• Journal of Veterinary Clinics
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• v.28 no.6
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• pp.562-565
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• 2011

A total of 29 eyes (25 dogs: one eye, 2 dogs: both eyes) with indolent corneal ulcer were treated with grid keratotomy from January 2008 to March 2010. The corneal lesions were reevaluated at 7-14 day intervals. The treatments had been repeated until fluorescein dye was not retained on the cornea and the epithelium did not appear to be loosely attached to the stromal layer. The healing rate of the corneal ulcers was 86.2%. The mean healing time ($mean{\pm}SD$) was $15.92{\pm}9.19$ days, ranged from 7 to 39 days. The lesions of remaining 4 eyes had deteriorated or not improved for more than 6 weeks. In those cases, $3^{rd}$ eyelid flap following grid keratotomy was applied. After 2 weeks, all of the eyes healed by the treatment. The results in this study suggest that grid keratotomy could be an excellent choice as an initial treatment for superficial corneal ulcers in dogs. In the cases of recurrence or to promote healing of the lesions, however, $3^{rd}$ eyelid flap following grid keratotomy is recommended.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.45-51
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• 1999

The purpose of this study is to investigate the effects of various factors in keratotomy for astigmatism correction on surgical outcomes by finite element method as well as animal experiments. Three kinds of surgical techniques were mechanically investigated : arcuate, straight, and inverse arcuate keratotomy. Among the three techniques the arcuate keratotomy is the most popular one while the other two techniques are being investigated in this area. The arcuate keratotomy was found to be more controllable and effective in reducing the refractive power than the others. In arcuate keratotomy it was found most effective when the incision was located in the middle position between the apex and the edge of the cornea from the results of experiment as well as finite element study. Regarding to the range of the corneal incision in arcuate keratotomy, the incision angle of 90$^{\circ}$ was found th be most effective in reducing refractive power than other angles even it was incised up to 150$^{\circ}$. Therefore, it was concluded that 90$^{\circ}$ of incision angle results in the largest decrease in refractive power in arcuate keratotomy. However, other important findings were that the effect of the surgery decreased with time so the visco-effect of the cornea and auto-healing process. Therefore, these factors should be considered in future studies.

• Journal of The Korean Ophthalmological Society
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• v.60 no.2
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• pp.126-134
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• 2019

Purpose: To assess the accuracy of toric intraocular lens (IOL) implantation by the location and size of the corneal incision. Methods: We retrospectively reviewed the medical records of 98 patients (98 eyes) who underwent phacoemulsification with toric IOL implantation from January 2014 to March 2017. The patients were divided into two groups: group 1 got an incision of the superior side of the cornea (n = 54) and group 2 received an incision on the temporal side of the eye (n = 44). For both groups, incisions were made at their steep corneal astigmatism axises. Each group was further divided into subgroups for whom different sized blades were employed (2.75 vs. 2.2 mm widths). We measured the refractive index and autokeratometric parameters. We postoperatively assessed residual astigmatism and any reduction thereof. Results: In both groups, uncorrected and best-corrected visual acuity, refraction cylinder astigmatism, and autokeratometric astigmatism improved statistically. Between two groups, corneal astigmatism decrease was not significant. Residual astigmatism also showed no significant differences between the two. Patients in both groups treated using 2.75 mm wide blades exhibited greater increases in corneal astigmatism. Conclusions: During cataract surgery, precise correction of astigmatism via toric IOL implantation is possible when surgically induced astigmatism is minimized by careful choice of the location and size of the corneal incision.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.37-38
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• 2006

본 연구에서는 압전체의 횡 진동모드를 이용한 압전 초음파 진동자를 설계 분석하였다. 이전의 란쥬반 진동자는 진동을 얻기 위하여, 복수의 원판 또는 사각판 형태의 압전 세라믹을 서로 반대 방향으로 분극하여 마주 보도록 설치한 후 전기적으로 병렬로 연결하고 상단 및 하단에 금속부을 부착하여 전체를 볼트로 조인 복잡한 구조와 큰 출력 파워를 갚는 반면, 본 연구에서는 판상형의 압전소자와 일체형 금속진동체를 이용하여 기계적 출력 파워 조절이 용이한 구조의 압전 진동자를 고안하여, 압전진동자의 횡 진동 모드를 이용함으로써 신뢰성과 정확도가 높고 진동효율이 최대가 되도록 설계하였다. 설계 개발된 압전 진동자는 진동의 크기 조절이 용이하여 일반 진동자 뿐 만 아니라, 외과 및 안과 수술에 있어서 인체조직이나 각막상피의 활성화를 유지한 상태에서 안전하게 절개 및 분리 시술용 진동자로 사용 할 수 있는 이점이있다. 압전 진동자는 유한요소법 시뮬레이션 프로그램 (ATILA 5.2.4)을 이용하여 설계를 하였으며 압전소자의 두께는 각각 0.2 mm, 0.5 mm로 제작하여 시뮬레이션 결과와 제작된 샘플의 특성을 비교하였고, 변위측정은 칼날을 결합 한 상태에서 공진 주파수대역 부근 주파수별로 측정 비교하였다.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1114-1121
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• 2018

Purpose: We report the clinical outcomes of patients undergoing additional widening of the limbal incision to prevent disease recurrence after conjunctivo-limbal autograft combined with pterygial excision. Methods: We retrospectively compared 95 eyes with primary and 12 eyes with recurrent pterygia randomized to treatment via two surgical methods: conjunctivo-limbal autograft alone and combined with widening of the limbal incision to allow for pterygial removal. We widened the limbal incisions by 1 mm on both the superior and inferior limbal margins and removed the pterygia. The outcomes were compared between 39 eyes undergoing conjunctivo-limbal autograft alone and 68 eyes undergoing conjunctivo-limbal autograft with widening of the limbal incision. Results: The mean overall postoperative follow-up period was $29.6{\pm}10.5months$ and conjunctivo-limbal autograft alone group was $27.4{\pm}11.5months$, combined with widening of the limbal incision group was $30.7{\pm}9.7months$. Six pterygia (15.4%; four primary and two recurrent) developed in those undergoing conjunctivo-limbal autograft alone and two (2.9%; one primary and one recurrent) in those undergoing additional widening of the limbal incision; the recurrence rate differed significantly between the two groups (p < 0.05). In the group treated with conjunctivo-limbal autograft alone, the mean time to development of a new primary pterygium was $6.3{\pm}3.4months$ and that to development of a recurrent pterygium $4.3{\pm}2.5months$; the respective values for the group undergoing additional widening of the limbal incision were $12.1{\pm}2.6$ and $8.4{\pm}4.6months$; the recurrence rates differed significantly (p < 0.05). Conclusions: Conjunctivo-limbal autograft with additional widening of the limbal incision used to treat both new primary and recurrent pterygia was more effective in terms of reducing pterygial recurrence than conjunctivo-limbal aAutograft alone.