When is refraction stable following routine cataract surgery? A systematic review and meta-analysis.

PURPOSE: We systematically reviewed the literature to investigate when refraction is stable following routine cataract surgery implanting monofocal intraocular lenses. Current advice recommends obtaining new spectacles 4-6 weeks following surgery. Due to advancements in surgical techniques, we hypothesised that refractive stability would be achieved earlier, which could have major short-term improvements in quality of life for patients. METHODS: Medline, CINAHL, AMED, Embase, Web of Science and the Cochrane Library were searched with key words chosen to find articles, which assessed refraction following uncomplicated cataract surgery. Citation chains and the reference lists of all included papers were searched. Unpublished literature was identified using OpenGrey (www.opengrey.eu). The review considered studies that measured refraction at regular intervals following surgery until stability was achieved. RESULTS: The search identified 6,680 papers. Two reviewers independently screened the abstracts and nine papers were found to fit the criteria, of which five were included in the meta-analysis. The quality of the papers was evaluated using the Methodological Index for Non-Randomised Studies (MINORS) instrument. Meta-analysis of 301 patients' data of spherical, cylindrical and spherical equivalent correction were performed using Review Manager 5 (RevMan 5.3) (https://revman.cochrane.org/). Refraction at 1-week versus the gold standard of 4-weeks showed no significant difference for sphere data (effect size and 95% confidence interval of; ES = 0.00, 95% CI: -0.17, 0.17; p = 1.00), cylindrical data (ES = +0.06; 95% CI: -0.05, 0.17; p = 0.31), and spherical equivalent (ES = -0.01; 95% CI: -0.12, 0.10; p = 0.90). Heterogeneity was non-significant (I2  < 25%) for all refractive elements. Data were similar for 2- versus 4-weeks post-surgery. Acquired data from one study highlighted a small number of patients with very unstable cylindrical corrections at 1-week post-operatively. CONCLUSIONS: No statistical difference was found when comparing sphere, cylindrical and spherical equivalent values at 1- and 4-weeks post cataract surgery. This suggests that new glasses could be provided 1-week after surgery. However, from a clinical perspective, a small number of patients (~7%) from an acquired dataset (N = 72) showed very unstable cylindrical corrections at 1-week. Further work is needed to determine why this is the case and how these patients can be detected.

Reduced Peripapillary and Macular Vessel Density in Unilateral Postgeniculate Lesions With Retrograde Transsynaptic Degeneration.

BACKGROUND: Retrograde transsynaptic degeneration (RTSD) of the retinal ganglion cells and retinal nerve fiber layer after postgeniculate injury has been well documented, but to the best of our knowledge, associated retinal microvascular changes have not been examined. The purpose of our study was to assess vessel density (VD) at macular and peripapillary regions in patients with RTSD. METHODS: Cross-sectional study including 16 patients with homonymous visual field defects secondary to unilateral postgeniculate visual pathway injury and 18 age-matched controls. All participants were examined with AngioVue optical coherence tomography angiography to measure the peripapillary vessel density and macular vessel density (pVD/mVD) as well as the peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell complex (GCC) thicknesses. The pRNFL and macular ganglion cell-inner plexiform layer (GCIPL) thicknesses also were evaluated using Cirrus OCT. A normalized asymmetry score (NAS) was calculated for GCIPL and GCC thickness, and mVD. RESULTS: Average pRNFL and macular GCIPL/GCC thicknesses were significantly thinner in both eyes of patients compared with control eyes (all P ≤ 0.05). Eight patients (50%), who showed a RTSD of the GCIPL map, had a relative thinning of the GCIPL/GCC ipsilateral to the brain lesion in both eyes (represented by a positive GCIPL-NAS/GCC-NAS). The mean pVD and mVD also were significantly reduced in patients (all P ≤ 0.05). There was a strong correlation between GCIPL-NAS/GCC-NAS and mVD-NAS index in both eyes (all r > 0.7, P = 0.001). Furthermore, there was a similar spatial pattern of damage for the macular GCC thickness and VD values. CONCLUSIONS: We demonstrated a significant VD decrease in peripapillary and macular areas of patients with RTSD because of postgeniculate lesions. The structural and microvascular asymmetry indexes were significantly correlated. These findings provide new insights regarding transsynaptic degeneration of the visual system.

Reduction of Peripapillary Vessel Density by Optical Coherence Tomography Angiography from the Acute to the Atrophic Stage in Non-Arteritic Anterior Ischaemic Optic Neuropathy.

PURPOSE: To analyse superficial peripapillary vascularization in non-arteritic anterior ischaemic optic neuropathy (NAION) at acute and atrophic (3 months) stage. PROCEDURES: Prospective case-control study including 6 patients with NAION and 10 age-matched healthy controls evaluated with optical coherence tomography angiography (OCT-A; Angioplex-Cirrus) at acute and atrophic stage. Apart from the -commercially provided measurements for vessel density (VD) and perfusion density (PD), a custom image analysis was used to quantify the peripapillary capillary density (PCD). RESULTS: NAION-group demonstrated a significant decrease in the PCD, VD and PD compared with fellow unaffected and control groups at acute and atrophic stage. At 3 months, the average and the temporal sector in PCD correlated with logMAR VA (-0.943, p = 0.005 and -0.829, p = 0.042 for average and temporal sectors respectively) and with MD (0.943, p = 0.005; and 0.899; p = 0.015, respectively). Over 3 months, there was a significant PCD reduction at the temporal sector and at the inner circle in VD and PD, which correlated with ganglion cell-inner plexiform layer (GCIPL) thinning over the 3 months period after the acute NAION (0.749, p = 0.020; 0.885, p = 0.002; 0.767, p = 0.016 respectively). CONCLUSION: Both strategies demonstrated a significant peripapillary microvascular dropout in NAION, but the customized analysis detected them -earlier. A progressive vessel reduction occurs within the first 3 months, which correlates with GCIPL thinning.

Automated Evaluation of Choroidal Thickness and Minimum Rim Width Thickness in Nonarteritic Anterior Ischemic Optic Neuropathy.

BACKGROUND: The aim of this study was to evaluate and compare peripapillary choroidal thickness (pCT) and macular choroidal thickness (CT), Bruch membrane opening-minimum rim width (BMO-MRW), retinal nerve fiber layer (RNFL) thickness, and optic disc area among nonarteritic anterior ischemic optic neuropathy (NAION) eyes, the contralateral unaffected eyes, and healthy control eyes. METHODS: Twenty-six patients diagnosed with NAION (29 affected and 21 unaffected eyes) and 29 healthy matched control individuals (29 eyes) were analyzed by swept-source optical coherence tomography. All participants underwent scanning by Spectralis optical coherence tomography to analyze BMO-MRW, RNFL thickness, and optic disc area. RESULTS: Mean pCT in the NAION eyes, unaffected fellow eyes, and the control group was 130.5 ± 72.1 µm, 149.6 ± 75.7 µm, and 103.7 ± 36.7 µm, respectively (analysis of variance [ANOVA], P = 0.04). Mean macular CT in the NAION eyes, unaffected fellow eyes, and the control group was 226.1 ± 79.8 µm, 244.6 ± 81.4 µm, and 189.9 ± 56.4 µm, respectively (ANOVA, P = 0.03). Mean and all sectorial RNFL and BMO-MRW thickness values were significantly thinner in the NAION eyes vs the unaffected fellow and control eyes (P ≤ 0.00). The unaffected fellow eyes in NAION patients showed a significantly thicker average and sectorial BMO-MRW values than control eyes (P ≤ 0.02) except for the nasal sector (P = 0.09). Mean optic disc area derived from BMO analysis was not significantly different among groups (ANOVA, P = 0.86). CONCLUSIONS: The fellow unaffected eyes in patients with NAION showed significantly thicker mean peripapillary and macular choroidal and BMO-MRW thicknesses than disease-free control eyes. No differences in the mean optic disc area were found. Both a thick peripapillary choroid and a thick neuroretinal rim might contribute to the development of NAION or possibly be a secondary phenomenon.

Optical Coherence Tomography to Differentiate Papilledema from Pseudopapilledema.

PURPOSE OF REVIEW: Mild papilledema may be difficult to distinguish by clinical observation from pseudopapilledema. An accurate diagnosis is critical to avoid invasive workup and unwarranted treatment. In this review, we focus on the development and subsequent role of optical coherence tomography (OCT) in detecting and differentiating optic nerve head drusen (ONHD) from papilledema and other causes of acquired swelling of the optic disc. RECENT FINDINGS: Newer OCT technologies which permit deeper penetration to improve detection of ONHD were also reviewed. Enhanced depth imaging (EDI) spectral-domain OCT and swept-source (SS) OCT are currently recognized as the most reliable and sensitive tools to diagnose ONHD. OCT devices currently available provide a means to quantify drusen dimensions, to evaluate the integrity of neighboring structures and to monitor axonal and neuronal damage, yielding additional information to better understand the relationship between the morphological features of drusen, and their effects on the structure and function of the optic nerve.

Relationship between lamina cribrosa displacement and trans-laminar pressure difference in papilledema.

PURPOSE: The purpose of this study was to describe morphological changes in lamina cribrosa (LC), prelaminar tissue thickness (PTT) and Bruch's membrane opening (BMO) in eyes affected by papilledema and correlate them with trans-LC-pressure difference (TLCD). METHODS: This was a prospective study, including twelve eyes newly diagnosed of papilledema. Eyes underwent scanning with Spectralis-OCT with enhanced depth imaging to compare BMO, anterior LC surface position (LC depth-LCD-) and PTT before and after oedema resolution. Correlation analysis between these parameters and TLCD was performed. RESULTS: TLCD inversely correlated with LCD at baseline and directly with LC reversal movement after lowering cerebrospinal fluid pressure (CSFP) (ρSpearman: -0.739, p = 0.006; ρSpearman: 0.844, p = 0.001 respectively). At onset, RNFL thickening and BMO were significantly larger in eyes with TLCD > -9.2 mmHg (group 2) compared with TLCD < -9.2 mmHg (group 1) [p = 0.007, p = 0.041 respectively]. A significant RNFL and BMO shrinking were observed, but they were significantly larger in group 2. The magnitude of LC displacement following oedema resolution was significantly larger and in the opposite direction in group 2 vs group 1 (-68.7 µm vs 19.5 µm, p = 0.016). TLCD correlated with RNFL thickening at baseline (ρSpearman: 0.667, p = 0.018) and with RNFL thinning at last visit (ρSpearman: 0.673, p = 0.017). TLCD correlated with mean deviation (MD) (ρSpearman: 0.712, p = 0.014) and visual field index (VFI) (ρSpearman: -0.657, p = 0.028) at onset. MD and VFI were worse in group 2. CONCLUSIONS: LC position was significantly related to TLCD in papilledema. Eyes with higher TCLD showed significantly larger backward LC movement, BMO shrinking and RNFL thinning after lowering CSFP compared with eyes with lower TLCD, where LC movement occurred in the opposite direction.

Success of Rigid Gas Permeable Contact Lens Fitting.

OBJECTIVES: To assess the percentage of successful rigid gas permeable (GP) contact lenses (CLs) fit for both refractive and therapeutic reasons. METHODS: New CLs (soft or GP) fittings were retrospectively analyzed and divided into refractive and therapeutic prescriptions. A standardized fitting protocol that included complete CLs information after a first eye examination, a diagnostic fitting visit, a dispensing visit, and a prescribing visit was used in all fittings. A GP fitting was defined as successful if full-time wear and optimal ocular surface physiology were both achieved at the review assessment 2 to 3 weeks after lens dispensing. RESULTS: Of 232 new CLs fittings analyzed, 166 were refractive fittings (71.6%) and 66 were therapeutic (28.4%). Of the refractive fittings, 88 subjects (53%) were initially fitted with GP CLs and 61 (69.3%) of these met the criteria for successful GP fitting. Within this group, a different percentage of successful fits were found for neophyte (72%), previous soft lens wearers (62%), and previous GP wearers (92.3%). Of the therapeutic fittings, 61 subjects (92.4%) were initially fitted with GP CLs and 59 (96.7%) of these met the criteria for successful GP fitting. CONCLUSIONS: Following a standardized CLs fitting protocol, a relatively high percentage of successful GP fits was achieved for refractive (7/10 subjects) and therapeutic (9/10 subjects) prescriptions. These results will improve the information available to patients and aid in their CL choices by providing them with a realistic attitude. It will also help eye care practitioners in their clinical activities by providing evidence-based information.

The influence of the refractive correction on the vision-related quality of life in keratoconus patients.

PURPOSE: The aim of this study was to assess the impact of refractive correction [spectacles vs rigid gas-permeable contact lenses (RGP CLs)] on the vision-related quality of life (VR-QoL) obtained with the standardized questionnaire, NEI-VFQ-25, in keratoconus patients compared with healthy myopic subjects. METHODS: The Spanish version of NEI-VFQ-25 was administered two consecutive times to 25 keratoconus patients (RGP CL wearers) and 25 healthy myopic subjects (RGP and soft CL wearers). The first time was to assess the VR-QoL for spectacle wearing, such as those for refractive correction, and the second time was for CL wearing. RESULTS: Keratoconus patients showed a lower VR-QoL impairment (P < 0.01) than healthy subjects in the total and all subscale score of NEI-VFQ-25 related to wearing spectacles. With CL correction, keratoconus patients showed a VR-QoL improvement with statistically significant differences (P < 0.04) in only four subscales, including distance activities, mental health, color vision and peripheral vision, compared with healthy subjects. In the keratoconus group, compared to spectacle use, CL wear improved the VR-QoL score (P = 0.01) and all subscales except for ocular pain (P < 0.01) and mental health (P = 0.25). CONCLUSIONS: The use of the NEI-VFQ-25 to explore the difference in the VR-QoL between healthy subjects and patients with keratoconus provides further evidence of improved VR-QoL with RGP CL wear compared with spectacles in keratoconus patients. RGP CL management in keratoconus patients could minimize the impact of the disease on the patient's well-being.

Rigid Gas Permeable Contact Lens Fitting Using New Software in Keratoconic Eyes.

PURPOSE: To determine the repeatability of the back optic zone radius (BOZR) of rigid gas permeable (GP) contact lens (CL) proposed by new software for fitting in healthy and keratoconus eyes and to compare with the diagnostic CL fitting method. METHODS: Three consecutive corneal topographies (Oculus-Keratograph) were performed and analyzed with APEX new software CL fitting (Hecht-Contactlinsen, Germany) in 40 healthy and 40 keratoconus eyes fitted with GP using conventional diagnostic method. The coefficient of variation (CV) of the BOZR suggested by APEX was calculated. The BOZR of both fitting methods (software versus diagnostic) were compared maintaining the same lens diameter. RESULTS: BOZR proposed by APEX showed good repeatability in healthy (CV = 0.32%) and keratoconus eyes (CV = 0.51%). APEX proposed flatter BOZR than the diagnostic method in healthy (7.91 ± 0.24 and 7.84 ± 0.26 mm, p < 0.01) and keratoconus eyes (7.34 ± 0.38 and 7.23 ± 0.37 mm, p < 0.01). A strong linear correlation in healthy (BOZR_Diagnostic_Method = (BOZR_APEX × 1.06) - 0.53; p < 0.01, R = 0.969) and keratoconus eyes (BOZR_Diagnostic_Method = (BOZR_APEX × 0.88) + 0.77; p < 0.01, R = 0.825) was found. A detailed analysis showed a similar trend in different keratoconus stages (Amsler-Krumeich classification); stage 1: 7.42 ± 0.30 and 7.40 ± 0.25 mm, BOZR_Diagnostic_Method = (BOZR_APEX × 0.81) + 1.38, R = 0.973; stage 2: 7.30 ± 0.44 and 7.23 ± 0.38 mm, BOZR_Diagnostic_Method = (BOZR_APEX × 0.84) + 1.07, R = 0.929; and stage 3: 7.33 ± 0.39 and 7.11 ± 0.40 mm, BOZR_Diagnostic_Method = (BOZR_APEX × 0.93) + 0.28, R = 0.831. Applying these regression formulas, the BOZR difference could be reduced in healthy (-0.01 ± 0.05 mm) and keratoconus eyes (-0.01 ± 0.14 mm) for each keratoconus stage (0.01 ± 0.04, 0.03 ± 0.10, and 0.02 ± 0.16 mm in stages 1, 2, and 3, respectively). CONCLUSIONS: APEX software provides repeatable BOZR in healthy and keratoconus eyes, but it tends to propose flatter BOZR than the diagnostic method. APEX BOZR should be improved with new equations and helping with the GP fitting procedure.

Repeatability of placido-based corneal topography in keratoconus.

PURPOSE: To determine and compare the repeatability of a Placido-based corneal topography (Oculus Keratograph) in a sample of healthy and keratoconus eyes. METHODS: The corneal topography, determined using the Oculus Keratograph, of 25 healthy and 25 keratoconus eyes was assessed three consecutive times. A single randomized eye was included per patient. Coefficient of variation (CV) of the eccentricity, corneal diameter, index of surface variance, index of vertical asymmetry, keratoconus index (KI), smallest sagittal curvature radius (Rmin), aberration coefficient, and maximum corneal power and minimum corneal power (diopters) in the 3.0-mm zone in addition to the maximum corneal power point (MCPP) (diopters) were calculated and compared between healthy and keratoconus eyes. RESULTS: Healthy eyes showed lower topographic values (p < 0.05) than keratoconus eyes, except with regard to the Rmin value. Corneal diameter (p = 0.45) was similar in both groups. All variables showed good CVs in healthy and keratoconus eyes (maximum corneal power [0.21 and 0.47%, respectively], minimum corneal power [0.19 and 0.36%], MCPP [0.22 and 0.77%], corneal diameter [0.27 and 0.33%], index of surface variance [4.82 and 3.10%], index of vertical asymmetry [7.05 and 3.80%], KI [0.29 and 0.72%], Rmin [0.53 and 0.78%], and aberration coefficient [0 and 4.00%]) except for the eccentricity CV (5.79 and 14.53%, respectively). Statistically significant differences (p < 0.05) between healthy and keratoconus groups were found for all variables, except with respect to the MCPP, eccentricity, corneal diameter, KI, and Rmin (p > 0.07). CONCLUSIONS: The Oculus Keratograph provides repeatable measurements of corneal topography in healthy and keratoconus eyes. These results could improve the topographical diagnosis of keratoconus, thus aiding in patient management.

Refractive stabilization and corneal swelling after cataract surgery.

PURPOSE: To determine the earliest time after cataract surgery when corneal swelling and automated refraction are stabilized sufficiently to allow reliable refractive prescription. METHODS: This was a prospective, nonrandomized, case series study of 124 consecutive eyes undergoing uneventful cataract surgery. Automated refraction and central corneal thickness (CCT) measurements were made at baseline before cataract surgery and on follow-up visits 1 day and weekly for 4 weeks afterward. Corneal swelling was determined as the percentage change in CCT after surgery. To determine the validity of automated refraction, it was compared with subjective refraction at the final visit. RESULTS: Corneal swelling decreased between the first postsurgical day and the first week and again between postsurgical weeks 1 and 2 (p < 0.01 each). Although thinning continued through the fourth postsurgical week, the changes were not significant. Both spherical and cylindrical refraction were stable 1 week after surgery, with the greatest change between the first postsurgical day and 1 week (p < 0.01). In replicate measurements of automated spherical refraction taken on the last visit, the intraclass correlation coefficient was 0.93. For automated cylindrical refraction, it was 0.81. CONCLUSIONS: Automated refraction is highly repeatable and can be used to monitor postsurgical refractive changes. Whereas corneal swelling becomes stable 2 weeks after cataract surgery, automated refraction becomes stable after 1 week and can be used to accurately prescribe corrective lenses at that time.

Repeatability and agreement of ARK-30 autorefraction after cataract surgery.

BACKGROUND: To evaluate the intra-test variability of ARK-30 handheld autorefractor and the agreement with subjective refraction and retinoscopy after uneventful cataract surgery. DESIGN: Prospective and non-randomized study that included 6 visits by patients undergoing uneventful cataract surgery at IOBA (Instituto de Oftalmobiología Aplicada) Eye Institute (University of Valladolid). PARTICIPANTS: The mean age of the 79 patients was 66.5years (range 23-90years). For the 124 eyes, the mean spherical equivalent of the sample at baseline visit was -3.59±6.28D (range -21.00D to +4.44D). METHODS: Automated refraction was performed on follow-up visits 1day and weekly for 4weeks. Retinoscopy and subjective refraction were conducted at the Week 4 follow up. MAIN OUTCOME MEASURES: Automated refraction. RESULTS: Sphere, cylinder and mean spherical equivalent, J(0) and J(45) coefficient variabilities were low in all visits. Standard deviations and the limits of agreement were smallest for the last visit. Subjective refraction sphere and cylinder values were more positive than autorefraction by 0.12±0.53D (P=0.031) and 0.23±0.42D (P<0.001), respectively. Comparison between autorefraction and retinoscopy showed a similar trend with the sphere and cylinder differences, 0.32±0.77D and 0.38±0.43D (P<0.05), respectively. CONCLUSIONS: The ARK-30 is sufficiently accurate and repeatable for automated refraction after uneventful cataract surgery. This instrument may be useful for monitoring refractive outcome in these patients.

Differences in the daily symptoms associated with the silicone hydrogel contact lens wear.

OBJECTIVE: To determine the differences in symptoms associated with daily wear of silicone hydrogel (lotrafilcon B) contact lenses (CLs) after CL insertion and at the end of wear and their relationship with environmental factors and multipurpose solutions (Solo-care Aqua, CIBA Vision, Duluth, GA and Hidro Health, Disop, Spain). METHODS: Fifty-four patients were fitted with lotrafilcon B CLs. Two multipurpose solutions were randomly assigned and prescribed in a double-masked crossover study with three visits. After each solution was used, two questionnaires were conducted, including a survey produced by us and Contact Lens Dry Eye Questionnaire. Our questionnaire included 10 items addressing discomfort, blurry vision, lens-handling problems, dryness, redness, tearing, burning, itching, discharge, and dissatisfaction. Patients were assigned scores from 0 (without symptoms) to 10 (symptoms unbearable) at two different times (after CL insertion and at the end of wear) and in two environments (outdoors and adverse environments). RESULTS: The average duration of CL wear was 8.32 +/- 2.27 hr/day and 5.85 +/- 1.30 days/week. All symptoms became worse (P < 0.05 Wilcoxon test, except lens handling) at the end of CL wear in all visits. The results were independent of the multipurpose solution used (P > 0.05 Friedman test), except for tearing, which showed statistical differences between visits (P = 0.03 Friedman test). Contact Lens Dry Eye Questionnaire showed increased dry eye symptoms at the end of wear (P < 0.05 Friedman test). CONCLUSIONS: Daily wear symptoms associated with lotrafilcon B CL increase with the time of wear. This increase in symptoms is nonrelated with the multipurpose solutions compared in this study.

Contact lens-induced corneal peripheral swelling: Orbscan repeatability.

PURPOSE: To compare the repeatability and agreement of corneal thickness measurements using central and peripheral ultrasound and Orbscan pachymetry to detect contact lens (CL)-induced corneal swelling after extended wear (EW). METHODS: Corneal thickness was measured in five corneal locations (central, superior, inferior, nasal, and temporal) with ultrasound and Orbscan pachymetry 1 week before CL wear commenced and after 1 week of EW. High oxygen permeability (lotrafilcon A) and low oxygen permeability (etafilcon A) CL were randomly fitted for EW in the right and left eyes of 20 subjects with normal ocular health to induce different amount of corneal swelling. RESULTS: Poor repeatability and poor agreement in peripheral ultrasound and Orbscan pachymetry was found between corneas with and without corneal swelling. Ultrasound coefficients of repeatability (central, superior, inferior, nasal, and temporal) in corneas without (0.95, 2.1, 3.2, 3.9, and 3.8%) and with (0.91, 1.89, 2.45, 2.66, and 2.26%) corneal swelling were higher than Orbscan coefficients of repeatability without (0.74, 1.67, 1.29, 1.11, and 1.11%) and with (0.74, 1.47, 1.28, 1.78, and 1.23%) corneal swelling. Lotrafilcon A induced significantly less corneal swelling in all five corneal locations compared with etafilcon A. Peripheral corneal swelling differences between lens types were significant only with Orbscan measurements (p < 0.05, Paired t-test and re-analysis of variance). CONCLUSIONS: The assessment of corneal thickness shows higher repeatability using Orbscan pachymetry than using ultrasound to measure corneas with and without corneal swelling and could be useful to study central and peripheral corneal swelling variations in CL EW.

Gas permeable contact lens fitting in keratoconus: Comparison of different guidelines to back optic zone radius calculations.

Purpose: Compare the agreement between the finally fitted back optic zone radius (BOZR) of a spherical gas permeable (GP) contact lense (CL) with those proposed by different guidelines currently available to fit GP CLs in keratoconus. Methods: The BOZR fitted in 81 keratoconus eyes (46 patients) were recorded and compared with the BOZR calculated with ten different guidelines (identified after a literature review) proposed to calculate the first diagnostic lens BOZR to be fitted in keratoconus. Arithmetic and absolute mean difference between both BOZR were calculated (paired t-test). The success rate of each guideline (difference between both BOZR ≤0.05 mm) was calculated for different keratoconus stages (Amsler-Krumeich classification). Agreement between BOZR was evaluated using Bland-Altman analysis. Results: The BOZR proposed by all guidelines correlated with the final BOZR that was fitted (R2 > 0.71; P < 0.01). A statistically significant difference was found between the BOZR suggested by all guidelines and the BOZR that was prescribed (P < 0.05), except for three Guidelines (P ≥ 0.11). CALCULENS.com presented the best agreement (mean difference of 0.00 ± 0.12 mm), and 50.6% of cases showed ≤0.05 mm of difference with the BOZR that was fitted. However, the worst guideline showed an agreement of -0.38 ± 0.22 mm, and just 3.8% of cases had ≤0.05 mm of difference with the final fitted BOZR. Conclusion: BOZR calculated with most of the analyzed guidelines shows statistical differences with final fitted BOZR, suggesting a lack of clinical validation of these guidelines. The selection of the BOZR with CALCULENS.com could provide a better starting point for spherical GP CL fitting in keratoconus eyes.

A comparison of two optical coherence tomography-angiography devices in pseudoexfoliation glaucoma versus primary open-angle glaucoma and healthy subjects.

PURPOSE: To compare peripapillary vascular parameters derived from two optical coherence tomography angiography devices in pseudoexfoliation glaucoma, primary open-angle glaucoma, and healthy controls and to evaluate their diagnostic accuracy. METHODS: Observational, cross-sectional study. In total, 20 eyes with pseudoexfoliation glaucoma, 20 primary open-angle glaucoma eyes matched by peripapillary retinal nerve fiber layer thickness, and 20 control eyes were recruited. Participants underwent standard automated perimetry and peripapillary retinal nerve fiber layer analysis by Optovue and Cirrus optical coherence tomography. Vascular parameters provided by Angiovue and Angioplex optical coherence tomography angiography were compared. Their diagnostic accuracy and correlation with structural and functional parameters were assessed. RESULTS: All peripapillary optical coherence tomography angiography vascular parameters were significantly different among groups (all p < 0.05). The whole image capillary density and peripapillary capillary density by Angiovue were significantly lower in pseudoexfoliation glaucoma compared with primary open-angle glaucoma (p = 0.009 and p = 0.001, respectively). Conversely, vascular parameters by Angioplex were not statistically different between primary open-angle glaucoma and pseudoexfoliation glaucoma. A good correlation was found using Angiovue between whole image capillary density and visual field mean deviation (0.758, p < 0.001), peripapillary capillary density and visual field mean deviation (0.729, p = 0.001), and peripapillary capillary density and peripapillary retinal nerve fiber layer thickness in eyes with pseudoexfoliation glaucoma (0.716, p = 0.001). Angiovue parameters showed higher area under the receiver operating characteristic curves than Angioplex to discriminate among groups. CONCLUSION: Only Angiovue detected a significantly lower capillary density in pseudoexfoliation glaucoma compared to primary open-angle glaucoma at similar glaucoma damage. Both, Angiovue and Angioplex demonstrated a decreased capillary density in glaucoma eyes compared to healthy eyes. Furthermore, Angiovue-derived vascular parameters showed better correlation with functional and structural parameters and a higher diagnostic capacity to discriminate among groups compared to Angioplex.

Lamina cribrosa position and Bruch's membrane opening differences between anterior ischemic optic neuropathy and open-angle glaucoma.

PURPOSE:: To compare the optic nerve head morphology among primary open-angle glaucoma, non-arteritic anterior ischemic optic neuropathy eyes, their fellow healthy eyes and control eyes, using spectral-domain optical coherence tomography with enhanced depth imaging. METHODS:: Observational cross-sectional study including 88 eyes of 68 patients. In this study, 23 non-arteritic anterior ischemic optic neuropathy eyes, 17 fellow unaffected eyes, 25 primary open-angle glaucoma eyes, and 23 age-matched control eyes were included. Peripapillary retinal nerve fiber layer thickness and optic disk area were evaluated. Bruch's membrane opening diameter, optic cup depth, anterior lamina cribrosa depth, and prelaminar tissue thickness were assessed. RESULTS:: Non-arteritic anterior ischemic optic neuropathy and primary open-angle glaucoma eyes had similar visual field mean deviation and peripapillary retinal nerve fiber layer thickness (P = 0.6 and P = 0.56, respectively). Bruch's membrane opening diameter was significantly larger in primary open-angle glaucoma eyes than in control eyes (P = 0.02). Lamina cribrosa and disk cup were deeper in eyes with primary open-angle glaucoma than both control and non-arteritic anterior ischemic optic neuropathy eyes (P < 0.001). Prelaminar tissue thickness was significantly thinner in primary open-angle glaucoma eyes than in non-arteritic anterior ischemic optic neuropathy eyes (P < 0.001). Lamina cribrosa was shallower in both non-arteritic anterior ischemic optic neuropathy and unaffected fellow eyes compared to healthy eyes (P < 0.001 and P = 0.04, respectively). No differences were found in the optic disk area. CONCLUSION:: A forward lamina cribrosa placement and not a smaller disk could be involved in the pathogenesis of non-arteritic anterior ischemic optic neuropathy. A significantly larger Bruch's membrane opening diameter was found in primary open-angle glaucoma eyes compared with control eyes. This issue has clinical implications because Bruch's membrane opening has been considered a stable reference for disk-related measures.

Simultaneous evaluation of the lamina cribosa position and choroidal thickness changes following deep sclerectomy.

PURPOSE:: To assess the changes in peripapillary and macular choroidal thickness, and in the lamina cribrosa position following deep sclerectomy. METHODS:: Prospective study, including 39 eyes with open-angle glaucoma following deep sclerectomy. Choroidal thickness was automatically measured using swept-source optical coherence tomography at four peripapillary locations (superior, temporal, inferior, and nasal) and at the macular area in nine fields plotted with Early Treatment Diabetic Retinopathy Study grid. Optic nerve head was evaluated by Spectralis optical coherence tomography with enhanced depth imaging technology. All measurements were performed preoperatively and at 1 week and 2 months after surgery. RESULTS:: The mean intraocular pressure significantly decreased 1 week and 2 months after surgery ( p < 0.001). A significant peripapillary choroidal thickening was observed at all locations 1 week postoperatively ( p ≤ 0.002) and in the temporal quadrant 2 months after surgery ( p = 0.027). There was a significant thickening in all macular choroidal thickness measurements at 1 week ( p < 0.001) and 2 months ( p < 0.05), except at subfoveal and inner nasal locations. The mean peripapillary and macular choroid thickness was 22.8% and 19.7% at 1 week and 6.2% and 7.8% at 2 months, respectively. A significant forward lamina cribrosa displacement occurred at every postoperative stage ( p < 0.001). Multivariate analysis showed a significant correlation between the magnitude of intraocular pressure reduction and the anterior lamina cribrosa movement (0.623, p = 0.000) and a negative correlation between the intraocular pressure change and the mean peripapillary and macular choroidal thickening (-0.527, p = 0.002; -0.568, p = 0.002, respectively). CONCLUSION:: There was a significant reversal lamina cribrosa displacement measured from Bruch's membrane opening reference despite a significant peripapillary choroidal thickening following deep sclerectomy. Both findings were significantly correlated with the change in intraocular pressure.

Measurement of corneal swelling variations without removal of the contact lens during extended wear.

PURPOSE: To validate the use of noncontact scanning slit pachymetry and OCT pachymetry measurements without contact lens (CL) removal, to determine corneal swelling variations during extended wear (EW). METHODS: Central corneal thickness (CCT) was measured with ultrasonic (US) pachymetry, noncontact scanning slit pachymetry (Orbscan II; Bausch & Lomb, Tampa, FL), and optical coherence tomography (OCT) 1 week before the wearing of CLs and during 1 week of EW. High-Dk (lotrafilcon A) and low-Dk (etafilcon A) soft CLs were randomly fitted for EW in the right and left eyes of 20 subjects with normal ocular health. Orbscan and OCT were also performed without CL removal after 3 and 7 days of wear. RESULTS: CCT measured with Orbscan and OCT showed a high correlation with US pachymetry. There were corneas with edema and without edema. Bland-Altman analysis showed a high level of agreement between Orbscan and OCT, with and without CL removal and with US pachymetry. High repeatability of Orbscan (r(2) = 0.000) and OCT (r(2) = 0.001) measurements without CL removal was also found. Etafilcon A lenses induced significantly higher corneal swelling than did lotrafilcon A lenses measured with Orbscan and OCT. CONCLUSIONS: Orbscan and OCT are accurate, noninvasive, and reproducible techniques for evaluation of CCT without CL removal. OCT has more accuracy and repeatability than does Orbscan. Both techniques allowed for measurement throughout the study period of the CCT differences induced by CL wear.

Reverse geometry contact lens fitting in corneal scar caused by perforating corneal injuries.

PURPOSE: To describe a reverse geometry rigid gas permeable (RGP) contact lens fitting in corneal scar caused by perforating corneal injuries with intraocular strange body. METHODS: A reverse geometry RGP lens, with large diameter, was empirically fitted in a 38-year-old male patient who had previous open globe injuries due to work accident in right eye. Corneal suture, vitrectomy and lens extraction were performed. Irregular corneal surface with corneal scar in line with the visual axis were found with low uncorrected visual acuity. RESULTS: Snellen visual acuity improved from counterfinger to 0.8 with high contact lens acceptance, 6-9h per day of wear. Only three diagnostic contact lenses, in two visits, were necessary. Orbscan simulated fluorescein pattern was different to definitive fluorescein pattern. CONCLUSIONS: Reverse geometry RGP contact lens, with large diameters, could be a good alternative in irregular corneal surface with corneal scar. Fluorescein pattern analysis could be the proper fitting technique. This fitting could involve less time and fewer visits. Computer-aided fitting was of limited value in these cases.