Lacrimal gland injection of platelet rich plasma for treatment of severe dry eye: a comparative clinical study.

BACKGROUND: We aimed to assess the efficacy of the injections of platelet rich plasma (PRP) for the treatment of severe dry eye disease (DED). RESULTS: In this retrospecitve interventional clinincal study, we included 28 eyes of 14 patients with severe DED who were diagnosed with Sjogren syndrome. Each patient received unilateral lacrimal gland injection of PRP at days 0, 30, 60 and 90 days while the other eye served as control group who received preservative free eye drops. We objectively assessed parameters at baseline, 1 month, 2 months and 3 months including ocular surface analyzer (OSA) namely; noninvasive tear breakup times (NIBUT), tear meniscus height (TMH), lipid layer thickness (LLT) in addition to the Schirmer test I, corneal fluorescein staining (CFS) and meiboscore. The mean age was 43.4 ± .7.85 years. Comparing different parameters, baseline data showed non-significant difference between injected eye group and control group. After 1 and 3 months of follow up, there were significant differences between both groups regarding NITBUT, TMH, LLT, CFS and Schirmer test, with p <  0.001 in favor of PRP group. CONCLUSION: Injection of PRP in lacrimal gland is simple, safe, and effective technique in treatment of severe dry eye; proved by improvement of tear film parameters through subjective and objective assessment. Further studies are needed to standardize the technique and to confirm these results.

Comparison between refractive outcomes of femtosecond laser-assisted cataract surgery and standard phacoemulsification.

BACKGROUND: To compare the visual and refractive outcomes of femtosecond laser assisted cataract surgery (FLACS) using Victus platform (Technolas Bausch and Lomb (B&L), Munich, Germany) and conventional phacoemulsification cataract surgery (CPCS). METHODS: A retrospective study of 100 eyes operated for cataract. FLACS was performed in 50 eyes and CPCS was done in another 50 eyes. Preoperative and 6 months postoperative visual and refractive evaluation (efficacy, safety, predictability, and surgically induced astigmatism) as well as higher-order aberrations were analyzed. Efficacy index which equals post-operative mean of uncorrected distance visual acuity (UDVA) divided by preoperative mean corrected distance visual acuity (CDVA) was calculated in both groups. Safety index equals post-operative mean of corrected distance visual acuity (CDVA) divided by preoperative mean CDVA. RESULTS: Logarithm of the Minimum Angle of Resolution (LogMAR), UDVA improved in both groups after surgery (p < 0.05). It was 0.23 ± 0.20 and 0.291 ± 0.311 log MAR in FLACS and CPCS groups respectively. Safety index was 1.777 in FLACS group and 1.744 in CPCS groups showing high degree of safety of both measures. Mean surgically induced astigmatism (SIA) was 0.35 ± 0.67 D and 0.901 ± 0.882 D in FLACS and CPCS groups respectively (p = 0.015). The post-operative comparison between both groups was in favor of CPCS group vs. FLACS group regarding total aberrations (0.563 ± 0.386 vs. 0.91 ± 1.20) (p = 0.03), while low order aberrations were significantly less in FLACS group vs. CPCS group (0.64 + 0.63 vs. 2.07 + 3.15) (p = 0.027). RMS high order aberration was higher in FLACS group vs. CPCS group but of no statistical significance 0.54 ± 0.96 vs. 0.328 ± 0.360 (p = 0.082). CONCLUSION: Femtosecond laser -assisted cataract surgery was a safe and precise procedure but enhanced visual outcomes only minimally when compared to conventional cataract surgery in experienced hands. Both FLACS and manual surgeries can achieve a high efficacy, predictability and safety with slight superior outcomes in FLACS. TRIAL REGISTRATION NUMBER: PACTR201804003256258 (date: 27 Mar 2018) Available at: https://pactr.samrc.ac.za/.

Expression levels of aldose reductase enzyme, vascular endothelial growth factor, and intercellular adhesion molecule-1 in the anterior lens capsule of diabetic cataract patients.

PURPOSE: To compare the levels of aldose reductase (ALR) enzyme, intercellular adhesion molecule-1 (ICAM-1), and vascular endothelial growth factor (VEGF) in the anterior lens capsule of diabetic versus nondiabetic patients. SETTING: Alexandria Main University Hospital, Alexandria, Egypt. DESIGN: Prospective case-control study. METHODS: The study enrolled patients undergoing cataract extraction and divided them into 3 groups: eyes that had proliferative diabetic retinopathy (PDR), eyes that had nonproliferative diabetic retinopathy (NPDR), and nondiabetic eyes. The anterior lens capsules were obtained by performing femtosecond laser-assisted capsulorhexis. Concentrations of ALR, ICAM-1, and VEGF in the lens capsule specimens were measured using human enzyme-linked immunosorbent assay. RESULTS: This study comprised 200 patients (200 eyes); 51 eyes had PDR, 49 eyes had NPDR, and 100 eyes were nondiabetic. The mean ALR, ICAM-1, and VEGF levels in the anterior capsule of diabetic group were 2.84 nanogram (ng)/mL ± 0.51 (SD), 87.73 ± 22.84 picogram (pg)/mL, and 75.53 ± 14.95 pg/mL, respectively; whereas, in the nondiabetic group, they were 1.44 ± 0.17 ng/mL, 35.45 ± 2.8 pg/mL, and 33.55 ± 5.47 pg/mL, respectively. In comparing the concentrations of these mediators, both the PDR and NPDR groups had significantly higher levels compared with the nondiabetic eyes (P < .001). In addition, eyes with PDR had significantly higher levels of these mediators than eyes with NPDR (P < .001). CONCLUSION: The concentrations of ALR, ICAM-1, and VEGF in the anterior lens capsule of diabetic patients are significantly higher than those of nondiabetics. A significantly higher level of 3 mediators in eyes with PDR compared with those with NPDR might allow the use of them as a biomarker for severity of diabetic retinopathy.

Vector analysis of astigmatic changes after small-incision lenticule extraction and wavefront-guided laser in situ keratomileusis.

PURPOSE: To evaluate and compare the efficacy of the astigmatic correction after wavefront-guided laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE) and in myopic eyes. DESIGN: Prospective case series. SETTING: Horus Vision Correction Center and Ellite Vision Correction Center, Alexandria, Egypt. METHODS: Myopic eyes with astigmatism up to 4.00 diopters (D) had wavefront-guided LASIK or small-incision lenticule extraction. Visual and refractive changes were evaluated during a 6-month follow-up. The astigmatic changes were evaluated using the Alpins method. RESULT: The study evaluated 107 eyes (55 patients), 52 eyes having wavefront-guided LASIK and 55 eyes, small-incision lenticule extraction. No statistically significant differences were found in the 6-month postoperative sphere between the 2 groups (P = .652). The postoperative manifest cylinder and spherical equivalent were significantly lower in the wavefront-guided LASIK group (P < .001). The 6-month postoperative cylinder was 0.50 D or less in all eyes in the wavefront-guided LASIK groups and in 79.8% in the small-incision lenticule extraction group (P < .001). Vector analysis showed a significantly higher difference vector (P < .001) and angle of error (P = .021) and a significantly lower correction index (P = .001) in the small-incision lenticule extraction group. The mean magnitude of error was -0.07 ± 0.20 (SD) and -0.20 ± 0.35 in the wavefront-guided LASIK group and small-incision lenticule extraction group, respectively (P = .012). CONCLUSION: Wavefront-guided LASIK and small-incision lenticule extraction were safe and effective for the correction of myopic astigmatism, although there was a trend toward undercorrection with small-incision lenticule extraction.

Comparative analysis of the efficacy of astigmatic correction after wavefront-guided and wavefront-optimized LASIK in low and moderate myopic eyes.

AIM: To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis (LASIK) in eyes with myopic astigmatism using wavefront-guided (WFG) and wavefront-optimized (WFO) ablation profiles. METHODS: Prospective study included 221 eyes undergoing LASIK: 99 and 122 eyes with low and moderate myopic astigmatism (low and moderate myopia groups). Two subgroups were differentiated in each group according to the ablation profile: WFG subgroup, 109 eyes (45/64, low/moderate myopia groups) treated using the Advanced CustomVue platform (Abbott Medical Optics Inc.), and WFO subgroup, 112 eyes (54/58, low/moderate myopia groups) treated using the EX-500 platform (Alcon). Clinical outcomes were evaluated during a 6-month follow-up, including a vector analysis of astigmatic changes. RESULTS: Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group (P≤0.041). Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups (P≤0.003). In moderate myopia group, a higher percentage of eyes with a postoperative cylinder ≤0.25 D was found in the WFG subgroup (90.6% vs 65.5%, P=0.002). In low and moderate myopia groups, the difference vector was significantly higher in the WFO subgroup compared to WFG (P<0.001). In moderate myopia group, the magnitude (P=0.008) and angle of error (P<0.001) were also significantly higher in the WFO subgroup. Significantly less induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups (P≤0.006). CONCLUSION: A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.

Wave Front-Guided Photorefractive Keratectomy Using a High-Resolution Aberrometer After Corneal Collagen Cross-Linking in Keratoconus.

PURPOSE: To evaluate the clinical outcomes of wave front-guided (WFG) photorefractive keratectomy (PRK) using a high-definition aberrometer in corneas with keratoconus at least 1 year after corneal collagen cross-linking (CXL). METHODS: Prospective uncontrolled interventional case series study including a total of 34 consecutive eyes of 25 patients with keratoconus previously treated with CXL. All cases underwent WFG PRK using the VISX STAR S4 IR excimer laser and the iDesign system. All eyes had keratoconus grade I or II according to the Amsler-Krumeich classification. Visual, refractive, and ocular aberrometric outcomes were evaluated during a 12-month follow-up. Astigmatic changes were analyzed with the Alpins vector method. RESULTS: A significant improvement was observed in the uncorrected and corrected distance visual acuities (P < 0.001). The mean efficacy and safety indices at 12 months postoperatively were 1.58 ± 1.11 and 1.96 ± 1.52, respectively. Manifest sphere and cylinder were reduced significantly (P < 0.001), with 76.5% of the eyes having a spherical equivalent within ±1.00 D at 12 months postoperatively. The mean difference vector and magnitude of error were 1.06 ± 0.92 and 0.43 ± 0.86 D, respectively. Some corneal irregularity indices were reduced significantly with surgery (P ≤ 0.005) as well as the level of ocular higher order aberrations, primary coma, and trefoil (P < 0.001). CONCLUSIONS: Sequential WFG PRK using the iDesign system and the STAR S4 IR excimer laser after CXL is an effective option to correct the spherocylindrical error and to minimize the level of higher order aberrations in mild and moderate keratoconus if the maximum intended ablation depth does not exceed 15% of the minimal corneal thickness.

Accuracy of Corneal Power Measurements for Intraocular Lens Power Calculation after Myopic Laser In situ Keratomileusis.

PURPOSE: To evaluate the accuracy of corneal power measurements for intraocular lens (IOL) power calculation after myopic laser in situ keratomileusis (LASIK). METHODS: The study evaluated 45 eyes with a history of myopic LASIK. Corneal power was measured using manual keratometry, automated keratometry, optical biometry, and Scheimflug tomography. Different hypothetical IOL power calculation formulas were performed for each case. RESULTS: The steepest mean K value was measured with manual keratometry (37.48 ± 2.86 D) followed by automated keratometry (37.31 ± 2.83 D) then optical biometry (37.06 ± 2.98 D) followed by Scheimflug tomography (36.55 ± 3.08). None of the K values generated by Scheimflug tomography were steeper than the measurements from the other 3 instruments. Using equivalent K reading (EKR) 4 mm with the Double-K SRK/T formula, the refractive outcome generated 97.8% of cases within ± 2 D, 80.0% of cases within ± 1 D, and 42.2% of cases within ± 0.5 D. The best combination of formulas was "Shammas-PL + Double-K SRK/T formula using EKR 4 mm." CONCLUSION: Scheimflug tomography imaging using the Holladay EKR 4 mm improved the accuracy of IOL power calculation in post-LASIK eyes. The best option is a combination of formulas. We recommended the use the combined "Shammas-PL ± Double-K SRK/T formula using EKR 4 mm"h for optical outcomes.

Wavefront-Guided Laser Treatment Using a High-Resolution Aberrometer to Measure Irregular Corneas: A Pilot Study.

PURPOSE: To evaluate in a pilot study the visual, refractive, corneal topographic, and aberrometric changes after wavefront-guided LASIK or photorefractive keratectomy (PRK) using a high-resolution aberrometer to calculate the treatment for aberrated eyes. METHODS: Twenty aberrated eyes of 18 patients undergoing wavefront-guided LASIK or PRK using the VISX STARS4IR excimer laser and the iDesign aberrometer (Abbott Medical Optics, Inc., Santa Ana, CA) were enrolled in this prospective study. Three groups were differentiated: keratoconus post-CXL group including 11 keratoconic eyes (10 patients), post-LASIK group including 5 eyes (5 patients) with previous decentered LASIK treatments, and post-RK group including 4 eyes (3 patients) with previous radial keratotomy. Visual, refractive, contrast sensitivity, corneal topographic, and ocular aberrometric changes were evaluated during a 6-month follow-up. RESULTS: An improvement in uncorrected (UDVA) and corrected visual acuity (CDVA) associated with a reduction in the spherical equivalent was observed in the three groups, but was only statistically significant in the keratoconus post-CXL and post-LASIK groups (P ≤ .04). All eyes gained one or more lines of CDVA after surgery. Improvements in contrast sensitivity were observed in the three groups, but they were only statistically significant in the keratoconus post-CXL and post-LASIK groups (P ≤ .04). Regarding aberrations, a reduction was observed in trefoil aberrations in the keratoconus post-CXL group (P = .05) and significant reductions in higher-order and primary coma aberrations in the post-LASIK group (P = .04). CONCLUSIONS: Wavefront-guided laser enhancements using the evaluated platform seem to be safe and effective to restore the visual function in aberrated eyes.

Comparison of visual outcomes after variable spot scanning ablation versus wavefront-optimized myopic LASIK.

PURPOSE: To compare the refractive and visual outcomes of variable spot scanning ablation versus the wavefront-optimized ablation for myopia and myopic astigmatism. METHODS: Fifty patients with myopia who underwent LASIK (100 eyes) were divided into two equal groups. Myopic correction performed using the variable spot scanning (VSS) ablation with the VISX STAR S4/IR platform (Abbott Medical Optics, Inc., Santa Ana, CA) (VSS group) and wavefront-optimized (WFO) ablation profile with the WaveLight Allegretto Wave Eye-Q platform (Alcon Laboratories, Inc., Fort Worth, TX) (WFO group). Manifest refraction, uncorrected distance visual acuity, and corrected distance visual acuity were obtained preoperatively and 1 day and 1 and 3 months postoperatively. Wavefront measurement and contrast sensitivity testing were done preoperatively and 3 months postoperatively. RESULTS: Postoperative mean refractive spherical equivalent was -0.14 ± 0.2 diopters for the VSS group and -0.15 ± 0.28 diopters for the WFO group. Forty-eight eyes of the VSS group and 47 eyes of the WFO group were within ±0.5 diopters. Postoperative mean corrected distance visual acuity was 1.05 ± 0.13 for the VSS group and 1.06 ± 0.12 for the WFO group. The postoperative uncorrected distance visual acuity was 1.01 ± 0.16 for the VSS group and 1.01 ± 0.11 for the WFO group. The safety index was 1.12 for the VSS group and 1.06 for the WFO group, whereas the efficacy index was 1.07 for the VSS group and 1.01 for the WFO group. The mean induced positive spherical aberration was 0.041 ± 0.046 µm for the VSS group and 0.195 ± 0.171 µm for the WFO group (P < .001). Mesopic contrast sensitivity testing showed no statistically significant differences between groups at all tested spatial frequencies. CONCLUSIONS: Both VSS and WFO treatments showed similar refractive and visual outcomes. Both induced significant positive spherical aberration, significantly more with WFO.

Four-year visual, refractive, and contrast sensitivity outcomes after wavefront-guided myopic LASIK using an advanced excimer laser platform.

PURPOSE: To evaluate the 4-year visual, refractive, and contrast sensitivity outcomes of wavefront-guided LASIK for the correction of low to moderate myopia using the VISX CustomVue technology (Abbott Medical Optics, Inc., Santa Ana, CA). METHODS: This was a prospective study including 255 consecutive eyes of 145 patients (age range: 19 to 55 years) with low to moderate myopia (mean spherical equivalent: -3.36 ± 1.71 diopters [D]) undergoing laser refractive surgery. Wavefront-guided LASIK was performed in all eyes using the VISX STAR S4 IR excimer laser platform and the CustomVue procedure for the ablation profile design. Visual, refractive, and contrast sensitivity changes were evaluated during a 4-year follow-up period. RESULTS: Postoperative logMAR uncorrected distance visual acuity was 0.1 or better (20/25 Snellen) in 98.0% and 100% of eyes at 1 and 4 years, respectively. At 4 years postoperatively, mean spherical equivalent was reduced significantly to a mean value of -0.22 ± 0.28 D (P < .01), with 97.3% of eyes with a spherical equivalent within ±0.50 D. The astigmatic power vector component J0 of manifest refraction was also reduced significantly (P < .01). Postoperative logMAR corrected distance visual acuity was 0.0 or better (20/20 Snellen) in 96.1% and 98.8% of eyes at 1 and 4 years, respectively. Improvement in contrast sensitivity was observed in some spatial frequencies between 1 and 4 years postoperatively. No significant correlations were found between 4-year contrast sensitivity and corrected distance visual acuity (0.024 ≤ r ≤ -0.120, P ≥ .06). CONCLUSION: Wavefront-guided LASIK using the VISX CustomVue technology provides an effective and predictable correction of low to moderate myopia in the long term, preserving the patient's visual acuity and quality.

International Values of Central Pachymetry in Normal Subjects by Rotating Scheimpflug Camera.

PURPOSE: In corneal refractive surgery, postoperative ectasia risk assessment routinely includes pachymetric analysis at the apex and thinnest point. We examined whether these data differ worldwide and constructed preliminary country-specific normative thresholds. DESIGN: This was a multicenter, cross-sectional study. METHODS: Using the Pentacam Eye Scanner (OCULUS GmbH, Wetzlar, Germany), we examined 1 randomly selected eye from each of 555 normal adults (8 countries, 6 continents), measuring the thinnest point location, central pachymetry (thinnest point, pupillary center, and apex), and the apex-thinnest point difference. International differences were assessed by 1-way analysis of variance. Normative thresholds were defined by 2- and 3-SD gates or Tukey method. RESULTS: The thinnest point averaged 0.44 mm temporal and 0.29 mm inferior to the apex. Individual thinnest points located more than 1.0 mm inferior represented fewer than 0.5% of normal corneas (>0.76 mm in the US subgroup). The mean thinnest-point pachymetry was 536 µm overall, and values less than 469 or 435 µm (-2 or -3 SD, respectively) would be expected in less than 2.5% or 0.15% of normal corneas, respectively. The thinnest-point pachymetry averaged 2 to 3 µm thinner than apical (range, 0-32 µm). Differences of greater than 8.5 µm would be expected in less than 0.5% of normal corneas overall. CONCLUSIONS: International differences were largely clinically insignificant. Nevertheless, it remains preferable to establish racial/geographic-specific normative values. We defined preliminary generalized and country-specific thresholds useful to the corneal refractive surgeon for identifying potentially abnormal corneas based on common pachymetric parameters, particularly the thinnest point by tomography.

International values of corneal elevation in normal subjects by rotating Scheimpflug camera.

PURPOSE: To examine whether clinically significant differences exist in corneal elevation data from a sampling of countries worldwide. SETTING: International multicenter. DESIGN: Evaluation of diagnostic test or technology. METHODS: One randomly selected eye of normal adults from 8 countries spanning 6 continents was examined using the Pentacam Eye Scanner. Anterior and posterior elevations were measured at the apex and thinnest point. Differences between countries were assessed by Kruskal-Wallis. Normative thresholds were defined according to the Tukey method. RESULTS: The study examined 1 eye of 555 patients. Median elevations were similar across countries. Upper limits of normal for collective international data were 3.5 µm, 6.0 µm, 7.5 µm, and 13.5 µm at the anterior apex, anterior thinnest point, posterior apex, and posterior thinnest point, respectively. These and country-specific thresholds were similar to normal values from previous data; however, country-specific thresholds flagged additional eyes in China, Egypt, and India. Those thresholds were 4.5 µm at the anterior thinnest point (China and Egypt), 7.4 µm at the posterior apex (India), and 11.0 µm and 12.0 µm at the posterior thinnest point (China and Egypt, respectively). CONCLUSIONS: In general, international variations were clinically insignificant; thus, current screening guidelines maintained their applicability. Notable exceptions were China, Egypt, and India, where country-specific thresholds may better reflect the test populations and minimize potential false negative results from screening. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Iris registration in wavefront-guided LASIK to correct mixed astigmatism.

PURPOSE: To investigate the predictability, safety, and efficiency of wavefront-guided laser in situ keratomileusis (LASIK) with iris-registration technology to correct mixed astigmatism. SETTING: Vision correction center, Alexandria, Egypt. METHODS: This retrospective double-blind study included randomly selected patients with mixed astigmatism who sought laser refractive surgery. Patients were divided equally into 3 groups and treated with conventional LASIK and manual marking, wavefront-guided LASIK and manual marking, or wavefront-guided LASIK with iris registration (LASIK+IR group). Eyes were analyzed preoperatively and up to 3 months postoperatively. RESULTS: The LASIK+IR group had better postoperative uncorrected visual acuity (100% 20/30 or better; 90% 20/20 or better; 20% 20/16 or better) than the other groups and did not lose preoperative best spectacle-corrected visual acuity, unlike the other groups. This group also had the highest percentage of eyes that gained lines of acuity (20% 1 line; 10% 2 lines). The LASIK+IR group had the highest predictability of spherical refraction (80% within +/-0.50 diopter [D]; 100% within +/-1.00 D [P<.05] and the highest predictability of cylinder refraction. The LASIK+IR eyes had a significantly smaller increase postoperatively in coma, trefoil, and secondary astigmatism. There was no significant difference between groups in spherical aberration or quadrafoil. The LASIK-IR group had the most improvement in scotopic contrast sensitivity (P<.05). CONCLUSIONS: Wavefront-guided LASIK with iris registration was more predictable, safe, and efficient than conventional or wavefront-guided LASIK with manual marking in correcting mixed astigmatism. Further studies are needed to confirm these results.