Higher-order aberrations following wavefront-guided photorefractive keratectomy and laser in situ keratomileusis

Background: We aimed to evaluate higher-order aberrations (HOAs) following wavefront-guided photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in patients with myopia and myopic astigmatism. Methods: This retrospective observational case-control study included patients who underwent wavefront-guided PRK (40 eyes of 20 patients) or LASIK (40 eyes of 20 patients) between August 2018 and November 2018 at the refractive surgery unit of Kayseri City Hospital Eye Clinic, Turkey. The corrected distance visual acuity (CDVA), manifest refraction, corneal topography, and HOAs were evaluated preoperatively and 3 months postoperatively in all patients. Results: The mean age ± standard deviation (SD) was 27.13 ± 5.54 years and 29.10 ± 4.38 years in the PRK and LASIK groups, respectively (P = 0.06). Both groups had a mean CDVA of 1.00. The mean ± SD of spherical and spherical equivalent values was -2.09 ± 1.56 diopter (D) and -3.03 ± 1.72 D in the PRK group and -2.23 ± 1.69 D and -3.35 ± 1.71 D in the LASIK group, respectively (P = 0.58). When the preoperative and postoperative HOAs and root mean square (RMS) values (for a 6-mm pupil diameter) were compared in the PRK group, a significant difference was found in vertical coma and total RMS values (P = 0.003 and P ˂ 0.001, respectively); in the LASIK group, there was a significant difference in preoperative and postoperative vertical coma and total RMS values (P = 0.0.001 and P ˂ 0.001, respectively). There was no significant difference in preoperative and postoperative vertical coma values between the two groups (P = 0.735 and P = 0.583, respectively). Conclusions: In terms of HOAs, total RMS values decreased significantly and vertical coma values increased significantly at 3 months postoperatively in both PRK and LASIK groups. However, there were no differences between the two groups

Evaluation of the change in retinal thickness after femtosecond laser-assisted laser in situ keratomileusis and photorefractive keratectomy

© 2021 Taylor & Francis Group, LLC.Purpose of the study: To investigate the change in individual retinal layer thickness by spectral-domain optical coherence tomography (SD-OCT) in eyes underwent femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and photorefractive keratectomy (PRK). Methods: In patients who underwent PRK and FS-LASIK, changes in the thickness of all retinal layers in the foveal, parafoveal, and perifoveal regions were evaluated by SD-OCT automated segmentation analysis at pre-operatively and different time points post-operatively. Results: Seventy-one eyes of 71 patients (38 patients in PRK, 33 patients in LASIK) were included. In the pre-operative period, mean spherical equivalent (SE), mean keratometry, axial length, and segmentation values of the retinal layers were similar (P> .05). In the PRK group, the pre-operative measurements of individual retinal layers did not show a statistically significant difference compared to the post-operative measurements on the 1st day, 1st week, and 1st month. In the FS-LASIK group, the mean inner nuclear layer (INL) thickness one day after the surgery was significantly higher than that before surgery in the foveal (21.22 ± 4.66 µm vs 19.03 ± 4.50 µm, P= .013) and parafoveal regions (41.98 ± 3.70 µm vs 40.56 ± 3.49 µm, P= .044). Conclusions: The findings of our study suggest that the increase of INL thickness may be due to temporary structural and circulatory changes of the retina that may occur in the suction phase in the FS-LASIK procedure

Comparison of the balafilcon A and samfilcon A lenses on postoperative pain control and epithelial healing time after photorefractive keratectomy: a contralateral eye study

To compare the effects of balafilcon A and samfilcon A silicone hydrogel bandage contact lenses on postoperative pain control and epithelial healing time after photorefractive keratectomy (PRK). Seventy-four eyes of 37 patients who underwent bilateral PRK were included in this randomized clinical trial study. In the end of the surgery, a balafilcon A lens was used in one eye and a samfilcon A lens was used in the fellow eye randomly. Pain, blurred vision, epiphora, photophobia, and foreign body sensation were assessed on the first and third postoperative day using a visual analogue scale (0 = no ocular pain or discomfort, 10 = highest level of ocular pain and discomfort). For balafilcon A and samfilcon A lenses, mean scores for pain were 6.22 +/- 2.81 and 3.11 +/- 2.90 on first postoperative day (p < 0.001) and 1.57 +/- 1.65 and 0.68 +/- 0.85 on third postoperative day (p = 0.001), respectively; mean scores for foreign body sensation were 6.11 +/- 2.53 and 3.19 +/- 2.72 on first postoperative day (p < 0.001) and 3.16 +/- 1.92 and 1.35 +/- 1.43 on third postoperative day (p < 0.001), also respectively; and mean scores for epiphora were 6.46 +/- 2.64 and 5.46 +/- 3.40 on first postoperative day (p = 0.007) and 1.68 +/- 1.60 and 1.32 +/- 1.31 on third postoperative day (p = 0.065), again respectively. No significant difference in blurred vision or photophobia emerged between the lenses on first and third postoperative day after PRK. On the third postoperative day, reepithelialization was complete in 83.7% of eyes with the balafilcon A lens and 89.1% of eyes fitted with the samfilcon A lens. Wearing samfilcon A lenses after photorefractive keratectomy can significantly manage pain, decrease foreign body sensation on first and third postoperative day, and reduce epiphora on first postoperative day

Evaluation of anterior segment parameters in patients with neurofibromatosis type 1

Purpose: To evaluate anterior segment parameters in patients with neurofibromatosis type 1 (NF1) in comparison to healthy individuals

Evaluation of foveal photoreceptor layer in eyes with macular edema associated with branch retinal vein occlusion after ozurdex treatment

The aim of this study was to evaluate the central retinal thickness (CRT), outer nuclear layer thickness (ONLT), photoreceptor layer thickness (PLT), photoreceptor layer integrity, and the correlation between visual acuity and PLT in eyes with branch retinal vein occlusion (BRVO) 2 months after treatment with intravitreal dexamethasone implant (Ozurdex; Allergan, Inc, Irvine, CA). In this prospective study, 32 eyes of 32 patients were enrolled. A single injection of Ozurdex was administered to all the patients. CRT, ONLT, and PLT were measured using spectral-domain optical coherence tomography before and 2 months after the injection. Best-corrected visual acuity (BCVA [logMAR]) and photoreceptor cell integrity were also evaluated. The average CRT, ONLT, PLT, and BCVA values for the sample group before the treatment were as follows: 707 +/- 261, 608 +/- 288, 70 +/- 25, and 0.96 +/- 0.22 A mu m, respectively. The average CRT, ONLT, PLT, and BCVA values for the sample group 2 months after the Ozurdex injection were as follows: 299 +/- 149, 211 +/- 138, 77 +/- 20, and 0.63 +/- 0.30 A mu m, respectively (p < 0.05). Two months after the Ozurdex injection, BCVA correlated with ONLT and PLT (r = 0.365, p = 0.048 and r = -0.488, p = 0.021, respectively), whereas BCVA was not correlated with CRT (r = 0.239, p = 0.189). Photoreceptor layer is associated with the visual function of eyes with macular edema secondary to BRVO. Also, ONLT seems to be more closely related to visual acuity improvement than CRT decrement

The assessment of choroidal thickness with spectral-domain optical coherence tomography during Valsalva maneuver

The purpose of the study was to evaluate the effect of Valsalva maneuver (VM) on choroidal thickness