and reduced vision ensued. Ultimately, both iris implants were extracted 5 years after implantation by a U.S. surgeon; the procedures resulted in corneal decompensation and progressive cataract development. Subsequent penetrating keratoplasty (PKP) was performed for the right eye, but it failed because of contact with the glaucoma tube shunt. She sought additional consultation and presented with the following findings: corrected distance visual acuity was 20/400 in the right eye and 20/40 in the left eye, IOP of 18 mm Hg in the right eye and 16 mm Hg in the left eye, pupils were nonreactive and fixed, and extraocular muscles and central visual field were normal. Pachymetry was 868 µm in the right eye and 653 µm in the left eye. Anterior segment examination in the right eye revealed a failed corneal graft with 3+ edema, peripheral anterior synechiae (PAS) for 360 degrees, shallow AC, Ahmed tube shunt at the 11 o'clock position and remnant iris adherent to the graft-host junction for 270 degrees, 3+ posterior subcapsular cataract, and 2+ cortical cataract (Figure 1JOURNAL/jcrs/04.03/02158034-202208000-00024/figure1/v/2022-08-01T210317Z/r/image-tiff). The sclera revealed multiple circular and circumferential atrophic blue spots consistent with high-energy transscleral CPC (Figure 2JOURNAL/jcrs/04.03/02158034-202208000-00024/figure2/v/2022-08-01T210317Z/r/image-tiff). In the left eye, she had remnant fixed dilated iris for 270 degrees, missing iris superiorly for 3 clock hours, an adequate AC, and 2+ cortical cataract (Figure 3JOURNAL/jcrs/04.03/02158034-202208000-00024/figure3/v/2022-08-01T210317Z/r/image-tiff). Posterior segment examination revealed a 0.5 cup-to-disc ratio in both eyes with normal vessels, macula, vitreous, and retinal periphery, bilaterally. Given this constellation of findings, how would you proceed?

Analysis of microkeratome thin flap architecture using Fourier-domain optical coherence tomography.

PURPOSE: To assess the corneal architecture and reproducibility of LASIK flap thickness created by the Amadeus II mechanical microkeratome (Ziemer Ophthalmic Systems AG) using Fourier-domain optical coherence tomography (OCT; Optovue Inc). METHODS: Anterior segment Fourier-domain OCT was used to analyze the morphology of 58 LASIK flaps from 30 patients created with the Amadeus II microkeratome 140-µm head and ML7090CLB blades (Med-Logics Inc) at 2 weeks postoperatively. Flap thickness was assessed at 10 points across the central 6 mm of the cornea (horizontal and vertical meridians). Postoperative central corneal flap thickness measured by Fourier-domain OCT was compared with intraoperative ultrasound pachymetry measurements. RESULTS: No significant difference was noted between central flap thickness measured by intraoperative pachymetry (107.2 ± 14 µm) and postoperative OCT (111.7 ± 11 µm; P=.07, correlation coefficient=0.86). Fourier-domain OCT measurements demonstrated functionally planar flap architecture (standard deviation [SD] of thickness across the flap=4.9 µm, SD range across the flap=2 to 9 µm) for the microkeratome flaps. CONCLUSIONS: The Amadeus II microkeratome with Med-Logics blades created thin, reproducible, functionally planar flaps as measured by Fourier-domain OCT. Central flap thickness measured by intraoperative ultrasound pachymetry was equivalent to that measured 2 weeks postoperatively by OCT.

Neurotrophic keratitis after penetrating keratoplasty for lattice dystrophy.

PURPOSE: To report clinical outcomes of a patient with unilateral neurotrophic keratitis following penetrating keratoplasty for lattice dystrophy treated with topical recombinant human nerve growth factor. OBSERVATIONS: A 75-year-old male with lattice dystrophy and history of herpes simplex keratitis, presented with recurrent neurotrophic ulceration in the right eye two years following penetrating keratoplasty. The patient was successfully treated with topical recombinant human nerve growth factor. CONCLUSION: Neurotrophic keratitis is a rare chronic disorder that affects quality of life due to the risk of vision loss. Topical recombinant human nerve growth factor is a novel and effective treatment option that may help improve optical quality and patient's satisfaction as shown in this case of recurrent neurotrophic keratitis.

Correlation of Intraoperative Optical Coherence Tomography of Crystalline Lens Diameter, Thickness, and Volume with Biometry and Age.

PURPOSE: To characterize crystalline lens dimensions derived from in vivo spectral-domain optical coherence tomography (SD-OCT) and identify associations among these parameters, ocular biometry, and age. METHODS: In this retrospective study, lens thickness (LT), lens diameter (LD), and lens volume (LV) were measured intraoperatively using SD-OCT in 293 eyes undergoing lens surgery. Correlations among LT, LD, LV, age, axial length (AL), and anterior chamber depth (ACD) were analyzed. Multiple regression analysis was performed to determine whether a combination of biometric data could predict LD and LV. RESULTS: Wide variations were observed in LT (3.6-5.7 mm), LD (7.5-11.9 mm), and LV (119.9-312.4 mm3) of aging eyes. Correlations among the 3 lens dimensions were statistically significant (LV-LT: r = 0.785; P < .001; LV-LD: r = 0.696; P < .001; and LT-LD: r = 0.121; P = .039). With age, the correlation coefficients of LT, LD, and LV were 0.526, 0.326, and 0.573, respectively (P < .001). Although there was significant correlation of AL with LT (r = -0.137; P = .002) and LD (r = 0.268; P < .001), it was not significant with LV (r = 0.084; P = .15). Subgroup analysis revealed that 19.8% of long eyes had LD >1 standard deviation (SD) above and that 5.2% had LD <1 SD below the mean LD. CONCLUSIONS: Dimensions of the aging lens vary considerably and are most accurately characterized by direct measurement of LT, LD, and LV, rather than making assumptions based on AL. These findings challenge historically proposed relationships between LD and AL and represent a normative dataset of contemporary geometric features of the aging lens, possibly aiding in surgical decision making and future developments in lens surgery.

Refractive Accuracy of Barrett True-K vs Intraoperative Aberrometry for IOL Power Calculation in Post-Corneal Refractive Surgery Eyes.

PURPOSE: To compare the refractive predictability of intraoperative aberrometry (IA, ORA, Alcon) and Barrett True-K/Universal II formulas for intraocular lens (IOL) power calculations in post-corneal refractive surgery and normal eyes. METHODS: Retrospective study of normal and post-corneal refractive surgery eyes that underwent cataract surgery with IA at tertiary academic center. Preoperatively, IOL power calculations were performed using Barrett Universal II (normal eyes) or Barrett True-K (post-corneal refractive surgery eyes) formulas. Intraoperatively, aphakic IA measurements were used for IOL power calculations. Mean absolute refractive prediction error (MAE) and the percentage of eyes with prediction error within ±0.50, ±0.75 and ±1.00 D were calculated. Refractive predictability was also evaluated in short, normal, and long eyes. RESULTS: Two hundred and seventy-three eyes were included in the analysis. No statistically significant differences were observed between the MAE of preoperative formulas and IA for post-hyperopic laser vision correction (LVC), post-myopic LVC, post-radial keratotomy (RK) and normal eyes. For prediction error within ±0.5 D in post-corneal refractive surgery eyes, range of agreement between Barrett True-K and IA ranged from 28% (7/25) of the time in post-RK eyes to 49% (40/81) of the time in post-hyperopic LVC; the corresponding value for Barrett Universal II/IA was 62% (64/103) in normal eyes. When there was disagreement, IA outperformed Barrett True-K in post-hyperopic LVC eyes and Barrett formula outperformed IA in post-myopic LVC, post-RK, and normal eyes. CONCLUSION: IA appears to be comparable to Barrett formulas for IOL power calculations in post-corneal refractive surgery and normal eyes. In post-hyperopic LVC, IA yields better results compared to Barrett True-K formula; in real-life scenarios, IA reveals statistical advantage over the Barrett True-K no history formula for eyes post-hyperopic LVC.

Enhanced visual acuity and image perception following correction of highly aberrated eyes using an adaptive optics visual simulator.

PURPOSE: To evaluate the changes in visual acuity and visual perception generated by correcting higher order aberrations in highly aberrated eyes using a large-stroke adaptive optics visual simulator. METHODS: A crx1 Adaptive Optics Visual Simulator (Imagine Eyes) was used to correct and modify the wavefront aberrations in 12 keratoconic eyes and 8 symptomatic postoperative refractive surgery (LASIK) eyes. After measuring ocular aberrations, the device was programmed to compensate for the eye's wavefront error from the second order to the fifth order (6-mm pupil). Visual acuity was assessed through the adaptive optics system using computer-generated ETDRS opto-types and the Freiburg Visual Acuity and Contrast Test. RESULTS: Mean higher order aberration root-mean-square (RMS) errors in the keratoconus and symptomatic LASIK eyes were 1.88+/-0.99 microm and 1.62+/-0.79 microm (6-mm pupil), respectively. The visual simulator correction of the higher order aberrations present in the keratoconus eyes improved their visual acuity by a mean of 2 lines when compared to their best spherocylinder correction (mean decimal visual acuity with spherocylindrical correction was 0.31+/-0.18 and improved to 0.44+/-0.23 with higher order aberration correction). In the symptomatic LASIK eyes, the mean decimal visual acuity with spherocylindrical correction improved from 0.54+/-0.16 to 0.71+/-0.13 with higher order aberration correction. The visual perception of ETDRS letters was improved when correcting higher order aberrations. CONCLUSIONS: The adaptive optics visual simulator can effectively measure and compensate for higher order aberrations (second to fifth order), which are associated with diminished visual acuity and perception in highly aberrated eyes. The adaptive optics technology may be of clinical benefit when counseling patients with highly aberrated eyes regarding their maximum subjective potential for vision correction.

Static and Dynamic Factors Associated With Extended Depth of Focus in Monofocal Intraocular Lenses.

PURPOSE: To analyze factors affecting depth of focus (DOF) and near vision functionality in eyes implanted with aspheric monofocal intraocular lenses (IOLs). METHODS: This prospective study included 111 eyes of 74 patients that underwent phacoemulsification with monofocal IOL implantation. Ninety-one normal eyes were randomized to receive aberration-free (n = 30) or negative-spherical aberration (SA) IOLs (n = 61). Twenty post-hyperopic femto-LASIK eyes received aberration-free IOLs. Corneal higher-order aberrations (SA, coma, trefoil, and corneal asphericity) for a 6 mm pupil were measured by Scheimpflug tomography. Ray-tracing metrics (visual Strehl optical transfer function [VSOTF], effective range of focus [EROF], sphere shift [SS], EROF-SS), pupil size measurements at far and near, and ocular and corneal SA were obtained using ray-tracing aberrometry. Distance-corrected near visual acuity (DCNVA) and subjective defocus curves up to ±4.0 diopters were evaluated. RESULTS: Multivariable logistic regression found corneal profile and IOL type to be determinants of extended DOF with monofocal IOLs. The aberration-free IOL group showed significantly better DCNVA and higher total SA than the negative-SA group. Post-hyperopic LASIK eyes showed significantly better DCNVA; higher negative SA, coma, and Q value (P < .05), and smaller pupil size (P = .05) than normal eyes implanted with aberration-free IOLs. CONCLUSION: Corneal profile and type of IOL implanted were the most important factors influencing near vision functionality with aspheric monofocal IOLs. Higher positive SA in the aberration-free group potentially led to better DCNVA than the negative-SA group in normal eyes. Hyperprolate corneas had better DOF curves and DCNVA than normal corneas. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Comparison of Biometry Measurements Using Standard Partial Coherence Interferometry versus New Scheimpflug Tomography with Integrated Axial Length Capability.

PURPOSE: To compare biometry measurements obtained by a partial interferometer biometer (IOLMaster 500) to the new Scheimpflug tomography with an integrated axial length biometer module (Pentacam AXL). PATIENTS AND METHODS: Cataract patients who underwent biometric measurements with the IOL Master 500 and the Pentacam AXL from July to November 2017 were enrolled in this study. Comparisons were performed for axial length (AL), keratometry (K), and anterior chamber depth (ACD). The Pearson correlation coefficient and the 95% limits of agreement (LoA) were calculated. Paired Student's t-tests and Bland-Altman plots were used to assess the differences between devices. RESULTS: One hundred and sixty-six eyes of 92 patients were analyzed. There were no statistically significant differences in AL (p=0.558) or flat K (p=0.196) values between the IOL Master 500 and Pentacam AXL measurements. Statistically significant differences were found between the two devices with respect to steep K, ACD, and mean K measurements (p<0.001). CONCLUSION: Both devices provided similar measurements of AL and flat K, though there were statistically significant differences in ACD, steep K, and mean K measurements.

Combined flanged intrascleral intraocular lens fixation with corneal transplant.

PURPOSE: To report clinical outcomes and surgical technique of flanged intrascleral intraocular lens fixation with double-needle combined with either penetrating keratoplasty (PKP) or ultrathin Descemet-stripping automated endothelial keratoplasty (UT-DSAEK). OBSERVATIONS: Five patients underwent combined flanged intrascleral intraocular lens fixation with double-needle technique and keratoplasty. Three patients underwent triple procedure (open sky intrascleral intraocular lens fixation with double-needle and PKP) secondary to ocular trauma or a failed corneal transplant. Two patients underwent combined UT-DSAEK and intrascleral intraocular lens fixation for pseudophakic bullous keratopathy (PBK) and anterior chamber intraocular lens (AC IOL). CONCLUSION: Flanged intrascleral intraocular lens fixation with double-needle technique combined with PKP or UT-DSAEK was shown to be a safe and effective method of visual rehabilitation without additional intraoperative complications.

Objective assessment of optical quality in dry eye disease using a double-pass imaging system.

PURPOSE: To assess optical quality dynamics using a double-pass (DP) system in patients with dry eye disease (DED). METHODS: Seventy-six eyes with DED and 44 control subjects were enrolled in this study. Each patient underwent ocular surface evaluation including fluorescein corneal staining and Schirmer's II test. Ocular Surface Disease Index (OSDI) questionnaire was used to assess subjective symptoms. Optical quality dynamics and tear film instability was analyzed using a DP system (HD AnalyzerTM, Visiometrics, Spain). Mean objective scatter index (OSI), maximum and minimum OSI, difference between maximum and minimum OSI (ΔOSI) were recorded with 40 consecutive scans over 20 s. RESULTS: The DED group had pronounced impairment of optical quality compared to the control group. Mean OSI (4.29±4.07), minimum (3.22±3.51) and maximum (5.72±4.52) OSI, ΔOSI (2.50±1.96), OSDI score (36.94±16.55), and fluorescein corneal staining (0.79±0.96) were statistically significantly higher than controls (p<0.05). Schirmer's II test was statistically significantly lower in the DED group compared to controls (10.08±7.85, 26.41±6.75, respectively; p<0.001). Three patterns of dynamic changes of OSI were proposed: ladder (continuous increase of OSI), seesaw (instability of OSI without improvement after blinking), and plateau (steady-high OSI). The ladder group showed the highest value of maximum OSI (6.93±4.13; p=0.03) and ΔOSI (3.76±2.08; p<0.001). CONCLUSION: DP imaging system provides an objective measurement of the visual quality in DED. Tear film instability may be assessed by dynamic changes of OSI over 20 s. In particular, the highest OSI values were observed in the ladder pattern group.

Lens anatomy parameters with intraoperative spectral-domain optical coherence tomography in cataractous eyes.

PURPOSE: To study correlations of crystalline lens anatomy and position parameters obtained using intraoperative spectral-domain (SD) optical coherence tomography (OCT) in cataract patients. METHODS: This retrospective study evaluated biometry data from 600 eyes of 399 cataract patients (mean age: 69±8.4 years) using intraoperative anterior segment SD-OCT during femtosecond laser-assisted cataract surgery. Lens anatomy and position parameters (anterior chamber depth [ACD] - center of the anterior cornea to the anterior lens capsule, lens thickness [LT] - distance between anterior and posterior lens capsules, and lens meridian position [LMP] - distance from center of the anterior cornea to intersection of the anterior and posterior lens) obtained with intraoperative SD-OCT, were correlated among themselves and with noncontact axial length (AL). Equatorial plane position (EPP) (distance between the plane of the lens equator and anterior capsule) was also studied. Pearson's coefficients (r-values) were determined for all correlation pairs. RESULTS: There was a moderate correlation between AL and ACD (r=0.451; P<0.001). LMP was found to correlate strongly with ACD (r=0.77; P<0.001) but very weakly with AL (r=0.089; P=0.04). There was a moderately strong inverse correlation between LT and ACD (r=-0.586; P<0.001) but the correlation between LT and AL and LT and LMP was found to be weak (r=-0.155; P<0.001 and r=-0.121, P=0.003, respectively). Correlation of the ratio of EPP/LT and LT was weakly positive (r=0.267; P<0.001). CONCLUSION: LMP correlated strongly with ACD but only minimally with AL. LT correlated fairly strongly with ACD but only minimally with LMP. This should stimulate additional research into the relationships among ocular and crystalline lens anatomy and IOL position after cataract surgery.

Method for optimizing topography-guided ablation of highly aberrated eyes with the ALLEGRETTO WAVE excimer laser.

PURPOSE: To evaluate the clinical outcomes of custom topographic neutralizing technique in treating highly aberrated eyes using the WaveLight ALLEGRETTO WAVE Excimer Laser. METHODS: A retrospective consecutive case series of 67 eyes with decentered ablations and 48 eyes with symptomatic small optical zones after previous LASIK underwent topography-guided retreatment with the ALLEGRETTO WAVE. Sixteen keratoconus eyes underwent topographic neutralizing technique photorefractive keratectomy (PRK). The study assessed preoperative and 6-month and 1-year postoperative results regarding best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), topography, and predictability. RESULTS: Sixty-seven eyes with previously decentered optical zones had an improvement of centration from 0.92 mm preoperatively to 0.30 mm postoperatively relative to pupil center (P<.01). Twenty-nine percent of these eyes gained 1 or more lines of BSCVA, whereas 71% had no change in BSCVA. Forty-eight eyes with previously small optical zones had an increase of the central monodioptric optical zone from 3.9 mm to 5.6 mm (P<.01). Nineteen percent of eyes had an improvement of at least 1 line, whereas 75% had no change in BSCVA and 6% lost 1 line. Sixteen keratoconus eyes had custom topographic neutralizing technique PRK as an alternative to penetrating keratoplasty. All eyes had improvement of astigmatism up to 5.00 diopters (D), with a mean change of 1.68+/-1.62 D. Best spectacle-corrected visual acuity was unchanged in 8 (50%) eyes, with 4 (25%) eyes gaining 1 line, 2 (12%) eyes gaining 2 lines, and 2 (12%) eyes losing 1 line of BSCVA at 6 months. CONCLUSIONS: Management of some highly aberrated eyes is now possible with topography-guided ablation using the WaveLight ALLEGRETTO platform and custom topographic neutralizing technique. Safety was acceptable for small optical zone and decentered ablation retreatments. The topography-guided ablation could be an alternative treatment for keratoconus patients if keratoplasty is otherwise indicated. The algorithms for custom topographic neutralizing technique need further refinement.

Comparative study of riboflavin-UVA cross-linking and "flash-linking" using surface wave elastometry.

PURPOSE: To investigate comparative stiffness values in porcine corneas after standard cross-linking and a new, rapid method of cross-linking (flash-linking) using surface wave elastometry. METHODS: Ten porcine eyes were treated using an ultraviolet A (UVA) double diode light source with a wavelength of 370 nm and delivering an irradiance of 4.2 mW/cm2 at a distance of 1.2 cm while applying 0.1% riboflavin-5-phosphate drops to the central cornea every 5 minutes as a photosensitizer for 30 minutes (riboflavin-UVA group). The next 10 porcine corneas were treated with a single application of a customized photoactive crosslinking agent and 30 seconds of UVA light at the same power and wavelength (flash-linking group). Following treatment, the Sonic Eye system (PriaVision Inc) was used to measure ultrasound surface wave propagation time between two fixed-distance transducers applied to the cornea along central horizontal and vertical positions. Intraocular pressure was continuously monitored. RESULTS: Mean surface wave velocity was determined from the last 5 of 10 sequential measurements for each eye, and was 90.87 +/- 15.26 m/s for all eyes with a mean standard deviation (SD) of 2.34 m/s among each eye in the riboflavin-UVA group versus 83.66 +/- 12.30 m/s with a mean SD of 2.69 m/s among each eye in the flash-linking group before treatment and 109.2 +/- 21.76 m/s with a mean SD of 2.15 m/s among each eye (riboflavin-UVA group) versus 109.2 +/- 18.42 m/s with a mean SD of 2.26 m/s among each eye (flash-linking group) after cross-linking. The mean surface wave velocity increased by 18.3 units from 90.87 to 109.2 m/s (P = .003) after cross-linking with riboflavin-UVA, and by 25.5 m/s from 83.66 to 109.2 m/s (P = .0001) after flash-linking. Surface wave velocity was noted to increase after both cross-linking techniques, but the differences observed did not reach statistical significance (P = .74). CONCLUSIONS: A new, rapid method of cross-linking (flash-linking) is introduced by the use of a customized photoactive cross-linking agent. The method demonstrates similar efficacy in stiffening the cornea (when measured with surface wave elastometry) in comparison to standard cross-linking, but requires only 30 seconds of UVA exposure.