Category: Peer-reviewed

A Quantitative Method for Assessing the Degree of Axial Proptosis in Relation to Orbital Tissue Involvement in Graves’ Orbitopathy – Corrected Proof

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Purpose:
To define a method of quantifying axial proptosis in patients with Graves’ orbitopathy (GO) and to validate a score that correlates with the orbital involvement and helps determine the degree of proptosis correction for elective orbital decompression.

Design:
Retrospective, case series.

Participants:
The study included 50 patients (group A) and 29 control subjects who underwent orbital computed tomography (CT). The method was then validated in another group of 21 patients with GO (group B).

Methods:
The orbital area (OA) was measured manually on the central axial section of the CT scan at a level where the lens is visualized. The OA intersects the projection of the globe and delimitates the chord of an arch (globe chord [OC]). The area of the circular sector under the chord (CA) represents the portion of the globe within the orbit.

Main Outcome Measures:
A CA-to-OA ratio was calculated to reduce the error due to variability of the measurements and to perform correlations with some of the clinical parameters of GO.

Results:
Measurement error was low (<2%). We did not observe significant differences in the mean OA of patients with GO (783.6±12.1 mm2) and controls (758.5±20.4 mm2; P = not significant). The OC value in patients with GO was 130.2±11.5 mm2, significantly lower than in controls (281.8±9.7 mm2; P<0.0001). The CA-to-OA ratio also was lower in patients with GO than in controls (0.16±0.01 vs. 0.38±0.01; P<0.0001). A significant correlation was found in patients with GO between the CA-to-OA ratio and proptosis (P<0.001), lid fissure (P = 0.004), and intraocular pressure (P<0.001). In group B, the CA-to-OA ratio was 0.18±0.02, significantly different from that of controls (P<0.0001) and inversely correlated with proptosis (P<0.0001) and lid fissure (P<0.045).

Conclusions:
By measuring the CA-to-OA ratio, we were able to quantify the degree of axial proptosis in patients with GO. The significant correlation of CA/OA with some orbital parameters confirms that this parameter also may be used as a measure of orbital involvement in GO.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Variants of Anterior Segment Dysgenesis and Cerebral Involvement in a Large Family With a Novel COL4A1 Mutation – Corrected Proof

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Purpose: To investigate the diverse ocular manifestations and identify the causative mutation in a large family with autosomal dominant anterior segment dysgenesis accompanied in some individuals by cerebral vascular disease.Design: Retrospective observational case series and laboratory investigation.Methods: Forty-five family members from 4 generations underwent ophthalmic examination. Molecular genetic investigation included analysis with single nucleotide polymorphism (SNP) markers and DNA sequencing. Whole exome sequencing was performed in 1 individual.Results: A broad range of ocular manifestations was observed. Typical cases presented with corneal clouding, anterior synechiae, and iris hypoplasia. Posterior embryotoxon, corectopia, and early cataract development were also seen. One obligate carrier and several other family members had minor ocular anomalies, thus confounding the scoring of affected and unaffected individuals. Cerebral hemorrhages had occurred in 4 individuals, in 3 at birth or during the first year of life. Seven patients with corneal clouding were considered “definitely affected” for linkage studies. Haplotype mapping revealed that they shared a 14 cM region in the terminal part of chromosome 13q that included the locus for COL4A1. The affected family members were heterozygous for a novel COL4A1 sequence variant c.4881C>G (p.Asn1627Lys) predicted to be damaging and not found among 185 local blood donors. Exome sequencing showed that this variant was the only one in the candidate region not found in dbSNP.Conclusion: Among the family members shown to carry the novel COL4A1 mutation, heterogenous presentations of anterior segment dysgenesis was seen. Testing family members for this mutation also made a definite diagnosis possible in patients with a clinical presentation difficult to classify. In families where anterior segment dysgenesis occurs together with cerebral hemorrhages, genetic analysis of COL4A1 should be considered.

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Argon Laser Photoablation of Superficial Conjunctival Nevus: Results of a 3-Year Study – Corrected Proof

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Purpose: To evaluate and report the results of a 3-year study investigating argon laser photoablation of superficial conjunctival nevus.Design: Retrospective, interventional case series.Methods: The medical charts of patients referred to our clinic for the removal of a conjunctival nevus were reviewed. Argon laser photoablation of superficial conjunctival nevi was performed for 230 patients during the period from March 2006 to February 2009. The clinical course, complications, and recurrence rates were evaluated.Results: The mean follow-up period was 71.29 ± 19.51 months (range, 36-100 months). The horizontal and vertical diameters of conjunctival nevi were 4.53 ± 1.85 mm and 3.41 ± 1.62 mm, respectively. Most nevi were faintly pigmented and located on the nasal bulbar conjunctiva. The argon laser spot size was 200 μm; its duration was 0.1 second; and the power was 321.50 ± 9.23 mW. One session was required to completely remove the nevus in 212 eyes (81%). The total number of laser spots that were required to remove 1 nevus was 107.83 ± 33.68 (range, 53-172) for cases in which the horizontal and vertical diameters were <4 mm. In all cases, the laser procedure resulted in complete removal of the conjunctival nevus. There were no significant complications, such as infection, corneal damage, or permanent injection.Conclusions: Argon laser photoablation could be a safe and effective treatment for benign superficial conjunctival pigmentation. This method is especially helpful for large conjunctival nevi, for which surgical excision would be impossible.

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Characterization of Microaneurysm Closure After Focal Laser Photocoagulation in Diabetic Macular Edema – Corrected Proof

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Purpose: To characterize microaneurysm closure following focal laser photocoagulation in diabetic macular edema (DME) using simultaneous fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT).Design: Retrospective observational case series.Methods: Leaking microaneurysms (n = 123) were analyzed in eyes (n = 29) with nonproliferative diabetic retinopathy (NPDR) that underwent navigated focal laser photocoagulation in DME and were followed at 3, 6, and 12 months. Closure of diabetic microaneurysms was characterized in detail following focal laser using SD-OCT.Results: Closure rate of microaneurysms by both FA and SD-OCT was 69.9% (84/123), 79.7% (98/123), and 82.9% (102/123) at 3, 6, and 12 months, respectively. Microaneurysm closure rate increased at 6 and 12 months compared to 3 months (P < .003, P < .001). Over half of closed microaneurysms (45/86, 52.3%) left hyperreflective spots while the remaining half (41/86, 47.7%) disappeared without any hyperreflectivity by SD-OCT at 3 months. Hyperreflective spots decreased at 6 (36/99, 36.4%) and 12 months (17/102, 16.7%) with a concomitant increase in complete loss of reflectivity at 6 (63/99, 63.6%) and 12 months (85/102, 83.3%). Smaller outer and inner diameters and heterogeneous lumen reflectivity were positively associated with microaneurysm closure at 12 months (P < .0001, P < .001, P < .03).Conclusions: Characterization of microaneurysms following focal laser photocoagulation resulted in hyperreflective spots and complete resolution of all reflectivity using SD-OCT. Smaller microaneurysms and those with heterogeneous lumen were positively associated with microaneurysm closure. These findings provide greater understanding of localized retinal changes following focal laser photocoagulation in DME treatment.

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Long-term Results After Transconjunctival Resuturing of the Scleral Flap in Hypotony Following Trabeculectomy – Corrected Proof

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Purpose: To present the 4-year follow-up results in the surgical treatment of hypotony following trabeculectomy with mitomycin C in glaucoma patients with additional flap sutures.Design: Retrospective interventional case series.Methods: Since 2006, 53 patients with hypotony maculopathy attributable to overfiltration following glaucoma surgery (trabeculectomy with mitomycin C) were included in this institutional study. We were able to follow up intraocular pressure (IOP) and distance-corrected visual acuity in 33 (62%) over 4 years, whereas all were followed over 2 years. To elevate IOP, we placed tangential transconjunctival sutures through the scleral flap and connected them to the adjacent sclera in all 53 patients.Results: Mean IOP prior to surgery was 3.55 mm Hg (± 2.05; range 0-8 mm Hg), 20.08 mm Hg (± 12.48) on the first postoperative day, 10.69 mm Hg (± 4.73) after 1 month, 10.12 mm Hg (± 3.95) after 6 months, 10.42 mm Hg (± 4.17) after 2 years, and 9.5 mm Hg (± 3.93) after 4 years. Mean visual acuity (VA) improved from 0.8 logarithm of minimal angle of resolution (logMAR) preoperatively to 0.5 after 1 month, and remained stable after 6 months at 0.3. Macular folds resolved in all patients and choroidal detachment in 51 patients (96%) after 6 months. IOP increase and vision improvement were statistically significant (<.05).Conclusion: Even 4 years after resuturing of the scleral flap through the intact conjunctiva, there is evidence that this surgical method is an effective and simple technique to treat hypotony maculopathy after glaucoma surgery.

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Effect of Day Length on Eye Growth, Myopia Progression, and Change of Corneal Power in Myopic Children

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Objective:
Because of the northern location of Denmark, the length of the day over the year varies from 7 to 17.5 hours. Experimental and clinical results suggest that the development of myopia may be related to ambient light exposure. The purpose of current study was to investigate whether axial eye growth, myopia progression, or corneal power change in Danish myopic children varies with the length of the day.

Design:
Cross-sectional study.

Participants:
Two hundred thirty-five children 8 to 14 years of age found to have myopia during screening for a clinical trial (ClinicalTrial.gov identifier, NCT00263471; accessed December 6, 2005). All children found to have any value of spherical equivalent that was myopic (<0 diopters [D]) at the first of 2 visits were included.

Methods:
Cycloplegic refraction was measured using an autorefractor, axial eye length, and corneal power using an automatic combined noncontact partial coherence interferometer and keratometer. The accumulated number of daylight hours during the measurement period was calculated for each participant using an astronomical table.

Main Outcome Measures:
Change over 6 months in axial length, refraction, and corneal power.

Results:
Accumulated hours of daylight ranged from 1660 to 2804 hours. Significant correlations were found between hours of daylight and eye elongation (P = 0.00), myopia progression (P = 0.01), and corneal power change (P = 0.00). In children with an average of 2782±19 hours of daylight, axial eye growth was 0.12±0.09 mm, myopia progression was 0.26±0.27 D, and corneal power change was 0.05±0.10 D per 6 months, whereas in children with an average of 1681±24 hours of daylight, axial eye growth was 0.19±0.10 mm, myopia progression was 0.32±0.27 D, and corneal power change was −0.04±0.08 D per 6 months.

Conclusions:
Eye elongation and myopia progression seem to decrease in periods with longer days and to increase in periods with shorter days. Children should be encouraged to spend more time outside during daytime to prevent myopia.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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