Clinical History Method versus Corneal Tomographers in Estimating Corneal Power after Photorefractive Surgery

AIMS: To investigate the concordance between the corneal power determined by various approaches with two tomographers (MS-39® and Galilei G6®) and the clinical history method (CHM) in patients undergoing photorefractive surgery with excimer laser for myopic errors. MATERIAL AND METHODS: Prospective cohort study. Patients undergoing keratorefractive surgery, and having pre- and postoperative keratometries, and tomographies, were included. RESULTS: In 90 eyes, the differences in the power estimated by the CHM and the one determined by four approaches with the corneal tomographers, which included measurements of the posterior cornea, did not show statistically significant differences in their averages. However, the 95% limits of agreement were very wide. After obtaining regression formulas to adjust the values of these four variables, the results of the agreement analysis were similar. CONCLUSION: Although certain values either directly determined or derived from measurements with the Galilei® and MS-39®corneal tomographers, approximated the estimated value of postoperative corneal power according to the CHM, due to the amplitude of their limits of agreement, these calculations must be taken with care, because they may not be accurate in a given eye.

ANATOMIC AND TOPOGRAPHIC CHANGES OF ANTERIOR SEGMENT STRUCTURES IN EHLERS-DANLOS SYNDROME PATIENTS WITH MYOPIA.

OBJECTIVE: The aim: Determination of anatomical and topographical relationships of the eyeball anterior segment structures to assess possible glaucoma development risk factors in SED patients with myopic refraction. PATIENTS AND METHODS: Materials and methods: Patients, aged from 10 to 34, have been examined since 2009. All the patients have undergone required medic and genetic examination as well as generally accepted ophthalmological one. Ultrasound biomicroscopy (UBM) has been performed using the VuMax II apparatus (Sonomed, USA) with a sensor frequency of 50 MHz. RESULTS: Results: Biomicroscopy found no symptoms such as pigment dispersion on the iris stroma, in the chamber anterior angle, iris transillumination and "Krukenberg's Spindle", which are characteristic for the ultrasound picture in pigment dispersion syndrome. CONCLUSION: Conclusions: 1. Clinical and functional study with the eyeballs mandatory ultrasound biomicroscopy have revealed functional space limitations for the structures of the iridociliary zone in patients with myopic type of eye structure in SED. 2. Detected congenital changes in the anterior segment structures (iridociliary cystic formations and residual mesodermal tissue) can lead to the emergence of intraocular blocks. 3. The research has identified conducive anatomical and topographic changes, which are likely to induce pigment dispersion syndrome or lead to the development of pigmentary glaucoma. 4. In our opinion, the UBM role in the early diagnosing and monitoring patients with SED syndrome is quite significant in terms of assessing the stability or dynamics of the changes received and possible complications. Ultrasound biomicroscopic scanning should be added to the list of necessary early diagnostic examinations to determine the markers and features of structures in SED.

Corneal Collagen Crosslinking (CXL) for Corneal Ectasia after Small Incision Lenticule Extraction (SMILE). / Korneales Kollagen-Crosslinking (CXL) bei Hornhautektasie nach SMILE (Small Incision Lenticule Extraction).

With an estimated incidence of 0.011%, the SMILE procedure seems to have the lowest risk of postoperative keratectasia among contemporary keratorefractive procedures. Nevertheless, due to the novelty of the procedure as well as the lack of data, no clear superiority over femto-LASIK or PRK can be stated at this time. In this respect, application of the identical tomographic screening criteria previously developed for excimer-based procedures is of paramount importance to minimize the risk of corneal ectasia. As an adjunct to conventional corneal tomography, newer imaging modalities such as OCT-based epithelial mapping should be used for preoperative screening before keratorefractive surgery. Corneal crosslinking is an established treatment modality for post-SMILE keratectasia, which promises high success rates especially in early stages. The present case report illustrates these diagnostic and therapeutic considerations.

Changes in Retinal Vessel Flow after Small Incision Lenticule Extraction.

Objective: In order to analyze changes in retinal vessel flow after small incision lenticule extraction (SMILE). Methods: A total of 32 patients (62 eyes) who underwent SMILE were enrolled in this prospective study. Optical parameters, including vessel density (VD), and perfusion density (PD) of foveal, parafoveal, and perifoveal regions, respectively, were measured before surgery and at 1 day, 1 week, 1 month, and 3 months postoperation. Preoperative parameters and surgical parameters were recorded. Results: Significant decreases in VD and PD on postoperative day 1 were detected in all quadrants, both in 3 mm and in 6 mm regions (P < 0.001). One month after surgery, VD returned to preoperative levels. None of the preoperative and surgical parameters were significantly correlated with the VD and PD fluctuations (all P > 0.05). Conclusion. VD may decrease significantly with regional disparity 1 day after SMILE while recovering at 1 month. Elevation of intraocular pressure due to suction may account for such changes.

Effect of Laser-assisted Subepithelial Keratectomy with Mitomycin C on Corneal Optical Density Measured with Confocal Microscopy.

SIGNIFICANCE: The development of confocal microscopy allows one to obtain high-resolution corneal images like its optical density. Some studies have evaluated the optical density with Scheimpflug cameras in the early post-operative period after photorefractive keratectomy, but no studies have evaluated the long-term evolution of optical density after surface ablation when mitomycin C is used. PURPOSE: This work aimed to study the changes in corneal optical density measured with confocal microscopy in eyes treated with laser-assisted subepithelial keratectomy (LASEK) and intraoperative mitomycin C (MMC) to correct myopia. METHODS: A study of 24 consecutive myopic eyes that underwent LASEK with 0.02% MMC and a control group of 24 healthy nontreated eyes was performed. Optical density was measured using the images by the confocal microscopy of the Heidelberg Retina Tomograph II with the Rostock Cornea Module. An analysis of confocal microscopy images was performed using the ImageJ software to obtain the optical density, in gray-scale units (GSU). The optical density of the stromal bed was evaluated 3 months, 15 months, and 3 years after surgery and was compared with the optical density at the equivalent depth of the stroma in controls. RESULTS: The mean values of optical density for the LASEK group were 81.7 ± 9.7, 78.6 ± 11.7, and 73.6 ± 18.7 GSU at 3 months, 15 months, and 3 years, respectively, and it was 61.8 ± 8.2 GSU for the control group. A statistically higher optical density 3 and 15 months after LASEK with MMC was found compared with controls (P < .001). No significant difference was found in optical density at 3 years post-operatively. CONCLUSIONS: Our study suggests that, after LASEK with MMC, the anterior corneal stroma has a higher optical density at 3 and 15 months post-operatively, which gradually returns to normal values 3 years after surgery.

Quantitative Analysis of Human Corneal Lenticule Surface Microstructure Irregularity with 3D Optical Profiler Using White Light Interferometry.

PURPOSE: To quantitatively evaluate the cutting quality of small incision lenticule extraction (SMILE) by measuring human corneal lenticule surface roughness in different areas with white light interferometer. METHOD: A white light interferometer was used to quantitatively measure the corneal lenticule surface roughness in different areas. Sixty-three myopic patients (102 eyes) who underwent SMILE surgery were recruited. The surface roughness of the central, pericentral, and peripheral parts of the corneal lenticule surface was measured in both the anterior and posterior planes. Differences in corneal lenticule surface roughness were analyzed between different myopic groups. RESULTS: The surface roughness of the anterior plane of the corneal lenticule was lower than the posterior plane in various areas (central, pericentral, and peripheral parts) (P < .01). Surface roughness gradually increased from the center to the periphery, in both the anterior and posterior planes (P < .01). There were no significant differences in the surface roughness of the central part in both the anterior and posterior planes between the low and high myopic groups. The surface roughness of the high myopic group was higher than that of the low myopic group in the peripheral part (P < .01). There were no significant differences among the three cylinder-specific groups. There was no significant correlation between two paired eyes. A positive correlation between posterior central surface roughness and the percentage tissue altered score (PTA) was found (r = 0.248, P = .012). CONCLUSIONS: The cutting surface of the corneal lenticule performed by femtosecond laser was evaluated with a white light interferometer and displayed inhomogeneity. Deeper cutting with higher myopia and some intraoperative complications, such as suction loss, may result in larger irregularities.

Transient Myopia Secondary to Supraciliary Effusion: Unusual Complication After an Uneventful Prolene Gonioscopy-assisted Transluminal Trabeculotomy.

PURPOSE: The purpose of this study was to report 2 cases experiencing a transient decrease in their vision due to the development of acute myopia after an uneventful prolene gonioscopy-assisted transluminal trabeculotomy (GATT) surgery. METHODS: A 52-year-old woman with primary open-angle glaucoma and an 8-year-old boy with juvenile glaucoma underwent uneventful GATT surgery. RESULTS: On the postoperative first day, both patients had mild shallow anterior chamber and intraocular pressures measured as 19 and 16 mm Hg, respectively. Both patients had myopia measured as -4.5 and -6.0 D, respectively. Fundus examination was unremarkable in the first patient, whereas it showed bilateral optic disc cupping and retinal nerve fiber layer atrophy in the second patient. In the first patient, supraciliary effusion was detected by using ultrasound biomicroscopy. Ultrasound biomicroscopy could not be performed in the second patient, but ocular ultrasonography revealed a thin layer of suprachoroidal fluid. Myopia was completely regressed, and visual acuity increased within 1 week of the follow-up in both patients. At the sixth month of the follow-up, intraocular pressures in both patients were under control without any antiglaucoma medications. CONCLUSION: Transient decrease in vision after the GATT surgery might occur secondary to supraciliary effusion leading to acute, transient myopia.

Identification of separated lenticular planes using optical coherence tomography.

PURPOSE: To discuss how optical coherence tomography can be used to identify separated lenticular planes during small incision lenticule extraction (SMILE). METHODS: SMILE procedures were performed on 26 eyes of 13 patients. An anterior segment optical coherence tomography examination was performed after laser scan. Anterior segment optical coherence tomography examinations were conducted again both after separation of the anterior lenticular plane in the right eye and after separation of the posterior lenticular plane in the left eye. Lenticule extraction was then completed, followed by another anterior segment optical coherence tomography examination. Anterior segment optical coherence tomography was also conducted on both eyes on the first day after surgery. Each measurement consisted of four line scans along the 45°, 90°, 135°, and 180° meridians. The brightness scores were compared between the two planes after the separation of one plane. RESULTS: Anterior segment optical coherence tomography showed two bright lines after laser scan. Along with all meridians, the brightness of the anterior plane was less in the right eye, for which only the anterior plane was separated, and the brightness of the posterior plane was less in the left eye, for which only the posterior plane was separated (all P < 0.001). After lenticule extraction in both eyes, anterior segment optical coherence tomography revealed that a smooth hyperreflective line existed between the cap and the residual stromal bed, and this line remained throughout the first day after surgery. CONCLUSION: The bubbles produced by the creation of the lenticule in SMILE mostly disappear by manual separation, and anterior segment optical coherence tomography can help the surgeon identify the separated lenticular planes.

"Yokoyama procedure" efficacy on non-highly myopic patients with acquired esotropia and hypotropia.

OBJECTIVE: To assess the efficacy of "Yokoyama Procedure," on non-highly myopic patients with acquired esotropia and hypotropia. METHODS: The study involved 10 eyes of 5 patients with eso-hypotropia. Inclusion criteria were acquired esotropic-hypotropic strabismus with lateral rectus inferior displacement and superior rectus nasal displacement confirmed by magnetic resonance imaging, refractive errors between ±6 D, and axial length < 27 mm. Range of full duction movements and maximum angles of abduction-sursumduction was measured in each eye before and after surgery. All patients underwent T1- and T2-weighted magnetic resonance imaging. The surgery was aimed at creating a junction between the muscle bellies of the superior and lateral rectus muscles. This junction was made approximately 14 mm behind the insertions using a non-absorbable mersilene 5/0 suture (Yokoyama procedure). RESULTS: Mean patient age was 64.8 ± 4.8 years. The mean globe axial length was 25.4 ± 0.76 mm and a mean corresponding spherical equivalent refraction of -3.7 ± 1.7 D was observed. Eight eyes on 10 had mild limitation in abduction, while the remaining 2 had no limitation. Three out of 10 eyes showed a moderate limited sursumduction, 5 eyes were categorized as mild, and the remaining 2 had no limitation. No evident post-operative limitation was present in any eye, in both abduction and sursumduction (p < 0.01). Pre-operative esotropia and hypotropia were, respectively, 32 ± 11 prismatic diopters and 25 ± 5 prismatic diopters, and they were significantly reduced after surgery as 9 ± 1.7 prismatic diopters and 6 ±1 prismatic diopters (p = 0.043), respectively. CONCLUSION: Yokoyama procedure is an effective, fast, reversible procedure to face eso-hypotropic acquired strabismus, even in patients with a clear magnetic resonance imaging displacement of superior and lateral rectus muscles, and absence of globe dislocation and of elevated myopia.

SURGICAL OUTCOMES OF MYOPIC TRACTION MACULOPATHY ACCORDING TO THE INTERNATIONAL PHOTOGRAPHIC CLASSIFICATION FOR MYOPIC MACULOPATHY.

PURPOSE: To compare treatment results of myopic traction maculopathy according to the international photographic classification for myopic maculopathy. METHODS: This was a retrospective, single-surgeon-based, observational case series of 35 consecutive eyes that underwent vitrectomy for myopic traction maculopathy. Eyes were classified into nonpathologic myopia (PM) (n = 15) and PM (n = 20) groups. Main outcome measures constituted best-corrected visual acuity (BCVA) and anatomical change. RESULTS: The mean follow-up was 32.03 ± 6.85 months. Axial length correlated with myopic maculopathy category (rho = 0.6836, P < 0.001). In the total group, BCVA improved from 20/61 to 20/36 (P = 0.001). In the subgroup, BCVA improved from 20/41 to 20/22 in the non-PM group (P = 0.002), whereas from 20/82 to 20/52 in the PM group (P = 0.048). Postoperative BCVA of the PM group was inferior to that of the non-PM group (P = 0.002) and the PM group was more likely to have postoperative BCVA <20/30 (odds ratio, 17.3; 95% CI, 2.6-325.0; P = 0.012). Two cases of macular hole retinal detachment occurred after surgery in the PM group. CONCLUSION: Because there are limited benefits of vitrectomy in myopic traction maculopathy accompanied by PM, careful consideration would be necessary when determining surgery. Optical coherence tomography should not be used alone in determining vitrectomy because myopic traction maculopathy can also have PM defined mainly by fundus photographs.

Repeatability of Cornea and Sublayer Thickness Measurements Using Optical Coherence Tomography in Corneas of Anomalous Refractive Status.

PURPOSE: To assess the repeatability of epithelial, stromal, and total corneal thickness measurements with spectral-domain optical coherence tomography (SD-OCT; RTVue-XR; Optovue, Inc., Fremont, CA) in patients with myopia, keratoconus, and corneas after transepithelial photorefractive keratectomy (PRK), small incision lenticule extraction (SMILE), and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). METHODS: A total of 352 eyes of 352 patients (75 myopic, 68 post-transepithelial PRK, 61 post-SMILE, 75 post-FS-LASIK, 20 mild keratoconus, and 53 advanced keratoconus eyes) were included. The epithelial, stromal, and total corneal thickness were recorded from the pachymetric map in the following four zones: (1) central 2-mm region, (2) eight paracentral regions within 2- to 5-mm diameter, (3) eight midperipheral regions within 5- to 7-mm diameter, and (4) eight peripheral regions within 7- to 9-mm diameter. Three successive scans were performed to evaluate the repeatability. RESULTS: For all zones up to 9-mm diameter, the coefficient of variation (CoV) for epithelial thickness measurements ranged from 1.7% to 3.5% for myopia, 2.6% to 6.2% for post-transepithelial PRK, 2.3% to 4.7% for post-SMILE, 4.0% to 6.3% for post-FS-LASIK, 2.5% to 6.2% for mild keratoconus, and 3.5% to 8.0% for advanced keratoconus. The CoV for stromal and total thickness measurements ranged from 0.2% to 2.0% for myopia, 0.7% to 4.2% for post-transepithelial PRK, 0.3% to 2.4% for post-SMILE, 0.3% to 1.9% for post-FS-LASIK, 0.6% to 3.0% for mild keratoconus, and 1.0% to 5.9% for advanced keratoconus. CONCLUSIONS: RTVue-XR SD-OCT showed excellent repeatability when generating the pachymetric map in myopic eyes. Measurements, especially for epithelial thickness, were relatively more variable for corneas with keratoconus and those having undergone keratorefractive surgery. [J Refract Surg. 2019;35(9):600-605.].

Morphologic and functional outcomes of different optical coherence tomography patterns of myopic foveoschisis after vitrectomy and inner limiting membrane peeling.

OBJECTIVE: To evaluate the morphologic and functional outcomes of different optical coherence tomography (OCT) patterns of myopic foveoschisis after vitrectomy with Inner Limiting Membrane (ILM) peeling. METHODS: In this prospective non-randomised study, 62 consecutive eyes with Myopic Foveoschisis were categorised into three groups according to OCT pattern: retinoschisis type (Rt) Group (23/62), foveal detachment type (FDt) Group (20/62) and macular hole type (MHt) Group (19/62). All patients underwent 25-Gauge vitrectomy and ILM peeling. Air or gas tamponade was used. All patients were observed at month 1, 2, 4 and 6 after surgery. MAIN OUTCOMES MEASURES: surgical success as resolution of myopic foveoschisis, central retinal thickness (CRT), IS/OS junction recovery and best-corrected visual acuity (BCVA) measurement. Any complication was reported. RESULTS: In all eyes OCT showed a resolution of the retinoschisis, foveal detachment and macular hole pattern, respectively. CRT significantly decreased in all Groups (p < .001), mainly in MHt. IS/OS junction recovery was mainly observed in MHt. BCVA significantly increased in all Groups (p < .01). A functional gain ≥2 Snellen lines occurred in 70, 85 and 68% in the Rt, FDt and MHt Group, respectively. Final BCVA was correlated with preoperative BCVA (R 0.74, p < 0.0001), postoperative CRT (R -0.49, p < 0.0001), and the recovery of IS/OS junction at 6 months (R 0.76, p < 0.0001). Few postoperative complications occurred. CONCLUSIONS: Vitrectomy with ILM peeling results in favourable anatomic and functional outcomes for different patterns of myopic foveoschisis.

Predictability of the vault after posterior chamber phakic intraocular lens implantation using anterior segment optical coherence tomography.

PURPOSE: To determine whether vault measurements after placement of a hole implantable collamer lens (hole ICL) (KS-AquaPORT) can be predicted by angle-to-angle (ATA) and white-to-white (WTW) measurements obtained with anterior segment optical coherence tomography (AS-OCT). SETTING: Sanno Hospital, Tokyo, Japan. DESIGN: Retrospective case series. METHODS: Eyes were observed for 3 months after hole ICL implantation for myopia or myopic astigmatism. Central vault, ATA, and WTW measurements were obtained before and after surgery using the swept-source AS-OCT CASIA2 system. RESULTS: The study included 44 eyes (23 patients). The mean patient age and preoperative spherical equivalent, ATA, and WTW values were 36.2 years ± 8.8 (SD), -6.23 ± 3.41 diopters (D), 12.03 ± 0.40 mm, and 11.72 ± 0.40 mm, respectively. The safety index and efficacy index 3 months postoperatively were 1.13 ± 0.21 and 0.91 ± 0.30, respectively. Regarding predictability, 93.2% of eyes were within ±0.50 D of the attempted correction and all eyes were within ±1.00 D. The reproducibility coefficients for the ATA distance and WTW distance were 0.998 and 0.960, respectively. The mean postoperative central vault was 491.6 ± 189.5 µm. There was a significant correlation between postoperative vault and the ICL size and ATA distance (Spearman rank correlation coefficient r = 0.59, P < .001) but not between the ICL size and WTW distance (r = 0.27, P = .08). CONCLUSION: The ATA measurements had higher reproducibility than the WTW measurements on AS-OCT, making it is a more important predictor of postoperative vault.

A Multicenter Study on Early Outcomes of Small-Incision Lenticule Extraction for Myopia.

This study was aimed to investigate the early clinical outcomes of small-incision lenticule extraction (SMILE) to correct both myopia and myopic astigmatism at major clinical centers in Japan. This case series consisted of two hundred fifty-two eyes of 130 consecutive patients who underwent SMILE surgery (29.5 ± 6.3 years, mean age ± standard deviation), with spherical equivalents of -4.33 ± 1.61 D. We determined the safety, efficacy, predictability, stability, and adverse events of this procedure. Corrected distance visual acuity significantly improved, from -0.18 ± 0.04 preoperatively to -0.19 ± 0.07 logMAR postoperatively (paired t-test, p < 0.001). Uncorrected distance visual acuity also significantly improved, from 1.05 ± 0.26 preoperatively to -0.15 ± 0.11 logMAR postoperatively (p < 0.001). 88% and 98% of eyes were within ± 0.5 and 1.0 D of the targeted correction, respectively. Changes in manifest spherical equivalent from 1 week postoperatively were 0.02 ± 0.35 D (p = 0.127). No vision-threatening complications were observed in any of the cases. SMILE performed well in the correction of myopic refractive errors, and we experienced no severe complications in this series, indicating its feasibility as a surgical option for the treatment of these eyes.

Longitudinal and Regional Non-uniform Remodeling of Corneal Epithelium After Topography-Guided FS-LASIK.

PURPOSE: To observe the epithelial remodeling over a 9-mm diameter cornea induced by topography-guided femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia correction using spectral-domain optical coherence tomography (SD-OCT). METHODS: Forty-three eyes of 22 patients who underwent topography-guided FS-LASIK for myopic correction were included. The "Pachymetrywide" scan pattern was used to generate the epithelial thickness map using SD-OCT preoperatively and 1, 3, and 6 months postoperatively. Epithelial thickness was compared and analyzed by section and zone. RESULTS: Compared to the preoperative values, the change in the average epithelial thickness in the central, paracentral, and mid-peripheral zones was 2.09, 4.53, and -0.87 µm at 1 month; 3.00, 4.61, and -0.97 µm at 3 months; and 3.28, 4.55, and -0.81 µm at 6 months postoperatively, respectively. From 1 to 3 months postoperatively, the central epithelial thickness changed significantly (P = .021), whereas the epithelial thickness in the paracentral (P = .973) and mid-peripheral (P = .996) zones stabilized. No significant epithelial thickness change was observed in the zones between 3 and 6 months postoperatively (all P > .05). The epithelial thickness in the paracentral inferotemporal section increased by 12.7% at 6 months after surgery. The central epithelial hyperplasia showed no correlation with the change in postoperative manifest refraction spherical equivalent (P = .313). CONCLUSIONS: After topography-guided FS-LASIK, the 9-mm diameter epithelial thickness showed a longitudinal and regional non-uniform redistribution. Central epithelial remodeling stabilized more slowly. The greatest increase in epithelial thickness was observed in the paracentral inferotemporal section. This epithelial remodeling did not cause refractive regression. [J Refract Surg. 2019;35(2):88-95.].

Screening Thresholds for the Corneal Tomography in a Myopic Pakistani Population.

OBJECTIVE: To evaluate key corneal tomography parameters for screening refractive surgery patients in Pakistani population. STUDY DESIGN: Cross-sectional, observation study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Ophthalmology AFIO, National University of Medical Sciences, Rawalpindi, Pakistan, from August 2013 to December 2016. METHODOLOGY: Myopic patients were evaluated by two separate observers on Allegro OculyzerII (Wavelight) for normal ocular examination. A total of 20 tomographic parameters, used for pre-refractive surgical evaluation, were included. Normality of data was evaluated using Kolmogorov-Smirnov test. Results for outliers were displayed as 2.5%, 5%, 95% and 97.5% percentiles. RESULTS: The sample of 451 patients (895 eyes), comprised of 61% (n=277) females and 39% (n=174) males (39%). The mean age was 26 +6.4 years (range of 18-62 years, M=F). Normal mean anterior segment values included; flat simulated keratometry (K1) 42.9 ±1.44 diopters (D), steep K2 43.9 ±1.52 D, K mean 43.4 ±1.43 D, K maximum 44.6 ±1.56 D, astigmatism -0.96 ±0.97 D, anterior chamber depth (ACD) 3.19 ±0.28 mm, front elevation at the thinnest point 4.11 ±2.44 um, and that at the back was 7.56 ±4.52 um progression index (PI) maximum 1.14 ±0.17, Ambrosio relational thickness maximum (ART max) 487.5 ±89.0 and pachymetry at thinnest point 542.2 ± 31.1 um. CONCLUSION: The study demonstrates key corneal tomography parameters, which can be useful for screening refractive surgery patients in Pakistani population.

A HS6ST2 gene variant associated with X-linked intellectual disability and severe myopia in two male twins.

X-linked intellectual disability (XLID) refers to a clinically and genetically heterogeneous neurodevelopmental disorder, in which males are more heavily affected than females. Among the syndromic forms of XLID, identified by additional clinical signs as part of the disease spectrum, the association between XLID and severe myopia has been poorly characterized. We used whole exome sequencing (WES) to study two Italian male twins presenting impaired intellectual function and adaptive behavior, in association with severe myopia and mild facial dysmorphisms. WES analysis detected the novel, maternally inherited, mutation c.916G > C (G306R) in the X-linked heparan sulfate 6-O-sulfotransferase 2 (HS6ST2) gene. HS6ST2 transfers sulfate from adenosine 3'-phosphate, 5'-phosphosulfate to the sixth position of the N-sulphoglucosamine residue in heparan sulfate (HS) proteoglycans. Low HS sulfation levels are associated with defective optic disc and stalk morphogenesis during mammalian visual system development. The c.916G>C variant affects the HS6ST2 substrate binding site, and its effect was considered "deleterious" by in-silico tools. An in-vitro enzymatic assay showed that the HS6ST2 mutant isoform had significantly reduced sulphotransferase activity. Taken together, the results suggest that mutant HS6ST2 is possibly involved in the development of myopia and cognitive impairment, characteristics of the probands reported here.

Nonleaking cystoid macular edema in Cohen syndrome.

An 11-year-old girl with a history of neutropenia, developmental delay, hypotonia, and intellectual disability was diagnosed with Cohen syndrome after genetic testing discovered homozygous mutation in the VPS13B gene. She was referred to a retinal specialist with a chief complaint of decreased peripheral vision. On examination, decreased visual acuity, pigmentary changes, and nonleaking cystoid macular edema were present in both eyes.

PEDIATRIC RETINAL DETACHMENT IN AN ASIAN POPULATION WITH HIGH PREVALENCE OF MYOPIA: Clinical Characteristics, Surgical Outcomes, and Prognostic Factors.

PURPOSE: To evaluate the clinical characteristics and surgical outcomes of pediatric retinal detachments (RDs) in an Asian population. METHODS: Retrospective review of 171 eyes of 152 pediatric patients with rhegmatogenous RD over a 20-year period. RESULTS: Myopia was the most common risk factor in our population. At 6 months, primary anatomical success was 60.7%, and overall anatomical success was 86.7%. A total of 46.8% had best-corrected visual acuity of 20/40 or better, and 81.6% had best-corrected visual acuity of 20/200 or better. In primary RDs, high myopia (≤-6D) patients had a lower primary anatomical success compared to patients with moderate myopia (≤-2D) (59.3 vs. 100% P = 0.03). Increasing age and absence of proliferative vitreoretinopathy were associated with anatomical and visual success. Pars plana vitrectomy as the primary procedure was associated with decreased odds of anatomical success. A longer duration of symptoms, cataract, and a larger RD extent were associated with poorer functional outcome. CONCLUSION: Myopia was the commonest risk factor for pediatric RD in our population. Good anatomical and functional outcome can be achieved with surgery. Increasing age at presentation and absence of proliferative vitreoretinopathy was associated with anatomical and functional success. High myopia was associated with poorer anatomical and functional outcome.