Axial Hyperopia Research Articles

Age-related increase in lens thickness and changes in the profile of anterior chamber angle in patients with moderate and high axial hyperopia

PURPOSE. To determine the age-related increase in lens thickness (LT), decrease in anterior chamber depth (ACD) and anterior chamber angle (ACA) in patients with short axial length (APA) of the eyes.METHODS. The study included 100 patients (200 eyes) with short AL (23 mm or less), with a transparent lens or with initial stage of age-related cataract: 46 men and 54 women, aged 19 to 85 years. The LT and ACD, ACA parameters were assessed using optical coherence tomography.RESULTS. In the total population of patients, LT increased by an average of 32 μm per year. At the same time, ACD and ACA decreased by an average of 14 µm and 0.3° per year, respectively (p<0.001). In men, LT increased by 35 μm per year, while in women it increased by 29 μm per year, the difference was not statistically significant (p=0.071). But the decrease in ACA in men averaged 0.38° per year, while in women it was 0.23° per year, this difference was statistically significant (p=0.003). In addition, the rate of decrease in the ACD in men and women also differed statistically significantly: 18 µm versus 11 µm per year (p=0.018).CONCLUSION. 1. According to our data, the annual increase in LT in eyes with short AL averages 32 μm, the decrease in ACD and ACA is on average 14 μm and 0.3° per year, respectively.2. We did not find a statistically significant gender difference in the rate of annual increase in LT, although the rate of decrease in ACA and ACD in men turned out to be statistically significantly higher.3. The obtained data on the annual changes in such morphometric parameters as LT, ACA and ACD in eyes with short AL are key in the formation of primary angle-closure glaucoma (PACG). It may allow a more precise prediction of the timeline of an increased risk of PACG in each particular case.

Поиски возможностей объективного критерия риска развития острого приступа глаукомы в анатомически коротких глазах

Purpose. To assess the prognostic significance of the LAF coefficient (Lens thickness/ Axial length Factor) as risk factor for acute attack of glaucoma in anatomically short eyes of Europeans. Material and methods. 1st group consisted of 24 patients (48 eyes) with axial hyperopia. 2nd group included 24 patients (48 eyes) with primary closure of the anterior chamber angle. The 3rd group was formed by 17 patients (34 eyes) with initial stage of primary angle-closure glaucoma. The 4th group included 35 patients (35 eyes) with an acute attack of glaucoma. The studied groups did not differ in age (p = 0.97) and gender (p = 0.28). Lens thickness and axial length (AL) were measured using A-scan on biometer IOLMaster 700 (Carl Zeiss®, Germany) with calculation of LAF coefficient. Results. The LAF coefficient in the 4th (acute attack) group was statistically significantly higher than in the first 3 groups. The best separation of the 1st and 4th groups is provided by LAF coefficient compared to lens thickness and AL indexes with sensitivity, specificity and the Area Under the Curve (AUC) of 89 %, 83 % and 0.9, respectively. LAF coefficient values greater than 2.332 in patients with short AL are objectively associated with high risk of acute attack of glaucoma. The average value of the LAF coefficient (2.528) obtained by us in the 4th (acute attack of glaucoma) group significantly exceeds these indexes in works of other authors, which may be due to morphometric features of structure of eyes of Europeans compared to eyes of Asians. Conclusion. The LAF coefficient provides better separation of the 1st and 4th groups, in comparison with the lens thickness indexes, and especially the AL. LAF coefficient values greater than 2.332 in eyes with short AL objectively indicate high risk of acute attack of glaucoma, as evidenced by high sensitivity, specificity, and AUC. Keywords: acute attack of glaucoma, LAF, lens thickness, short axial length, risk factor

Морфометрические особенности, характеризующие повышенный риск развития острого приступа закрытоугольной глаукомы у пациентов с осевой гиперметропией высокой степени, планирующих проведение рефракционной операции

Purpose. To study of quantitative and qualitative morphometric characteristics of the anterior chamber (AC) depth, lens thickness (LT), corneal-iris angle in young patients with high axial hyperopia planning refractive surgery. Material and methods. The main group – 35 patients (70 eyes) with high axial hyperopia. Inclusion criteria: absence of ophthalmic and systemic somatic pathology. The best corrected visual acuity (BCVA) is from 0.7 to 1.0. The comparison group included 35 patients (70 eyes) with primary closure of the anterior chamber angle (ACA) in combination with high hyperopia. Inclusion criteria: the presence of functional block of the ACA in at least 2 quadrants, the absence of signs of glaucomatous optic neuropathy. BCVA – from 0.6 to 0.9. All patients underwent gonioscopy of the ACA in 4 quadrants, optical coherence tomography, assessment of morphometric parameters of the anterior segment of the eyes. Results. The analysis of morphometric parameters revealed statistically significant differences in patients of the main group relative to the comparison group: in the AC depth in the central zone – 2.8 ± 0.3 vs. 2.4 ± 0.25 mm; LT – 4.0 ± 0.35 vs. 4.5 ± 0.3 mm; ACA width – 19.6 ± 4.4° vs. 13.1±5.1°; AC depth in the periphery – 1.0 ± 0.21 vs. 0.5 ± 0.37 mm, respectively. Next, we determined whether anyone from the main group had ACA values similar to the average values of this indicator of the comparison group (13.1 ± 5.1°): in 6 eyes of the main group (3 men aged 40 to 45 years) the values of the ACA turned out to be minimal, not significantly differing from the comparison group. In addition, in 7 eyes of 6 patients of the main group, the index of the AC depth in the periphery was less than 0.5 mm with normal values of the AC depth in the central zone, which was comparable with similar values in the comparison group. Conclusion. Among the examined patients with hyperopia at the age of 39 to 45 years, with axial length values from 19 to 22 mm, an increased risk of developing an acute angle-closure glaucoma occurred in 9 patients (26 %). Keywords: hyperopia; refractive surgery; acute angle-closure glaucoma

Relatively anterior lens position in primary angle-closure glaucoma eyes with long axial length.

To evaluate the refractive status and ocular biometric parameters in primary angle-closure glaucoma (PACG) eyes with different axial lengths (ALs). In total, 742 Chinese PACG subjects with complete ophthalmic examinations were enrolled. The refractive status was categorized as myopia (spherical equivalent [SE] ≤-0.5 D), emmetropia (-0.5 D < SE < +0.5 D), and hyperopia (SE ≥+0.5 D), whereas the AL was divided into short (AL <22.5 mm), regular (22.5 ≤ AL <23.5 mm), and long (AL ≥23.5 mm). The refractive status and ocular biometric parameters were compared among different AL groups. The mean AL of the PACG eyes was 22.53 ± 0.84 mm (range: 19.68-25.57 mm). The refractive status was significantly different among different AL groups (P < 0.001). Also, 92.6% of hyperopic PACG eyes showed AL <23.5 mm, and 19.0% of myopic PACG eyes showed AL ≥23.5 mm. The SE showed significant differences among different AL groups only in the hyperopic subjects (P = 0.012). The AL was significantly longer in myopic eyes (P < 0.001). The PACG eyes with longer AL exhibited lower keratometry, longer central anterior chamber depth and corneal diameter, and lens position and relative lens position closer to the anterior (P < 0.001). Axial hyperopia was common in PACG eyes, and axial myopia was not uncommon. Relatively anterior lens position could explain the occurrence of PACG in the eyes with long AL.

Eyeglass correction: influence on the morphometric parameters of the anterior chamber and the eye hydrodynamics in presbyopes with hyperopia

The work of accommodative apparatus has a regulatory effect on the hydrodynamics of eye and it is involved in ensuring the normal outflow of intraocular fluid (IOF). Age-related weakening of accommodation leads to a deterioration in the state of hydrodynamics, and especially significant shifts are expected in patients with axial hyperopia in the anatomical boundaries of “short” eye.Purpose. To evaluate the effect of correction with progressive lenses and monofocal ones on hydrodynamic indicators and certain morphometric parameters of the anterior chamber in presbyopic patients with hyperopia under conditions of long-term habitual professional eye strain.Material and methods. 25 subjects (50 eyes) of 44–55 y. o. (mean age 47 ± 1,6 years) were examined in January-July 2022. There were 8 males and 17 females with presbyopia and hyperopia. All patients were examined at the end of their working day: the first examination was performed in the initial state without correction, the second one − under using correction with monofocal lenses (control group) or progressive ones (main group). The examination methods included visometry, autorefractometry, pneumotonometry, ultrasound biometry, computerized tonography, determination of accommodation amplitude using the push-up test, optical coherence tomography of the eye anterior segment.Results. The critic tension of hydrodynamics, the decreasing of anterior chamber depth and iridocorneal angle width were revealed in presbyopic hyperopic patients under the conditions of eye strain at a near distance without correction with eyeglasses. Using of correction with progressive lenses led to significant increasing of the accommodation amplitude (p &lt; 0,001), decreasing of IOP (p &lt; 0,001), increasing of aqueous humor outflow (p &lt; 0,001), deepening of the anterior chamber (p &lt; 0,001) and increasing of the iridocorneal angle width (p &lt; 0,001) compared to the initial state. No significant changes in these parameters were revealed in the users of monofocal lenses compared to the initial state.Conclusion. Using of progressive lenses as a permanent correction has a positive effect on ocular hydrodynamics and morphometric parameters of the anterior chamber in presbyopic hyperopes. Lack of correction in hyperopic patients of presbyopic age not only causes of eye fatigue but also can lead to disruption of hydrodynamic balance and development of glaucoma.

Analysis of accuracy of twelve intraocular lens power calculation formulas for eyes with axial hyperopia.

The purpose was to compare twelve intraocular lens power calculation formulas for eyes smaller than 22.0 mm in terms of absolute error (AE), the percentage of postoperative emmetropia, and agreement interval in Bland-Altman analysis. The data of hyperopic patients who underwent uneventful phacoemulsification between January 2016 and July 2021 were reviewed. Intraocular lens power was calculated using Holladay 1, SRK/T, Hoffer Q, Holladay 2, Haigis, Barrett Universal II, Hill-RBF, Ladas, Kane, Emmetropia Verifying Optical (EVO), Pearl-DGS, and K6 formulas. Three months after phacoemulsification, refraction was measured, and the mean AE was calculated. The percentage of patients with full visual acuity (VA) without any correction, with ± 0.25D, ±0.5D, ±0.75D, and limits of agreement for each formula was established. Seventy-two patients, whose ocular axial length (AL) ranged between 20.02 mm and 21.98 mm, were included. The Kane formula achieved the lowest mean AE of 0.09 ± 0.09 just before EVO (0.12 ± 0.09), Hill-RBF (0.17 ± 0.12), and Hoffer Q formulas (0.19 ± 0.16). In addition, with the Kane formula, the percentage of patients with full VA without any correction (80.6%) was the highest ahead of EVO and Hoffer Q formulas (51.5% and 50.0%, respectively). Finally, Kane, EVO, and Hill-RBF obtained the lowest agreement interval (0.4923, 0.5815, and 0.7740, respectively). The Kane formula is recommended for intraocular lens power calculation for eyeballs with the AL smaller than 22.0 mm. The EVO formula gives very promising results in regarding the accuracy of intraocular lens power for hyperopic eyes.

Intraoperative aberrometry versus preoperative biometry for intraocular lens power selection in patients with axial hyperopia.

This study was conducted to evaluate the accuracy of intraoperative aberrometry (IA) in intraocular lens (IOL) power calculation and compare it with conventional IOL formulas. This was a prospective case series. Eyes with visually significant cataract and axial hyperopia (AL <22.0 mm) underwent IA-assisted phacoemulsification with posterior chamber IOL (Alcon AcrySof IQ). Postoperative spherical equivalent (SE) was compared with predicted SE to calculate the outcomes with different formulas (SRK/T, Hoffer Q, Haigis, Holladay 2, Barrett Universal Ⅱ and Hill-RBF). Accuracy of intraoperative aberrometer was compared with other formulas in terms of mean absolute prediction error (MAE), percentage of patients within 0.5 D and 1 D of their target, and percentage of patients going into hyperopic shift. Sixty-five eyes (57 patients) were included. In terms of MAE, both Hoffer Q (MAE = 0.30) and IA (MAE = 0.32) were significantly better than Haigis, SRK/T, and Barrett Universal Ⅱ (P < 0.05). Outcomes within ±0.5 D of the target were maximum with Hoffer Q (80%), superior to IA (Hoffer Q > IA > Holladay 2 > Hill-RBF > Haigis > SRK/T > Barrett Universal Ⅱ). Hoffer Q resulted in minimum hyperopic shift (30.76%) followed by Hill-RBF (38.46%), Holladay 2 (38.46%), Haigis (43.07%), and then IA (46.15%), SRK/T (50.76%) and Barrett Universal Ⅱ (53.84%). IA was more effective (statistically significant) in predicting IOL power than Haigis, SRK/T, and Barrett Universal Ⅱ although it was equivalent to Hoffer Q. Hoffer Q was superior to all formulas in terms of percentage of patients within 0.5 D of their target refractions and percentage of patients going into hyperopic shift.

Biometric risk factors for acute glaucoma attack

PURPOSE. To assess the prognostic significance of the LAF coefficient (Lens thickness/Axial length factor) as a risk factor for acute glaucoma attack in anatomically short eyes of Europeans.METHODS. Group 1 consisted of 24 patients (48 eyes) with axial hyperopia. Group 2 included 24 patients (48 eyes) with primary closure of the anterior chamber angle. Group 3 — 17 patients (34 eyes) with initial stage of primary angleclosure glaucoma. Group 4 — 35 patients (35 eyes) with an acute attack of glaucoma. The studied groups did not differ in age (p=0.97) and gender (p=0.28). Lens thickness and axial length (AL) were measured by A-scan with calculation of the LAF coefficient.RESULTS. The LAF coefficient in group 4 (acute attack) was statistically significantly higher than in the other three groups. The best separation of groups 1 and 4 was seen in LAF coefficient compared to lens thickness and AL with sensitivity, specificity and the area under the curve (AUC) of 89%, 83% and 0.9, respectively. LAF coefficient values greater than 2.332 in patients with short AL are objectively associated with high risk of acute attack of glaucoma. The average value of the LAF coefficient (2.528) observed in group 4 (acute attack of glaucoma) significantly exceeds these parameters in works of other authors, which may be associated with morphometric structural features of the eyes of Europeans compared to the eyes of Asians.CONCLUSION. The LAF coefficient provides better separation of group 1 and 4 in comparison with lens thickness and, especially, axial length. LAF coefficient values greater than 2.332 in eyes with short AL objectively indicate high risk of acute attack of glaucoma, as evidenced by high sensitivity, specificity, and AUC.

Intraocular lens formula comparison in axial hyperopia with a high-power intraocular lens of 30 or more diopters.

To compare the accuracy of intraocular lens (IOL) power calculation formula predictions (Barrett Universal II, Emmetropia Verifying Optical [EVO] 2.0, Haigis, Hill-RBF 2.0, Holladay 1, Holladay 2, Hoffer Q, Kane, Olsen, and SRK/T) when using the Alcon SA60AT IOL of 30 or greater diopter (D) power. Kaiser Permanente, California, USA. Multicenter retrospective consecutive case series. Data from patients having uneventful cataract surgery with insertion of a ≥30 D SA60AT IOL and preoperative LENSTAR 900 biometry were included. A single eye per qualifying patient was randomly selected for inclusion in the analysis. Lens constants were optimized using a large dataset of the same IOL model including the full range of axial lengths. The optimized lens constants were then used to calculate the predicted refraction for each formula, which was compared with the actual refractive outcome to give the prediction errors. Included in the study were 182 eyes of 182 patients. From highest to lowest, the percentage of eyes with a prediction error within ±0.50 D was the Kane (58.8%), EVO 2.0 (57.7%), Haigis (55.5%), Holladay 2 (54.9%), Olsen (53.3%), Holladay 1 (50.5%), Hill-RBF 2.0 (43.9%), SRK/T (42.9%), Barrett Universal II (36.8%), and Hoffer Q (35.7%) formulas. The Kane formula had a statistically significant lower mean absolute prediction error compared with all formulas (P < .05) except the EVO 2.0 formula. The Kane formula had the lowest prediction error of the formulas studied, which was statistically significant compared with all formulas except the EVO 2.0 formula.

Expanding the clinical and genetic spectrum of Heimler syndrome

BackgroundHeimler syndrome (HS) is a rare hereditary systemic disorder, partial clinically overlapping with Usher syndrome. So far, our knowledge of HS is very limited, many cases are misdiagnosed or may not even be diagnosed at all. This study aimed to analyze the clinical and genetic characteristics of HS, and to evaluate potential phenotype–genotype correlations.ResultsTwo HS cases caused by PEX1 mutations were identified, and a novel likely pathogenic mutation, PEX1 c.895_896insTATA, was found. The main ophthalmic finding of the two patients was consistent with retinitis pigmentosa accompanied by cystoid macular edema, but short axial length and hyperopia were also observed as two previously unreported ocular phenotypes. Analysis of the literature showed that of the 29 HS patients previously reported, 12 had PEX6 mutations, 10 had PEX1 mutations, two had PEX26 mutations, and the remaining patients were not genetically tested. Three novel genotype–phenotype correlations were revealed from analysis of these patients. First, most genotypes of every HS patient include at least one missense variant; second, at least one mutation in PEX1 or PEX6 gene affects the AAA-ATPase region in every HS patient with retinal dystrophy, suggesting AAA-ATPase region is a hypermutable region in patients with a retinal dystrophy; third, there are no significant differences between PEX1-, PEX6-, and PEX26-associated phenotypes.ConclusionNext-generation sequencing is important for the diagnosis of HS. This study expands the clinical and genetic spectrum of HS, and provides additional insights into genotype–phenotype correlations, which is vital for accurate clinical practice, genetic counseling, and pathogenesis studies.

Assessment of Changes in Cyliary Muscle in Patients with Hypermetropy Using Mathematical Modeling Methods

Background. Age-related decline in accommodation in patients with emmetropia, myopia and hyperopia is characterized by multidirectional changes in the thickness of the ciliary muscle and the configuration of the inner apex of the ciliary body. The structural and functional state of the ciliary muscle and its individual components and the patterns of their change with age in patients with hyperopia remain little studied.Aim: to study the structural and functional state of the ciliary muscle and its components in patients with hyperopia using mathematical modeling methods.Methods. 110 patients (220 eyes) with axial hyperopia were examined. The first group consisted of patients aged 18–30 years – 20 people. The second group consisted of 80 patients aged 45–65 years. The control group consisted of 30 healthy volunteers aged from 18 to 30 years. All patients underwent ultrasound biomicroscopy, on the basis of which a spatial-mathematical model was created using the ImageJ software package.Results and conclusion. In patients with hyperopia, in the aging process there is a transformation of the ciliary body and the restructuring of its muscular components. Structural irido-ciliary relationships in young patients with emmetropia and hyperopia significantly differ in the location and configuration of the inner apex of the ciliary body, the degree of emphasis on the circular portion of the ciliary muscle.

Variants in myelin regulatory factor (MYRF) cause autosomal dominant and syndromic nanophthalmos in humans and retinal degeneration in mice.

Nanophthalmos is a rare, potentially devastating eye condition characterized by small eyes with relatively normal anatomy, a high hyperopic refractive error, and frequent association with angle closure glaucoma and vision loss. The condition constitutes the extreme of hyperopia or farsightedness, a common refractive error that is associated with strabismus and amblyopia in children. NNO1 was the first mapped nanophthalmos locus. We used combined pooled exome sequencing and strong linkage data in the large family used to map this locus to identify a canonical splice site alteration upstream of the last exon of the gene encoding myelin regulatory factor (MYRF c.3376-1G>A), a membrane bound transcription factor that undergoes autoproteolytic cleavage for nuclear localization. This variant produced a stable RNA transcript, leading to a frameshift mutation p.Gly1126Valfs*31 in the C-terminus of the protein. In addition, we identified an early truncating MYRF frameshift mutation, c.769dupC (p.S264QfsX74), in a patient with extreme axial hyperopia and syndromic features. Myrf conditional knockout mice (CKO) developed depigmentation of the retinal pigment epithelium (RPE) and retinal degeneration supporting a role of this gene in retinal and RPE development. Furthermore, we demonstrated the reduced expression of Tmem98, another known nanophthalmos gene, in Myrf CKO mice, and the physical interaction of MYRF with TMEM98. Our study establishes MYRF as a nanophthalmos gene and uncovers a new pathway for eye growth and development.

Comparison between Refractive Outcome of Primary Piggyback Intraocular Lens versus Secondary Lens Iris Claw Lens in Posterior Microphthalmos.

Purpose To compare the refractive outcome of 2 different methods of intraocular lens implantation in cases of posterior microphthalmos, primary piggyback IOLs versus secondary iris claw lenses. Methods This study was a retrospective interventional comparative study that included 60 eyes of 30 patients. The included patients had bilateral microphthalmos with high axial hyperopia and had undergone a lens-based surgical procedure for hyperopia correction. The included patients were equally divided into two groups. The first group had undergone refractive lens exchange (RLE) with primary piggyback IOL implantation. The second group undergone RLE with maximum available IOL power implanted followed by a secondary implantation of Artisan iris-fixated IOL (Ophtec B.V., Groningen, the Netherlands). Results The 2 groups were highly comparable to each other regarding the mean age, axial length (AL), manifest refraction (MR), and K readings. Postoperatively, there was a statistically significant difference between the 2 groups regarding the manifest refraction spherical equivalent (MRSE), mean absolute error (MAE), and uncorrected distance visual acuity (UDVA). There was no significant difference between the 2 groups regarding the CDVA. At 36 months, 20% and 73% of the eyes were within ±0.5 D of intended refraction at 36 months in 1ry piggyback and 2ry Artisan groups, respectively. Fifty-three percent and 93% of the eyes were within ±1.0 D of intended refraction at 36 months in 1ry piggyback and 2ry Artisan groups, respectively (p=0.001). Conclusion Secondary procedure with implantation of iris-fixated intraocular lens yielded very good results for treatment of axial hyperopia in cases of posterior microphthalmos. The primary piggyback IOL showed less satisfactory results with cases of under correction and the possible complication of interlenticular opacification. Both groups showed good safety parameters.

Correlation between central corneal thickness and axial errors of refraction

Aim This study aimed to determine the correlation between central corneal thickness (CCT) and axial refractive errors (axial myopia and axial hyperopia). Patients and methods A total of 84 eyes were included in this study. They were classified into three groups (group 1, which included 28 axially myopic eyes; group 2, which included 28 axially hyperopic eyes; and group 3, which included 28 emmetropic eyes). CCT was obtained by pentacam, axial length was obtained by A-Scan ultrasonography, and refraction was obtained with auto-refractometer after cycloplegia and being confirmed with trial lenses. Results The study showed that the mean CCT in the myopia group (group 1) was 531 nm, mean CCT in the hyperopia group (group 2) was 523.5 nm, and mean CCT for the emmetropia group (group 3) was 555 nm. CCT was obtained by pentacam, axial length (AL) was obtained by ultrasound A-scan, and refraction was obtained by auto-refractometer after cycloplegia and being confirmed with trial lenses. Discussion CCT was found to be thinner in axially ametropic eyes compared with emmetropic eyes. CCT did not differ statistically between different grades of the same refractive error. CCT decreased with age but not with sex or AL. Conclusion The study revealed that axial errors of refraction had a correlation with CCT and that CCT of axially ametropic eyes showed thinner corneas than emmetropic eyes.

The effect of unilateral disruption of the centrifugal visual system on normal eye development in chicks raised under constant light conditions

The centrifugal visual system (CVS) comprises a visually driven isthmic feedback projection to the retina. While its function has remained elusive, we have previously shown that, under otherwise normal conditions, unilateral disconnection of centrifugal neurons in the chick affected eye development, inducing a reduced rate of axial elongation that resulted in a unilateral hyperopia in the eye contralateral to the lesion. Here, we further investigate the role of centrifugal neurons in ocular development in chicks reared in an abnormal visual environment, namely constant light. The baseline ocular phenotype of constant light-reared chicks (n = 8) with intact centrifugal neurons was assessed over a 3-week post-hatch time period and, subsequently, compared to chicks raised in normal diurnal lighting (n = 8). Lesions of the isthmo-optic tract or sham surgeries were performed in another seventeen chicks, all raised under constant light. Ocular phenotyping was performed over a 21-day postoperative period to assess changes in refractive state (streak retinoscopy) and ocular component dimensions (A-scan ultrasonography). A pathway-tracing paradigm was employed to quantify lesion success. Chicks raised in constant light conditions with an intact CVS developed shallower anterior chambers combined with elongated vitreous chambers relative to chicks raised in normal diurnal lighting. Seven days following surgery to disrupt centrifugal neurons, a significant positive correlation between refractive error asymmetry between the eyes and lesion success was evident, characterized by hyperopia in the eye contralateral to the lesion. By 21 days post-surgery, these contralateral eyes had become emmetropic, while ipsilateral eyes had developed relative axial hyperopia. Our results provide further support for the hypothesis that the centrifugal visual system can modulate eye development.

Disruption of the Centrifugal Visual System Inhibits Early Eye Growth in Chicks

Emmetropization, the process by which neonatal refractive errors are reduced toward zero, is partially dependent on brain-retina connectivity. Here, we investigated the role of the centrifugal visual system, a visually driven retinal feedback projection, as one potential influence on this complex mechanism. Lesions of the isthmo-optic nucleus/tract or sham surgeries were performed in fifty-four 4- to 5-day-old chicks to disrupt centrifugal efferents to the contralateral retina. Prior to surgery, baseline refractive error measurements were made using streak retinoscopy. Postoperative ocular phenotyping, which (in addition to retinoscopy) comprised A-scan ultrasonography and infrared keratometry, was performed 7 days and 21 days postsurgery. A pathway-tracing paradigm was used to determine lesion success, whereby an injection of wheat-germ agglutinin was made into the vitreous chamber contralateral to the lesion. Postmortem, tissue processing, immunohistochemistry, and stereological analysis of intact centrifugal neurons were performed. Subsequently, chicks were divided into quartile groups based on percentage lesion success. Seven days postsurgery, chicks in the quartile of highest percentage lesion success exhibited significant axial hyperopia in the "treated eye" (contralateral to the lesion) relative to the "control eye" (ipsilateral to the lesion) eye, when compared with subjects within quartile groups of lower percentage lesion success (P = 0.004). However, by 21 days postsurgery, the induced hyperopia was no longer evident. Unilateral disruption of centrifugal efferents to the retina of the contralateral eye induces an initial axial hyperopia, which is subsequently reversed through increased vitreous elongation in the affected eyes.

Combined Correction of Axial Hyperopia and Astigmatism Using the Light Adjustable Intraocular Lens

To determine whether residual spherical and cylindrical errors could be corrected postoperatively using spatially profiled UV light irradiation in patients with axial hyperopia undergoing cataract surgery and implantation of a light adjustable, silicone intraocular lens (LAL). We conducted a prospective, nonrandomized clinical trial. The LALs were implanted in eyes with axial lengths <22.20 mm and were treated with a spatial intensity profile delivered by a digital light delivery device to induce a targeted spherical and cylindrical refractive change postoperatively. Once the desired correction was achieved, the LAL was treated again to lock-in the lens power. We studied 15 eyes of 15 patients with axial hyperopia. The manifest refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BCVA) were determined with follow-up time of 12 months to determine the achieved refractive corrections and their stability. We measured UCVA, BCVA, achieved versus targeted refractive outcome, and refractive stability with a follow-up time of 12 months. Of 15 eyes, 14 (93%) achieved ± 0.5 diopters (D), and 10 (67%) were within ± 0.25 D of the targeted refractive adjustment up to 12 months postoperative follow-up. Only 1 treated eye showed a change of 0.38 D in manifest spherical equivalent refraction, the remaining 14 eyes showed <0.25 D change between 1 month post lock-in, and at the 3-, 6-, and 12-month postoperative visits. The light-adjustable lens is a promising technology with the potential to reduce the rate of postoperative refractive surprises up to 2 D of spherical and cylindrical errors after cataract surgery. Postoperative refractive errors were successfully corrected with precision and significant improvement in UCVA and without compromising BCVA using the light-adjustable intraocular lens technology. The data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures.

Adjustierung von sphärozylindrischen Refraktionsfehlern bei hyperopen Augen: 6 Monatsergebnisse nach Kataraktchirurgie und Implantation einer lichtadjustierbaren Intraokularlinse

The aim of this study was to determine whether residual spherical and cylindrical errors could be corrected postoperatively in a non-invasive manner using ultraviolet irradiation in patients with axial hyperopia undergoing cataract surgery and implantation of a light-adjustable lens, silicone intraocular lens (LAL) (Calhoun Vision, Pasadena, CA). In a prospective, non-randomised clinical trial at Center for Vision Science, Ruhr University Eye Clinic, Bochum, Germany, 15 eyes of 15 patients with axial hyperopia (less than 22.2 mm) were studied. The manifest refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA) were determined with a follow-up time of six months to determine the achieved refractive corrections and their stability. The adjustment and lock-in procedures were well tolerated by patients. Preoperative refraction was in mean + 2.56 D as spherical equivalent, postoperative before adjustment + 1.01 D, one month after lock-in procedure + 0.03 D, after 3 months + 0.12 D and after 6 months 0.0 D (± 0.21 D). 6 months after lock-in all patients reached an uncorrected visual acuity of 20/30 or better, 10 of 15 patients reached 20/25 and 1 patient 20/20. The data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures. Postoperative refractive errors were successfully corrected with precision and significant improvement in UCVA and without compromising BSCVA using the light adjustable intraocular lens technology. Our data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures. The light-adjustable lens is a promising technology with the potential to eliminate postoperative refractive surprises of up to 2 diopters of refractive and cylindrical error following cataract surgery.

Congenital Axial High Myopia Detected by Prenatal Ultrasound

High-resolution prenatal ultrasound can allow for early detection and monitoring of many fetal anomalies, including those involving the globe and orbit. The authors present a case of congenital axial high myopia that was diagnosed at 33 gestational weeks and monitored by prenatal ultrasonography. Some systemic abnormalities that can be associated with congenital high myopia are reviewed. High ammetropias, anisometropia, and either axial myopia or axial hyperopia can be detected in utero and give this early detection a greater chance of treating and reversing the devastating effects of amblyopia.

Evanescent White Linear Flecks and Posterior Microphthalmos: New Features of a Recently Established Disease

Posterior microphthalmos is a rare autosomal recessive condition with normal anterior segment and small posterior segment resulting in axial hyperopia and retinal folding. The proband from a consanguineous Turkish family was clinically investigated at 5 months of age and followed for the next 8 years. At five months of age, refraction revealed a severe hyperopia of + 10 diopters in both eyes (OU) with a mean axial length of 16.5 mm. Fundus examination showed a dystrophic maculo-papillar bundle. Multiple whitish deep intraretinal linear lesions sparing the macula were present in the mid-periphery with no preferential orientation. By 8 years of age, visual acuity was 20/25 in the right eye (OD) and 20/30 in the left eye (OS) with S + 14 OU. The whitish linear lesions had disappeared and were replaced by retinal pigment epithelium alterations. Optical coherence tomography (OCT) revealed a thickened retina with normal appearance at the site of the linear lesions. This is the first report of long-term follow-up and OCT findings in this rare ocular developmental abnormality.