Haab striae: Optical coherence tomographic analysis

Posterior corneal morphological changes in primary congenital glaucoma

Purpose:

To compare posterior corneal morphology between older treated and younger untreated children with primary congenital glaucoma (PCG) using anterior segment optical coherence tomography (ASOCT) and intraoperative OCT (iOCT), respectively.

Methods:

In this comparative study, ASOCT of older PCG children were compared with iOCT of younger untreated PCG patients. Differences between the two groups with respect to posterior corneal morphology were studied.

Results:

Observed morphological patterns within posterior cornea in older treated (age: 72–300 months) children (87 eyes) included Descemet’s membrane (DM) excrescences (70%), thickened DM (35%), intracameral twin protuberances (92%), and DM detachment (26%). Changes within pre-Descemet’s layer (PDL) (28%) included thickening, breaks, and detachments. Extent of Haab’s striae was associated with thickness of DM/PDL complex (P = 0.008) when analyzed in the treated group. In contrast, in the untreated group (n = 53 eyes, age 1–63 months), posterior corneal changes were limited to diffuse hyper-reflectivity of the DM/PDL complex, with absence of DM tears.

Conclusion:

Posterior cornea thickens and Haab’s striae become more circumscribed in eyes of older treated children compared to untreated PCG eyes, probably reflecting a healing response of posterior cornea over time.

Corneal Endothelial Changes in Patients With Primary Congenital Glaucoma

PRCIS

Specular microscopic parameters were found to be decreased in patients with primary congenital glaucoma (PCG). Patients with PCG and Haab striae had lower endothelial cell density (ECD) and central corneal thickness (CCT) than those without Haab striae did. The type of surgery (viscogoniotomy, viscotrabeculotomy, or combined viscotrabeculotomy and trabeculectomy) did not affect specular microscopic parameters.

PURPOSE

The purpose of this study was to compare specular microscopic parameters such as corneal ECD, coefficient of variation (CV), hexagonal cell percentage (HEX), and CCT between patients with PCG and healthy controls; to determine the predictive ability of Haab striae for endothelial cell changes PCG by comparing patients with and without Haab striae; and to investigate if the type of surgery used to treat glaucoma (viscogoniotomy, viscotrabeculotomy, or combined viscotrabeculotomy and trabeculectomy) affects specular microscopic parameters.

METHODS

A cross-sectional specular microscopic analysis of patients with PCG and healthy controls was performed. One hundred eyes of 62 patients with PCG with and without Haab striae and 101 eyes of 101 healthy controls were enrolled in this study. Specular microscopic parameters, including ECD, HEX, CV, and CCT, of all subjects were evaluated.

RESULTS

Patients with PCG showed significantly lower ECD and CCT than healthy controls did. Those with Haab striae had lower ECD and CCT but no differences in age, HEX, and CV compared with those without Haab striae. ECD, CV, HEX, or CCT did not significantly differ among patients treated with the 3 different types of surgery.

CONCLUSIONS

Prolonged exposure to elevated intraocular pressure during prenatal and/or early postnatal life results in structural changes in immature infant corneas. Specular microscopic parameters differed significantly between healthy controls and patients with PCG. The type of surgery had no effect on these parameters. Among patients with PCG, those with Haab striae had isolated corneal endothelial cell loss without morphologic changes within the endothelium.

Corneal densitometry and biomechanical properties in patients with primary congenital glaucoma

OBJECTIVE

To describe corneal densitometry, topographic measurements, and biomechanical properties in patients with primary congenital glaucoma (PCG) and healthy patients. To examine correlations between variables and determine their glaucoma diagnostic capacity.

METHODS

This was a cross-sectional, case-control study conducted in 50 eyes of 50 patients with PCG (G1) and 40 eyes of 40 healthy patients (G2). The variables determined in each participant were: intraocular pressure, best corrected visual acuity (BCVA), corneal densitometry, topographic data using the Pentacam HR-Scheimpflug imaging system (Oculus Optikgerate GmbH, Wetzlar, Germany), and corneal hysteresis (CH) and corneal resistance factor (CRF) using the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Depew, NY).

RESULTS

Overall densitometry was significatively higher in the PCG group (G1: 17.94 ± 4.99 vs G2: 13.25 ± 1.96, p < 0.001). CH (G1: 8.02 ± 11.35 vs G2: 11.35 ± 1.42, p < 0.001) and CRF (G1: 9.48 ± 2.83 vs G2: 10.77 ± 1.34, p < 0.001) were lower in the glaucoma group. Mean posterior, central, and anterior elevation and mean keratometry were higher in G1 (p < 0.05). In the PCG group, overall densitometry showed significant correlation with CH (r = -0.321, p = 0.028) and with BCVA (r = -0.498, p = 0.002). AUCs (areas under the curve) for CH and overall densitometry were high (0.839 and 0.899 respectively) and the best overall densitometry; CH and CRF cutoffs were 14.0, 9.3 and 9.2 respectively.

CONCLUSION

Densitometry is increased, and biomechanical corneal properties are decreased in patients with PCG. Densitometry and visual acuity showed a negative and significant correlation, so this measurement could be used as an indirect parameter of BCVA in the clinical practice.