CHORIORETINAL FOLDS IN PATIENTS WITH CENTRAL SEROUS CHORIORETINOPATHY.

BACKGROUND AND PURPOSE: To the best of our knowledge, there is no study of patients with central serous chorioretinopathy associated with chorioretinal folds, since a short mention in Gass' stereoscopic atlas. We report here six cases with this association. METHODS: Six patients with both conditions were examined in our institution and underwent fluorescein angiography and optical coherence tomography. RESULTS: Patients were 3 men and 3 women, aged 44 years to 82 years. All patients were hyperopic and two received corticosteroids. Fluorescein angiography showed pigmentary changes, diffuse leakage areas typical of chronic central serous chorioretinopathy, and chorioretinal folds mainly located in the upper temporal part of the fundus. Enhanced depth imaging optical coherence tomography was performed in 5 cases and revealed a thick choroid in all cases (mean subfoveal choroidal thickness: 381 µm, range: 280-510 µm). CONCLUSION: Although possibly coincidental, the presence of chorioretinal folds in hyperopic central serous chorioretinopathy eyes could be due to the excessive thickness of the choroid in eyes with hyperopia related to short axial length.

Ablation of mpeg+ Macrophages Exacerbates mfrp-Related Hyperopia.

Purpose: Proper refractive development of the eye, termed emmetropization, is critical for focused vision and is impacted by both genetic determinants and several visual environment factors. Improper emmetropization caused by genetic variants can lead to congenital hyperopia, which is characterized by small eyes and relatively short ocular axial length. To date, variants in only four genes have been firmly associated with human hyperopia, one of which is MFRP. Zebrafish mfrp mutants also have hyperopia and, similar to reports in mice, exhibit increased macrophage recruitment to the retina. The goal of this research was to examine the effects of macrophage ablation on emmetropization and mfrp-related hyperopia. Methods: We utilized a chemically inducible, cell-specific ablation system to deplete macrophages in both wild-type and mfrp mutant zebrafish. Spectral-domain optical coherence tomography was then used to measure components of the eye and determine relative refractive state. Histology, immunohistochemistry, and transmission electron microscopy were used to further study the eyes. Results: Although macrophage ablation does not cause significant changes to the relative refractive state of wild-type zebrafish, macrophage ablation in mfrp mutants significantly exacerbates their hyperopic phenotype, resulting in a relative refractive error 1.3 times higher than that of non-ablated mfrp siblings. Conclusions: Genetic inactivation of mfrp leads to hyperopia, as well as abnormal accumulation of macrophages in the retina. Ablation of the mpeg1-positive macrophage population exacerbates the hyperopia, suggesting that macrophages may be recruited in an effort help preserve emmetropization and ameliorate hyperopia.

Screening Thresholds for the Corneal Tomography in Hyperopic Pakistani Population.

OBJECTIVE: To evaluate key corneal tomography parameters for screening mixed astigmatism and hyperopic males and females for refractive surgery and to compare the data to a previously studied myopic group in Pakistani population. STUDY DESIGN: Cross-sectional, observational study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Ophthalmology AFIO, National University of Medical Sciences, Rawalpindi, Pakistan, from August 2013 to August 2018. METHODOLOGY: WaveLight Allegro Oculyzer II diagnostic device was used to examine eyes of 106 adult hyperopic patients in order to determine normal values of 20 parameters, which are considered most clinically applicable for refractive surgery screening. Kolmogorov-Smirnov test was used to evaluate normality of data. Results for outliers were displayed as 2.5%, 5%, 95% and 97.5% percentiles. RESULTS: Two hundred and nine eyes were examined; 110 men and 99 women with overall mean age of 31+11.7 years. Normal mean anterior segment values included: flat simulated keratometry (K1) 42.1±1.84 diopters (D), steep K2 43.8 ± 1.93 D, K maximum 44.4 ± 1.93 D, K mean 42.9 ± 1.75 D, astigmatism -1.3 ± 1.75 D, pachymetry at thinnest point 546.9 ± 33.3 um, front elevation at thinnest point 5.2 ± 3.47 um, and at the back was 14.1 ± 6.60 um, Ambrosio relational thickness maximum 472.0 ± 88.73, progression index (PI) maximum 1.2 ± 0.18, and anterior chamber depth (ACD) 2.7 ± 0.35 mm. CONCLUSION: Hyperopic patients had greater front and back elevation and pachymetry but lesser keratometry, anterior chamber depth and chamber volume as compared to myopic patients in Pakistani population. Front and back elevation data in this hyperopic study population was slightly higher than previously published studies. Key Words: Refractive surgery, Corneal tomography, Screening, Hyperope.

Refractive Changes After Corneal Stromal Filler Injection for the Correction of Hyperopia.

PURPOSE: To evaluate a new non-ablative and adjustable procedure for laser ablative refractive corneal surgery in hyperopia using the injection of a biocompatible liquid filler material into a stromal pocket. METHODS: A total of 120 stromal pockets were created using a clinical femtosecond laser system in 96 rabbit corneoscleral discs and 24 whole globes. Pockets were cut at a depth of 120 or 250 µm below the epithelial surface. Hyaluronic acid was injected manually into the pocket. To determine the refractive changes, three-dimensional optical coherence tomography images and a specifically developed picture recognition Matlab (The Mathworks) routine were used. RESULTS: After injection, a steepening of the anterior and flattening of the posterior corneal surface was observed, which led to hyperopic correction. The two main factors determining the amount of correction were the pocket depth and the injected volume. After the pocket was homogeneously filled, an initial refractive increase was observed, followed by a linear relation between the injected volume and the refraction increase. CONCLUSIONS: This possible clinical protocol for controlled refraction correction of hyperopia suggests a potential readjustable clinical application. [J Refract Surg. 2020;36(6):406-414.].

Human allograft refractive lenticular implantation for high hyperopiccorrection.

Hyperopia is a common form of refractive error in the United States. Many refractive errors can be treated with refractive surgery methods such as laser in-situ keratomileusis and photorefractive keratectomy; however, in patients with large degrees of hyperopia (≥+5.0 diopters [D]), these surgical methods are limited because of higher rates of refractive regression. Lenticule Intrastromal Keratoplasty (LIKE) is a surgical procedure that can be used to correct refractive errors in patients with high hyperopia. The authors describe the first intrastromal implantation of an allograft lenticule performed for the primary correction of hyperopia in the United States, and demonstrate that LIKE is potentially an effective procedure for the correction of high hyperopia. Mechanisms for achieving the intended refractive correction and the complications our patient experienced, including epithelial ingrowth and flap necrosis, are discussed.

Comparision of Optical Low Coherence Reflectometry Versus Ultrasonic Biometry in High Hypermetropia.

PURPOSE: To compare anterior chamber depth (ACD), axial length (AL), and lens thickness (LT) measurements obtained by the Lenstar LS 900 (Haag-Streit AG) optical low-coherence reflectometry with those obtained by the A-scan contact ultrasound among patients with moderate and high hypermetropia. METHODS: Fifty-two eyes of 52 patients with moderate and high hypermetropia (spherical equivalent of +4 D or more) were examined in this study measurements of ACD, AL, and LT obtained by Lenstar were compared with those obtained by applanation A-scan ultrasound. All measurements were obtained by two independent examiners. The interdevice agreements were evaluated with Bland-Altman analyses. RESULTS: The mean age of the patients was 54.78±12.77 years (range 18-74 years). The mean spherical equivalent refractive power was +5.16±1.12 D (+4.0 to +8.75). The mean values of ACD, AL, and LT with A-scan were 3.05±0.34, 21.55±0.75, and 4.33±0.49 mm, respectively, whereas these values were 2.99±0.45, 21.58±0.78, and 4.20±0.44 mm, respectively, with Lenstar. There was statistically significant difference of LT between the two methods (P=0.02). The mean differences (lower/upper limit of agreement) of the ACD, AL, and LT values for A-scan ultrasound and Lenstar were -0.06 (-0.594/0.474), 0.04 (-0.380/0.459), and -0.12 (-0.739/0.502), respectively. CONCLUSION: Among patients with moderate and high hypermetropia, the biometric measurements of ACD, AL, and LT by ultrasound and optical biometry were determined to be correlated and there was a high degree of agreement between contact A-scan ultrasonic biometry and Lenstar.

Assessing Repeatability of Pupillometric Measurements in the Eyes of Refractive Surgery Candidates Using Infrared Pupillometer.

PURPOSE: To assess the repeatability of measuring pupil dynamics using an infrared pupillometer. METHODS: A total of 124 eyes of 124 patients scheduled for corneal laser refractive surgery were separated into myopic and hyperopic groups and further subdivided based on high or low levels of astigmatism. Measurements were taken using dynamic pupillometry (Topolyzer Vario; Alcon Laboratories, Inc., Sinking Spring, PA). Main outcome measures were pupil diameter size, the distance between the pupil center and the keratoscopic axis, and the spatial shift of the pupil center. Repeatability of measurements was assessed from test-retest repeatability (2.77 Sw), coefficient of variation, and intraclass correlation coefficient (ICC). RESULTS: The 2.77 Sw of all measured parameters was lower than 0.36 and 0.44 mm for myopic and hyperopic eyes, respectively. ICCs of the pupil diameter measurements were higher than 0.963 and 0.926 in myopic and hyperopic eyes, respectively. ICCs of the distance between the pupil center and the corneal vertex along the x-axis were higher than 0.934 and 0.994 in myopic and hyperopic eyes, respectively. Along the y-axis, ICCs of this distance were higher than 0.417 in myopic eyes and higher than 0.504 in hyperopic eyes. The pupil center shift measurement ICCs were lower than 0.482 and 0.526 for myopic and hyperopic eyes, respectively. CONCLUSIONS: In all groups, the Topolyzer Vario showed excellent repeatability when measuring pupil dynamic parameters except when measuring pupil center shift and distance between the pupil center and the corneal vertex along the vertical axis. [J Refract Surg. 2017;33(8):552-557.].

Wound healing profiles of hyperopic-small incision lenticule extraction (SMILE).

Refractive surgical treatment of hyperopia still remains a challenge for refractive surgeons. A new nomogram of small incision lenticule extraction (SMILE) procedure has recently been developed for the treatment of hyperopia. In the present study, we aimed to evaluate the wound healing and inflammatory responses of this new nomogram (hyperopic-SMILE), and compared them to those of hyperopic-laser-assisted in situ keratomileusis (LASIK), using a rabbit model. A total of 26 rabbits were used, and slit lamp biomicroscopy, autorefractor/keratometer, intraocular pressure measurement, anterior segment optical coherence tomography, corneal topography, and in vivo confocal microscopy examinations were performed during the study period of 4 weeks. The corneas were then harvested and subject to immunofluorescence of markers for inflammation (CD11b), wound healing (fibronectin) and keratocyte response (HSP47). The lenticule ultrastructual changes were also analyzed by transmission electron microscopy. Out results showed that hyperopic-SMILE effectively steepened the cornea. Compared to hyperopic-LASIK, hyperopic-SMILE had less postoperative wound healing response and stromal interface reaction, especially in higher refractive correction. However, compared to myopic-SMILE, hyperopic-SMILE resulted in more central deranged collagen fibrils. These results provide more perspective into this new treatment option for hyperopia, and evidence for future laser nomogram modification.

[Ocular biometry in children with hypermetropia: utility of the Lenstar LS 900 optical biometer (Haag-Streit(®))]. / Étude de la biométrie oculaire chez l'enfant hypermétrope : apport du biomètre Lenstar LS 900 (Haag-Streit(®)).

PATIENTS AND METHODS: Biometric measurements were recorded in the eyes of 238 children with hypermetropia (3-16 years of age), using the Lenstar 900 biometer (Haag-Streit(®)) with no contact. Four refractive groups were divided by objective refraction and spherical equivalent (group 1, more than 6.00 D; group 2, +4.50 to +99 D; group 3, +3.00 to +4.49 D; group 4, +1.50 to +2.99 D). Many parameters (i.e., axial length of the eye, anterior chamber depth, crystalline lens thickness, and central pachymetry) were analyzed in refractive groups. Two statistical analyzes were carried out: Pearson correlations on the various measurements and nonparametric tests (LSD tests). RESULTS: This statistical study showed the refractive characteristics of this pediatric population and the incidence of refraction on ocular biometry. There was a correlation between crystalline lens thickness, axial length, and anterior chamber depth. Axial length was significantly correlated in a positive way with age (r=0.332, p<0.001) and with anterior chamber depth (r=0.403, p<0.001), and in a negative way with crystalline lens thickness (r=-0.427, p<0.001). The study of refractive group parameters found a significant difference (p<0.01) between groups in axial length level. Anterior chamber depth decreased when the spherical equivalent increased. The study of crystalline lens thickness found a significant difference (p<0.01) between all four groups and pachymetry, as well as between groups 1 and 4 (p<0.05). CONCLUSION: The Lenstar LS 900 biometer (Haag-Streit(®)) provided a complete biometrical assessment of children's eye in a single and easy measurement procedure. In this pediatric population with hypermetropia, axial length of the eye was mainly correlated with spherical equivalent and other biometric parameters. The relation between these various parameters was influenced and modified by age.

Hyperopic shift from posterior migration of hydrophilic acrylic intraocular lens optic.

UNLABELLED: Two cases that developed a delayed hyperopic shift in refraction following implantation of a single-piece hydrophilic intraocular lens (IOL) are described. The haptics of the Akreos Adapt IOL were flexed anteriorly by capsular contraction, leaving a marked gap between the optic and the anterior capsule. A third case that had marked capsule phimosis and similar anterior flexion of the haptics but with a stable refraction is also described. In this case, the anterior and posterior leaves of the capsule fused peripherally and the IOL optic position was normal. The effective power of an IOL depends on the distance between the apex of the cornea and the center of the optic. Capsule contraction without fusion of the peripheral capsule can make the haptics of this IOL design flex anteriorly with posterior movement of the optic and a hyperopic shift in refraction. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Variation in Schlemm's canal diameter and location by ultrasound biomicroscopy.

PURPOSE: To measure variations in diameter and location of Schlemm's canal in vivo by ultrasound biomicroscopy. DESIGN: Prospective, single-institution, consecutive case series. PARTICIPANTS: Ninety-four patients with and without glaucoma. METHODS: Under topical anesthesia, an 80-MHz iUltrasound probe (iScience Interventional, Inc., Menlo Park, CA) placed at the 12-o'clock position was used to measure the canal's diameter and its distance from both the anatomic limbus (corneoscleral junction) and the angle (the base of the canal and the angle of iris insertion). MAIN OUTCOME MEASURES: Diameter and location of the canal were measured relative to gender, age, intraocular pressure, race, diagnosis, previous glaucoma surgery, pachymetry, refraction, lens type, axial length, and keratometry. RESULTS: The average canal diameter was 121 microm (+/-45 microm). The canal diameter in hyperopes was larger than the canal diameter in myopes (180+/-69 microm vs. 122+/-45 microm; P<0.001). The diameter of Schlemm's canal was smaller in patients with previous glaucoma surgery compared with patients without glaucoma surgery (98+/-20 microm vs. 125+/-4 microm; P<0.01). The mean distance between the angle and Schlemm's canal was found to be smaller in hyperopes than in myopes (281 vs. 335 microm; P = 0.03). The location of the canal in black patients compared with white patients was found to be more posterior from the limbus (659+/-92 microm vs. 624+/-73 microm; P = 0.05). Similarly, canal location in patients with corneal thickness of more than 555 microm was found to be more posterior to the limbus (702 vs. 625 microm; P<0.01) compared with those with thinner corneas. CONCLUSIONS: When measured in vivo with ultrasound biomicroscopy, Schlemm's canal diameter was significantly smaller (121 microm) than demonstrated in previous histopathologic studies.

Ultrasonographic ocular diameters in Nigerians.

BACKGROUND: There is little information on the biometric ultrasonography of the eyeball, especially in Africans. The eyeball diameters form the basis for the calculation of the intraocular lens power and diagnosis of axial hypermetropia and myopia OBJECTIVE: To determine the ocular diameters of healthy Nigerian eyes. METHODS: Measurements of the eyeball in volunteers were taken on the B-mode image using a Medison's Sonoace 1500 ultrasound machine using a 6.5 MHz curvi-linear transducer placed over the closed eyelid. The vertical, horizontal and axial diameters of the eyes of healthy subjects were recorded. The age and sex of the subjects were also recorded. RESULTS: Four hundred eyes of 200 subjects comprising 125 females (62%) and 75 (38%) males (38%) were studied. The age range was 3-92 years with an overall mean age of 41.48 +/- 23.26 years for both sexes. The mean axial eyeball diameter for the entire study population was 21.7 +/- 0.16 mm. There was a gradual increase in all eyeball diameters with age. The highest value for eyeball diameter (22.5 +/- 0.18 mm) was recorded for the elderly age group. The (SD) mean eyeball diameters for males were slightly higher than that for the females; mean for males, 21.8 +/- 0.13 mm, 95% CI = 21.781-21.819, vs females, 21.6 +/- 0.14 mm, 95% CI = 21.581-21.619. However, the difference was not statistically significant (p = 0.409). CONCLUSIONS: The eyeball diameters found in this sample of Nigerians are lower than the dimensions reported in Caucasians. These values may be used as reference values for normal African eyes.

Sweet hyperopia: refractive changes in acute hyperglycemia.

PURPOSE: A prospective study was performed to evaluate refractive and ocular biometric changes in acute hyperglycemic status in patients with diabetes mellitus. METHODS: From January to August 2002, 48 eyes of 24 patients with persistent diabetes and a plasma glucose level>or=17 mmol/L or HbA1c>or=10.0% on admission were enrolled in this prospective study. Upon admission to Tri-Service General Hospital in Taipei, Taiwan, these patients underwent intensive glycemic control. The basic ophthalmic examinations, including visual acuity, intraocular pressure measurement, slit lamp, and fundus examinations, were conducted. The ocular parameters including refraction, anterior chamber depth, lens thickness, axial length, mean keratometry, and thinnest corneal thickness were evaluated by A-mode scan and Orbscan II. Each patient underwent clinical follow-up visits at 1, 2, and 4 weeks after the acute hyperglycemic episode. RESULTS: Of the 24 patients, 18 were male and 6 were female. The mean age of the patients was 55 years (range: 38 to 69). Comparing the refractive status on admission and at week 4, the authors found that 8 cases (16 eyes, 33%) showed hyperopia during hyperglycemia (+1.9+/-0.8 D), but in the other 16 cases (32 eyes, 67%), there were no significant changes. In addition, there were also no significant changes in anterior chamber depth, lens thickness, axial length, thinnest corneal thickness, or mean keratometry in the follow-up period. CONCLUSIONS: Transitory hyperglycemia produces hyperopia. The alteration in refractive index in the lens may contribute to the hyperopic change, but no change of ocular biometrics in lens or cornea is observed.

[Changes of eye refraction, corneal power and lens power during growth in emmetropia, myopia and hyperopia]. / Zmiany refrakcji okaz oraz mocy optycznej rogówki i soczewki w trakcie rozwoju osobniczego w miarowosci, krótkowzrocznosci i nadwzrocznosci.

PURPOSE: The aim of this study was to evaluate changes of eye refraction, corneal power and lens power during growth in emmetropia, myopia and hyperopia. MATERIAL AND METHODS: We examined 183 children (363 eyes) aged 4 to 19 with emmetropia, myopia and hyperopia. All measurements were performed after cycloplegia with 1% tropicamidum. Total refraction and corneal power was examined with autokeratorefractometer. Then we used ultrasound biometer Ocuscan (Alcon, USA), to measure axial length of the eye. Lens power was calculated with use of SRK II formula. RESULTS AND CONCLUSIONS: Mean refractive error in whole group in the age of 4 was +2,86D and was gradually decreasing to reach OD in the age of 14. Between 4th and 14th years old, myopia increases slowly and then acceleration of this process was observed. In hyperopic eyes between 4th and 16th years old, refractive error decreases gradually and then stabilization was noted. Mean corneal power between 4th and 19th years old, decreased in emmetropia and myopia by 1.24D and 2.19D respectively, and increased by 0.38D in children with hyperopia. This changes took place before 10th years old. Mean lens power between 4th and 19th years old, decreased in emmetropia by 2.01 D, in myopia by 1.43D and in hyperopia by 1.78D. This changes took place before 12th years old.

Excimer laser phototherapeutic keratectomy in eyes with anterior corneal dystrophies: short-term clinical outcomes with and without an antihyperopia treatment and poor effectiveness of ultrasound biomicroscopic evaluation.

PURPOSE: To evaluate the use of high-frequency ultrasound biomicroscopy (UBM) in determining the depth of corneal pathology in eyes undergoing excimer laser phototherapeutic keratectomy (PTK) for primary or recurrent anterior stromal corneal dystrophies. Corneal clarity, visual acuity, and refractive changes in eyes with and without an antihyperopia treatment were also analyzed. METHODS: Twenty eyes of 14 patients with anterior stromal corneal dystrophies were treated with PTK. Eyes were evaluated pre- and 6-8 weeks postoperatively with slit-lamp biomicroscopy, manifest refraction, keratometry, computerized corneal topography, ultrasound pachymetry, and UBM. RESULTS: Nineteen of 20 corneas (95%) had greatly improved corneal clarity after PTK. Mean uncorrected Snellen vision improved from 20/102 to 20/69, and best corrected vision improved from 20/62 to 20/38. Nine eyes (45%) improved two or more lines of uncorrected vision, and 13 eyes (65%) improved two or more lines of best corrected vision. Mean change in spherical equivalent was just -0.92 diopters (SD 4.3 diopters); however, the range was large (-13 to +3.88 diopters). UBM measurement of central corneal pathology did not correlate significantly with the actual PTK ablation depth (P = 0.07). The amount of antihyperopia treatment did not correlate with changes in manifest refraction spherical equivalent, keratometry, or computerized corneal topography readings but did correlate with length of time until corneal reepithelialization after PTK (P = 0.003). CONCLUSIONS: PTK resulted in improvements in corneal clarity and visual acuity in most patients with superficial corneal stromal dystrophies. UBM was not an effective tool to accurately measure the depth of corneal pathology preoperatively. The combined approach of minimizing ablation depth and selective use of an antihyperopia treatment resulted in minimal mean change in spherical equivalent; however, the range was large. PTK is a very good minimally invasive technique to improve vision in eyes with anterior stromal corneal dystrophies.

[Transient visual decrease after photodynamic therapy]. / Passagere Visusminderung nach photodynamischer Therapie. Ein refraktives Problem?

BACKGROUND: After photodynamic therapy (PDT) some patients complain about a transient decrease of visual acuity during the first postoperative week. PATIENTS AND METHODS: Prior to and at 2 days and 1 week after PDT the following parameters were measured: (1) best corrected visual acuity (VA), (2) changes in refraction, and (3) A scan ultrasound biometry was carried out. Linear and 3-D optical coherence tomography was performed in three cases. A total of 53 PDT treatments were followed-up in 24 patients. RESULTS: Comparison of the pre- and postoperative refraction demonstrated a mean hyperopic shift of +0.35 diopters (dpt) in 43% of treatments (23/53) on the second postoperative day. The hyperopic shift reduced to +0.07 dpt after 1 week. The best corrected VA remained stable or was even better in 68% (36/53) on the second postoperative day. A decrease in VA could be noticed in 32% (17/53) at this time which declined to 23% (12/53) after 1 week. Measurement of the cornea-retina distance using A-scan ultrasound biometry disclosed a mean axial reduction of 0,13 mm at the second postoperative day. This correlates closely with an average hyperopic shift of 0,35 dpt. OCT examination disclosed a transient macular edema in the treated retinal areas. CONCLUSIONS: A transient hyperopic shift can be measured in 43% on the second postoperative day. The subjective decrease in visual acuity measured over the postoperative days was mainly due to a transient hyperopic shift in our patients. OCT findings disclosed a transient macular edema of the retina treated with PDT, which may relate to a hyperopic shift.

Oculometric characteristics of extreme hypermetropia in two faroese families.

PURPOSE: To describe and analyze the oculometric features of small eyes with high hypermetropia in two Faroese families, with emphasis on refractive components. METHODS: Members of the two families (N=40; age, 1 to 77 years), including 15 cases of extreme hypermetropia (+7.5 to +19.25 D), had an ophthalmic evaluation including refractometry, keratometry, and axial ocular measurements using A-scan ultrasound. Eye-wall thickness was assessed using B-scan. Nonparametric statistics were used, mainly the Mann-Whitney U test. RESULTS: In the two families, there were six and nine probands, respectively, with hypermetropia more than +7 D and short eyes as defined by axial eye lengths <21 mm. The median corrected visual acuity was 0.4 (range, 0.2 to 0.9). Gross fundus abnormalities were not observed. All 15 had a short posterior segment with a thick eye wall and a relatively thick lens. Furthermore, steep and rather small corneas were present. In one of the families, 70% of the affected had a corneal curvature radius of < or =7.0 mm. Five probands from family 2 were labeled as possibly affected because of hypermetropia and borderline axial length findings (21 to 22 mm). The remaining 20 subjects had visual acuity and oculometric findings within physiologic limits. CONCLUSIONS: The axial measurement features in our series of highly hypermetropic eyes mainly presented as an extension downward from the hypermetropic bottom line of the normal distribution. The axial shortness of the eyes was primarily the result of a short posterior eye segment ("posterior microphthalmos"). A steep cornea was a feature in most small eyes in our series, particularly in one family branch.

The effect of central corneal thickness on estimates of the anterior chamber depth.

BACKGROUND: The slitlamp can be used to estimate the anterior chamber depth (ACD). The length of a slit object is increased until the corneal and iris/lens images appear to just touch. Multiplying the just-touching-slit-length (JTSL) by a conversion factor gives an estimate of the ACD as measured by ultrasonography. The purpose of this study was to determine if central corneal thickness (CCT) affects the accuracy of this technique. METHODS: The ACD of 50 subjects was measured by A-scan ultrasonography and estimated by the slitlamp technique. CCT was measured by ultrasonic pachometry. The refractive error was determined subjectively. RESULTS: The average ultrasonographic ACD for all subjects was 3.32 +/- 0.65 mm. The average JTSL was 2.46 +/- 0.38 mm. The conversion ratio between the ultrasonographic ACD and the average JTSL was 1.35. The predicted ACD using the regression equation of JTSL on the ultrasound anterior chamber depth (USACD) was 3.32 +/- 0.54 mm. The corresponding value using the regression equation of JTSL and CCT on USACD was exactly the same, that is, 3.32 +/- 0.54 mm. CONCLUSION: Incorporation of CCT into a regression equation does not improve the accuracy of the Smith technique.

High-frequency ultrasound biomicroscopy of silicone posterior chamber phakic intraocular lens for hyperopia.

PURPOSE: To study the intraocular position and anatomic relationships of the PRL-III phakic refractive lens (PRL), a posterior chamber phakic intraocular lens (PCP IOL), in cases of hyperopia using ultrasound biomicroscopy (UBM). SETTING: Centro Oftalmológico Real Vision, Madrid, Spain, and Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense, Madrid, Spain. METHODS: Eleven phakic hyperopic eyes of 6 patients who had PRL implantation were examined by UBM 1 month after surgery. The PRL position, PRL-crystalline lens peripheral distance, and central distance between the corneal endothelium and the PRL were measured. RESULTS: Eight eyes had both haptics on the zonule, 2 had 1 haptic in the sulcus and 1 on the zonule, and 1 had 1 haptic in the sulcus and the other in the ciliary body. The mean PCP IOL-crystalline lens peripheral distance in the minor axis was 239.7 microm +/- 179.4 (SD) and the mean PCP IOL-endothelium central distance, 2146.98 +/- 219.6 microm. Contact between the PCP IOL and crystalline lens was observed in 1 eye. CONCLUSIONS: In this study of hyperopic eyes, the PRL was located on the zonule in most cases. However, the location of the haptics in the sulcus and contact between the PCP IOL and the crystalline lens that occurred in some cases suggest further study of possible long-term complications is needed.