Correction of pre-existing astigmatism with phacoemulsification using toric intraocular lens versus spherical intraocular lens and wave front guided surface ablation.

BACKGROUND: This study aimed to evaluate toric intraocular lens to correct of pre-existing astigmatism at the time of phacoemulsification compared to using of spherical intraocular lens followed by wavefront guided surface ablation. RESULTS: The patients were classified into three groups: Group A with 20 eyes of 19 patients having phacoemulsification with spherical intraocular lens only as a control group, group B with 20 eyes of 14 patients had phacoemulsification with toric intraocular lens and group C with 20 eyes of 16 patients had phacoemulsification with spherical intraocular lens and wavefront guided PRK three months later. Comparison pre-operative data for all groups showed no statistically significant difference regarding UCVA, BCVA, MRSE, and refractive astigmatism (P>0.05). Post operatively, there was a statistically significant difference for UCVA, BCVA, MRSE, and refractive astigmatism for group A compared to group B (P<0.05) and group A compared to group C but there was no statistically significant difference for group B compared to C regarding all these parameters (P>0.05). CONCLUSION: In this study, we found similar effects for both techniques in astigmatism corrected groups while both differed from the control group that was not corrected. Correcting preexisting astigmatism during cataract surgery should be in mind in every case to improve visual outcomes. Longer period of follow up are required to evaluate stability of these techniques and possibility of regression.

Correlation Between Changes in Lamina Cribrosa Structure and Visual Field in Primary Open-Angle Glaucoma.

PURPOSE: To investigate the correlation between changes in lamina cribrosa (LC) structure using enhanced depth imaging (EDI) and severity of visual field (VF) affection in primary open-angle glaucoma (POAG). PATIENTS AND METHODS: This prospective cross-sectional study was carried out on 52 glaucomatous eyes of 28 POAG patients who attended Tanta University Eye Hospital and 40 normal eyes of 20 age-matched normal subjects from April 2020 to March 2021. POAG patients were classified according to the modified Hodapp-Anderson-Parrish grading scale based on the MD of the standard automated perimetry (SAP) visual field into two groups: group (1) - mild-to-moderate POAG patients (MD ≤ 12 dB), group (2) - severe POAG patients (MD ≥ 12 dB) and the third group included normal (control) age- and gender-matched individuals. RESULTS: There was no statistically significant difference between the three groups regarding lamina cribrosa thickness nor lamina cribrosa area and there was no statistically significant correlation between MD and LC thickness, LC area (P-value=0.395 and 0.644). There was a statistically significant correlation between MD and anterior lamina cribrosa surface depth (P-value=0.002) and there was a statistically significant positive correlation between MD and prelaminar neural tissue (PLNT) thickness and prelaminar neural tissue (PLNT) area (P-value= 0.023 and <0.001, respectively). CONCLUSION: EDI-OCT is a useful biomarker of structural changes in ONH and LC, and we recommended it to be a part of the routine monitoring of patients with POAG.

Corneal endothelial cells changes in different stages of Keratoconus: a multi-Centre clinical study.

PURPOSE: To assess the corneal endothelial cells morphology and count in keratoconus patients and their correlation with different stages of keratoconus. METHODS: Prospective non randomized multi-centric clinical study included 150 eyes of 150 keratoconus patients. Four centers in Egypt participated in this study included: Departments of Ophthalmology in Alexandria University, Tanta University and Port Said University and Alex I-Care hospital. Pentacam (Wavelight Oculyzer II) and specular microscopy (Tomey EM-3000) were done to all eyes. Keratoconic eyes were classified according to Amsler classification into stage 1, 2 and 3. Stage 1 included 99 eyes, stage 2 included 32 eyes & stage 3 included 19 eyes. RESULTS: The mean age of keratoconus patients was 24.07 ± 6.154 years. Forty five cases were males (30%) and 105 cases were females (70%). There was statistically significant difference in endothelial cell density (p < 0.001) and coefficient of variation (p = 0.012) between different stages of keratoconus eyes. Regarding cell surface area, there was statistically significant difference in cell surface area between different stages of keratoconus eyes (p < 0.001). In addition, for cell morphology, there was statistically significant difference between different stages of keratoconus eyes (p < 0.001). CONCLUSIONS: Qualitative and quantitative structural changes were seen in endothelial cells of keratoconus eyes by using specular microscopy. For stages 1 and 2, keratoconus may not affect the corneal endothelim significantly. The endothelium in stage 3 shows significant changes regarding polymegathism and pleomorphism.

Long-Term Refractive Outcome of Small Incision Lenticule Extraction in Very High Myopia.

PURPOSE: To assess the stability, safety, predictability, and efficacy of small incision lenticule extraction (SMILE) in high myopia. METHODS: The study was conducted as a retrospective noncomparative analysis of the records of 495 eyes of 270 patients treated by the ReLEx SMILE technique for a mean spherical myopic error of -12.84 ± 2.47 D (range: -10.0 to -14.0 D) combined with a mean astigmatism of -1.17 ± 1.34 D (up to -4.0 D). The mean LogMAR corrected distance visual acuity (CDVA) was 0.2 ± 0.6. In this study, 225 patients had the bilateral SMILE procedure, whereas 45 patients had a single eye treated with SMILE. RESULTS: One month after surgery, the mean refractive error was 20.72 ± 0.88 D (range: +1 to 21.5 D), and the mean postoperative astigmatism was -0.83 ± 1.04 D. The mean LogMAR UDVA was 0.2 ± 0.34. In the last follow-up visit, 3 years after surgery, all the before mentioned parameters were the same or within minimal changes with no statistically significant difference from the earlier results. However, the spherical error demonstrated a significant change from -0.72 ± 0.88 D at 1 month to -1.17 ± 1.01 D at the end of the follow-up. However, this change had an insignificant visual impact. At the end of the follow-up period, approximately 94% of patients had unchanged CDVA or gained one or more lines, 6% lost one line of CDVA, and 1% lost 2 lines. CONCLUSIONS: SMILE may be effective and safe, with a stable and predictable outcome for correction of very high myopia.

Visual and refractive outcomes of posterior chamber phakic IOL in stable keratoconus.

We evaluated the visual and refractive outcomes after phakic visian toric implantable collamer lens (ICL) insertion in stable keratoconus (KC). This retrospective study investigated toric ICL implantation in 14 eyes of 8 patients with stable KC. After 6mo, the mean uncorrected distance visual acuity improved significantly from 0.77 to 0.15 logMAR. The mean best corrected distance visual acuity (BCDVA) improved from 0.18±0.1 to 0.15±0.1 logMAR. Fifty percent of eyes maintained their preoperative BCDVA; 42.8% gained one line. There was no statistical difference in high order or coma aberration. The mean refractive manifest spherical equivalent (MSE), mean refractive manifest spherical error, mean manifest astigmatism decreased significantly postoperatively. At 6mo postoperatively, our achieved mean spherical equivalent was approximately 74%. No intraoperative or postoperative complications occurred. Toric ICL implantation was effective, predictable and safe to correct refractive error and improve visual acuity in patients with stable KC.

Prevalence and topographical characteristics of keratoconus in patients with refractive errors in the Egyptian delta.

PURPOSE: To study the prevalence of keratoconus (KC) and the topographical characteristics of the affected corneas in patients with refractive errors who were seeking refractive surgery in the Egyptian delta. METHODS: A retrospective study covering four and half years (Jan 2012-June 2016) where the topographical data of 8124 participants were obtained from the records of a refractive center in the Nile delta region, Egypt. The diagnosis of KC was based on the Holladay criteria in one or both eyes, using the Pentacam scans, whereas grading of KC was based on the Amsler-Krumeich classification. RESULTS: The prevalence of KC was 1.12% (91/8124 participants) with 95% confidence interval 0.91-1.3. Of all the affected cases, 5 cases (5.5%) had unilateral, and the other 86 cases (94.5%) had bilateral KC. The affected and unaffected subjects did not show any significant difference regarding gender. Sixty-eight (38.4%) eyes had stage 1 KC, 53 eyes (29.9%) had stage 2, 27 eyes (15.3%) had stage 3, and 29 eyes (16.4%) had stage 4 KC. It was most prevalent (1.2%) among cases with astigmatism (P < 0.001). CONCLUSION: Keratoconus was found in 1.12% of patients seeking refractive surgery, with no gender preference. Most cases had bilateral affection. Astigmatism was the most common refractive error to be associated with keratoconus.

Conductive keratoplasty for the correction of low to moderate hyperopia: U.S. clinical trial 1-year results on 355 eyes.

OBJECTIVE: To document the 1-year safety, efficacy, and stability results of 355 eyes treated in the multicenter study of conductive keratoplasty (CK) used to correct low to moderate hyperopia. DESIGN: Nonrandomized comparative (self-controlled) trial. PARTICIPANTS: Twenty surgeons at 13 centers performed CK on the eyes of all patients enrolled in a multicenter, 2-year, U.S. phase III clinical trial. Treated eyes had +0.75 to +3.00 diopters (D) of hyperopia and < or =0.75 D of cylinder. Patients were 40 years of age or older. INTERVENTION: Low-energy, high-frequency current was applied directly into the peripheral corneal stroma through a delivery tip inserted at 8 to 32 treatment spots. The number of treatment spots was increased for increasing levels of hyperopia, but the amount of radiofrequency energy remained constant. Emmetropia was intended. All eyes were treated once (there were no retreatments). MAIN OUTCOME MEASURES: Data from 355 eyes with 1 year of follow-up were analyzed for safety and stability, and data from 318 eyes were analyzed for efficacy and predictability, as well as stability and safety. All patients reported on satisfaction and quality of vision after surgery. RESULTS: At 1 year, uncorrected visual acuity was < or =20/20 in 56%, < or =20/25 in 75%, and < or =20/40 in 92% of eyes. The manifest refractive spherical equivalent refraction was within 0.50 D in 63%, within +/-1.00 D in 89%, and within +/-2.00 D in 99%. Seven of 355 eyes lost 2 lines of best spectacle-corrected visual acuity at 1 year, but no eye lost >2 lines. One eye of 355 had induced cylinder of >2.00 D. The cycloplegic refractive spherical equivalent changed a mean of 0.25 +/- 0.50 D between months 3 and 6, 0.11 +/- 0.41 D between months 6 and 9, and 0.11 +/- 0.35 D between months 9 and 12. Refractive stability seemed to be attained by 6 months and remained stable through 12 months. Histology and confocal microscopy showed deep penetration of the treatment into the stroma. Endothelial cell counts were not changed by the treatment. CONCLUSIONS: CK seems to be safe, effective, and stable for correcting low to moderate spherical hyperopia in patients 40 years old or older. Treatment penetration is deep and cylindrical in shape, and it does not damage the corneal endothelium. Uncorrected visual acuity, predictability, and stability are as good as or better than those obtained with other techniques used to correct hyperopia.