Morphometric analysis of the lens in human aniridia and mouse Small eye.

Congenital aniridia is caused by heterozygous mutations in the PAX6 gene. In this disease, congenital iris and foveal hypoplasia is associated with juvenile onset cataract, glaucoma, and corneal keratopathy. In rodents, Pax6 mutations result in a congenital reduction in ocular size that is not typically described in human aniridia. Here, the ocular morphometry of aniridia patients is compared with the lens phenotype of Pax6+/tm1/Pgr mice to reveal whether there are species differences in Pax6 regulation of lens development and homeostasis. Ultrasound biometry (UBM) revealed that eleven percent of aniridia patients exhibited mild microphthalmia while the anterior chamber depth of aniridic eyes was significantly reduced from 6 months of age onward. Although aniridic lens thickness was normal from birth, it was significantly decreased in aniridic lenses older than 30. Notably, 86% of aniridic lenses exhibited cataractous changes in this cohort. In addition, a significant proportion of aniridia patients develop lens subluxation as they age associated with reduced lens diameter as measured by anterior segment optical coherence tomography (AS-OCT). Analysis of young adult Pax6+/tm1/Pgr mouse lenses by micro-computed tomography (microCT), bright field and dark field imaging revealed that they are reduced in size but did not exhibit overt cataracts at this age. Overall, this study reveals that congenital microphthalmia as assessed by axial length, or microphakia, as assessed by lens thickness, are not typical in human aniridia, although these are primary manifestations of Pax6 mutations in mice, suggesting that PAX6 regulates some aspects of lens development differently between these species.

Initial results of trifocal diffractive IOL implantation.

BACKGROUND: Bifocal intraocular lenses (IOL) are designed to reduce dependence on eyeglasses after surgery, but they cannot provide full range of vision, and have a drop of visual acuity in the intermediate distance. This problem may be solved with a trifocal lens, which produces three useful focal points. This study was conducted to evaluate clinical outcomes, functional vision and spectacle independence in patients with trifocal diffractive IOLs. METHODS: Thirty-six eyes after implantation of diffractive intraocular lens MIOL-Record were evaluated. This IOL has a diffractive lens profile binary in phase and produces three useful foci. Outcome measures recorded 6 months postoperatively were uncorrected and distance-corrected (far, near, intermediate) visual acuities, contrast sensitivity (under photopic and mesopic condition), root-mean-square (RMS) of higher order aberrations (HOA), patients' quality of life (visual function questionnaire VFQ-25, halos and glare presence, overall satisfaction), and spectacle independence. RESULTS: Postoperatively, monocularly, the uncorrected (UDVA) and the corrected distance visual acuity (CDVA) were 0.74 +/- 0.21 and 0.86 +/- 0.23 respectively (P < 0.05). No differences were found between uncorrected (UNVA)-0.85 +/- 0.13 and best distance-corrected near visual acuity (CNVA) 0.89 +/- 0.12 (P > 0.05). The uncorrected (UIVA) and best distance-corrected acuities of intermediate vision (CIVA) at 50 cm were 0.58 +/- 0.16 and 0.6 +/- 0.2 respectively. The photopic contrast sensitivity was within the standard normal range. But under dim light conditions it was inferior at all spatial frequencies by more than 0.2 logarithmic units. The mean aberration values were: total HOA RMS-0.816 +/- 0.362 mum, spherical aberration (SA)-0.207 +/- 0.136 mum, coma-0.335 +/- 0.206 mum. The percentage of patients achieving spectacle freedom was 94%. On the questionnaire, 25% of patient noted nighttime halos; glare difficulty was reported by 16.7% of patients, difficulties with night vision persisted in 22.3% of cases. CONCLUSION: Diffractive trifocal intraocular lens MIOL-Record provided good uncorrected distance, intermediate and near vision, gave high rates of spectacle freedom and overall patient satisfaction.

Femtosecond Laser-Assisted LASIK in Children With Hyperopia and Anisometropic Amblyopia: 7 Years of Follow-up.

PURPOSE: To analyze clinical and functional results of femtosecond laser-assisted laser in situ keratomileusis (FSLASIK) in children with hyperopia and unilateral anisome-tropic amblyopia. METHODS: The study included 24 patients (24 eyes) aged 5 to 15 years. Before the surgery, the mean manifest refractive spherical equivalent (MRSE) of amblyopic eyes was +3.90 ± 1.60 diopters (D) (range: +1.50 to +6.80 D) and the mean refractive anisometropia was 3.06 ± 1.64 D (range: 0.87 to 7.50 D). Every patient had at least 1 year of ineffective traditional amblyopia treatment before surgery. The mean follow-up period was 7 years (range: 6.9 to 7.4 years). RESULTS: At the final follow-up visit, the mean MRSE of operated eyes was +0.41 ± 1.35 D (range: -1.13 to +3.88 D) (P < .001) and anisometropia in MRSE notation was 1.39 ± 1.15 D (range: 0.00 to 4.63 D). Postoperative spherical equivalent was within ±0.50, ±1.00, and ±2.00 D in 31%, 38%, and 92%, respectively. There were no complications. All patients showed a one to seven line gain of corrected distance visual acuity. CONCLUSIONS: FS-LASIK was an effective method of hyperopia correction in this cohort of children with amblyopia, resulting in reduction in anisometropia, restoration of refractive balance, and functional improvement in the amblyopic eye when traditional methods failed. [J Refract Surg. 2020;36(6):366-373.].

Clinical and morphological manifestations of aniridia-associated keratopathy on anterior segment optical coherence tomography and in vivo confocal microscopy.

PURPOSE: The study aimed to evaluate clinical and morphological changes in the limbal palisades of Vogt (POV) at different stages of aniridia-associated keratopathy (AAK) and to assess possible utility of anterior segment optical coherence tomography (AS-OCT) for the visualization of limbal progenitor structures as it correlates to laser scanning confocal microscopy (LSCM) data. METHODS: The study involved 32 patients (59 eyes) with congenital aniridia. AAK stage was defined based on biomicroscopy. Assessment of limbal zone and detection of POVs in identical areas was performed by LSCM (HRT3) and AS-OCT (RTVue XR Avanti) using 3D Cornea (En Face mode) and Cornea Cross Line protocols. RESULTS: Intact and changed POVs were found in 8/8 stage 0 eyes, in 1/21 stage I and 2/13 stage II eyes. Spearman's correlation coefficient in assessing the consistency of the POV diagnostic results by LSCM and AS-OCT for the inferior limbus was rS = 0.85 (P < 0.05), for the superior limbus - rS = 0.53 (P < 0.05). AS-OCT was less sensitive for detection of partially present POVs in superior limbus. The negative correlation between AAK stage and POV preservation was determined (rS = -0.5, P < 0.05). There was no correlation between AAK stage and patient age (rS = 0.235, P = 0.209). Three patients with PAX6 3' deletion showed stage 0 AAK with intact or slightly disturbed POVs morphology and transparent cornea. CONCLUSION: AS-OCT may be an additional diagnostic tool for POV visualization in vivo in aniridic patients. Its diagnostic accuracy is subject to selection of anatomic region, nystagmus and the degree of POV degradation.

Artificial iris-lens diaphragm in reconstructive surgery for aniridia and aphakia.

PURPOSE: To determine the efficacy and safety of surgical implantation of artificial iris-lens diaphragm in patients with anatomic or functional iris deficiencies, aphakia or cataract. SETTING: Svyatoslav Fyodorov MNTK Eye Microsurgery, Cheboksary, Russia. METHODS: Twenty eyes of 19 consecutive patients with combined iris and lens pathology of traumatic or congenital etiology were identified for an interventional noncomparative case series. The newly proposed model of an elastic iris-lens diaphragm with a colored haptic and additional support elements was implanted using various fixation approaches. RESULTS: Fifteen eyes (75%) experienced improvement in corrected visual acuities. The best spectacle-corrected visual acuity (BSCVA) in 2 eyes did not change, while the uncorrected visual acuity (UCVA) in these eyes increased. There were 3 eyes in which BSCVA deteriorated with no change or even slight improvement in UCVA. All patients were satisfied with the cosmetic results of the surgery and reported a decrease in glare and photophobia. There was 1 intraoperative complication of vitreous hemorrhage. Postoperatively, 2 cases of hyphema, 1 case of ciliochoroidal detachment, 4 eyes with exaggerated immediate postoperative reaction, and 1 eye with persistent low-grade cyclitis were observed. In 1 eye, there was persistent intraocular pressure rise. One eye showed signs of cystoid macular edema. No iris-lens diaphragm decentrations and no new or extensions of old retinal detachments were seen during the follow-up period. CONCLUSIONS: Artificial iris-lens diaphragm implantation effectively improved postoperative outcomes by correcting aphakia, reducing glare disability, and addressing cosmetic issues faced by iris-deficient, and aphakic or cataract patients. Although the iris-lens diaphragm appears to be safe, long-term results must be clarified in studies with longer follow-up and a larger patient population.