Pediatric Keratoconus in A Tertiary Eye Center in Alexandria: A Cross-sectional Study.

PURPOSE: To describe the clinical presentation, risk factors, and treatment choices documented in a pediatric keratoconus population treated at a tertiary referral center in Alexandria, Egypt. METHODS: : A cross-sectional study of 80 patients with keratoconus aged 18 years or younger referred to the cornea clinic at the Alexandria University Main Hospital between July 2018 and October 2019 was included. Patients' history, initial presentation, best spectacle corrected visual acuity (BSCVA), clinical signs, topographic data, and treatment were recorded. RESULTS: Thirty patients were younger than 14 years and 50 were 14 years or older. Elements of the initial presentation included decreased vision in 26 patients, itching in 20 patients, both visual impairment and itching in 16 patients, accidental discovery during vision screening at school in 15 patients, and hydrops in three patients. All patients had bilateral keratoconus, except for four patients who had previously been treated by keratoplasty (n = 156 eyes). The mean logMAR BSCVA was 0.79 ± 0.63. The mean of the average keratometry (AveK), maximum keratometry (Kmax), central corneal thickness (CCT) and thinnest pachymetry reading were 51.16 ± 7.31 D, 59.18 ± 10.38 D, 458.44 ± 55.87 µ 440.08 ± 60.18 µ, respectively. 57 eyes (36%) had stage 1 disease, 43 eyes (28%) had stage 2 disease, 17 eyes (11%) had stage 3 disease and 39 eyes (25%) had stage 4 disease, respectively. No statistically significant differences in the LogMAR BSCVA, keratometry values, CCT, thinnest pachymetry reading, and the Amsler-Krumeich (AK) staging existed between the two age groups or between boys and girls. Crosslinking was indicated in 69 eyes (44%), while keratoplasty was the only viable solution for 39 eyes (25%), with three patients requiring keratoplasty in both eyes. CONCLUSION: Keratoconus in children can result in severe loss of vision. Keratoconus screening programs in elementary schools should be considered in populations with a high incidence of keratoconus for early detection and adequate intervention.

Deep Anterior Lamellar Keratoplasty with Large Descemet's Membrane Perforation: Should We Stop Conversion to Penetrating Keratoplasty?

PURPOSE: To evaluate the outcome of eyes with large Descemet's membrane (DM) perforation during deep anterior lamellar keratoplasty (DALK). METHODS: A retrospective, interventional case series of 12 eyes with completed DALK, despite DM perforation larger than 4 mm in its widest dimension. The main outcome measures included graft clarity, endothelial cell density (ECD), corrected distance visual acuity (CDVA), and DM detachment. RESULTS: The mean age of patients was 26.8 ± 11.4 years. Preoperative pathology included keratoconus (n = 10), macular dystrophy (n = 1), and postmicrobial keratitis corneal scar (n = 1). The average size of DM perforation was 6.5 mm ± 1.3 mm. At the end of the follow-up period (median 15 months, range 6-53 months), the mean CDVA was 0.32 ± 0.09 logMAR and the mean ECD was 1830.8 ± 299.7 cells/mm2. Nine patients (75%) developed DM detachments postoperatively and was managed by intracameral air injection once in six eyes, and twice in three eyes. Other complications included persistent localized stromal edema at the site of DM defect in one eye and Urrets Zavalia syndrome in one eye. CONCLUSION: Completing DALK in eyes with large DM perforation provides good visual acuity, endothelial cell count and may be superior to penetrating keratoplasty regarding long-term graft survival if confirmed in future comparative studies.

Safety and Indicative Effectiveness of Porcine Corneal Lenticular Implants in Patients with Advanced Keratoconus and Post Lasik Ectasia: A Retrospective Clinical Study.

PURPOSE: This study aimed to evaluate the safety and feasibility of implanting decellularized porcine corneal lenticules in a femtosecond laser-assisted pocket for patients with advanced keratoconus and post-Lasik ectasia. METHODS: This is a retrospective clinical study of implanting a porcine corneal lenticular implant in seven eyes: six with advanced keratoconus and clear cornea and one with advanced post-Lasik ectasia with a follow-up for 12 months. The lenticules are extracted from porcine tissue, subjected to a decellularization process, intensely cross-linked, sterilized and packed. They are 7 mm in diameter with at 100-120-micron thickness. The femtosecond laser was used to create an intra-stromal pocket, and then the lenticules were implanted inside the pocket followed by corneal cross-linking 3 months later for six out of seven eyes. RESULTS: Five patients had keratoconus (6 eyes) and one patient (one eye) had post-Lasik ectasia. Visual acuity improved in all patients except for one case at 6 and 12 months and this was statistically significant (P=0.002 and 0.007). At one-year follow-up, the mean central corneal thickness increased from 389.43 ± 45.41 to 429.33± 63.20 µm, the maximum keratometry decreased from 64.8 ±5.11 to 62.82± 6.16 D, the mean corneal resistance factor (CRT) increased from 5.67 to 8.42, and the total higher-order aberrations decreased from 1.80 to 1.16. Both changes in the CCT and CRF were statistically significant. One eye had wrinkles and opacified graft, and it was exchanged 3 months postoperatively. CONCLUSION: Porcine corneal lenticules implantation is immunologically safe and well tolerated in patients with advanced keratoconus and post-Lasik ectasia and may be feasible as an alternative to keratoplasty.

Scheimpflug Imaging in Operated Primary Congenital Glaucoma.

PURPOSE: To report the corneal tomographic characteristics of eyes that had surgery for controlled primary congenital glaucoma (PCG) and to compare it with an age-matched group of normal children. METHODS: The study was conducted on 44 (24 right) eyes of 27 children (18 boys) who had surgery for PCG and 60 (31 right) eyes of 32 age-matched control children (9 boys). Children with PCG had a thorough ophthalmic examination and the demographic and medical and surgical history was retrieved from the patients' clinical chart records. After clinical examination, the study participants underwent Scheimpflug imaging using the Pentacam (Oculus Optikgeräte GmbH). RESULTS: Both study and control children were approximately 9 years of age at the time of the study (P = .39). The eyes with PCG had a spherical equivalent mean ± standard deviation of -4.70 ± 3.50 diopters (D). Eyes with PCG demonstrated a cylinder of -2.80 ± 2.10 D, flatter corneas than control eyes (P = .0002 and .0012 for flat and steep keratometry, respectively), and statistically significantly higher astigmatism (P = .011) and thinner corneas, both at pupil center (P < .001) and thinnest location (P < .001). There was a statistically significant negative correlation between the postoperative axial length (at the time of the scan) and each of the Scheimpflug parameters flat keratometry (P = .002), steep keratometry (P = .003), pachymetry at pupil center (P = .01), and pachymetry at thinnest location (P = .009). CONCLUSIONS: The eyes of patients with PCG have thinner, flatter, and more astigmatic corneas than the eyes of age-matched control children. [J Pediatr Ophthalmol Strabismus. 2021;58(4):218-223.].

Dynamics of Big Bubble Formation During Deep Anterior Lamellar Keratoplasty in Eyes with Advanced Keratoconus.

PURPOSE: To study the dynamics of big bubble (BB) formation in eyes with advanced keratoconus (KC) during deep anterior lamellar keratoplasty (DALK). METHODS: A retrospective review of medical records and videos of DALK surgeries performed during the period from January 2013 to December 2019 on keratoconic eyes. Eyes with formed BB, in the presence of a relatively clear stroma, were included. We studied the following parameters the location of BB commencement, duration from the start of the bubble until complete formation, and the pattern of air passage during the formation process. RESULTS: A total of 37 eyes met the inclusion criteria. Type 1 BB was formed in 22 eyes with a mean formation time of 1.9 ± 1.1 seconds and a mean bubble diameter of 7.6 ± 1.1 mm. Type 1 BB started in the center as a small dome expanding centrifugally with preceding localized stromal whitening in 19 eyes and without whitening in three eyes. Type 2 BB was formed in 14 eyes with a mean formation time of 0.3 ± 0.12 seconds and a mean bubble diameter of 7.4 ± 1.8 mm. Type 2 BB started in the center in 13 eyes and the mid periphery in one eye, through either direct access to the plane between Descemet's membrane and the pre-Descemet's layer in six eyes, or preceded by a small intrastromal bubble in eight eyes. Mixed bubble was observed in one eye, which started as a small central Type 1 BB followed by the rapid formation of a Type 2 BB. CONCLUSION: Eyes with KC are associated with central commencements of both Type 1 and Type 2 BB during DALK. Duration of BB formation was significantly faster in Type 2 BB, with most starting as a small intrastromal bubble before air gain access to the plane between DM and stroma.

Impact of Donor Age on Corneal Endothelium-Descemet Membrane Layer Scroll Formation.

OBJECTIVE: To correlate corneal endothelium-Descemet membrane (EDM) layer parameters of scroll tightness with donor age, endothelial cell density (ECD), and history of diabetes. METHODS: Endothelium-Descemet membrane layer scrolls were harvested from 26 corneoscleral buttons using the SCUBA technique by a cornea-fellowship trained ophthalmologist masked to donor age. Two independent outcome parameters were used to characterize the scrolling severity of successfully harvested tissue: scroll width and tendency for EDM scroll formation (referred to as scroll rating on a 1-4 scale: incomplete scroll formation to tightly scrolled). RESULTS: Mean donor age was 59 ± 17 (15-69) years. Mean ECD of EDM scroll was 2,451 ± 626 (range: 1,307-3,195) cells per square millimeter. Using stepwise linear regression, a significant correlation was found between scroll width and donor age (R=0.497, P<0.05). Additionally, a significant inverse correlation was found between scroll width and ECD (R=-0.605, P<0.05). There was no statistically significant correlation between a donor history of diabetes and the parameters of scrolling tendency. CONCLUSIONS: Our data suggest that using older donors reduces EDM scroll tightness.