Incidence and Risk Factors for Retinopathy of Prematurity (ROP) in Biggest Neonatal Intensive Care Unit in Itay Elbaroud City, Behera Province, Egypt.

AIM OF THE WORK: To evaluate the incidence and risk factors for development of retinopathy of prematurity (ROP) in the biggest neonatal intensive care unit (NICU) in Itay Elbaroud City, Behera province, Egypt. METHODS: We studied data of 240 newly born infants with gestational age (GA) ≤34 weeks or birth weight (BW) ≤2000 g or infants with unstable course who were admitted to the biggest NICU in Itay Elbaroud City, Behera province, Egypt, between October 1, 2018 and October 31, 2020. There is no standard screening system in Egypt. Furthermore, we had screened babies more than 1500 g, more than 32 weeks and found signs of ROP, so we decided to expand our inclusion criteria to include babies up to 2000 g of birth weight and up to 34 weeks gestational age in addition to older and heavier babies with unstable course in NICUs. Clinical information about perinatal neonates was collected by reviewing medical charts. The main outcomes are the incidence and severity of ROP. The relationship of clinical risk factors and the development of ROP were analyzed. RESULTS: The overall incidence of ROP was 34.1%, and the overall incidence of type 1 ROP was 26.3% of infants. ROP was significantly associated with GA (odds ratio; OR: 6.8; (3.7-12.3), BW (OR: 4.1; 2.3-7.3), apnea, supplementary oxygen administration, and thrombocytopenia. CONCLUSION: The incidence of ROP is high in Itay Elbaroud city, Behera Province, Egypt. Immaturity, low birth weight, low gestational age, oxygen administration, apnea, thrombocytopenia, and jaundice are important risk factors for development of ROP.

Comparison of corneal biomechanical changes after LASIK and F-SMILE with CorVis ST.

PURPOSE: To evaluate changes in corneal biomechanics after LASIK and F-SMILE. SETTING: Elite Eye Center, Tanta, Egypt. DESIGN: Prospective, randomized, unmasked, interventional comparative case series. PATIENTS AND METHODS: A total of 60 eyes were equally divided into two groups; group A: received LASIK and group B: received F-SMILE. Pentacam and CorVis ST parameters were compared before and 6 months after procedures. P ⩽ 0.05 was used for significance of results. RESULTS: bIOP decreased by 0.762 ± 1.211 mmHg in group A (p = 0.092), and by 2.52 ± 1.389 mmHg in group B (p < 0.001) and the difference between groups became significant (p = 0.001). A1 increased significantly in group A only (p = 0.036); while A2 decreased insignificantly in both groups. DAR increased significantly in both groups (p < 0.001, p = 0.022), but the difference between groups remained insignificant (p = 0.461). IR increased significantly in group A only (p < 0.001) and the difference between groups became significant (p = 0.026). ARTH decreased in both groups (p = 0.245, p = 0.695) and the difference remained insignificant (p = 0.928). SP-A1 decreased in group A by 8.89 ± 1.38 mmHg/mm (p = 0.637), and by 32.6 ± 4.39 mmHg/mm in group B (p < 0.001) and the postoperative difference between groups was significant (p = 0.013). CBI increased significantly in group A (p < 0.001), but insignificantly in group B (p = 0.098) and postoperative difference between groups was highly significant (p < 0.001). A significant correlation was found between change in CCT and corresponding changes in DAR, IR, and ARTH after surgery in both groups. CONCLUSION: The significant differences between groups postoperatively as regards bIOP (p = 0.001), IR (p = 0.026), SP-A1 (p = 0.013), and CBI (p < 0.001) indicate stiffer corneas after F-SMILE and suggest less influence on corneal biomechanics than LASIK.

Pattern electroretinogram changes in patients with primary open-angle glaucoma in correlation with visual field and optical coherence tomography changes.

PURPOSE: To study the pattern electroretinogram changes in primary open-angle glaucoma patients in correlation with visual field changes and optical coherence tomography measurements of retinal nerve fiber layer thickness in the peripapillary region in an attempt to evaluate the clinical value of pattern electroretinogram as an objective test of functional deficit in glaucoma. PATIENTS AND METHODS: The study included 81 eyes of 81 participants: 50 primary open-angle glaucoma patients, 16 primary open-angle glaucoma suspects, and 15 controls. All subjects underwent visual field testing using 24-2 Humphrey standard automated perimetry, peripapillary retinal nerve fiber layer average thickness using the 3.4-mm circular scan of the Heidelberg OCT spectralis and pattern electroretinogram using CSO RetiMax device in accordance with the International Society for Clinical Electrophysiology of Vision guidelines. RESULTS: We had three main groups: normal, glaucoma suspect, and primary open-angle glaucoma patients, and the last group included three subgroups: mild, moderate, and severe. There was significant difference in the visual field mean deviation, peripapillary retinal nerve fiber layer average thickness, and most pattern electroretinogram measured parameters between the three main groups and in between primary open-angle glaucoma subgroups. There was significant positive correlation between visual field mean deviation and the peripapillary retinal nerve fiber layer average thickness, P50 amplitude, and P50-N95 amplitude (p < 0.001, p = 0.018, and p < 0.001, respectively). Significant negative correlation was also found between peripapillary retinal nerve fiber layer average thickness and N95 amplitude (p < 0.001). Significant positive correlation was found between retinal nerve fiber layer average thickness and P50-N95 amplitude (p = 0.001). Significant negative correlation was found between peripapillary retinal nerve fiber layer average thickness and N95 amplitude (p = 0.001) and significant positive correlation of retinal nerve fiber layer average thickness with P50-N95 amplitude (p = 0.017) in primary open-angle glaucoma patients. CONCLUSION: Peripapillary retinal nerve fiber layer average thickness shows significant negative correlation with pattern electroretinogram N95 amplitude and a significant positive correlation with P50-N95 amplitude. In combination with optical coherence tomography, pattern electroretinogram can be used to objectively assess functional loss in glaucoma.

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.

Evaluation of the Effectiveness of Cross-Linking Combined With Photorefractive Keratectomy for Treatment of Keratoconus.

PURPOSE: To evaluate the effectiveness and safety of combined epithelium-off cross-linking (CXL) with photorefractive keratectomy (CXL Plus) for correction of the myopic and astigmatic components of keratoconus. METHODS: Seventy-nine eyes of 46 patients who underwent CXL Plus were enrolled in this retrospective, multicenter, noncomparative clinical study. Uncorrected distance visual acuity, corrected distance visual acuity, refraction, keratometry, and pachymetry measurements were recorded preoperatively and at 3, 6, 12, and 18 months during follow-up. RESULTS: The mean (±SD) preoperative uncorrected distance visual acuity and corrected distance visual acuity were 1.00 ± 0.22 logarithm of the minimum angle of resolution (logMAR) and 0.62 ± 0.38 logMAR, respectively, and improved to 0.71 ± 0.36 logMAR and 0.32 ± 0.18 logMAR postoperatively. The mean k value, mean corneal thickness at the thinnest location, and mean myopic and astigmatic components decreased from 46.58 ± 0.97 D, 473 ± 29 µm, 3.65 ± 1.72 D, and 1.83 ± 0.69 D preoperatively to 43.79 ± 1.17 D, 431 ± 38 µm, 1.02 ± 0.78 D, and 1.15 ± 0.26 D, respectively, during follow-up. Eleven eyes had delayed epithelial healing, 2 had stromal opacities, 1 had primary herpes simplex keratitis, and 5 showed progression of keratoconus. CONCLUSIONS: CXL Plus improved the refractive status of keratoconus during 18 months of follow-up, despite its potential early postoperative complications of delayed epithelial healing and corneal haze. CXL Plus reduced the myopic component more than the astigmatic component of keratoconus. However, the safety and stability of the procedure were offset by longer-term postoperative complications and a high rate of postoperative progression of keratoconus.

"Ultrathin" DSAEK tissue prepared with a low-pulse energy, high-frequency femtosecond laser.

PURPOSE: To evaluate the endothelial cell survival and stromal bed quality when creating deep stromal cuts with a low-pulse energy, high-frequency femtosecond laser to produce "ultrathin" tissue for Descemet stripping automated endothelial keratoplasty. METHODS: Seventeen corneas were used for this study. Five corneas were cut with the laser at a depth of 420 to 500 µm to produce a tissue thickness of approximately ≤70 µm. Five corneas served as an uncut comparison group. Vital dye staining and computer digitized planimetry analysis were performed on these corneas. The 7 remaining corneas were cut for scanning electron microscopy evaluation. RESULTS: The mean central posterior stromal thickness of cut corneas was 60.6 µm (range, 43-72 µm). Endothelial cell damage in cut and comparison corneas was 3.92% ± 2.22% (range, 1.71%-6.51%) and 4.15% ± 2.64% (range, 1.21%-7.01%), respectively (P = 0.887). Low-magnification (×12) scanning electron microscopy revealed a somewhat irregular-appearing surface with concentric rings peripherally. Qualitative grading of higher magnification (×50) central images resulted in an average score of 2.56 (between smooth and rough). CONCLUSIONS: Ultrathin tissue for Descemet stripping automated endothelial keratoplasty can be safely prepared with minimal endothelial cell damage using a low-pulse energy, high-frequency femtosecond laser; however, the resulting stromal surface quality may not be optimal with this technique.

In vitro evaluation of endothelial cell loss using the Neusidl Corneal Inserter.

PURPOSE: To determine the immediate endothelial cell loss (ECL) resulting from insertion of a precut donor button using the Neusidl Corneal Inserter (NCI) and compare it with the previously published ECL resulting from insertion of a folded donor button using non-coapting forceps. METHODS: Ten corneas were precut for Descemet stripping automated endothelial keratoplasty and trephinated to a diameter of 8.0 mm (n = 5) or 8.5 mm (n = 5). Each tissue was placed onto the platform of a new NCI spatula and inserted into a cadaveric whole globe through a 5.2 mm incision. The tissue was carefully removed and stained with trypan blue and alizarin red to detect damaged endothelium. ECL was estimated using Adobe Photoshop planimetry. Mean ECL was compared with previously reported studies of forceps insertion with a one-sample t test, using SPSS v. 19. Geographic patterns of ECL were also documented. RESULTS: Mean ECL was 15.6% (95% confidence interval, 13.8-17.4). We were unable to detect a difference in ECL compared with previous insertion methods studied (P < 0.001). The pattern of damage from the NCI was different than that previously seen with forceps insertion. CONCLUSION: Immediate endothelial damage resulting from use of the NCI for insertion of Descemet stripping automated endothelial keratoplasty tissue is comparable with that seen with a standard forceps technique, but with a different damage pattern.

Peripheral endothelial cell damage after trephination of donor tissue.

PURPOSE: To evaluate and quantify the degree and pattern of donor endothelial cell damage, which occurs with mechanical trephination of donor corneal tissue. METHOD: Twenty donor corneal-scleral tissues were used for these paired experiments. The tissues were randomized for trephination with 10 tissues trephinated by an 8.0-mm-diameter Barron trephine (Katena, Denville, NJ), and 10 tissues trephinated with an 8.0-mm-diameter UltraFit Coronet trephine (distributed by Angiotech, British Columbia, Canada) by the same investigator. Trephinated corneal buttons were then stained with vital dye stain, and the endothelial layer image captured with digital photography. The images were then analyzed by digital planimetry, and the pattern and quantity of endothelial damage was determined by an investigator who was masked to the specific trephine used for the individual tissue. RESULTS: Trephination created a pattern of circular damage at the edge of the donor button in every case with no break in continuity of the circle, but some portions of the circle were wider than others. Occasional, scattered, peripheral small areas also displayed damage, but no significant striae, stretch, or other central damage was noted in any donor. The mean percent damage in the series was 6.35% +/- 0.90% (range: 4.33%-7.78%). The UltraFit Coronet trephinations averaged damage of 5.64% +/- 0.85% (range: 4.33%-6.69%), and the Barron trephinations averaged damage of 6.50% +/- 0.95% (range: 4.92%-7.78%). Although 8 of 10 experimental pairs of trephinations demonstrated less peripheral endothelial damage with the UltraFit Coronet trephine, the mean damage between each group did not reach statistical significance in this small series. (P = 0.08) CONCLUSIONS: Donor mechanical trephination of full-thickness corneal tissue creates relatively consistent amounts of peripheral edge damage and likely no central endothelial damage. There may exist differences in edge damage between different mechanical trephination systems, and a direct comparison to laser-created trephination is needed.

Descemet's stripping automated endothelial keratoplasty (DSAEK) using corneal donor tissue not acceptable for use in penetrating keratoplasty as a result of anterior stromal scars, pterygia, and previous corneal refractive surgical procedures.

PURPOSE: The purpose of this study was to evaluate outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) using anterior stromal flawed (ASF) donor corneas that were unsuitable for use in full-thickness penetrating keratoplasty as a result of stromal scars, pterygia, or previous corneal refractive surgery and to compare results with DSAEK using standard tissue. METHODS: We conducted a review of our initial 42 (19 with 6-month follow up) consecutive DSAEK surgeries using ASF tissue compared with 357 (199 with 6-month follow up) time-matched controls using standard tissue. Intraoperative and perioperative complications, including dislocations and primary graft failures, were compared. Six-month best spectacle-corrected vision, incidence of rejection episodes, postoperative refractive astigmatism, keratometric values, pre- and postoperative topography-derived surface asymmetry index, and surface regularity index were compared. RESULTS: One surgeon-cut ASF tissue was perforated before surgery and was discarded. No surgeon-cut standard tissue was perforated. No intraoperative complications and no episodes of primary graft failure or pupillary block glaucoma occurred in either group. One (2.4%) postoperative graft dislocation and one (5.2%) graft rejection episode occurred in the study group. There were 10 (2.8%) dislocations and 8 (2.2%) graft rejection in the controls. A statistically similar significant improvement in best spectacle-corrected vision occurred in both groups. Corneal topography, pachymetry, and manifest astigmatism were not significantly different between groups. CONCLUSION: Postoperative results of DSAEK using donor tissue excluded from use in penetrating keratoplasty as a result of stromal flaws are equivalent to results using standard donor tissue. Central corneal thickness measurements should be performed before cutting to avoid tissue perforation. The use of ASF tissue for DSAEK will expand the cornea donor pool.

Endothelial keratoplasty: the influence of insertion techniques and incision size on donor endothelial survival.

PURPOSE: To determine the acute endothelial cell damage from trephination and tissue insertion in endothelial keratoplasty (EK) surgery. The influence of insertion technique (forceps insertion vs "pull-through" insertion) of donor tissue and incision size (3 vs 5 mm length) was assessed. METHODS: Forty precut 8.-mm-diameter donor posterior buttons were used in this study. Thirty-five buttons were inserted through a limbal incision of either 3 or 5 mm length into the anterior chamber of cadaver eyes and then removed through an open sky technique without further trauma. Five buttons that were trephined but not inserted served as a control group. Vital dye staining and computer digitized planimetry were used to analyze the tissue and quantify the total damaged area over the entire endothelial surface. Five buttons for each of 7 insertion techniques were used. The 8 tissue groups evaluated were as follows: group 1: control group of trephination only, with no insertion; group 2: forceps with folded tissue through 5-mm incision; group 3: suture pull through of nonfolded tissue through a 5-mm incision; group 4: forceps pull through of Busin glide folded tissue through a 5-mm incision; group 5: forceps with folded tissue through a 3-mm incision; group 6: suture pull through with folded tissue through a 3-mm incision; group 7: suture pull through with nonfolded tissue through a 3-mm incision; and group 8: forceps pull through of Busin glide folded tissue through a 3-mm incision. RESULTS: The control group demonstrated 9% +/- 2% peripheral cell damage from simple trephination of the tissue but without insertion. In the 5-mm incision surgeries, forceps insertion (group 2) caused 18% +/- 3% loss, suture pull-through insertion (group 3) caused 18% +/- 2% loss, and Busin glide pull through (group 4) caused 20% +/- 5% loss. There were no significant differences in damage between any of the 5-mm incision group techniques (P > 0.99). In the 3-mm incision surgeries, forceps insertion (group 5) caused a 30% +/- 3% loss, pull through with folded tissue (group 6) caused 30% +/- 5% loss, pull through with nonfolded tissue (group 7) caused 56% +/- 4% loss, and Busin glide pull through (group 8) caused a 28%+/- 5% loss. There was no difference in damage among the 3-mm groups (P > 0.96), with the exception of group 7 where pulling the unfolded tissue through a 3-mm incision was significantly worse than all other techniques (P < 0.001). There was significantly greater cell area damage in the 3-mm groups (36%) than in the 5-mm groups (19%) (P <0.001). Large patterns of striae with cell loss were seen in the 3-mm groups emanating from the peripheral traction site, regardless of whether the traction to pull the tissue through the incision and into the chamber was generated by a suture or cross-chamber forceps. Direct forceps insertion caused circular patterns of injury at the tip compression site regardless of incision size, but this damage was multiplied and exacerbated by insertion through a smaller incision. CONCLUSIONS: Smaller size (3 mm) incisions for EK surgery result in greater acute endothelial area damage than larger size (5 mm) incisions. Pull-through insertion techniques through a 5-mm incision seem equivalent in the amount of induced area damage to that of forceps insertion. Compressive injury from the incision appeared less when the tissue was folded than when not folded. Insertion with any technique through a 3-mm incision resulted in larger areas of endothelial damage. All these iatrogenic death zones outside the central endothelial area would be missed clinically by standard early specular microscopy after EK surgery.

An easy and inexpensive method for quantitative analysis of endothelial damage by using vital dye staining and Adobe Photoshop software.

PURPOSE: We developed a simple, practical, and inexpensive technique to analyze areas of endothelial cell loss and/or damage over the entire corneal area after vital dye staining by using a readily available, off-the-shelf, consumer software program, Adobe Photoshop. The purpose of this article is to convey a method of quantifying areas of cell loss and/or damage. METHODS: Descemet-stripping automated endothelial keratoplasty corneal transplant surgery was performed by using 5 precut corneas on a human cadaver eye. Corneas were removed and stained with trypan blue and alizarin red S and subsequently photographed. Quantitative assessment of endothelial damage was performed by using Adobe Photoshop 7.0 software. RESULTS: The average difference for cell area damage for analyses performed by 1 observer twice was 1.41%. For analyses performed by 2 observers, the average difference was 1.71%. Three masked observers were 100% successful in matching the randomized stained corneas to their randomized processed Adobe images. CONCLUSIONS: Vital dye staining of corneal endothelial cells can be combined with Adobe Photoshop software to yield a quantitative assessment of areas of acute endothelial cell loss and/or damage. This described technique holds promise for a more consistent and accurate method to evaluate the surgical trauma to the endothelial cell layer in laboratory models. This method of quantitative analysis can probably be generalized to any area of research that involves areas that are differentiated by color or contrast.