PURPOSE:To investigate the characteristics of apparently stable forms of tomographically unilateral keratoconus (KC). METHODS:In this retrospective case-control study, strict unilaterality criteria were applied to select tomographically unilateral cases with ≥3 years of follow-up. For comparison, a healthy cohort and two bilateral KC cohorts were matched to the tomographically unilateral cases. All patients were selected from The Rotterdam Eye Hospital, whereas healthy controls were selected from the population-based Rotterdam Study. After cohort selection, several risk factors and 25 Pentacam features were assessed. Unaffected (i.e. tomographically non-keratoconic) eyes from the tomographically unilateral cases were compared to matched healthy eyes, matched bilateral KC eyes and affected unilateral KC eyes. Furthermore, affected tomographically unilateral KC eyes were compared to matched bilateral KC eyes. Statistical analysis relied on Wilcoxon signed-rank tests and conditional logistic regression. RESULTS:From 1006 assessed cases, 18 (1.8%) tomographically unilateral cases were selected. Their median (interquartile range) follow-up was 5.7 (4.3-8) years. Eczema and asthma were more prevalent among tomographically unilateral patients (28% each) compared to bilateral patients (6% and 9%) (p = 0.01 and p = 0.05, signed-rank test). We could not detect meaningful Pentacam differences between unaffected unilateral eyes and matched healthy eyes. Expectedly, significant differences were detected between unaffected unilateral eyes and affected (bilateral or unilateral) eyes. Lastly, the ectatic features of affected unilateral eyes seemed comparable to their bilateral counterparts, but their high-order aberrations were significantly lower. CONCLUSION:Our findings support the existence of tomographically unilateral KC. Understanding how tomographic unilaterality ensues may offer valuable insights into KC aetiology.

IMPORTANCE Highmyopia incidence and prevalence is increasing worldwide, and the visual burden caused bymyopia is expected to rise accordingly. Studies investigating the occurrence ofmyopic complications in individuals of European ancestry with highmyopia are scarce, hampering insights into the frequency ofmyopic retinal complications in European individuals and their visual burden. OBJECTIVE To assess the frequency ofmyopic macular features in individuals of European ancestry with highmyopia. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional analysis of the Dutch Myopia Study (MYST) and individuals with highmyopia from the Rotterdam Study (RS) included 626 patients with highmyopia (spherical equivalent of refractive error [SER] <=-6 diopters [D] or axial length [AL] >= 26 mm) who underwent an extensive ophthalmic examination including multimodal retinal imaging. In addition to this combination of a population-based cohort study and mix-based highmyopia study, a systematic literature review was also performed to compare findings with studies of individuals of Asian ancestry. EXPOSURES Highmyopia, age, and AL. MAIN OUTCOMES AND MEASURES Frequency ofmyopic macular and optic disc features: tessellated fundus, myopic macular degeneration (MMD), staphyloma, peripapillary intrachoroidal cavitation, peripapillary atrophy (PPA), and "plus" lesions (choroidal neovascularization, Fuchs spot, and lacquer cracks). RESULTS The mean (SD) SER of the combined study population (MYST and RS) was -9.9 (3.2) D; the mean (SD) age was 51.4 (15.1) years, and 387 (61.8%) were women. The prevalence of MMD was 25.9% and increased with older age (P for trend <.001), lower SER (odds ratio [OR], 0.70; 95% CI, 0.65-0.76; P <.001), and higher AL (OR, 2.53; 95% CI, 2.13-3.06; P <.001). Choroidal neovascularization or Fuchs spot was present in 2.7%(n = 17), both lesions in 0.3% (n = 2), and lacquer cracks in 1.4%(n = 9). Staphyloma, PPA, and MMD were highly prevalent in visual impaired and blind eyes (frequency was 73.9%[20 of 27], 90.5%[19 of 21], and 63.0%[17 of 27] of unilateral blind eyes for MMD, staphyloma, and PPA, respectively). Seven previous studies in Asian populations reported a variable MMD frequency ranging from 8.3% to 64%, but frequencies were similar for comparable risk profiles based on age and SER. CONCLUSIONS AND RELEVANCE In this cross-sectional study of a highlymyopic Dutch population of European ancestry, myopic retinal features were frequent; were associated with age, SER, and AL; and occurred in all visually severely impaired eyes. The absence of treatment options for most of these retinal complications emphasizes the need for effective strategies to prevent highmyopia.

Purpose:To study the relatively high effect of the refractive error gene GJD2 in human myopia, and to assess its relationship with refractive error, ocular biometry and lifestyle in various age groups. Methods:The population-based Rotterdam Study (RS), high myopia case-control study MYopia STudy, and the birth-cohort study Generation R were included in this study. Spherical equivalent (SER), axial length (AL), axial length/corneal radius (AL/CR), vitreous depth (VD), and anterior chamber depth (ACD) were measured using standard ophthalmologic procedures. Biometric measurements were compared between GJD2 (rs524952) genotype groups; education and environmental risk score (ERS) were calculated to estimate gene-environment interaction effects, using the Synergy index (SI). Results:RS adults carrying two risk alleles had a lower SER and longer AL, ACD and VD (AA versus TT, 0.23D vs. 0.70D; 23.79 mm vs. 23.52 mm; 2.72 mm vs. 2.65 mm; 16.12 mm vs. 15.87 mm; all P < 0.001). Children carrying two risk alleles had larger AL/CR at ages 6 and 9 years (2.88 vs. 2.87 and 3.00 vs. 2.96; all P < 0.001). Education and ERS both negatively influenced myopia and the biometric outcomes, but gene-environment interactions did not reach statistical significance (SI 1.25 [95% confidence interval {CI}, 0.85-1.85] and 1.17 [95% CI, 0.55-2.50] in adults and children). Conclusions:The elongation of the eye caused by the GJD2 risk genotype follows a dose-response pattern already visible at the age of 6 years. These early effects are an example of how a common myopia gene may drive myopia.

Keratoconus is characterised by reduced rigidity of the cornea with distortion and focal thinning that causes blurred vision, however, the pathogenetic mechanisms are unknown. It can lead to severe visual morbidity in children and young adults and is a common indication for corneal transplantation worldwide. Here we report the first large scale genome-wide association study of keratoconus including 4,669 cases and 116,547 controls. We have identified significant association with 36 genomic loci that, for the first time, implicate both dysregulation of corneal collagen matrix integrity and cell differentiation pathways as primary disease-causing mechanisms. The results also suggest pleiotropy, with some disease mechanisms shared with other corneal diseases, such as Fuchs endothelial corneal dystrophy. The common variants associated with keratoconus explain 12.5% of the genetic variance, which shows potential for the future development of a diagnostic test to detect susceptibility to disease.

ImportanceMyopia (ie, nearsightedness) is becoming the most common eye disorder to cause blindness in younger persons in many parts of the world. Visual impairment due to myopia is associated with structural changes of the retina and the globe because of elongation of the eye axis. How axial length-a sum of the anterior chamber depth, lens thickness, and vitreous chamber depth-and myopia relate to the development of visual impairment over time is unknown.ObjectivesTo evaluate the association between axial length, spherical equivalent, and the risk of visual impairment and to make projections of visual impairment for regions with high prevalence rates.Design, Setting, and ParticipantsThis cross-sectional study uses population-based data from the Rotterdam Study I (1990 to 1993), II (2000 to 2002), and III (2006 to 2008) and the Erasmus Rucphen Family Study (2002 to 2005) as well as case-control data from the Myopia Study (2010 to 2012) from the Netherlands. In total, 15 404 individuals with data on spherical equivalent and 9074 individuals with data on axial length were included in the study; right eyes were used for analyses. Data were analyzed from September 2014 to May 2016.Main Outcomes and MeasuresVisual impairment and blindness (defined according to the World Health Organization criteria as a visual acuity less than 0.3) and predicted rates of visual impairment specifically for persons with myopia.ResultsOf the 15 693 individuals included in this study, the mean (SD) age was 61.3 (11.4) years, and 8961 (57.1%) were female. Axial length ranged from 15.3 to 37.8 mm; 819 individuals had an axial length of 26 mm or greater. Spherical equivalent ranged from -25 to +14 diopters; 796 persons had high myopia (ie, a spherical equivalent of -6 diopters or less). The prevalence of visual impairment varied from 1.0% to 4.1% in the population-based studies, was 5.4% in the Myopia Study, and was 0.3% in controls. The prevalence of visual impairment rose with increasing axial length and spherical equivalent, with a cumulative incidence (SE) of visual impairment of 3.8% (1.3) for participants aged 75 years with an axial length of 24 to less than 26 mm and greater than 90% (8.1) with an axial length of 30 mm or greater. The cumulative risk (SE) of visual impairment was 5.7% (1.3) for participants aged 60 years and 39% (4.9) for those aged 75 years with a spherical equivalent of -6 diopters or less. Projections of these data suggest that visual impairment will increase 7- to 13-fold by 2055 in high-risk areas.Conclusions and RelevanceThis study demonstrated that visual impairment is associated with axial length and spherical equivalent and may be unavoidable at the most extreme values in this population. Developing strategies to prevent the development of myopia and its complications could help to avoid an increase of visual impairment in the working-age population.

To investigate the clinical presentation, isolated organism, treatment, and morbidity of contact lens–associated microbial keratitis needing hospitalization.

Purpose: To investigate the long-term effect of oral acyclovir administered during the first 6 months after penetrating keratoplasty (PK) for herpetic eye disease (HED). Methods: A 5-year follow-up was undertaken for a patient population from a placebo-controlled, randomized trial on acyclovir prophylaxis after keratoplasty. In this former study the effectiveness of oral acyclovir prophylaxis was significant during the first 2 years after keratoplasty. Prospective data such as graft survival, graft clarity, vascularization, infective events, and rejection episodes were obtained from the national keratoplasty follow-up registry. Additional clinical data were derived from the medical charts. Results: For 47 of the original 63 enrolled patients, the 5-year follow-up was completed. Comparing the acyclovir group with the placebo group, we found that with regard to the cumulative clinically evident recurrences, there was a statistically significant lower monthly event rate in the acyclovir group (P = 0.037). There were no statistically significant differences in visual acuity or in the use of oral aciclovir between the two treatment groups. The incidences of graft failure, vascularization, and medication or surgery for glaucoma were too low to analyze differences between the two groups. Conclusion: The results of our study suggest that oral acyclovir prescribed during the first 6 months after PK for HED protects against clinically evident HED recurrences during the first 5 years following PK.

Purpose: To report the long-term sequelae of a case of bilateral chemical keratitis caused by airbag deployment. Methods: Case report and review of the literature. Results: A 21-year-old woman presented with bilateral reduced vision, photophobia, and tearing after a car accident. Examination revealed some facial burns and severe chemical injury to the cornea and conjunctiva. Immediate irrigation with physiologic saline solution and subsequent treatment with topical antibiotics, corticosteroids, and vitamin C resulted in full restoration of vision but could not prevent permanent corneal damage. Conclusions: Severe alkali injury of the cornea generally has a good prognosis but can lead to permanent damage and persistent complaints of dry eye.

PURPOSE:To review retrospectively the charts of all 190 patients who underwent penetrating keratoplasty for keratoconus in one hospital during a 5-year period (1995-2000), with special attention paid to contact lens fitting.METHODS:The frequency of postoperative contact lens use, the time to fit lenses after grafting, tolerance and visual acuity, and postoperative risks for the graft were studied.RESULTS:The authors successfully fitted large-diameter (12 mm) tricurve rigid gas-permeable contact lenses for 90 (47%) of 190 penetrating keratoplasty patients with good tolerance. There were nine dropouts, and 91 eyes were corrected in another way. Fitting contact lenses after grafting usually started after 8.5 months (range, 1-60 months). The average tolerance was 9.2 hours a day (range, 2-12 hours), and best-corrected visual acuity was 20/25 (range, 20/16-20/200). The average follow-up was at least half a year. The average age of the patient at the first lens fitting was 36.2 years (range, 14-75 years). There was no increased risk in graft rejection.CONCLUSIONS:Twelve-millimeter rigid gas-permeable contact lens wear was successful in 47% of patients who underwent penetrating keratoplasty for keratoconus. It does not interfere with the use of chronic postoperative topical medication, nor does it increase the risk of corneal graft rejection. It is necessary to recommend likely use of contact lenses to patients who have undergone grafting surgery.

To determine the prophylactic effect of oral acyclovir on the recurrence rate of herpetic eye disease after penetrating keratoplasty.A randomized, double-masked, placebo-controlled multicenter trial.Sixty-eight consecutive patients (68 eyes) with corneal opacities due to herpetic eye disease who underwent penetrating keratoplasty.Oral acyclovir 400 mg twice daily or placebo tablets for 6 months.The recurrence rate of herpetic eye disease-related events and rejection episodes, proven by viral cell culture or polymerase chain reaction.During the 2-year follow-up period, there were 3 culture-proven herpetic eye disease recurrences in the acyclovir group and 9 in the placebo group. Lifetime survival analysis of the probability of remaining free from recurrence revealed a significantly reduced risk of recurrent herpetic disease in the acyclovir-treated group.This study suggests that oral acyclovir effectively prevents herpes-related recurrences after penetrating keratoplasty in herpetic eye disease.

Background: The hereditary Reis–Bückler dystrophy is one of the anterior localised corneal dystrophies with superficial reticulated opacities, sometimes in combination with recurrent attacks of corneal erosion. Phototherapeutic keratectomy (PTK) is now the first method to consider for managing this disease when intervention is required.