Best Spectacle-corrected Distance Visual Acuity Research Articles

Development of a Web-Based Algorithm for Understanding the Intraocular Lens-Based Surgery in Stable and Progressing Keratoconus for Non-Specialist Ophthalmologists

Purpose To propose an algorithm to facilitate lens-based surgery in keratoconus. Methods A literature review was performed to prepare a software algorithm based on cone location, stability, best spectacle-corrected distance visual acuity (BSCVA) level and whether there is a clear or cataractous lens. The software usability was assessed through a 10-question questionnaire and two hypothetical keratoconus case histories (moderately simple and moderately complex) given to 15 trainees. The usability questionnaires were graded on a Likert scale (1 = strongly disagree to 5 = strongly agree) and two case histories (1 = very difficult to 7 = very easy). Results The algorithm can be found at https://www.sussexeyelaserclinic.co.uk/keratoconus/. Thirteen trainees completed the questionnaire. 91.9% would frequently use it; for 100%, it was easy to use independently without technical support; for 63.7%, it was strongly integrated; for 100%, it was consistent; 100% thought that most people would learn to use it quickly, 91.9% found the system not cumbersome to use, felt very confident to use it and need not learn a lot to use it. The first case was found easy by 63.7% and the second by 45%. Conclusion We present an algorithm as a guide for lens-based surgery in stable and progressing keratoconus, which is classified based on cone location. This algorithm will help trainee and “non-specialist” ophthalmic surgeons understand the pre-operative planning for the surgery and referral to the “specialist” corneal surgeon, considering factors such as progression, BSCVA, keratometry, topography and apex location of the cone in keratoconus patients.

Rotational stability and refractive outcomes of the DFT/DATx15 toric, extended depth of focus intraocular lens

PurposeTo quantitatively assess postoperative rotational stability and visual acuity with the DFT/DATx15 extended depth of focus (EDOF) toric intraocular lens (IOL).MethodsIn this prospective case series, thirty-five patients with a calculated IOL power between + 15.0 D and + 25.0 D, corneal astigmatism between 0.75 D and 2.25 D, and no significant ocular pathology underwent cataract surgery. Primary outcome was rotational stability of the IOL at 1 month post-operatively. Secondary outcomes included residual refractive astigmatism, absolute residual astigmatism prediction error, and monocular distance and intermediate visual acuities.ResultsMean absolute postoperative IOL rotation was 1.1 ± 0.2 degrees, with no rotation of more than 3 degrees at the final visit. Monocular mean best spectacle-corrected distance visual acuity (BSCDVA) improved from logMAR 0.27 ± 0.030 to 0.078 ± 0.017 (P < .001). Monocular uncorrected distance visual acuity (UCDVA) improved from 0.93 ± 0.096 to 0.18 ± 0.022 (P < .001). Best spectacle-corrected intermediate visual acuity (DSCIVA) was 0.17 ± 0.025, and uncorrected intermediate visual acuity (UCIVA) was 0.27 ± 0.040. Residual regular astigmatic refractive error was 0.21 ± 0.047 D.ConclusionsThe toric DFT/DATx15 EDOF lens showed excellent rotational stability and effective and predictable correction of astigmatism. Its refractive outcomes and safety profile were similar to those identified in prior studies of the non-toric DFT/DAT015 EDOF IOL. A small difference in monocular BSCDVA, of uncertain clinical significance, was found when comparing these outcomes with prior DFT/DAT015 data. The trial was retrospectively registered on November 5, 2021 (TRN ​​NCT05119127).

Objective Quantification of Image Quality and Optical Scatter Before and After Nd:YAG Capsulotomy Using a Double-Pass Technique.

PurposeThe purpose of this study is to evaluate and compare the correlation between changes in vision and HD Analyzer dual-pass metrics versus changes in vision and conventional subjective slit lamp gradings in pseudophakic patients with posterior capsular opacity undergoing neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy.Patients and MethodsHigh contrast (HC) and low contrast (LC) best spectacle-corrected distance visual acuity (BCVA) and HD Analyzer evaluation were prospectively performed on patients with mild-to-moderate posterior capsular opacification (PCO) and monofocal and accommodating intraocular lens implants. Differences between pre- and post-operative measurements were calculated, along with the correlation of HD Analyzer metrics and slit lamp grading to changes in visual acuity.ResultsFollowing Nd:YAG capsulotomy (n=29), there was statistically significant improvement in HC-BCVA and LC-BCVA, decrease in optical scatter, and corresponding improvement in Strehl ratio and HD Analyzer values at all contrast levels tested (p≤0.05). Pearson test showed a high correlation between the improvement in HC-BCVA (r coefficient = 0.78) and LC-BCVA (r coefficient = 0.71) to the improvement in Objective Scatter Index (OSI). There was a higher correlation of change in HC-BCVA to pre-op OSI (r2=0.61) than to the subjective PCO grading score (r2 = 0.19). There was also a higher correlation of change in LC-BCVA to pre-op OSI (r2 = 0.49) than to subjective grading (r2 = 0.16).ConclusionThe HD Analyzer provides objective measurements of forward light scatter (ie, light directed towards the retina) that can assist with both PCO grading and prediction of improvement of visual quality after YAG laser capsulotomy with higher accuracy than conventional slit lamp assessment based upon backscatter (ie, light traveling to the observer) in patients tested with monofocal and accommodating intraocular lens implants.

Long‐term outcomes of posterior chamber phakic intraocular lens implantation in keratoconus

BackgroundIn this retrospective observational case series study, the aim was to evaluate the long‐term safety, efficacy, stability and predictability of posterior chamber phakic intraocular lens (pIOL) implantation to correct myopia and myopic astigmatism associated with keratoconus.MethodsUncorrected distance visual acuity (UDVA), best spectacle‐corrected distance visual acuity (BSCDVA), refraction and adverse effects were evaluated in 23 keratoconic eyes of 13 patients after five-years with Visian ICMV4 pIOL (STAAR Surgical).ResultsThe mean pre‐operative spherical equivalent and cylinder changed from −5.35 ± 2.82 D and −3.14 ± 1.58 D to −0.78 ± 1.31 D and −1.56 ± 1.53 D, respectively, five-years post‐operatively. Before the surgery the mean Snellen decimal BSCDVA was 0.60 ± 0.20. The mean UDVA and BSCDVA changed to 0.74 ± 0.22 and 0.88 ± 0.16, respectively. A total of 82.5-per cent of eyes achieved 6/12 or better UDVA post‐operatively. The mean safety and efficacy indices were respectively, 1.47 ± 0.32 and 1.24 ± 0.34. No eye lost a line of visual acuity and 19 eyes gained one or more lines. An endothelial cell loss of 7.88-per cent occurred. No significant changes were seen in intraocular pressure, steep, flat and mean keratometry. The crystalline lens was clear.ConclusionThe clinical outcomes of the current study demonstrate the safety, efficacy and predictability of the implantable collamer lens (toric and non‐toric) in the correction of myopia and myopic astigmatism associated with keratoconus. The patients’ refractions achieved early stability and remained stable during the course of the study.

Corneal Cross-Linking in Pediatric Patients: Evaluating Treated and Untreated Eyes-5-Year Follow-Up Results.

To evaluate the long-term results of corneal collagen cross-linking (CXL) for treatment of pediatric keratoconus and the long-term outcomes of the fellow untreated keratoconic eye in patients younger than 18 years old. A retrospective case analysis was performed on 88 eyes of 44 patients aged 18 years or younger, with keratoconus, who underwent CXL in at least 1 eye. Follow-up measurements, for the treated and untreated eye pair, taken up to 5 years after treatment, were compared with baseline values. Parameters included uncorrected distance visual acuity (UCDVA), best spectacle-corrected distance visual acuity (BCDVA), manifest refraction, pachymetry, and corneal topography and tomography. Mean age of patients was 15.6 ± 2.1 years. For the treated eyes, during all years of follow-up, UCDVA improved significantly (from 0.83 ± 0.30 to 0.72 ± 0.28 logMAR; P = 0.01). Improvement in BCDVA was not statistically significant (from 0.28 ± 0.19 to 0.23 ± 0.15 logMAR; P = 0.06). The manifest cylinder showed a significant reduction (from 5.8 ± 3.6 to 4.3 ± 2.5 diopters; P = 0.006). There was no significant change in maximum keratometry. Average keratometry and corneal thickness reduced significantly (P = 0.009 and P = 0.002, respectively). Five patients had very mild corneal haze after CXL. For the fellow untreated eyes-during 5 years of follow-up, UCDVA showed a slight decrease that was not statistically significant. BCDVA, average keratometry, and maximum keratometry remained stable. Our long-term follow-up study suggests that CXL is a safe procedure in the pediatric age, and there is no urgency in treating pediatric patients with keratoconus without proof of progression.

Cataract Surgery Performed by High Frequency LDV Z8 Femtosecond Laser: Safety, Efficacy, and Its Physical Properties.

Background: The aim of our study was to investigate the safety and efficacy of the LDV Z8 femtosecond laser in cataract surgery compared to the conventional procedure. Methods: This prospective study was performed at the Swiss Eye Research Foundation, Eye Clinic ORASIS, Reinach, Switzerland. The study included 130 eyes from 130 patients: 68 treated with femtosecond laser-assisted cataract surgery (FLACS) using the FEMTO LDV Z8 and 62 treated with conventional phacoemulsification. Capsulotomy and lens fragmentation in the laser group were performed with the FEMTO LDV Z8 femtosecond laser system, which employs a new, low-energy, high repetition rate laser process for cataract surgery. In the conventional group, the capsulotomy was performed by a cystotome, and lens fragmentation was achieved by the stop-and-chop. Results: Ease of phacoemulsification (on a 4-point scale), the completeness of capsulotomy (on a 10-point scale), effective phacoemulsification time (seconds), uncorrected distance visual acuity (UCVA), best spectacle-corrected distance visual acuity (BSCVA), spherical equivalent (SE), and safety of the procedure were evaluated. The total follow-up time was three months. Conclusions: FLACS with the FEMTO LDV Z8 system was characterized by complete and reproducible capsulotomy and highly effective lens fragmentation. Postoperative visual outcomes were excellent, and the safety of the procedure was optimal.

Astigmatism management in cataract surgery with Precizon(®) toric intraocular lens: a prospective study.

PurposeThe purpose of this study was to evaluate the visual and refractive outcomes and rotational stability of the new aspheric Precizon® toric intraocular lens (IOL) for the correction of corneal astigmatism in cataract surgery.SettingDepartment of Ophthalmology, Hospital Geral de Santo António – Centro Hospitalar do Porto, EPE and Hospital de Pedro Hispano, Matosinhos, Portugal.DesignThis was a prospective clinical study.Patients and methodsA total of 40 eyes of 27 patients with corneal astigmatism greater than 1.0 diopter (D) underwent cataract surgery with implantation of Precizon® toric IOL. IOL power calculation was performed using optical coherence biometry (IOLMaster®). Outcomes of uncorrected (UDVA) and best-spectacle corrected distance visual acuities (BCDVA), refraction, and IOL rotation were analyzed at the 1st week, 1st, 3rd, and 6th month’s evaluations.ResultsThe median postoperative UDVA was better than preoperative best-spectacle corrected distance visual acuity (0.02 [0.06] logMAR vs 0.19 [0.20] logMAR, P<0.001). At 6 months, postoperative UDVA was 0.1 logMAR or better in 95% of the eyes. At last follow-up, the mean spherical equivalent was reduced from −3.35±3.10 D to −0.02±0.30 D (P<0.001) with 97.5% of the eyes within ±0.50 D of emmetropia. The mean preoperative keratometric cylinder was 2.34±0.95 D and the mean postoperative refractive cylinder was 0.24±0.27 D (P<0.001). The mean IOL rotation was 2.43°±1.55°. None of the IOLs required realignment.ConclusionPrecizon® toric IOL revealed very good rotational stability and performance regarding predictability, efficacy, and safety in the correction of preexisting regular corneal astigmatism associated with cataract surgery.

Outcomes of deep anterior lamellar keratoplasty in keratoconic eyes with previous hydrops

AimTo evaluate outcomes of deep anterior lamellar keratoplasty (DALK) in keratoconic eyes with previous hydrops.MethodsIn this retrospective, non-comparative study, keratoconic eyes with previous hydrops that underwent DALK were included. DALK...

Correlation of Topometric and Tomographic Indices with Visual Acuity in Patients with Keratoconus

ABSTRACT Purpose To evaluate the correlations of Pentacam keratometric, topometric (derived from front surface curvature) and tomographic (derived from 3D corneal shape analysis) indices with best corrected visual acuity in patients with keratoconus. Materials and methods One eye randomly selected of 123 patients with bilateral keratoconus was retrospectively enrolled. All patients underwent a comprehensive ophthalmic examination including subjective refraction, distance best-spectacle corrected visual acuity (DCVA) measurement, and rotating Scheimpflug corneal tomography (Pentacam HR; Oculus, Wetzlar, Germany) at the same office visit. The correlations between the logarithm of the minimum angle of resolution (LogMAR) of DCVA and keratometric indices, topometric indices and tomographic indices were tested with nonparametric Spearman correlation coefficients (?). Results The mean LogMAR DCVA was 0.32 (~20/42) ±0.27 [range: −0.10 (20/15) to 1.30 (20/400)]. There were strong correlations between DCVA and many keratometric, topometric and tomographic indices. A strong positive correlation was found between DCVA and BAD-Df (ρ = 0.648, p &lt; 0.001), BAD-Db (ρ = 0.633, p &lt; 0.001), K2 (ρ = 0.643, p &lt; 0.001), Kmax (ρ = 0.608, p &lt; 0.001), TKC (ρ = 0.558, p &lt; 0.001), BAD-D (ρ = 0.577, p &lt; 0.001), ISV (ρ = 0.573, p &lt; 0.001), CKI (ρ = 0.530, p &lt; 0.001), KI (ρ = 0.531, p &lt; 0.001). A strong negative correlation was seen between DCVA and Asph Q front 30° (ρ = −0.521, p &lt; 0.001). Conclusion There are significant correlations between visual acuity and Pentacam parameters. Such parameters may be considered for improving staging of the disease, as well as for monitoring progression or treatment as outcome measures. There is a potential for combining parameters to enhance the correlations. How to cite this article Lopes BT, Ramos IC, Faria-Correia F, Luz A, de Freitas Valbon B, Belin MW, Ambrósio R Jr. Correlation of Topometric and Tomographic Indices with Visual Acuity in Patients with Keratoconus. Int J Kerat Ect Cor Dis 2012;1(3):167-172.

Correction of Presbyopia in Hyperopia With a Center-distance, Paracentral-near Technique Using the Technolas 217z Platform

To analyze the results of hyperopic patients treated with a peripheral presbyLASIK algorithm for the correction of presbyopia. The study included 44 eyes of 22 hyperopic patients treated with a peripheral presbyLASIK technique using a Technolas 217z excimer laser. Mean patient age was 56 years (range: 47 to 72 years), mean preoperative spherical equivalent refraction was +1.21 +/- 0.77 diopters (D) (range: +0.50 to +4.00 D), and mean spectacle near addition was +1.76 +/- 0.42 D (range: +1.00 to +2.75 D). The Peripheral Multifocal LASIK (PML) ablation pattern creates a multifocal corneal profile over a 6.5-mm diameter, performing the distance correction first in a 6-mm optical zone and then near correction in a 6.5-mm zone. Main outcome measures were uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA) for near and distance, spherical equivalent refraction, contrast sensitivity, and corneal aberrations. Six months postoperatively, mean binocular UCVA was 1.06 +/- 0.13 for distance and 0.84 +/- 0.14 for near. Mean postoperative spherical equivalent refraction was -0.42 D (range: -1.12 to +0.87 D). Two (4.5%) eyes lost 1 line of BSCVA for distance and near vision, and 20 (45%) eyes gained 1 line of distance BSCVA. Contrast sensitivity decreased for 3, 6, 12, and 18 cycles/degree. Corneal aberration analysis showed a slight increase in coma and decrease in spherical aberration. The peripheral presbyLASIK technique used in this study is a safe and efficient treatment that may improve functional near vision in presbyopic patients with low and moderate hyperopia (from +0.50 to +3.00 D).

Visual Function With Bilateral Implantation of Monofocal and Multifocal Intraocular Lenses: A Prospective, Randomized, Controlled Clinical Trial

To evaluate visual function of three types of multifocal intraocular lenses (IOLs) and one monofocal IOL (as the control group) after cataract surgery. One hundred fourteen patients participated in a prospective, randomized, controlled clinical study and received monofocal Tecnis Z9000 (AMO) (n = 24, 48 eyes); symmetric diffractive multifocal Tecnis ZM900 (AMO) (n = 26, 52 eyes); zonal refractive multifocal ReZoom (AMO) (n = 32, 64 eyes); and asymmetric diffractive multifocal TwinSet (Acri.Tec) (n = 32, 64 eyes) IOLs. Mean binocular distance best spectacle-corrected visual acuity (BSCVA) (logMAR) was 0.05 for controls, 0.08 for ZM900, 0.07 for ReZoom, and 0.11 for TwinSet, with mean binocular distance BSCVA at near of 0.49, 0.06, 0.22, and 0.11, respectively. Mean contrast sensitivity was better for the monofocal IOL group than for the multifocal IOLs. Patients assigned to TwinSet had less favorable contrast sensitivity scores. Patients with monofocal IOLs had more frequently recommended near addition (74%) than those with multifocal IOLs. Patients with refractive ReZoom had also recommended near addition more frequently than the two diffractive groups. The percentage of dysphotopsia phenomena was 81% in patients with diffractive multifocal ZM900 compared with 48% in patients with monofocal IOLs, 53% with refractive ReZoom, and 47% with diffractive TwinSet. The monofocal IOL showed better visual function and lesser photic phenomena than multifocal IOLs but patients were spectacle dependent. ReZoom provided better distance BSCVA than the TwinSet diffractive model. Patients with Tecnis and TwinSet diffractive multifocal IOLs were more spectacle independent than patients with ReZoom. Patients with TwinSet had the worst visual function. Patients implanted with the Tecnis diffractive ZM900 were those reporting more photic phenomena.

Wavefront-guided Excimer Laser Vision Correction After Multifocal IOL Implantation

To investigate the use of wavefront-guided LASIK after multifocal intraocular lens (IOL) implantation to correct residual ametropia and higher order aberrations. In a prospective, nonrandomized case series, wavefront-guided LASIK was performed in 27 eyes (19 patients) after multifocal IOL implantation (Tecnis diffractive IOL, n = 20; ReSTOR diffractive IOL, n = 4; ReZoom refractive IOL, n = 3) using the VISX STAR S4 IR excimer laser. Visual acuity, manifest refraction, and wavefront error were examined pre- and 3 months postoperatively. In the Tecnis group, results before (after) LASIK were: sphere +1.06 +/- 0.77 diopters (D) (-0.03 +/- 0.28 D; P = .0001), cylinder -1.13 +/- 0.73 D (-0.14 +/- 0.25 D; P = .00004), distance uncorrected visual acuity (UCVA) 20/45 +/- 0.09 (20/29 +/- 0.16; P = .00004), near UCVA 20/30 +/- 0.24 (20/25 +/- 0.16; P = .001), and higher order aberrations (4-mm pupil) 0.14 +/- 0.05 microm (0.18 +/-0.03 microm; P = .02). Distance and near best spectacle-corrected visual acuity (BSCVA) did not change. In the ReSTOR group, results before (after) LASIK were: sphere +0.75 +/- 0.56 D (+0.13 +/- 0.22 D), cylinder -1.50 +/- 0.47 D (-0.13 +/- 0.22 D), distance UCVA 20/40 +/- 0.07 (20/26 +/- 0.07), near UCVA 20/44 +/- 0.05 (20/25 +/- 0.0), and higher order aberrations (4-mm pupil) 0.14 +/- 0.03 microm (0.20 +/- 0.02 microm). Distance and near BSCVA did not change. In the ReZoom group, results before (after) LASIK were: sphere +0.08 +/- 1.20 D (0.00 D), cylinder -0.83 +/- 0.120 D (0.00 D), distance UCVA 20/40 +/- 0 (20/25 +/- 0), near UCVA 20/60 +/- 0.09 (20/150 +/- 0.18), and higher order aberrations (4-mm pupil) 0.43 +/- 0.04 microm (0.39 +/- 0.03 microm). Patients lost one line of distance BSCVA and two lines of near BSCVA. Wavefront-guided LASIK is safe and effective in diffractive multifocal IOLs to correct residual refractive error, but higher order aberrations did not improve. It is not recommended in refractive multifocal IOLs, as these cannot be measured reliably with current wavefront sensors.

Potentially Accommodating 1CU Intraocular Lens: 1-year Results in 553 Eyes and Literature Review

To investigate the advantages, clinical outcomes, and safety after implantation of the 1CU (HumanOptics AG) optic shift intraocular lens (IOL) in comparison with a conventional monofocal IOL. In a prospective non-randomized study, 553 eyes implanted with the 1CU IOL were examined. In a control group, a monofocal posterior chamber IOL (MCTE, Dr Schmidt) was implanted in 219 eyes. Follow-up was performed at 1, 6, and 12 months postoperatively. The clinical effect for near visual acuity was evaluated by subjective measurements using an accommodometer, defocusing curve, and Nieden charts. No significant differences were noted in distance best spectacle-corrected visual acuity (BSCVA) between groups. Average near visual acuity with distance BSCVA for the 1CU was 0.41 and 0.35 for the control group. The difference in the accommodation response between both groups measured with the accommodometer was 11 cm (P < .01). The refraction tolerance for the 1CU was 0.25 D whereas the MCTE revealed no refraction tolerance (P < .01). Decentration and tilting of the 1CU resulted in explantation of three IOLs. The 1CU indicates a minor statistical advantage of half a reading step towards monofocal IOLs measured with subjective methods in near point, defocusing curve, and near visual acuity with distance BSCVA. This could be due to pseudophakic accommodation by the optic shift mechanism or a result of additional pseudophakic pseudoaccommodation. The accommodative effect of the 1CU differed from patient to patient and was not predictable.

Fourier Analysis of Single Running Suture Adjustment in Penetrating and Deep Lamellar Keratoplasty

To prospectively evaluate clinical and visual results of running suture adjustment after keratoplasty. Thirty-seven eyes of 33 patients received running suture adjustment after keratoplasty. Changes in uncorrected visual acuity, distance best spectacle-corrected visual acuity (BSCVA), refraction, and Fourier analysis constituents were assessed before and after suture adjustment. Thirty eyes, which had improvement of distance BSCVA soon after suture adjustment, maintained improvement at 1 year, whereas 7 eyes with decreased distance BSCVA soon after suture adjustment experienced no improvement at 1 year. Patients with poor distance BSCVA at 1 year had significantly higher high order irregularity than patients with better distance BSCVA despite similar cylindrical power outcomes.