Kim Donghee, Park Sang-Eun, Hwang Jiyi, Kang Nanyoung, Jung Ji Seung, Park Kyung-Mee
Laboratory of Veterinary Surgery and Ophthalmology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea.
Front Vet Sci. 2024 May 9;11:1366997. doi: 10.3389/fvets.2024.1366997. eCollection 2024.
This study investigates the relationship between ciliary muscle dynamics, thickness, and the regulation of intraocular pressure (IOP), focusing on the progression of cataracts and changes post-phacoemulsification. It explores how these factors impact canine ocular health, particularly in the context of cataract development and subsequent surgical intervention.
Data was collected using Ultrasound Biomicroscopy (UBM) from dogs at the Veterinary Medical Teaching Hospital of Chungbuk National University, Korea. The study involved 57 eyes from 35 dogs, categorized into five groups: 13 normal eyes, 14 with incipient cataracts, 12 with immature cataracts, 6 with mature cataracts, and 12 post-phacoemulsification. UBM measurements assessed various ciliary muscle parameters including ciliary body axial length (CBAXL), ciliary process-sclera angle (CPSA), longitudinal fibers of ciliary muscle thickness (Lf-CMT), and longitudinal and radial fibers of ciliary muscle thickness (LRf-CMT).
Findings indicated a decrease in CBAXL and an increase in Lf-CMT as cataracts progressed in severity. Post-phacoemulsification, there was a notable increase in CBAXL and a decrease in CPSA, Lf-CMT, and LRf-CMT, compared to both cataractous and normal eyes. Regression analysis revealed a significant positive association between CBAXL and IOP, alongside a negative association between Lf-CMT and IOP. These findings suggest that variations in ciliary muscle dynamics and thickness, as influenced by cataract progression and phacoemulsification, have distinct impacts on intraocular pressure.
The study proposes that phacoemulsification leads to ciliary muscle contraction, causing an inward and anterior movement of the ciliary muscle. This movement results in the narrowing of the ciliary cleft and constriction of the unconventional outflow pathway, potentially causing an increased risk of glaucoma post-surgery. Our research contributes to understanding the anatomical and physiological changes in the canine eye following cataract surgery and underscores the importance of monitoring IOP and ciliary muscle dynamics in these patients.
本研究调查睫状肌动力学、厚度与眼内压（IOP）调节之间的关系，重点关注白内障的进展及超声乳化术后的变化。它探讨了这些因素如何影响犬类眼部健康，特别是在白内障发展及后续手术干预的背景下。
在韩国忠北国立大学兽医学院教学医院，使用超声生物显微镜（UBM）收集犬类的数据。该研究涉及35只犬的57只眼睛，分为五组：13只正常眼睛、14只初期白内障眼睛、12只未成熟白内障眼睛、6只成熟白内障眼睛和12只超声乳化术后眼睛。UBM测量评估了各种睫状肌参数，包括睫状体轴向长度（CBAXL）、睫状突 - 巩膜角（CPSA）、睫状肌纵向纤维厚度（Lf - CMT）以及睫状肌纵向和径向纤维厚度（LRf - CMT）。
研究结果表明，随着白内障严重程度的进展，CBAXL减小，Lf - CMT增加。与白内障和正常眼睛相比，超声乳化术后，CBAXL显著增加，CPSA、Lf - CMT和LRf - CMT减小。回归分析显示，CBAXL与IOP之间存在显著正相关，Lf - CMT与IOP之间存在负相关。这些发现表明，受白内障进展和超声乳化影响的睫状肌动力学和厚度变化对眼内压有明显影响。
该研究提出，超声乳化导致睫状肌收缩，引起睫状肌向内和向前移动。这种移动导致睫状间隙变窄和非常规流出途径收缩，可能导致术后青光眼风险增加。我们的研究有助于理解白内障手术后犬眼的解剖和生理变化，并强调在这些患者中监测IOP和睫状肌动力学的重要性。
