The Postnatal Growth and Retinopathy of Prematurity Model: A Multi-institutional Validation Study.

PURPOSE: The G-ROP model was proposed to improve the retinopathy of prematurity (ROP) screening efficiency. It is based on gestational age, birth weight and postnatal weight gain. The current study aimed to validate the G-ROP model's ability to predict ROP in cohorts of premature infants from Egypt and the United Kingdom (UK). METHODS: We retrospectively reviewed the records of preterm infants born between 1st of January and 30th of June 2018 with a known outcome for ROP screening and regular weight measurements until day 39 after birth. We applied the G-ROP model to the study group and calculated the sensitivity of the model for detecting Early Treatment of ROP (ETROP) study type 1 ROP and for any ROP and calculated the reduction of the number of infants requiring ROP screening by the model application. RESULTS: We applied the G-ROP model on 605 infants (504 from Egypt and 101 from the UK). The model successfully predicted all type 1 ROP cases (100% sensitivity) in both cohorts (95% confidence interval [CI], 91.1-100% in the Egyptian cohort and 65.5-100% in the UK cohort). The model reduced the number of infants requiring screening by 14.1% in the Egyptian cohort and 21.8% in the UK cohort. CONCLUSIONS: The G-ROP model was successfully validated for detecting type 1 ROP and in both cohorts from Egypt and the UK.

Corneal biomechanics in different age groups.

PURPOSE: To report on the corneal biomechanical characteristics, namely the corneal hysteresis (CH), corneal resistance factor (CRF), as well as the intraocular pressure (IOP) goldman compensated (IOPg), and the cornea compensated (IOPcc), using the ocular response analyzer (ORA) in different age groups in a cohort of normal individuals from the second decade to the seventh decade and beyond. PATIENTS AND METHODS: The study was a cross-sectional survey conducted on 997 eyes of 508 normal individuals presenting for a routine ophthalmic examination at Alexandria Main University Hospital in Alexandria University, Alexandria, Egypt. The study subjects were age stratified into decades (10-20, 21-30, 31-40, 41-50, > 50) and the ORA parameters (CH, CRF, IOPg, IOPcc) reported and stratified. Correlations were sought between the ORA parameters and the age, gender, and laterality. RESULTS: The study was conducted on 997 (502 right) eyes of 508 (234 males) normal individuals. The mean ± SD ages of the study groups were 14.7 ± 3.2, 25.9 ± 3.0, 35.3 ± 2.8, 44.6 ± 2.9, and 61.1 ± 7.7 years. The mean ± SD of the CH in the study groups were 10.9 ± 2.4, 9.8 ± 1.5, 9.8 ± 1.4, 9.7 ± 1.7, and 9.5 ± 1.6 mmHg and of the CRF were 10.9 ± 2.4, 9.5 ± 1.7, 9.4 ± 1.8, 9.6 ± 1.9, and 9.6 ± 1.8 mmHg. A statistically significant negative correlation was found between age and each of CH and CRF. IOPcc demonstrated a fairly constant trend in the different age groups whereas IOPg demonstrated an initial decline followed by a gradual rise over time. CONCLUSION: The corneal biomechanical properties CH and CRF decrease with age. IOPg and IOPcc change minimally with age.

Corneal Safety and Stability in Cases of Small Incision Lenticule Extraction with Collagen Cross-Linking (SMILE Xtra).

PURPOSE: To assess the safety and stability in cases of small incision lenticule extraction with collagen cross-linking (SMILE Xtra). METHODS: This study was a retrospective interventional comparative study that included 60 eyes of 30 patients divided equally into two groups: SMILE Xtra and SMILE alone. The inclusion criteria were patients >18 years of age, myopic error >6 D, thinner cornea <520 microns, and abnormal corneal topography. Outcome data were recorded including uncorrected distance visual acuity and corrected distance visual acuity (UDVA and CDVA), manifest refraction spherical equivalent (MRSE), central corneal thickness, average keratometry, endothelial cell density, corneal resistance factor (CRF), and corneal densitometry. The follow-up period was 24 months. RESULTS: There was a significant difference between the 2 groups regarding UDVA, CDVA, and MRSE at 1 month. In the SMILE Xtra group, 90% of eyes had postoperative UDVA of 20/20 and 97% had UDVA of 20/30 at 24 months. At 24 months, 26 eyes (87%) vs. 25 eyes (84%) were within ±0.50 D of attempted correction in SMILE Xtra and SMILE groups, respectively. Regarding stability, both groups showed improvement of MRSE at 1st month postoperatively and remained stable along the 24 months of follow-up. CRF and corneal densitometry were higher in the SMILE Xtra group along the whole follow-up period (p=0.001). CONCLUSION: Combining corneal cross-linking with SMILE procedure (SMILE Xtra) is a promising tool to prevent ectasia in high-risk patients. It is a safe and simple procedure that can be offered to patients undergoing SMILE with risk for ectasia. Trial registration no: PACTR201810577524718.

Corneal biomechanical changes in eyes with small incision lenticule extraction and laser assisted in situ keratomileusis.

BACKGROUND: Evaluating the corneal biomechanical changes using the Ocular Response Analyzer and the Corvis ST in eyes with incision lenticule extraction (SMILE) and laser assisted in situ keratomileusis (LASIK). METHODS: This is a retrospective study that included 50 eyes equally divided into two groups. The first group included eyes that underwent SMILE procedure using VisuMax® 500 kHz laser system (Carl Zeiss Meditec, Jena, Germany) and the second group included eyes that underwent LASIK procedure using the EX500 Allegretto excimer laser platform (Wavelight GmbH, Erlangen, Germany). The Ocular Response Analyzer (ORA) and the Corvis ST (CST) measured the corneal biomechanical changes before and after the procedures. RESULTS: The ORA showed significant decrease of corneal hysteresis (CH) and corneal resistance factor (CRF) in both groups postoperatively. The percentage of change of CH and CRF were found to be significantly higher in group II. There was no significant difference in the IOP with the ORA and the CST pre and postoperatively in either group. Using CST, the deformation amplitude and HC peak distances increased significantly in both groups. It was also noted that the mean percentage of change of the deformation amplitude was nearly five times higher in group II than group I. CONCLUSION: Both LASIK and SMILE substantially decreased the corneal biomechanical properties with greater reduction in the LASIK group.

The accuracy of axial length measurements in cases of macula-off retinal detachment.

OBJECTIVE: To assess the accuracy of axial length measurements in cases of macula-off retinal detachment using different methods (optical biometry, A-scan ultrasound, and combined applanation vector-A/B-scan biometry). METHODS: This prospective clinical study included 100 eyes of 100 patients who underwent vitrectomy alone or phacovitrectomy for macula-off retinal detachment. All patients included signed an informed consent. Preoperative examination of the patients included recording the axial length measurements using optical biometry, A-scan ultrasound, and combined applanation vector-A/B-scan biometry. RESULTS: The mean postoperative IOLMaster axial length after macular reattachment was 26.11 ± 2.91 mm. The mean preoperative IOLMaster axial length with macula-off was 25.32 ± 2.72 mm. The mean preoperative A-scan axial length with macula-off was 25.29 ± 2.80 mm. The mean preoperative vector-A/B-scan axial length with macula-off was 26.03 ± 2.90 mm. The preoperative vector-A/B-scan mean absolute error was 0.59 ± 0.48 D (range, 0.10-2.25 D). CONCLUSIONS: Regular methods (optical biometry and A-scan biometry) of measuring the axial length in cases with a detached macula proved to be variable and less accurate. The vector-A/B-scan offered good measurements of the actual axial length in the patients. This was reflected on more accurate postoperative refractive outcome.

Chronic candida endophthalmitis as a cause of intermediate uveitis.

Intermediate uveitis is a subset of intraocular inflammation where vitritis is the most consistent sign, with or without snowball opacities or snow banks over the pars plana. Some patients will have an associated underlying systemic disease such as sarcoidosis, multiple sclerosis, ocular tuberculosis, inflammatory bowel disease, possibly Behçet's disease and intraocular lymphoma, whereas some will be classified as pars planitis in case of the lack of an identifiable systemic disease association. Our patient, a 47-year-old woman, developed intermediate uveitis after cataract surgery in her right eye, was misdiagnosed as pars planitis, and received steroid monotherapy for 8 months. Her inflammation only fully resolved after vitrectomy with removal of the intraocular lens (IOL) and capsular bag. Oral fluconazole and intravitreal amphotericin B injection had failed to resolve her inflammation when Candida albicans was identified as the cause of her persistent intermediate uveitis.