In vivo confocal microscopy findings after SMILE refractive surgery technique.

OBJECTIVE: To evaluate confocal microscopy finding after SMILE surgery by in vivo confocal microscopy and stromal lenticule and stromal interface accuracy planed vs measured. METHOD: Thirty eyes of 15 patients were evaluated before and 1 month after SMILE surgery by using confocal microscopy. Cellular morphology was studied. Planed stromal lenticule thickness was compared vs measured stromal lenticule thickness after surgery by comparing the total stromal corneal thickness before vs after surgery. Stromal corneal interface was evaluated and depth of this planed interface was compared vs measured post-surgery interface depth. RESULTS: Sub-epithelial nerve plexus was absent at 1 month after surgery. Activated keratocytes were found before and after stromal corneal interface depth. There was not statistical significant difference between mean planed stromal lenticule vs. post-surgery measured (102.3 ± 25.7 vs. 104.2 ± 29.9 mm; p = 0.73). There was not statistical significant difference between mean planed stromal interface depth vs. post-surgical measured (113.7 ± 8.2 vs. 120.5 ± 17.3 mm; p = 0.058). CONCLUSIONS: Confocal microscopy is useful to evaluate changes after SMILE surgery; lenticule thickness and stromal interface depth are exact.

OBJETIVO: Evaluar los hallazgos mediante microscopía confocal in vivo de pacientes operados de cirugía SMILE, la exactitud del lentículo estromal y la profundidad de la interfaz estromal planeados versus medidos. MÉTODO: Treinta ojos de 15 pacientes operados de SMILE se estudiaron mediante microscopía confocal antes y al mes de la cirugía. Se evaluaron la morfología celular, el espesor del lentículo estromal planeado versus el medido en el posoperatorio mediante la diferencia entre el espesor estromal preoperatorio y el postoperatorio, así como la interfaz estromal, y se comparó la profundidad de esta interfaz estromal planeada con la medida en el posoperatorio. RESULTADOS: Se observó la ausencia del plexo nervioso subepitelial al mes del posoperatorio y una activación de queratocitos anterior y posterior a la profundidad de la interfaz estromal. No hubo diferencia en el lentículo estromal planeado versus el medido en el posoperatorio (102.3 ± 25.7 vs. 104.2 ± 29.9 mm; p = 0.73). No hubo diferencia entre la profundidad de la interfaz estromal planeada y medida (113.7 ± 8.2 vs. 120.5 ± 17.3 mm; p = 0.058). CONCLUSIONES: Tras la cirugía SMILE se pueden evaluar los cambios mediante microscopía confocal; el espesor del lentículo y la profundidad de la interfaz son exactos.

Corneal densitometry in patients with keratoconus undergoing intrastromal Ferrara ring implantation.

OBJECTIVE: Evaluation of central corneal densitometry changes following Ferrara corneal ring segment implantation in patients with keratoconus, especially the correlation between corneal densitometry and keratometry. METHODS: Retrospective, non-comparative, interventional study based on the review of medical records of patients diagnosed with keratoconus who underwent Ferrara corneal ring segment implantation. Pre and post-operative corneal densitometry measurements obtained with Pentacam HR (Oculus, Wetzlar, Germany) were analyzed. The follow-up time was 3 months, and data comparison was made, using specific statistical analysis, with the data of 3 months postoperatively. RESULTS: The study sample consisted of 43 eyes of 36 patients. The mean corrected visual acuity improved from 0.82 LogMAR preoperatively (SD ± 0.33) to 0.19 LogMAR (SD ± 0.13) postoperatively. The mean spherical equivalent varied from -4.63 (SD ± 3.94) preoperatively to -2.16 (SD ± 2.63) postoperatively. Asphericity varied from -0.69 (SD ± 0.32) preoperatively to -0.27 (SD ± 0.31) postoperatively. The mean maximum K was 54.01D (SD ± 3.38) preoperatively and 51.50D (SD ± 2.90) postoperatively. The mean anterior densitometric value was 18.26 (SD ± 2.03) preoperatively and 17.66 (SD ± 1.84) postoperatively. CONCLUSION: Corneal densitometry is an interesting technology that should be studied in keratoconus patients. Our results suggest that the corneal densitometry in the cornea's anterior layer reduces after ICRS implantation and correlates with corneal keratometry. Further studies should be performed to increase the knowledge in this field.

A Comparative Study of Laser In Situ Keratomileusis Flaps Created Using Single-Functional Versus Multifunctional Femtosecond Laser for Refractive Surgery.

PURPOSE: To compare laser in situ keratomileusis flaps created at the programmed target thickness of 120 µm using the LenSx multifunctional and the FS200 single-functional femtosecond lasers as evaluated by anterior segment optical coherence tomography (AS-OCT). METHODS: This was a prospective, comparative, consecutive, blinded, nonrandomized study. Patients with stable refraction for over a year were consecutively allocated to the LenSx group or the FS200 group (n = 66; 33 patients in each group). All the patients underwent refractive surgery in both eyes. Previous eye surgery, ocular pathology associated with refractive errors, pregnancy, breastfeeding, and use of medication that causes ocular adverse effects constituted the exclusion criteria. Corneal topography, corneal tomography, dilated fundoscopy, applanation tonometry, ultrasonic pachymetry, dynamic and static refraction, visual acuity, and AS-OCT were evaluated before and after surgery. AS-OCT flap thickness was measured at 20 points on each cornea. RESULTS: In the LenSx group, AS-OCT flap thickness differed significantly from the target thickness at 2 of 20 points (mean differences of 2.106 and 1.803 µm). In the FS200 group, 6 of 20 measurements differed significantly (mean differences ranging from 1.121 to 2.121 µm). The 2 lasers were similarly successful in creating regular and uniform flaps. The agreement between the 2 blinded examiners regarding the AS-OCT flap thickness measurements was excellent (intraclass correlation coefficient >0.75) in both groups. CONCLUSIONS: Both femtosecond lasers were safe and capable of creating highly reproducible, uniform, and regular flaps at the target preoperative thickness of 120 µm. The LenSx multifunctional femtosecond laser offers the advantage of allowing both cataract and corneal surgeries.

A 3-year follow-up study of a new corneal inlay: clinical results and outcomes.

PURPOSE: Here, we report the results of a 3-year follow-up analysis of the outcomes of the Flexivue Microlens corneal inlay. PATIENTS: Non-dominant eyes (n=31) of emmetropic presbyopic patients (spherical equivalent: -0.5 to 1.00 dioptre). METHODS: A Flexivue Microlens corneal inlay was implanted after the creation of a 300 µm deep stromal pocket using a femtosecond laser. Patients were followed up according to a clinical protocol involving refraction, anterior segment imaging analysis (Oculyser), optical quality analysis (OPD-Scan), monocular binocular uncorrected and corrected visual acuity tests, contrast sensitivity measurements (photopic and mesopic), satisfaction questionnaire results and adverse event reporting. RESULTS: Thirty patients were examined at the 3-year follow-up in this ongoing study. The mean uncorrected near visual acuity improved to Jaeger 1 in 76.9% of eyes treated with the inlays (vs 87.1% at the 1-year follow-up). All eyes improved four lines in all visits, except for four patients for whom the inlay was explanted. Patients reported that their near vision was good or excellent in 73.3% of cases (vs 90.3% in the first year). The UDVA remained stable over time. Three patients were explanted due to blurred vision for near-point and far-point distances. One patient developed a superficial corneal ulcer after 20 months. Two patients underwent cataract removal. Four patients underwent inlay exchange to increase near power correction. CONCLUSIONS: The Presbia Flexivue Microlens provided presbyopia treatment by improving near vision. Manageable complications may occur over the long term. CLINICAL TRIAL REGISTRATION NUMBER: U1111-1185-5684 and 0310451200000550.

Persistence of granular corneal dystrophy type-1 deposits in the predescemetic layer after big-bubble deep anterior lamellar keratoplasty.

We report intraoperative finding of Granular Corneal Dystrophy Type-1 (GCD1) deposits after stromal pneumodissection in deep anterior lamellar keratoplasty (DALK) in a 61-year-old female. Pneumodissection was performed from the center to the periphery of the cornea, characterizing a big bubble type 1 technique which dissects the deep stroma from the predescemetic layer. After stromal removal, persistence of whitish deposits inside the predescemetic layer was noted. During post-operative evaluation, anterior biomicroscopy and anterior segment optical coherence tomography showed granular opacities between the patient's Descemet's membrane and the donor cornea, suggesting possible involvement of the predescemetic layer in GCD1. This may require the surgeon's attention to choose between DALK keratoplasty or penetrating keratoplasty.

Persistence of granular corneal dystrophy type-1 deposits in the predescemetic layer after big-bubble deep anterior lamellar keratoplasty / Persistência de depósitos da distrofia corneal granular tipo-1 na camada pre-Descemet após transplante lamelar anterior profundo

ABSTRACT We report intraoperative finding of Granular Corneal Dystrophy Type-1 (GCD1) deposits after stromal pneumodissection in deep anterior lamellar keratoplasty (DALK) in a 61-year-old female. Pneumodissection was performed from the center to the periphery of the cornea, characterizing a big bubble type 1 technique which dissects the deep stroma from the predescemetic layer. After stromal removal, persistence of whitish deposits inside the predescemetic layer was noted. During post-operative evaluation, anterior biomicroscopy and anterior segment optical coherence tomography showed granular opacities between the patient's Descemet's membrane and the donor cornea, suggesting possible involvement of the predescemetic layer in GCD1. This may require the surgeon's attention to choose between DALK keratoplasty or penetrating keratoplasty.

RESUMO Relatamos o achado intraoperatório de persistência dos depósitos de Distrofia Granular Tipo 1 (GCD1) após pneumodissecção estromal no transplante de córnea lamelar anterior profundo (DALK) em uma mulher de 61 anos. A pneumodissecção começou a partir do centro para a periferia da córnea, caracterizando uma big bubble tipo 1, que disseca o estroma profundo da camada pré-Descemet. Após a remoção do estroma, notamos a persistência de depósitos esbranquiçados no interior da camada pré-Descemet. Na avaliação pós-operatória, a biomicroscopia anterior e a tomografia de coerência óptica do segmento anterior evidenciaram opacidades granulares entre a membrana de Descemet e a córnea doadora, sugerindo o possível envolvimento da camada pré-Descemet na GCD1, o que pode chamar atenção do cirurgião para decidir entre manter o DALK ou converter para transplante penetrante.

Ultrasound biomicroscopy after palliative surgical procedures for bullous keratopathy: a descriptive comparative study.

PURPOSE: To describe quantitative and qualitative features of eyes with advanced bullous keratopathy assessed using ultrasound biomicroscopy, before and after anterior stromal puncture (ASP) or amniotic membrane transplantation (AMT) procedures to relieve chronic pain. METHODS: The present descriptive comparative study included 40 eyes of 40 patients with chronic intermittent pain due to bullous keratopathy who were randomly assigned to one of the two treatments (AMT or ASP). Ultrasound biomicroscopy (Humphrey, UBM 840, 50 MHz transducer, immersion technique) was used, and a questionnaire about pain intensity was completed preoperatively and postoperatively at days 90 and 180, respectively. Exclusion criteria were age<18 years, presence of concurrent infection, ocular hypertension, and absence of pain. RESULTS: In a 180-day follow-up, the AMT group exhibited mean central corneal thickness (CCT), 899.4 µm preoperatively and 1122.5 µm postoperatively (p<0.001); mean epithelial thickness (ET), 156.4 µm preoperatively and 247.8 µm postoperatively (p<0.001); and mean stromal thickness (ST), 742.9 µm preoperatively and 826.3 µm postoperatively (p=0.005). The ASP group exhibited mean CCT, 756.7 µm preoperatively and 914.8 µm postoperatively (p<0.001); mean ET, 102.1 µm preoperatively and 245.2 µm postoperatively (p<0.001); and mean ST, 654.6 µm preoperatively and 681.5 µm postoperatively (p<0.999). Correlations between CCT and pain intensity in the AMT group (p=0.209 pre- and postoperatively) and the ASP group (p=0.157 preoperatively and p=0.426 at the 180-day follow-up) were not statistically significant. Epithelial and stromal edema, Descemet's membrane folds, epithelial bullae, and the presence of interface fluid were frequently observed qualitative features. CONCLUSION: CCT increased over time in both groups. The magnitude of CCT did not correlate with pain intensity in the sample studied. The presence of interface fluid was a qualitative feature specifically found in some patients who underwent AMT.

Laser in situ keratomileusis: ablation on the flap and stromal bed in a primary treatment.

PURPOSE: To analyze outcomes of laser in situ keratomileusis (LASIK) performed on the flap and on the stromal bed at the same time in a primary treatment. SETTING: Instituto de la Visión, Buenos Aires, Argentina. METHODS: Twenty-two cases (13 female, 9 male) were studied retrospectively; the mean age of the patients was 33.15 years +/- 10.44 (SD). Inclusion criteria were low pachymetry or topographic asymmetry. Twenty cases (90.9%) presented with low pachymetry (512.2 +/- 21.40 mum), and 2 cases (9.1%) presented with topographic asymmetry (inferior-superior difference more than 1.5 diopters [D]). Ablation was performed on the flap from the back and on the bed. The flap was made using the Technolas Hansatome microkeratome and the ablation by the Technolas 217z excimer laser (both by Bausch & Lomb). Preoperatively, the spherical equivalent (SE) was -5.61 +/- 1.72 D, the cylinder was -1.78 +/- 1.24 D, and the best spectacle-corrected visual acuity (BSCVA) was 0.77 +/- 0.19. Difficulties and complications of the technique, efficacy and safety index, and aberrations were analyzed. RESULTS: According to the surgical plan and our nomogram, diopters corrected on the flap were -1.73 +/- 1.08 and on the bed were -4.77 +/- 1.89. The mean follow-up was 8.28 +/- 2.19 months. At 6 months, the SE was -0.21 +/- 0.39, vectorial change was 1.69 +/- 0.74, and the BSCVA was 0.77 +/- 0.20. Postoperatively, no eye had an increase in refractive astigmatism. Uncorrected visual acuity was 20/40 or better in all cases (100%) and 20/25 or better in 13 cases (59.1%). Regarding gained and lost lines of BSCVA, 54.5% conserved the lines, 18.2% lost 1 line, 9.1% gained 1 line, and 18.2% gained 2 lines. CONCLUSIONS: Simultaneous ablation on the flap and on the bed in cases of low pachymetry or topographical asymmetry was predictable, effective, and safe.

Ferrara intrastromal corneal ring segments for severe keratoconus.

PURPOSE: Intrastromal Ferrara ring segments were inserted in eyes with severe keratoconus to evaluate safety and efficacy of this procedure. METHODS: Intrastromal Ferrara ring segments were placed in 36 eyes of 35 patients with severe keratoconus, who were evaluated after 12 months of follow-up. All patients had highly disabling visual acuity, contact lens intolerance, and a previous indication for penetrating keratoplasty. Statistical analysis included preoperative and postoperative uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, anterior chamber depth, keratometry, and pachymetry. RESULTS: No patient had a loss of visual acuity. Uncorrected visual acuity improved in 28 eyes (77.78%) and best spectacle-corrected visual acuity improved in 29 eyes (80.56%). Spherical equivalent refraction decreased from -7.29 +/- 3.12 D to -4.80 +/- 3.04 D at 12 months after Ferrara intrastromal ring segment implantation. Corneal topography and ultrasound biomicroscopy showed corneal flattening, demonstrated by thinning of the central cornea and a reduction in anterior chamber depth. Segment decentration occurred in one eye (2.7%), asymmetric positioning of the segments in two eyes (5%), inadequate depth in two eyes (5%), migration of the segments in two eyes (5%), segment extrusion in five eyes (13.8%), conjunctivitis in one eye (2.7%), bacterial keratitis in one eye (2.7%), and hydrops in one eye (2.7%). CONCLUSIONS: With these early results, Ferrara intrastromal ring segments appear to be an alternative for the treatment of severe keratoconus.