Intrastromal corneal ring segments: effect of depth of implantation in visual, refractive, and topographic outcomes in patients with keratoconus.

PURPOSE: To evaluate visual, refractive, and topographic outcomes of intracorneal ring segment implantation in relation to the achieved segment depth, using the manual technique. SETTING: Ophthalmology Department, Hospital de Braga, Braga, Portugal. DESIGN: Retrospective cohort study. METHODS: We obtained 104 eyes of 93 patients with keratoconus submitted to Ferrara intracorneal ring segment (ICRS) implantation, using a manual technique. Subjects were divided into 3 groups according to the achieved depth of implantation: 40% to 70% (Group 1), 70% to 80% (Group 2), and 80% to 100% (Group 3). Visual, refractive, and topographic variables were evaluated at baseline and 6 months. Topographic measurement was performed using Pentacam. Thibos-Horner and Alpins methods were used to analyze the vectorial change of refractive and topographic astigmatism, respectively. RESULTS: We found a significant improvement of uncorrected distance visual acuity and corrected distance visual acuity in all groups at 6 months ( P < .005); no differences were observed regarding safety and efficacy indexes in the 3 groups ( P > .05). Manifest cylinder and spherical equivalent significantly reduced in all groups ( P < .05). Topographic evaluation showed a significant improvement of all parameters in the 3 groups ( P < .05). A shallower (Group 1) or deeper (Group 3) implantation was associated with topographic cylinder overcorrection, a higher magnitude of error, and a higher mean centroid postoperative corneal astigmatism. CONCLUSIONS: ICRS implantation with the manual technique showed to be equally effective in visual and refractive outcomes despite the depth of implantation; however, shallower or deeper implants were associated with topographic overcorrection and a higher mean centroid postoperative astigmatism, which explain the lower topographic predictability associated with manual surgery for ICRS implantation.

Efficacy and safety after posterior chamber Implantable Collamer Lens implantation according to preoperative anterior chamber depth: Short-term comparative study.

PURPOSE: To compare visual, refractive, and safety outcomes of posterior chamber Implantable Collamer Lens (ICL) implantation for the correction of myopia according to the preoperative anterior chamber depth (ACD). METHODS: Retrospective, comparative study, patients submitted to implantation of myopic posterior-chamber phakic Implantable Collamer Lens (ICL), model V4C/V5, minimum follow-up of 12 months; two groups were created: Group 1 (ACD 2.80 to 2.99 mm) and Group 2 (ACD equal to or greater than 3.00 mm). The parameters evaluated were uncorrected and corrected visual acuity, subjective refraction, efficacy and safety index, predictability, endothelial cell density, central vault, anterior chamber angle and postoperative complications. A total of 558 eyes from 298 patients were evaluated: 111 eyes (19.9%) in group 1 and 447 eyes (80.1%) in group 2. RESULTS: At 12 months, the efficacy index was similar in both groups (p = 0.264); the safety index was higher in group 1 (p = 0.031); the mean central Vault was significantly lower in group 1 (212.8 vs 410.6 µm; p < 0.001). Respectively, 93 (83.8%) and 366 (84.1%) eyes were within ±0.50 D of targeted refraction. Anterior chamber angle significantly decreased during follow-up in both groups (p < 0.001; p < 0.001). Intraocular pressure did not change significantly (p = 0.310 and p = 0.446, respectively). There were no significant differences in endothelial cell density loss (p = 0.278) or in the rate of complications observed (p = 0.733). CONCLUSIONS: ICL implantation is an effective and safe procedure in eyes with shallow anterior chambers, with visual and refractive results and complication rates identical to those obtained in deeper anterior chambers.

Efficacy and Safety After Toric Posterior Chamber Implantable Collamer Lens and Toric Iris-Fixated Foldable Phakic Intraocular Lens for Myopic Astigmatism.

PURPOSE: To compare visual, refractive, and safety outcomes of toric posterior chamber Implantable Collamer Lens (T-ICL) (STAAR Surgical) and toric iris-fixated foldable phakic intraocular lens (IOL) (T-Artiflex; Ophtec BV) implantation for the correction of myopic astigmatism. METHODS: This retrospective cohort study included 312 eyes of 312 patients who had phakic IOL implantation for myopic astigmatism. Two groups were defined: 205 eyes that underwent T-ICL implantation and 107 eyes that underwent T-Artiflex implantation. Safety, efficacy, and predictability outcomes were evaluated preoperatively and at 12 months postoperatively. Refractive and corneal astigmatic vector analysis were performed using the Alpins method. RESULTS: One year postoperatively, uncorrected distance visual acuity was 0.05 ± 0.18 (T-ICL) and 0.10 ± 0.16 (T-Artiflex) logMAR, with efficacy indexes of 1.16 ± 0.27 and 1.05 ± 0.31, respectively (P < .001). Safety indexes were 1.28 ± 0.30 and 1.21 ± 0.31, respectively (P = .04). Spherical equivalent was within ±0.50 diopters (D) of emmetropia in 165 (80.5%) and 88 (82.2%) eyes, respectively. Refractive astigmatic analysis showed an index of success of 0.28 ± 0.33 (T-ICL) and 0.31 ± 0.26 (T-Artiflex) (P = .07). Surgically induced corneal astigmatism was 0.48 ± 0.74 and 0.81 ± 0.61 D, respectively (P < .001). Mean endothelial loss was 1.11% and 2.05%, respectively (P = .42). Six (2.9%) eyes in the T-ICL group and 1 (0.9%) eye in the T-Artiflex group had phakic IOL repositioning due to significant misalignment. No vision-threatening complications occurred. CONCLUSIONS: Both the T-ICL and T-Artiflex groups showed high visual and refractive efficacy with a good safety profile for the correction of myopic astigmatism. T-ICL implantation demonstrated significantly better efficacy and safety indexes after 12 months. Vector analysis showed similar refractive astigmatic correction in both groups, but T-Artiflex implantation revealed higher surgically induced corneal astigmatism. [J Refract Surg. 2022;38(6):339-347.].

Intraocular Lens Position and Anterior Chamber Parameters Evaluation After Nd:YAG Laser Posterior Capsulotomy for Posterior Capsular Opacification Using Anterior Segment Swept-Source Optical Coherence Tomography.

PURPOSE: To evaluate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy on intraocular lens (IOL) position and anterior segment parameters with a new swept-source anterior segment optical coherence tomography (AS-OCT) device (Anterion®, Heidelberg Engineering GmbH). PATIENTS AND METHODS: A total of 50 eyes from 50 consecutive patients were included. All patients had visually significant posterior capsular opacification (PCO) after uneventful phacoemulsification surgery with manual capsulorhexis and single-piece C-loop acrylic IOL implantation (AcrySof® SA60AT) and were treated with Nd:YAG laser. Anterior segment images were captured with Anterion® in non-dilated conditions before and one month after the procedure. In the "Metrics App", we collected data of the anterior chamber angle (ACA) 3 and 9 o'clock, the anterior chamber depth (ACD), the anterior chamber volume (ACV), and the central corneal thickness (CCT). We also collected demographic and clinical data [age, gender, months from surgery to Nd: YAG capsulotomy, pre- and post-capsulotomy corrected distance visual acuity (CDVA) and spherical equivalent, and axial length]. RESULTS: We did not find a statistically significant difference in ACD after the Nd:YAG capsulotomy (3.96 ± 0.55 vs 3.97 ± 0.55 mm, p = 0.10). In 28 patients, we noted a backward movement of the IOL; in the remaining 22, the IOL moved forward or did not change at all. We did not observe significant changes in ACA at the 3 and 9 o'clock reference points, ACV, or CCT. There was an improvement in CDVA after the procedure (0.37 ± 0.21 vs 0.12 ± 0.27 logMAR, p = 0.015), without statistically significant differences in SE (-0.15 ± 0.84 vs -0.25 ± 0,93, p = 0.42). Axial length was not correlated with ACD variations after the procedure (p = 0.67). CONCLUSION: Our results show that Nd:YAG laser capsulotomy does not change the axial position of a single-piece C-loop acrylic IOL inside the capsular bag, as well as other anterior chamber parameters.

Posterior chamber collamer phakic intraocular lens implantation: Comparison of efficacy and safety for low and moderate-to-high myopia.

PURPOSE: To compare visual, refractive and safety outcomes of central-hole posterior chamber collamer phakic intraocular lens implantation for low and moderate-to-high myopia. SUBJECTS/METHODS: This retrospective cohort study included 338 eyes submitted to posterior chamber collamer phakic intraocular lens implantation that completed a 12-month postoperative follow-up. Two groups were defined depending on preoperative spherical equivalent: group 1 comprised 106 eyes with manifest spherical equivalent of -6.00 D or less; group 2 comprised 232 eyes with manifest spherical equivalent higher than -6.00 D. Effectiveness, predictability, stability and safety outcomes were compared preoperatively and at 1, 6 and 12 months postoperatively. RESULTS: At 1-year postoperative, uncorrected and corrected visual acuities were 0.02 ± 0.17 and -0.01 ± 0.12 logMAR (group 1) and 0.04 ± 0.20 and 0.01 ± 0.16 logMAR (group 2), with an efficacy index of 1.05 ± 0.17 and 1.17 ± 0.28. Respectively, 92 (86.8%) and 199 (85.8%) eyes were within ±0.50 D of targeted refraction, and postoperative manifest refraction changes were -0.07 ± 0.25 D and -0.07 ± 0.35 D. Intraocular pressure did not change significantly. The mean rate of endothelial cell loss was 1.12% and 1.10%, respectively. One case of anterior subcapsular cataract (group 2) was observed. ICL exchange occurred in one case (group 1) and three cases (group 2). No vision-threatening complications were reported. CONCLUSION: The posterior chamber collamer phakic intraocular lens implantation demonstrated high visual and refractive efficacy with an excellent safety profile for the correction of both low and moderate-to-high myopia, revealing equivalent 1-year outcomes regardless of the degree of preoperative myopia.

Long-term efficacy and safety results after iris-fixated foldable phakic intraocular lens for myopia and astigmatism: 6-year follow-up.

PURPOSE: To evaluate the long-term efficacy and safety of iris-fixated foldable phakic intraocular lenses (pIOLs) for the management of myopia and astigmatism after 6-year follow-up. SETTING: Ophthalmology Department, Hospital Braga, Portugal. DESIGN: Retrospective cohort study. METHODS: Patients included underwent iris-fixated foldable Artiflex pIOL implantation between January 2010 and December 2013. Follow-up evaluations were performed 6 months postoperatively and every 12 months until 72 months. Preoperative and follow-up data on uncorrected and corrected distance visual acuity (CDVA), manifest refraction, endothelial cell density (ECD), and anterior chamber depth (ACD) were analyzed. RESULTS: A total of 177 eyes of 98 patients with a mean age of 32.33 ± 7.13 years were analyzed. There was a statistically significant improvement in CDVA from 0.09 ± 0.02 logMAR preoperatively to 0.04 ± 0.02 logMAR (P < .0001) at 6 years postoperatively. The spherical equivalent demonstrated a statistically significant improvement from -9.50 ± 2.93 diopters (D) to -0.41 ± 0.45 D at 6 years. At 72 months, the efficacy and safety indexes were 0.94 and 1.15, respectively. A mean loss of 31.77 cells/mm2 (1.19%) was observed each year until the sixth year. The overall mean ECD loss after correction for the physiological loss was 3.02% after 6 years. No correlations were observed between the mean ECD loss and the preoperative ACD. CONCLUSIONS: The Artiflex pIOL was a safe, effective, and a stable option to correct myopia. A mean ECD loss of 3.02% was observed over 6 years. No pIOL was explanted due to corneal decompensation.

Five-year long-term outcomes of intrastromal corneal ring segment implantation using the manual technique for keratoconus management.

PURPOSE: To evaluate the long-term effectiveness, safety, and stability of Ferrara-type intrastromal corneal ring segments (ICRS) by manual surgery implantation in patients with keratoconus. SETTING: Ophthalmology Department, Hospital de Braga, Braga, Portugal. DESIGN: Retrospective cohort study. METHODS: This study included 124 eyes that had ICRS implantation using the manual technique with a follow-up of 5 years. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), subjective refraction, keratometry, aberrometry, and pachymetry maps were evaluated preoperatively and at 6 months, 1 year, and 5 years postoperatively. A secondary analysis of all variables was performed comparing 2 subgroups of patients: a group younger than 30 years and a group of 30 years or older. RESULTS: At 5 years, both mean UDVA and CDVA improved significantly (P < .0001) from a preoperative value of 0.91 ± 0.36 to 0.46 ± 0.32 logMAR and 0.40 ± 0.27 to 0.22 ± 0.20 logMAR, respectively. Spherical equivalent, refractive cylinder, and all topography values significantly decreased postoperatively (P < .0001). No regression was observed in any visual or topographic parameter during the entire follow-up. Regarding the subgroup analysis, both younger and older patients demonstrated similar and stable results from the preoperative to the 5-year visit, except for minimum pachymetry value change over time. CONCLUSIONS: Ferrara-type ICRS implantation significantly improved visual acuity, refractive error, and topographic values; the improvement was stable throughout a 5-year follow-up period. This study confirms that ICRS implantation surgery for keratoconus is a stable procedure in a long-term follow-up, regardless of the preoperative patient's age.

Comparison of clinical outcomes between manual and femtosecond laser techniques for intrastromal corneal ring segment implantation.

PURPOSE: The purpose was to compare the visual, refractive and aberrometric results of intrastromal corneal ring segments implantation with manual dissection and femtosecond laser-assisted surgery. METHODS: This is a multicentre study, which included consecutive patients with paracentral keratoconus, in which the difference between the axes of the topographic flattest and the coma aberration was <60°, who had Ferrara-type intrastromal corneal ring segment implantation using manual dissection or femtosecond laser technique. LogMAR uncorrected (uncorrected distance visual acuity) and corrected (corrected distance visual acuity) distance visual acuity, refractive errors and the root mean square for corneal coma-like aberration were recorded before and at 6 months after surgery. RESULTS: The study included 84 and 110 eyes in the manual group and in the femtosecond group, respectively. After surgery, there was a statistically significant improvement in uncorrected distance visual acuity and corrected distance visual acuity for both groups (p < 0.0001), and there were no statistically significant differences between groups (p > 0.3). For both groups, there was a reduction in spherical equivalent after intrastromal corneal ring segment implantation (p < 0.0001). There were no statistically significant differences between groups in the magnitude of spherical equivalent reduction (p = 0.34) The magnitude of the root mean square coma-like reduction was 0.93 ± 0.76 and 0.83 ± 0.80 µm in the manual and femtosecond group, respectively (p = 0.2). While in the femtosecond laser group no complications were reported, in the manual group, the intraoperative or postoperative complications rate was 13.09%. CONCLUSION: Although both surgical techniques provide comparable visual, refractive and aberrometric outcomes, it should be noted that the femtosecond laser is a safer surgical procedure, with no complications reported.

Comparison of Complication Rates between Manual and Femtosecond Laser-Assisted Techniques for Intrastromal Corneal Ring Segments Implantation in Keratoconus.

Purpose: To compare the incidence of complications between manual and femtosecond-laser assisted surgery for intrastromal corneal ring segments (ICRS) implantation.Material and methods: This study included keratoconus patients who had ICRS implantation using manual dissection and using the femtosecond laser with a minimum follow-up of 12 months. Uncorrected (UDVA) corrected (CDVA) distance visual acuity (CDVA), refraction, corneal topography and aberrometry, pachymetry map and slit-lamp microscopy were assessed before and after surgery.Results: The study included 265 eyes in the manual group and 111 in the femtosecond laser group. In the manual group, there were complications in 48 eyes (18.11%); while in the femtosecond laser 4 eyes had a complication (3.6%). In the manual group, the most frequent complications were ICRS exchange/adjustment for visual and refractive enhancement (25 eyes; 9.43%) and late ICRS spontaneous extrusion (15 eyes; 5.66%). In the manual group, 81.25% of complications were observed during the first 3 years of surgeon's experience. Eyes who suffered a complication had preoperatively higher mean refractive (p = .002) and topographic cylinder (p = .003) and lower UDVA (p = .005) and CDVA (p = .002). After a second surgical procedure for complication management visual, refractive and topographic outcomes significantly improved.Conclusion: Manual mechanical ICRS surgery shows a higher rate of intra- and postoperative mechanical and refractive complications when compared to femtosecond laser assisted technique. The incidence is specially higher during the surgeon's first years of implementation of the technique.

Effect of superior blepharoplasty on tear film: objective evaluation with the Keratograph 5M - a pilot study / Efeito da blefaroplastia superior no filme lacrimal - avaliação objetiva com ceratógrafo 5M - estudo piloto

ABSTRACT Purpose: To evaluate the effect of superior blepharoplasty on the tear film using the corneal topographer Keratograph 5M. Methods: A prospective study was performed of 27 eyes of 14 patients with superior dermatochalasis who underwent superior blepharoplasty between May and June 2016. Conservative upper eyelid blepharoplasty was performed by an en bloc resection of anterior lamellar tissue that included skin, subcutaneous tissue, and the orbicularis oculi muscle. All the eyes were imaged using the noninvasive tear breakup time tools of the Keratograph 5M. The following parameters were recorded in each patient before and 6 weeks after surgery: first noninvasive Keratograph 5M tear breakup time (the time at which the first breakup of tears occurs) and average noninvasive Keratograph 5M tear breakup time (the average time of all breakup incidents). The exclusion criteria were ophthalmological pathology, previous eyelid surgery, use of eye drops, systemic pathology, and medication that interferes with lacrimal tears. Results: The mean age of the patients was 65.1 years (range, 51-84); 86% were female. Student's t-test was used to compare the values of first and average noninvasive Keratograph 5M tear breakup times before and after surgery. The values for first noninvasive Keratograph 5M tear breakup time evaluated before and after surgery were not significantly different (9.04 and 8.71, respectively; p=0.926). The values for average noninvasive Keratograph 5M tear breakup time evaluated before and after surgery were also not significantly different (13.01 seconds and 13.14 seconds, respectively; p=0.835). Conclusions: The results of this pilot study suggest that upper blepharoplasty does not affect tear breakup time according to the objective evaluation of breakup time with the Keratograph 5M.

RESUMO Objetivos: Avaliar o efeito da blefaroplastia superior no filme lacrimal, utilizando o topógrafo de córnea Keratograph 5M. Métodos: Foi realizado estudo prospectivo de 27 olhos de 14 pacientes com dermatocálase superior submetidos à blefaroplastia superior entre maio e junho de 2016. A blefaroplastia palpebral superior conservadora foi realizada por ressecção em bloco de tecido lamelar anterior que incluiu pele, tecido subcutâneo e músculo orbicular do olho. Todos os olhos foram fotografados usando as ferramentas não-invasivas de tempo de ruptura do lacrimal do Keratograph 5M. Os seguintes parâmetros foram registrados em cada paciente antes e 6 semanas após a cirurgia: primeiro tempo não-invasivo de ruptura lacrimal de Keratograph 5M (o tempo em que ocorre o primeiro rompimento dos rasgos) e média não-invasiva do tempo de ruptura lacrimal (tempo médio de todos os incidentes de ruptura). Os critérios de exclusão foram: patologia oftalmológica, cirurgia anterior das pálpebras, uso de colírio, patologia sistêmica e medicação que interfere na ruptura lacrimal. Resultados: A idade média de idade dos pacientes foi de 65,1 anos (variação entre 51-84); 86% eram do sexo feminino. O teste t de Student foi usado para comparar os valores não-invasivos do tempo de ruptura lacrimal do Keratograph 5M e do tempo de ruptura lacrimal não invasivo do mesmo antes e após a cirurgia. Os valores não-invasivos do tempo de ruptura lacrimal do Keratograph 5M avaliados antes e após a cirurgia não foram significativamente diferentes (9,04 e 8,71, respectivamente; p=0,926). Os valores do tempo médio de ruptura lacrimal do Keratograph 5M avaliados antes e após a cirurgia, também não foram significativamente diferentes (13,01 e 13,14 segundos, respectivamente; p=0,835). Conclusão: Os resultados deste estudo piloto sugerem que a blefaroplastia superior não afeta o tempo de ruptura lacrimal de acordo com a avaliação objetiva do tempo de ruptura com o Keratograph 5M.

Effect of superior blepharoplasty on tear film: objective evaluation with the Keratograph 5M - a pilot study.

PURPOSE: To evaluate the effect of superior blepharoplasty on the tear film using the corneal topographer Keratograph 5M. METHODS: A prospective study was performed of 27 eyes of 14 patients with superior dermatochalasis who underwent superior blepharoplasty between May and June 2016. Conservative upper eyelid blepharoplasty was performed by an en bloc resection of anterior lamellar tissue that included skin, subcutaneous tissue, and the orbicularis oculi muscle. All the eyes were imaged using the noninvasive tear breakup time tools of the Keratograph 5M. The following parameters were recorded in each patient before and 6 weeks after surgery: first noninvasive Keratograph 5M tear breakup time (the time at which the first breakup of tears occurs) and average noninvasive Keratograph 5M tear breakup time (the average time of all breakup incidents). The exclusion criteria were ophthalmological pathology, previous eyelid surgery, use of eye drops, systemic pathology, and medication that interferes with lacrimal tears. RESULTS: The mean age of the patients was 65.1 years (range, 51-84); 86% were female. Student's t-test was used to compare the values of first and average noninvasive Keratograph 5M tear breakup times before and after surgery. The values for first noninvasive Keratograph 5M tear breakup time evaluated before and after surgery were not significantly different (9.04 and 8.71, respectively; p=0.926). The values for average noninvasive Keratograph 5M tear breakup time evaluated before and after surgery were also not significantly different (13.01 seconds and 13.14 seconds, respectively; p=0.835). CONCLUSIONS: The results of this pilot study suggest that upper blepharoplasty does not affect tear breakup time according to the objective evaluation of breakup time with the Keratograph 5M.

Predictability of Tunnel Depth for Intrastromal Corneal Ring Segments Implantation Between Manual and Femtosecond Laser Techniques.

PURPOSE: To compare the predictability of intrastromal tunnel depth creation for intrastromal corneal ring segments (ICRS) implantation between manual dissection and femtosecond laser using a high-resolution anterior segment optical coherence tomography (AS-OCT). METHODS: This multicenter study included patients with keratoconus who had Ferrara-type ICRS implantation at Hospital de Braga using manual dissection and at the Fernandez-Vega Ophthalmological Institute using the femtosecond laser technique. The intended depth of implantation was compared to the achieved postoperative ICRS depth of each case, measured using a swept-source AS-OCT (CASIA SS-1000; Tomey Corporation, Nagoya, Japan) at three points (proximal, central, and distal end of the implant). RESULTS: The study included 105 eyes in the manual group and 53 eyes in the femtosecond laser group. The differences of the intended versus the achieved depth were statistically higher in the manual group for all positions measured (Wilcoxon ranked-sum, P < .001). In the manual group, there were significant differences between the mean values of intended and achieved depth after surgery for the three locations measured (Wilcoxon signed-rank, P < .05), whereas there were no significant differences in the femtosecond laser group. In the manual group, the proximal part of the stromal tunnel was significantly shallower (-40.87 ± 69.03 µm) than the central (-25.54 ± 71.00 µm) and distal (-26.52 ± 73.22 µm) parts (Friedman test, P < .05). CONCLUSIONS: ICRS implantation assisted by a femtosecond laser provides a more precise procedure considering dissection depth when compared with the manual dissection technique. Such an advantage may provide more predictable clinical results and safer procedures with the femtosecond laser. [J Refract Surg. 2018;34(3):188-194.].

Comparative study of induced changes in effective lens position and refraction after Nd:YAG laser capsulotomy according to intraocular lens design.

PURPOSE: To evaluate and compare the changes in refraction and effective intraocular lens (IOL) position between a plate-haptic IOL and a c-loop single-piece IOL after neodymium-doped yttrium aluminium garnet (YAG) laser posterior capsulotomy. METHODS: In a prospective study, anterior chamber depth and subjective refraction were measured in 110 pseudophakic eyes from 110 patients, before and 1 month after YAG laser capsulotomy. Patients were divided into 2 groups according to the IOL design: group 1 (plate-haptic acrylic hydrophilic AT LISA tri 839MP®) and group 2 (c-loop acrylic hydrophobic single-piece AcrySof® SA60AT). Lens position was obtained through optical coherence biometry (Biograph WaveLight OB820®). RESULTS: YAG laser capsulotomy was performed 37.8±9.8 months after surgery in group 1 and 40.6±8.6 months in group 2 (p=0.125). Significant changes were found in the lens effective position after treatment in the 2 groups. The YAG posterior capsulotomy led to a change of anterior chamber depth in group 1 from 4.03±0.32 mm to 3.86±0.34 mm (p=0.02) and in group 2 from 4.03±0.37 mm to 4.14±0.45 mm (p=0.025). After YAG laser posterior capsulotomy, no significant changes were observed in mean spherical equivalent, sphere or cylinder for both groups (p>0.05). CONCLUSION: YAG laser posterior capsulotomy can induce a significant change in the IOL position according to the IOL type; however, the refractive change after treatment is clinically insignificant.

Correlation between different Scheimpflug-based lens densitometry analysis and effective phacoemulsification time in mild nuclear cataracts.

PURPOSE: To assess the correlations between preoperative Scheimpflug-based lens densitometry and effective phacoemulsification time (EPT) in age-related nuclear cataracts. DESIGN: Retrospective consecutive study. METHODS: The setting was the Ophthalmology Department, Hospital de Braga, Portugal. The study population included 50 eyes (42 patients) with age-related nuclear cataracts submitted to uneventful phacoemulsification surgery. Different analysis methods of Scheimpflug-based lens densitometry were performed: Pentacam Nucleus Staging (PNS) score with an ordinal scale from 0 to 5 and three-dimensional (3D), linear and region of interest (ROI) methods, which are displayed on an absolute scale (from 0 to 100%). EPT was calculated for the cataract surgery, which was performed by the same surgeon. Correlations between lens densitometry variables and EPT were determined using Pearson or Spearman correlation coefficients according to data normality. RESULTS: There were significant correlations between EPT and average density and maximum density variables derived from the 3D (r = 0.596, p < 0.001; r = 0.632, p < 0.001, respectively) and ROI (r = 0.527, p < 0.001; r = 0.575, p < 0.001, respectively) methods. The average density was the only parameter derived from the linear analysis that showed a significant correlation with EPT (r = 0.293, p = 0.039). The PNS score did not show a significant correlation with EPT (rho = 0.124, p = 0.390). CONCLUSION: The densitometric parameters based on the 3D method showed the highest correlations with EPT. The referred lens densitometric analysis approach may be used in preoperative assessment in order to predict EPT more efficiently in age-related nuclear cataracts.

Adjustment of Intrastromal Corneal Ring Segments After Unsuccessful Implantation in Keratoconic Eyes.

PURPOSE: To evaluate visual, refractive, and corneal topography outcomes in eyes with keratoconus that have undergone exchange/adjustment surgery with a new intrastromal corneal ring segment (ICRS) combination after unsuccessful visual and/or refractive outcomes after primary ICRS surgery. METHODS: A retrospective nonrandomized case series was conducted including consecutive eyes of patients with keratoconus that underwent ICRS adjustment after an unsuccessful visual outcome. Patients were divided into 2 groups: group 1 was made up of patients with Intacs ICRSs that were exchanged for the Ferrara ICRS type, and group 2 consisted of patients who maintained the same ICRS type after undergoing ICRS adjustment surgery (change of the arc length or thickness). Uncorrected distance visual acuity, best-corrected distance visual acuity (CDVA), keratometry, asphericity, higher-order aberrations, and corneal regularity indexes (ISV and IHD) (Pentacam HR; OCULUS) were assessed preoperatively and 12 months after each procedure. RESULTS: Twenty-six eyes from 26 patients were included, 8 eyes in group 1 and 18 eyes in group 2. The eyes in both groups improved their CDVA values after ICRS exchange, in group 1 from 0.27 ± 0.11 preoperatively to 0.54 ± 0.17 postoperatively (P = 0.001), and in group 2 from 0.34 ± 0.22 to 0.61 ± 0.15 (P < 0.0001). In both groups, there was also a significant improvement in the refractive cylinder, topographic cylinder, and coma after ICRS adjustment (P < 0.05). CONCLUSIONS: ICRS implantation has been shown to be a reversible and adjustable surgical procedure for keratoconus treatment. Good outcomes can be obtained after ICRSs are exchanged.

Correlations of Objective Metrics for Quantifying Dysfunctional Lens Syndrome With Visual Acuity and Phacodynamics.

PURPOSE: To study the relationship between objective metrics for quantifying crystalline lens dysfunction with visual impairment and phacodynamics parameters in age-related nuclear cataracts. METHODS: A total of 51 eyes (34 patients) with age-related nuclear cataract had phacoemulsification. The Dysfunctional Lens Index (0 to 10 points) was measured by a ray-tracing aberrometry (iTrace Visual Function Analyzer; Tracey Technologies, Houston, TX). The average lens density (0 to 100) was evaluated using a rotating Scheimpflug system (Pentacam HR; Oculus Optikgeräte GmbH, Wetzlar, Germany), and the nuclear opalescence score was subjectively assessed using the Lens Opacities Classification System III (LOCS III). The different parameters for evaluating crystalline lens dysfunction were correlated with preoperative corrected distance visual acuity (CDVA) and cumulative dissipated energy (CDE). RESULTS: There was a negative linear correlation between the Dysfunctional Lens Index and the LOCS III nuclear opalescence and Scheimpflug-measured average density (r =-0.728 and r = -0.771, respectively; both P < .01). The preoperative CDVA was correlated with the Scheimpflug-measured lens nuclear density value (r = 0.612, P < .01) and Dysfunctional Lens Index score A (r =-0.670, P < .01). The CDE was more strongly correlated with Dysfunctional Lens Index and Scheimpflug-derived average density (r =-0.744 and r = 0.700, respectively; both P < .01) than with LOCS III nuclear opalescence (r = 0.646, P < .01). CONCLUSIONS: The Dysfunctional Lens Index was correlated with the Scheimpflug-measured average density, subjective lens grading, and preoperative CDVA. This metric also presented the highest correlation with phacodynamics. Correlation with other clinical measures related to visual quality and impairment are still needed. [J Cataract Refract Surg. 2017;33(2):79-83.].

Scheimpflug lens densitometry and ocular wavefront aberrations in patients with mild nuclear cataract.

PURPOSE: To test correlations between Scheimpflug optical densitometry and ocular higher-order aberrations (HOAs) in patients with mild nuclear cataract. SETTING: Cornea and Refractive Surgery Department, Hospital de Braga, Braga, Portugal. DESIGN: Retrospective single-center study. METHODS: In eyes with mild nuclear cataract, lens densitometry was evaluated by Scheimpflug imaging (Pentacam HR), which provided an objective quantification (mean density and maximum density) and grading (nuclear staging score) of the crystalline lens. A visual function analyzer that combines ray-tracing aberrometry and Placido disk-based topography (iTrace) was used to evaluate the total ocular and internal HOAs. RESULTS: The study comprised 40 eyes of 30 patients. The mean density of the lens nucleus was 8.99% ± 0.76% (SD) (range 7.5% to 10.8%), and the mean maximum density was 27.96% ± 6.97% (range 16.9% to 56.1%). Regarding the score of nuclear staging of the Scheimpflug device, 28 eyes had level 0 and 12 eyes had level 1. Significant positive correlations were found between the mean density and maximum density parameters and the internal HOAs (ρ = 0.661, P < .001 and ρ = 0.570, P < .001, respectively). CONCLUSIONS: There were significant correlations between the quantification parameters derived from Scheimpflug lens densitometry and ocular HOAs. The integration of these technologies can help in clinical decision making and in understanding the subjective symptoms of patients with mild nuclear cataracts. FINANCIAL DISCLOSURE: Dr. Ambrósio is a consultant to Oculus Optikgeräte GmbH, Alcon Surgical, Inc., and Carl Zeiss Meditec AG. None of the other authors has a financial or proprietary interest in any material or method mentioned.

Comparison of Dysfunctional Lens Index and Scheimpflug Lens Densitometry in the Evaluation of Age-Related Nuclear Cataracts.

PURPOSE: To describe the Dysfunctional Lens Index (DLI) from ray-tracing aberrometry and to test its correlations with logMAR corrected distance visual acuity (CDVA) and lens grading based on the Lens Opacities Classification System III (LOCS III) and the Scheimpflug-based lens density. METHODS: The DLI was calculated by the i-Trace Visual Functional Analyzer (Tracey Technologies, Houston, TX). Forty eyes of 30 patients with mild to moderate age-related nuclear cataract were included retrospectively. Nuclear opalescence grading was obtained by slit lamp using the LOCS III, and objective lens densitometry was evaluated by Scheimpflug imaging (Pentacam HR; Oculus Optikgeräte GmbH, Wetzlar, Germany). The average density parameter obtained by Scheimpflug imaging of the nucleus lens was considered. RESULTS: The DLI showed a high negative linear correlation with the LOCS III nuclear opalescence score (r = -0.662; P < .01). The average density of the lens nucleus was positively correlated with the LOCS III nuclear opalescence score (r = 0.682; P < .01). The CDVA had a stronger relationship with the DLI parameter (r = -0.702, P < .01) compared to the average density values (r = 0.630, P < .01). CONCLUSIONS: The DLI was correlated with the LOCS III nuclear opalescence score and the Scheimpflug-based lens density. The DLI had a stronger correlation with CDVA compared to the LOCS III classification or the Scheimpflug-based lens density. The DLI may improve the preoperative evaluation of nuclear cataract and the monitoring of its progression.

Application of different Scheimpflug-based lens densitometry methods in phacodynamics prediction.

PURPOSE: To evaluate the correlations between preoperative Scheimpflug-based lens densitometry metrics and phacodynamics. METHODS: The Lens Opacities Classification System III (LOCS III) was used to grade nuclear opalescence (NO), along with different methods of lens densitometry evaluation (absolute scale from 0% to 100%): three-dimensional (3D), linear, and region of interest (ROI) modes. Cumulative dissipated energy (CDE) and total ultrasound (US) time were recorded and correlated with the different methods of cataract grading. Significant correlations were evaluated using Pearson or Spearman correlation coefficients according to data normality. RESULTS: A positive correlation was detected between the NO score and the average density and the maximum density derived from the 3D mode (r=0.624, P<0.001; r=0.619, P<0.001, respectively) and the ROI mode (r=0.600, P<0.001; r=0.642, P<0.001, respectively). Regarding the linear mode, only the average density parameter presented a significant relationship with the NO score (r=0.569, P<0.001). The 3D-derived average density and maximum density were positively correlated with CDE (rho =0.682, P<0.001; rho =0.683, P<0.001, respectively) and total US time (rho =0.631 and rho =0.668, respectively). There was a linear relationship between the average density and maximum density of the ROI mode and CDE (rho =0.686, P<0.001; rho =0.598, P<0.001, respectively) and total US time (rho =0.642 and rho =0.644, respectively). The average density was the only parameter derived from the linear mode that showed a significant correlation with CDE (rho =0.522, P<0.001) and total US time (rho =0.450, P<0.001). CONCLUSION: Specific Scheimpflug-derived densitometric parameters of the nucleus correlated with phacoemulsification parameters. The use of the appropriate densitometry approach can predict more efficiently the phacodynamics.

Photorefractive keratectomy for myopia and myopic astigmatism correction using the WaveLight Allegretto Wave Eye-Q excimer laser system.

To analyze photorefractive keratectomy (PRK) outcomes in myopia and myopic astigmatism correction using the WaveLight Allegretto Wave Eye-Q(®) excimer laser system (WaveLight Laser Technologie AG, Erlangen, Germany). 222 eyes of 151 patients underwent PRK (mean age 33.5 ± 6.8 years). Pre-operative best spectacle-corrected visual acuity (BSCVA) ranged from 0.4 to -0.1 logMAR (mean -0.03 ± 0.06). Mean spherical equivalent (SE) was -3.29 ± 1.20 D. Efficacy, predictability and safety were evaluated. Minimum follow-up was 3 months. Accountability at 3 and 6 months was 100 and 54 %, respectively (median follow-up 5 months, mean 5.2 ± 2.6 months). At 3 months, mean uncorrected visual acuity (UCVA) was -0.02 ± 0.07 logMAR, BSCVA -0.03 ± 0.05 logMAR, efficacy index 0.98 and safety index 1.02. UCVA was ≥20/16 in 40.1 %, ≥20/20 in 86.5 % and ≥20/25 in 98.2 %. Mean SE was -0.02 ± 0.20 D. Residual refractive error was ± 0.13 D in 81.5 %, ± 0.25 D in 88.7 % and ± 0.50 D in 97.7 %. At 6 months, outcomes were similar: mean UCVA was -0.02 ± 0.07 logMAR, BSCVA -0.03 ± 0.06 logMAR, efficacy index 1.00 and safety index 1.03. UCVA was ≥20/16 in 43.7 %, ≥20/20 in 86.6 % and ≥20/25 in 96.6 %. Mean SE was -0.02 ± 0.17 D. Residual refractive error was ± 0.13 D in 86.6 %, ± 0.25 D in 93.3 % and ± 0.50 D in 98.3 %. Refractive stability was achieved at 3 months. No patient lost more than one line of BSCVA. There were no retreatments. The WaveLight Allegretto Wave Eye-Q is effective, predictable and safe in low-to-moderate myopia and myopic astigmatism PRK correction.