A New Night Vision Disturbances Parameter and Contrast Sensitivity as Indicators of Success in Wavefront-guided Enhancement

Visual and refractive outcomes after bilateral implantation of an enhanced monofocal intraocular lens: prospective study

PURPOSE

To evaluate visual and refractive outcomes, as well as patient satisfaction after bilateral implantation of an enhanced monofocal intraocular lens (IOL) with emmetropia as a target refraction.

SETTING

San Carlos Hospital, Madrid, Spain.

DESIGN

Prospective, monocentric, noncomparative study.

METHODS

Adults 21 years or older suitable for cataract surgery and with corneal astigmatism <1.50 diopters (D) were bilaterally implanted with the RayOne EMV IOL and followed up for 3 months. Outcomes measures included refraction, monocular and binocular uncorrected distance visual acuity, corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity, distance-corrected intermediate visual acuity (DCIVA), and defocus curve, aberrometry, and satisfaction. Visual symptoms were assessed using the CatQuest-9SF questionnaire.

RESULTS

50 eyes of 25 patients were included. At month 3, the mean manifest spherical equivalent was -0.39 ± 0.28 D, with all eyes within 1.00 D. Binocularly, uncorrected, at distance, 68% of patients could read ≤0.0 logMAR and 95% ≤0.2 logMAR; at intermediate 59% of patients could read ≤0.1 and 100% ≤0.2 logMAR. Mean monocular CDVA was -0.03 ± 0.06 logMAR and mean monocular DCIVA was 0.28 ± 0.07 logMAR. Binocular defocus curve demonstrated a visual acuity ≤0.2 logMAR over a 2 D range from +1.00 D to -1.25 D. Satisfaction was good in 96% of patients.

CONCLUSIONS

Bilateral implantation of an enhanced monofocal IOL with emmetropia as a target provided excellent binocular CDVA and good DCIVA, with a high level of satisfaction.

The influence of pupil diameter upon and subjective quality of vision following implantable collamer lens (ICL V4c) implantation: An observational study

This study aimed to assess the change in pupil size and its influence on subjective quality of vision (QoV) in subjects with implanted collamer lenses (ICLs). This retrospective study assessed 53 participants (53 eyes) implanted with ICL (V4c) and categorized them into incremental groups according to pupil diameter. Preoperative and postoperative photopic and mesopic pupil diameter, uncorrected distance visual acuity (UDVA), and QoV questionnaire scores were assessed and compared. Postoperatively, at 3 months, UDVA was -0.10 ± 0.06 logarithm of the minimum angle of resolution (LogMAR), and mean QoV for day and night was 9.34 ± 0.76 and 8.58 ± 1.29, respectively. The mean mesopic and photopic pupil diameters were 6.59 ± 0.79 mm and 4.61 ± 0.74 mm, respectively. Photopic pupil diameter negatively correlated with "QoV day" (Rs = -0.413, P = .001), positively correlated with "haloes" (Rs = 0.568*, P < .001) and "blurred vision" (Rs = 0.243, P = .04) respectively. Mesopic pupil diameter negatively correlated with "QoV night" (Rs = -0.426, P = .001), positively correlated with "haloes" (Rs = 0.624*, P < .001), "starburst" (Rs = 0.233, P = .046) and "difficulty focusing" (Rs = 0.27, P = .025), respectively. Participants had excellent VA at 3-month follow-up. Photopic and mesonic pupil diameter negatively correlated with QoV day and QoV night scores, respectively. Pupil diameter was found to have a more significant effect on visual symptoms at night, and lower QoV due to larger pupil size was more noticeable at night. Further investigation is needed to explore the importance of pupil diameter and its impact on the QoV in ICL implanted patients.

Visual and Refractive Outcomes Following Laser Blended Vision With Non-linear Aspheric Micro-anisometropia (PRESBYOND) in Myopic and Hyperopic Patients

PURPOSE

To report 6-month visual and refractive outcomes following PRESBYOND Laser Blended Vision (Carl Zeiss Meditec) treatment using non-linear aspheric micro-anisometropia laser in situ keratomileusis (LASIK) for the correction of myopic and hyperopic presbyopia.

METHODS

A retrospective, non-comparative study of 139 consecutive patients with a mean age of 53.13 ± 5.84 years (range: 42 to 70 years) treated with LASIK-induced micro-anisometropia using the MEL 90 excimer laser and VisuMax femtosecond laser (both Carl Zeiss Meditec). The target refraction was plano for distance eyes (dominant eye) and between -0.50 and -1.50 diopters (D) for near eyes. Patients were observed for 6 months.

RESULTS

A total of 278 eyes (78 myopic and 200 hyperopic) from 139 patients completed the study. Mean preoperative spherical equivalent (SE) was -3.40 ± 1.83 D (range: -0.50 to -8.25 D) for myopic eyes and +1.61 ± 0.98 D (range: -1.25 to +4.63 D) for hyperopic eyes. Mean postoperative SE refraction of distance eyes was +0.20 ± 0.35 D (range: -0.38 to +1.00 D) and -0.14 ± 0.42 D (range: -1.38 to +0.88 D) for myopic and hyperopic eyes, respectively. Mean postoperative SE refraction of near eyes was -0.90 ± 0.44 D (range: -0.13 to -2.25 D) and -1.21 ± 0.48 D (range: -0.13 to -2.25 D) for myopic and hyperopic eyes, respectively. Mean binocular uncorrected near visual acuity was 0.70 ± 0.28 logMAR (range: 0.32 to 1.00 logMAR) and 0.79 ± 0.27 logMAR (range: 0.25 to 1.00 logMAR) for myopic and hyperopic eyes, respectively. Mean binocular uncorrected distance visual acuity was 1.19 ± 0.18 logMAR (range: 0.63 to 1.25 logMAR) and 1.14 ± 0.26 logMAR (range: 0.40 to 1.25 logMAR) for myopic and hyperopic eyes, respectively. Stereoacuity was better than 100 seconds of arc in 79% of myopic eyes and 85% of hyperopic eyes and all vision quality scores were greater than 90 of 100. No eyes lost two or more lines.

CONCLUSIONS

The non-linear aspheric micro-anisometropia protocol resulted in safe and effective visual outcomes in patients with both myopic and hyperopic presbyopia. [J Refract Surg. 2022;38(5):288-297.].

Aberrometric, Keratometric, and Visual Outcomes After Trans-Epithelial Topography-Guided Phototherapeutic Keratectomy for the Treatment of Irregular Corneas

Purpose

To assess the safety, aberrometric and keratometric changes, and stability of trans-epithelial topography-guided phototherapeutic keratectomy (TE-TG-PTK) with mitomycin C (MMC) using the ALLEGRO Topolyzer platform for the treatment of irregular astigmatism.

Methods

This is a retrospective case series including 57 eyes that underwent TE-TG-PTK + MMC using the ALLEGRO Topolyzer platform for the treatment of irregular astigmatism. CDVA, manifest refraction (MR), keratometry readings, and aberrometry readings were analyzed at 1, 3, 6, and 12 months.

Results

Causes of corneal irregularity included non-infectious leucoma (n=23), infectious leucoma (n=7), adenoviral keratitis (n=20), corneal haze (n=2), post-penetrant keratoplasty (PKP) (n=1), and others (n=4). Overall, 76% of the eyes (n=40) gained lines of vision; patients gained 1, and 2 or more lines of vision in 76%, and 38% of cases, respectively. Only 1 patient (2%) lost 5 lines of vision. Mean preoperative CDVA (LogMAR) was 0.37 ±0.31 and improved to 0.14 ±0.18 (p<0.001) at final follow-up (12 months). CDVA remained unchanged in 10 eyes (21%). No significant changes were observed in mean keratometry (Kmean) and keratometric astigmatism readings. Regarding aberrometry, only changes in coma proved to be significant 6 months after surgery (P<0.01). No intraoperative/postoperative complications were reported.

Conclusion

At final follow-up, significant improvements were observed in CDVA and coma. TE-TG-PTK + MMC proved to be an effective and safe procedure for the treatment of corneal irregular astigmatism due to several causes.

Corneal wavefront aberrations and subjective quality of vision after small incision lenticule extraction

PURPOSE

To analyse in depth the associations between objectively measured corneal higher-order aberrations (HOAs) and subjectively perceived visual quality after small incision lenticule extraction (SMILE) as quantified with the standardized and clinically validated quality of vision (QOV) questionnaire.

METHODS

This cross-sectional study included patients after bilateral simultaneous SMILE for the treatment of myopia and/or myopic astigmatism with plano target refraction. Scheimpflug imaging (Pentacam HR; Oculus Optikgeräte GmbH, Wetzlar, Germany) was used to objectively quantify corneal HOAs. The standardized and validated QOV questionnaire was employed to gauge patients' subjectively perceived visual quality regarding frequency, severity and bothering effect of visual disturbances.

RESULTS

A total of 394 eyes of 197 patients with a mean age of 32.4 ± 7.7 years and a mean postoperative follow-up of 24.3 ± 14.1 months were included. SMILE induced a statistically significant (p < 0.001) increase in spherical aberration (0.074 ± 0.131 µm), coma (0.142 ± 0.179 µm), trefoil (0.018 ± 0.067 µm) as well as in total HOAs (0.191 ± 0.176 µm). Surgically induced and postoperative levels of HOA showed no correlation with the three QOV scores representative of overall visual symptom frequency, severity and bothering effect (all R² values ≤ 0.016). In addition, the associations between specific visual symptoms (e.g. starburst) and singular HOA terms (e.g. haloes) were very weak (all Rho values ≤ 0.164).

CONCLUSIONS

Small incision lenticule extraction induced significant amounts of corneal HOAs that, however, showed no clear relationships to patient-reported QOV or specific long-term visual symptoms.

Incidence and Outcomes of Optical Zone Enlargement and Recentration After Previous Myopic LASIK by Topography-Guided Custom Ablation

PURPOSE

To report the incidence, visual and refractive outcomes, optical zone enlargement, and recentration using topography-guided CRS-Master TOSCA II software with the MEL 80 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) after primary myopic laser refractive surgery.

METHODS

Retrospective analysis of 73 eyes (40 patients) with complaints of night vision disturbances due to either a decentration or small optical zone following a primary myopic laser refractive surgery procedure using the MEL 80 laser. Multiple ATLAS topography scans were imported into the CRS-Master software for topography-guided ablation planning. The topography-guided re-treatment procedure was performed as either a LASIK flap lift, a new LASIK flap, a side cut only, or photorefractive keratectomy. Axial curvature maps were analyzed using a fixed grid and set of concentric circles superimposed to measure the topographic optical zone diameter and centration. Follow-up was 12 months.

RESULTS

The incidence of use in the population of myopic treatments during the study period was 0.79% (73 of 9,249). The optical zone diameter was increased by 11% from a mean of 5.65 to 6.32 mm, with a maximum change of 2 mm in one case. Topographic decentration was reduced by 64% from a mean of 0.58 to 0.21 mm. There was a 44% reduction in spherical aberration, 53% reduction in coma, and 39% reduction in total higher order aberrations. A subjective improvement in night vision symptoms was reported by 93%. Regarding efficacy, 82% of eyes reached 20/20 and 100% reached 20/32 (preoperative CDVA was 20/20 or better in 90%). Regarding safety, no eyes lost two lines of CDVA and 27% gained one line. Regarding predictability, 71% of re-treatments were within ±0.50 diopters.

CONCLUSIONS

Topography-guided ablation was effective in enlarging the optical zone, recentering the optical zone, and reducing higher order aberrations. Topography-guided custom ablation appears to be an effective method for re-treatment procedures of symptomatic patients after myopic LASIK. [J Refract Surg. 2018;34(2):121-130.].

Refractive and topographic errors in topography-guided ablation produced by epithelial compensation predicted by 3D Artemis VHF digital ultrasound stromal and epithelial thickness mapping

PURPOSE

To describe and quantify the errors inherent to topography-guided ablation of irregular corneas due to natural epithelial thickness compensatory remodeling.

METHODS

Artemis very high-frequency (VHF) digital ultrasound scanning (ArcScan Inc) was performed on a cornea that had undergone radial keratotomy with inferior and superior trapezoidal keratotomies, resulting 27 years later in high irregular astigmatism (+6.50 -8.00 × 101) and severe loss of corrected distance visual acuity (CDVA) to 20/50. The epithelial thickness profile was highly irregular, masking a significant proportion of the true stromal irregularity from front corneal surface topography, which would have resulted in significant inaccuracies had a topography-guided ablation been performed. The stromal ablation pattern of a transepithelial phototherapeutic keratectomy (PTK) ablation was modeled, which appeared logically to reduce the areas of abnormal stromal surface elevation and resembled a hyperopic astigmatic ablation of approximately 3.50 diopters of cylinder. Artemis-assisted transepithelial PTK was performed to target the stromal irregularity masked by epithelium.

RESULTS

Artemis-assisted transepithelial PTK induced a refractive change similar to that predicted (+2.24 -3.97 × 120), demonstrating the refractive shift produced by the epithelium. The epithelial thickness profile became relatively regular and CDVA returned to 20/20⁻². Two topography wavefront-guided ablations were performed to correct the remaining topographic irregularity and refractive error, resulting in a near plano refraction, significantly lower higher order aberrations, and CDVA of 20/20⁺².

CONCLUSIONS

A knowledge of stromal surface shape and power shift produced by epithelial thickness profile alterations after corneal surgery has the potential of improving the efficacy and safety of custom corneal ablation.

Is topography-guided ablation profile centered on the corneal vertex better than wavefront-guided ablation profile centered on the entrance pupil?

PURPOSE

To illustrate the hypothesis that corneal vertex centration is superior to entrance pupil centration when guiding an ablation by wavefront.

METHODS

In one case example of therapeutic retreatment for treatment zone decentration after primary radial keratotomy (RK) centered on the entrance pupil (line of sight), both a whole-eye wavefront-guided ablation profile (WASCA data) and a topography-guided ablation profile (Atlas data) were generated using the CRS-Master (Carl Zeiss Meditec) and compared. The patient had a large vertical angle kappa. Corneal topography demonstrated that the zone of flattening was decentered superiorly with reference to the corneal vertex and the patient reported severe night vision disturbances.

RESULTS

The wavefront-guided profile, centered on the line of sight, was symmetrical because the wavefront was dominated by spherical aberration induced by the primary RK treatment. On the other hand, the topography-guided profile, centered on the corneal vertex, was asymmetric with an inferior region of ablation, which would logically improve the topographic decentration. The topography-guided profile was chosen for photorefractive keratectomy using the MEL 80 excimer laser (Carl Zeiss). Ten months after the procedure, the treatment zone was topographically well centered on the corneal vertex. Whole-eye higher order root-mean-square (RMS) was reduced by 43% and corneal higher order RMS was reduced by 61%. The patient reported large subjective improvement in the quality of vision and marked reduction in night vision disturbances.

CONCLUSIONS

This case provides evidence that wavefront data centered on the entrance pupil center may not represent the patient's view and the treatment zone should preferably be centered on the corneal vertex rather than the entrance pupil center.

Repeatability of layered corneal pachymetry with the artemis very high-frequency digital ultrasound arc-scanner

PURPOSE

To assess the three-dimensional repeatability of thickness measurements for epithelium, stroma, cornea, flap, and residual stromal bed using the Artemis very high-frequency (VHF) digital ultrasound arc-scanner (ArcScan Inc).

METHODS

Five consecutive measurements were obtained for 10 eyes of 10 patients 1 year after LASIK using the Artemis VHF digital ultrasound arc-scanner across the central 10-mm diameter of the cornea. Repeatability analysis was performed for thickness measurements for each corneal layer-epithelium, stroma, cornea, flap, and residual stromal bed. The standard deviation of repeated measurements (point-repeatability) was calculated for each measurement location in 0.1-mm steps for the 10×10-mm matrix. The pooled standard deviation of the point-repeatability for each measurement location within the central 1-, 2-, and 3-mm radius was calculated (region-repeatability). The corneal thickness of the baseline scan set was compared to that of subsequent scan sets within the same session and plotted over time to assess any possible hydration effects of the immersion technique.

RESULTS

The repeatability at the corneal vertex was 0.58 μm for epithelium, 1.78 μm for stroma, 1.68 μm for cornea, 1.68 μm for flap, and 2.27 μm for residual stromal bed. The region-repeatability within the central 1-mm radius was 1.01 μm for epithelium, 3.44 μm for stroma, 3.35 μm for cornea, 2.81 μm for flap, and 3.97 μm for residual stromal bed. The mean difference in corneal thickness from the baseline value was within 1.25 μm for each of the subsequent four scan sets over a 5-minute immersion period.

CONCLUSIONS

Layered pachymetry of the epithelium, stroma, cornea, flap, and residual stromal bed showed high repeatability with the Artemis VHF digital ultrasound arc-scanner. The high repeatability validates the use of the Artemis for in vivo layered pachymetry.

Combined corneal topography and corneal wavefront data in the treatment of corneal irregularity and refractive error in LASIK or PRK using the Carl Zeiss Meditec MEL 80 and CRS-Master

PURPOSE

To assess the efficacy, safety, and accuracy of TOSCA II (Topography Supported Custom Ablation) treatments for the correction of high corneal aberrations and refractive error following previous ocular surgery.

METHODS

Forty-eight eyes of 32 patients were included for study. Indications for TOSCA II treatment included small optical zone, decentered ablation, subjective visually significant higher order aberrations, and irregularly irregular astigmatism induced by LASIK, photorefractive keratectomy, radial keratotomy, conductive keratoplasty, cataract surgery, and deep lamellar keratoplasty. An ablation profile based on corneal topography data and corneal wavefront and manifest refraction was created using the CRS-Master software (Carl Zeiss Meditec) to treat corneal irregularity and refractive error simultaneously. Postoperative assessments were performed at 1 week and 1, 2, 3, 6, and 12 months.

RESULTS

Mean attempted spherical equivalent refraction (SE) was -1.12 +/- 1.97 diopters (D) (range: +1.13 to -10.50 D). Mean attempted cylinder correction was 1.34 +/- 1.65 D (range: 0.00 to 7.75 D). Median age was 38 years (range: 19 to 68 years). Median follow-up was 9.4 months. Accuracy: mean deviation from the intended SE correction was -0.19 +/- 0.94 D, 60% of eyes were within +/- 0.50 D and 77% of eyes were within +/- 1.00 D of the intended SE. Cylinder: the correction ratio was 1.49 +/- 0.85 and the error ratio was 0.87 +/- 0.69.

EFFICACY

56% of eyes achieved uncorrected visual acuity of 20/20 or better and 88% achieved 20/40 or better.

SAFETY

34% of eyes gained one or more lines of best spectacle-corrected visual acuity, 15% lost one line, and no eye lost two or more lines. Contrast sensitivity: for the subset of eyes with below normal contrast sensitivity preoperatively, there was a statistically significant improvement in contrast sensitivity at 3 cycles per degree (cpd), 6 cpd, and 12 cpd (P < .05). Stability: the average change in refraction between 3 months and 1year was +0.38 +/- 0.30 D. Higher order aberrations: the average higher order root-mean-square decreased by 21% and the average spherical aberration decreased by 41%.

CONCLUSIONS

The MEL 80 CRS-Master TOSCA II software appears to be an effective treatment for decentrations, optical zone enlargement, and reduction of higher order aberrations. The refractive outcome was satisfactory after one treatment.

Patient satisfaction and visual symptoms after wavefront-guided and wavefront-optimized LASIK with the WaveLight platform

PURPOSE

To investigate patient satisfaction and visual symptoms after wavefront-guided LASIK.

METHODS

A prospective, randomized, double-masked, controlled study comprised 200 eyes of 100 young patients who underwent LASIK for myopia and astigmatism. Patients were randomly divided into two different treatment groups: standard ablation using wavefront-optimized profiles (wavefront-optimized group) and aberration customized aspheric treatment ablation (customized group) using the WaveLight ALLEGRETTO platform. Patients were asked to complete questionnaires regarding reasons for surgery, satisfaction, and visual symptoms. Patients were followed for 6 months.

RESULTS

The most frequent motivating factor for surgery was to improve uncorrected visual acuity (UCVA) in the wavefront-optimized and customized groups (both 100%), followed by freedom from spectacles (86.9% vs 96.3%). At 6 months postoperatively, over 95% of patients in both groups reported their UCVA was as good as anticipated and they were satisfied with the surgery and would recommend the operation to a friend or family member. Satisfaction was not correlated with age, attempted refractive error, residual refractive error, postoperative UCVA, or root-mean-square higher order aberration. The rate of postoperative overall visual symptoms was reduced and the mean analog scores of the symptoms in both groups did not change significantly postoperatively (P > .05). The rate of visual symptoms such as glare (8.7% vs 7.4%), halo (0% vs 7.4%), and night driving difficulty (8.7% vs 3.7%) decreased after LASIK at 6 months postoperatively in the wavefront-optimized and customized groups, respectively.

CONCLUSIONS

Patient satisfaction was achieved in young myopic patients who underwent wavefront-guided and standard ("wavefront-optimized") LASIK. The rate of visual symptoms such as glare, halo, and night driving difficulty decreased postoperatively after both treatment protocols.

[Aspheric profiles for refractive laser ablation of the cornea]

Conventional ablation profiles for excimer lasers for myopic refractive correction of the cornea are of spheric geometry. Therefore, they induce additional imaging aberrations into the optical system of the eye, most notably spherical aberration. This is a major cause of the observed deterioration of visual quality after such corrections, especially under low illumination and ensuing larger pupil diameter. Therefore, aspheric ablation profiles compromizing the preexisting imaging/visual quality of the eye as little as possible are currently being developed and optimized for all laser platforms. Employed methods include customized correction profiles on the basis of individual wavefront data of the anterior corneal topography on the one hand, and correction profiles that minimize the induced spherical aberration in a "standardized" way on the other hand. We demonstrate for a particular laser platform how such profiles must be developed and optimized. Mathematical theoretical calculations appear to be an indispensable but insufficient prerequisite. The biological reaction of the corneal stroma and epithelium ("biodynamic response") can only be determined experimentally and must lead to adjustment of the calculated ablation algorithm. The results show that aspheric profiles developed on this basis can lead to significant reduction of induced spherical aberration. The obtainable effect is, however, limited by the biological response and the ensuing peripheral ablation depth and volume.