Corneal Breakthrough Haze After Photorefractive Keratectomy With Mitomycin C: Incidence and Risk Factors.

PURPOSE: To identify preoperative and intraoperative factors affecting breakthrough corneal haze incidence after photorefractive keratectomy (PRK) with mitomycin C (MMC). METHODS: In this retrospective study of PRK performed at the Care Vision Refractive Laser Center, Tel Aviv, Israel, a total of 7535 eyes (n = 3854 patients; mean age ± SD, 26 ± 6 years; 55% men) underwent PRK with intraoperative MMC application. Patients with histories of corneal pathology or surgery were excluded. Incidence, time of onset, and corneal haze severity were documented on follow-up of 118 ± 110 days. Eyes were grouped by preoperative refraction [low (≤-3D), moderate (-3D to -6D), or high (>-6D) myopia; low (≤3D) or high (>3D) astigmatism; low or high hyperopia]; by intraoperative time (above or below 40 seconds); and by MMC application time (above or below 40 seconds). The main outcome measures were incidence, onset time, and severity of corneal haze. RESULTS: The haze incidence was 2.1% in eyes with high myopia versus 1.1% in those with low to moderate myopia (P = 0.002), and 3.5 times higher in eyes with high than with low astigmatism (P < 0.05). The overall incidence was higher in eyes treated for hyperopia (10.8%) than for myopia (1.3%) (P = 0.0001). In eyes with moderate myopia, the haze incidence was lower in MMC application time ≥40 seconds (0%) than in <40 seconds (1.3%) (P = 0.03). After surgery, a mild early haze incidence peaked at 68.8 ± 6 days and severe late haze at 115 ± 17 days (P = 0.02). CONCLUSIONS: Hyperopic and large myopic or astigmatic corrections carry higher risk of haze. Longer MMC application might have beneficial haze prevention.

Refractive error change and vision improvement in moderate to severe hyperopic amblyopia after spectacle correction: Restarting the emmetropization process?

PURPOSE: The aims of the study were to develop guidelines for prescribing spectacles for patients with moderate to severe hyperopic amblyopia and to demonstrate how emmetropization progresses. METHODS: Children with hyperopic amblyopia who had a spherical equivalent of ≥ +4.0 diopters (D) or more were included, while those who had astigmatism of > 2.0 D or anisometropia of > 2.0 D were excluded. The patients were divided into a full correction group and an under-correction group according to the amount of hyperopia correction applied. The under-correction group was further subdivided into a fixed under-correction group and a post-cycloplegic refraction (PCR) under-correction group. The duration of amblyopia treatment and changes in initial hyperopia were compared between the groups. RESULTS: In total, 76 eyes of 38 patients were analyzed in this study. The full correction group and under-correction group were subjected to 5.5 months and 5.9 months of amblyopia treatment, respectively (P = 0.570). However, the PCR under-correction group showed more rapid improvement (2.9 months; P = 0.001). In the under-correction group, initial hyperopia was decreased by -0.28 D and -0.49 D at 6 months and 12 months, respectively, after initial cycloplegic refraction. Moreover, the amount of hyperopia under-correction was correlated with the amount of hyperopia reduction (P = 0.010). CONCLUSION: The under-correction of moderate to severe hyperopic amblyopia has beneficial effects for treating amblyopia and activating emmetropization. PCR under-correction can more rapidly improve visual acuity, while both fixed under-correction and PCR under-correction can induce emmetropization and effectively reduce initial hyperopia.

Associação entre hiperopia e outros erros refrativos e visuais em crianças / Associations between hyperopia and others refractive and visual errors in children

RESUMO Objetivo: Investigar a associação da hipermetropia com ambliopia, estrabismo, anisometropia e astigmatismo. Métodos: A hiperopia foi classificada em Grupo 1: maior ou igual a +5.00D; Grupo 2: maior que +3.25D e menor que +5.00D, com diferença de equivalente esférico maior ou igual a 0.50D; Grupo 3: maior que +3.25D e menor que +5.00D, com diferença de equivalente esférico menor que 0.50D e Grupo 4: com equivalente esférico maior e igual a +2.00D. O Grupo controle pertencente ao equivalente esférico menor que +2.00D. Resultados: A presença de hipermetropia maior e igual a SE+2.00D foi significativamente associada à maior proporção de crianças com ambliopia (27,2 vs. 14,8%, OR = 2,150, p<0,001) e estrabismo (70,8 vs. 39,3%, OR = 3,758, p<0,0001. A presença de hipermetropia também foi significativamente associada à maior proporção de anisometropia nos grupos com hipermetropia maior e igual a SE+2.00 (29,1 vs. 9,9%, OR = 3,708, p<0,0001) e astigmatismo (24 vs. 9,9%, OR = 2,859 p<0,0001). Conclusão: A presença e magnitude da hipermetropia entre crianças foram associadas à maior proporção de erros refrativos e visuais, como estrabismo, ambliopia, astigmatismo e anisometropia.

RESUMO Objective: Evaluate ocular trauma cases related to falling in elderly patients e compare the prevalence and severity of the cases. Methods: A series of cases was made with 52 patients aging 60 or more within the period of 36 months presenting ocular trauma related to falling, whereas the prevalence between the gender, the need for hospitalization or surgery and subsequent visual deficit were evaluated, as well as the severity of the cases. Results: Thirty-three (63.5%) of 52 patients were from the female gender, over which 30.3% had need for surgery and 18.2% developed visual deficit and 19 (36.5%) were from the male gender where 42.1% needed surgery and 26.3% developed visual deficit. Conclusions: The study has shown a higher prevalence of cases in the female gender, although the severity was higher in the male gender.

One Year Outcomes of Photorefractive Keratectomy with the Application of Mitomycin-C in the Treatment of Mild to Moderate Hyperopia.

PURPOSE: To evaluate refractive and visual outcomes of photorefractive keratectomy with mitomycin-C. (PRK-MMC) for the treatment of mild to moderate hyperopia. MATERIALS AND METHODS: This case series enrolled 21 patients with up to +5.50 diopters (D) of hyperopia. All 42 eyes were treated with the Concerto (Wavelight) or the Technolas 217-Z (Bausch and Lomb) excimer laser. Outcome measures included best corrected distance vision acuity (BCVA) and uncorrected distance vision correction and refraction at 1, 3, 6, and 12 months postoperatively. RESULTS: Mean patient age was 44.8 ± 11.3 years. Preoperatively, mean manifest refractive spherical equivalent (MRSE) was + 2.00 D ± 0.76 D and mean spherical refractive error was + 2.57 D ± 0.87 D (range, +1.25 D to + 5.50 D). At 12 months postoperatively, mean MRSE was + 0.1 D ± 0.61 D. MRSE was within ± 0.50 D of emmetropia in 29 eyes (69%), and 18 eyes (43%) had 20/20 uncorrected distant visual acuity. BCVA increased by two lines or more in three eyes (7.1%) and one line in two eyes (4.7%); 31 eyes showed no change, three eyes (7.1%) lost one line, and three other eyes (7.1%) lost two lines of BCVA. No eyes lost more than two lines of BCVA. Complications included Grade 2 peripheral haze in two eyes which cleared by 12 months postoperatively. CONCLUSION: PRK-MMC was a safe and predictable method for the correction of mild to moderate hyperopia.

The scleral rigidity of eyes with different refractions.

BACKGROUND: The weakened biomechanical properties of the sclera is an important feature of myopic eyes. The quantitative evaluation in vivo of posterior scleral resistance to the elongation remains a challenge. METHODS: This study comprised 172 eyes from 86 subjects with a mean age of 20.6 years (range, 18-28 years). Ultrasound biometry was performed using an immersion technique and the A-scan device (the Biometer AL-1000 -TOMEY). The axial length of the eye was measured twice: before and during the application of an external pressure of 30 g on the eye. The difference between two mean values of AL measurements before and during the pressure application was considered as a degree of change in the axial length that resulted from the IOP elevation. The data were entered into an Excel spreadsheet (Microsoft Corp.) for subsequent analysis. Statistical analysis was performed using SigmaPlot software (version 11.0, Systat Software, Inc.). A value of 0.05 or less was considered statistically significant. RESULTS: The means ± SD of axial changes before and during the external pressure for hyperopia, emmetropia, myopia 0.5-3.0 D, myopia 3.25-6.0 D, myopia 6.25-12.0 D and myopia over 12.0 D were as follows: 0.03 ± 0.01 mm, 0.05 ± 0.01 mm, 0.18 ± 0.07 mm, 0.31 ± 0.02 mm, 0.38 ± 0.07 mm, and 0.51 ± 0.9 mm, respectively. The difference among groups was statistically significant. CONCLUSIONS: In conclusion, our study indicates that the biomechanical properties of the scleral coat, in terms of stretching and AL elongation, are measurable. The hypermetropic and emmetropic eyes possessed stiff sclera. The extent of AL remained practically unchanged during IOP elevation in these eyes. The absolute majority of the myopic eyes revealed a biomechanical weakness of the scleral shell. A higher degree of myopia was associated with increased AL elongation. Our approach to measuring the biomechanical properties of the sclera may have clinical significance in the future.

Refractive error in Nigerian adults: prevalence, type, and spectacle coverage.

PURPOSE: To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by off-the-shelf spectacles. METHODS: Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause. RESULTS: Included in the survey were 13,599 (89.9%) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9% of mild visual impairment (<6/12-6/18), 57.1% of moderate visual impairment (<6/18-6/60), 11.3% of severe visual impairment (<6/60-3/60), and 1.4% of blindness (<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2% and 2.1%, respectively. Spectacles could improve the vision of 1279 (9.4%) and 882 (6.5%) participants at the 6/12 and 6/18 level, respectively, but only 3.4% and 4.4% of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from <6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles. CONCLUSIONS: Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.

Can information on the purpose of spectacle use and age at first use predict refractive error type?

PURPOSE: To assess the sensitivity and specificity of predicting refractive error type using information from a four-item questionnaire on the purpose of spectacle use and age at first use. METHODS: The Sydney Myopia Study examined 1,740 year 1 (78.9% response) and 2,353 year 7 students (75.3% response) from a random cluster sample of 34 primary and 21 secondary schools across Sydney. Parents of participants completed a four-item questionnaire that sought data on parental spectacle use, age at first use, and purpose of use (for clear distant vision, close work, or both). Prescriptions were obtained for 720 of 3,209 (22%) parents (73% of those approached) for validation. A receiver operating characteristic (ROC) curve was used to determine the optimal cutoff age for spectacle use in myopia classification. RESULTS: Using the ROC curve, a cutoff age of 30 years at first spectacle use produced the highest accuracy in determining myopia. We combined information on the purpose for using spectacles (for distant and near vision) and age of first use at 30 years or younger to determine myopia, otherwise hyperopia. Validated against prescriptions, the sensitivity and specificity of these predictions were 0.89 and 0.83, respectively, for myopia. The specificity was 0.92 for hyperopia and 0.80 for astigmatism, though corresponding sensitivities were lower at 0.23 and 0.46, respectively. CONCLUSIONS: In a sample of the parents of Sydney Myopia Study participants, information on the purpose of spectacle use with an age-at-first-use criterion can identify myopic refractive error with reasonable sensitivity and specificity. This four-item questionnaire may assist future epidemiological studies of screening for myopia.

[Infant ametropias and their evolutions (myopia, hyperopia, astigmatism)]. / Ametropies de l'enfant et leurs évolutions (myopie, hypermétropie, astigmatisme).

Infant ametropias are defined as the whole optic caracteristics of the eyeball which do not allow a clear vision whithout functional disorder. As the sensorial maturity is only achieved at 4 to 5 years, the limits of ametropias are variable before that age. The majority of ametropias is constituted as early as 9 months and may be detected by a refractive examination under cycloplegia. This situation is especially true for hyperopia and astigmatism. The more important are initial ametropias the more unchanged they remain. At 9 months, 1 infant out of 5 present a non-physiological refraction. From 4 to 5 years, 1 child out of 4 needs a refractive correction. Significant myopias are uncommon in infants. They generally appear between 7 and 12 years.

Long-term evaluation of hyperopic laser in situ keratomileusis.

PURPOSE: To evaluate the efficacy, safety, and predictability of hyperopic laser in situ keratomileusis (H-LASIK). SETTING: Departments of Ophthalmology, Hadassah University Hospital, Jerusalem, and Assaf Harofeh Medical Center, Zerifin, Israel. METHODS: This prospective noncomparative case series studied the results of H-LASIK in the first 92 consecutive eyes of 50 patients with up to +10.25 diopters (D) of hyperopia. For analysis, the patients were divided into 3 groups based on preoperative hyperopia: low hyperopia (< +3.00 D), moderate hyperopia (> or = +3.00 to 6.00 D), and high hyperopia (> or = +6.00 D). RESULTS: Forty-two patients, 77 eyes (83.7%), were followed for at least 12 months. At 12 months, the mean manifest spherical equivalent was +0.33 +/- 0.65 D (93.1% of eyes within +/-1.0 D of the intended correction) in the low myopia group, +0.21 +/- 0.60 D (92.3% within +/-1.0 D of the intended correction) in the moderate hyperopia group, and +1.62 +/- 1.50 D (36.4% within +/-1.0 D of the intended correction) in the high hyperopia group. The uncorrected visual acuity (UCVA) was 20/40 or better in all eyes (100%), 24 eyes (92.3%), and 13 eyes (59.1%) in the low, moderate, and high hyperopia groups, respectively. Comparing the UCVA at the last examination with the best corrected visual acuity (BCVA) before surgery in all patients showed that 59 eyes (76.6%) were within +/-1 line and 18 eyes (23.4%) were within +/-2 or more lines of the preoperative BCVA. Three eyes (3.9%) in the high hyperopia group lost 2 or more lines of BCVA. Three eyes (3.9%) had flap- related complications. Eight patients (15 eyes) with a follow-up less than 12 months did not have intraoperative or postoperative complications. CONCLUSION: Laser in situ keratomileusis was a safe, effective, and predictable procedure for hyperopia up to +6.0 D and less predictable for higher hyperopia.

Screening for amblyopia in preverbal children with photoscreening photographs. III. improved grading criteria for hyperopia.

OBJECTIVE: To examine the ability of the Medical Technology and Innovations (MTI), Inc., Photoscreener (Cedar Falls, IA) to detect hyperopia and to improve the photograph grading criteria to screen for amblyopiogenic levels of hyperopia. DESIGN: Cross-sectional study and reanalysis. PARTICIPANTS AND TESTING: In previous work, 392 participants received a complete ophthalmologic examination and were photographed using the MTI Photoscreener. For this study, all 209 participants with normal examination findings (65 children) or hyperopia without anisometropia (144 children) were selected. The data were reanalyzed using modified photograph grading and ophthalmologic examination failure criteria. Potential reasons for why many children with hyperopia passed photoscreening were explored. MAIN OUTCOME MEASURES: We determined whether a study participant would pass or fail screening with a given photograph grading and ophthalmologic examination failure criteria. RESULTS: Most children with hyperopia of +2.00 to +3.50 diopters (D) passed screening with the MTI instrument, in most cases because their photographs lacked bright crescents. When bright crescents in at least two of the four possible meridians were the grading guideline for screening failure and the pediatric ophthalmologists' consensus hyperopia failure criteria (> +3.50 D) were adopted, the sensitivity for hyperopia detection was 100% and the specificity was 88%. Identical results were obtained using the American Academy of Ophthalmology Preferred Practice Pattern hyperopia failure criteria (>/= +4.50 D). CONCLUSIONS: The MTI photograph grading guidelines can be simplified, and the ophthalmologic examination failure criteria for hyperopia can be improved. The presence of a bright crescent in the lower or the left pupillary margin indicate hyperopia in an amblyopiogenic range (> +3.50 D).

A acomodaçäo tônica nas categorias refrativas / Tonic accomodation and refractive state

A autora comparou os resultados do exame de refraçäo por dois métodos diferentes: a retinoscopia para perto que mede a acomodaçäo tônica e a refraçäo sob ciclopegia, onde a acomodaçäo tônica é igual a zero, em condiçöes uniformizadas. A diferença entre os dois resultados, nos dois métodos, foi observada nos três grupos refrativos (míopes, hipermétropes e emétropes) sendo constatado que a acomodaçäo tônica é maior nos hipermétropes que nos míopes

[Hypermetropia]. / L'hypermétropie.

Hypermetropia, like myopia, is a defect of axial refraction, most often due to reduction of the anteroposterior diameter of the eyeball. Hypermetropia is normal in the young child and usually diminishes with age. Moderate hypermetropia is generally well tolerated in young subjects. When severe or associated with functional changes, hypermetropia should be corrected by prescription lenses. Contrary to myopia, definitive treatment by surgery is not yet current practice in hypermetropia.

Alteraçöes refrativas induzidas pelo óleo de silicone intraocular / Refractive change from use of intraocular silicone oil

Os autores determinaram as variaçöes refracionais induzidas pelo óleo de silicone intra-ocular em onze fácicos e em 13 olhos afácicos. Nos olhos fácicos houve um aumento na hipermetropia de 6,4 D, em média, e nos afácicos houve uma reduçäo na hipermetropia de 7,4 D, em média. Essas variaçöes refracionais säo devidas, fundamentalmente, ao maior índice de refraçäo do silicone, quando comparado com os índices de refraçäo dos meios dióptricos oculares

Retinal function in high refractive error assessed electroretinographically.

The retinal function of patients with high refractive error was studied electroretinographically. Thirty-one hypermetropic patients, 7 myopic patients, and 7 patients with either unilateral or bilateral aphakia participated in the study. The ERG responses were measured in the light- and dark-adapted states. It was found that myopic eyes were characterised by subnormal amplitude but normal pattern, expressed by normal relationship between the b-wave amplitude and the a-wave amplitude. In aphakia the ERG responses were of normal amplitude and pattern. However, the hypermetropic patients could be divided into 3 groups. One group included subjects with a subnormal b-wave to a-wave relationship. The second group was characterised by a normal b- to a-wave relationship, while patients belonging to the third group exhibited supernormal b-wave to a-wave relationship. This classification of hypermetropic subjects did not correlate with the axial length of the eye or the refraction of the ocular media.

[The different forms of hypermetropia and the necessity of their precise correction (author's transl)]. / Die verschiedenen Formen der Hypermetropie und die Wichtigkeit ihrer genaueren Korrektion.

The author presents a detailed analysis of hypermetropia. He defines its three pathogenetically important forms:--facultative, relative and absolute, starting from the principles of Donders and based upon the dioptrics of Gullstrand. The author then deals with the pathological processes caused by hypermetropia, especially with the formation of strabismus. Finally he discusses the effects of the three forms of hypermetropia and of the associated other deficiencies of refraction.