Changes in Corneal Sensitivity after Cataract Surgery

PURPOSE: To evaluate the changes in corneal sensitivity following cataract surgery with a limbal incision. METHODS: The sensitivity threshold was measured in 53 eyes following procedures using a superior limbal incision (42 eyes) or a temporal limbal incision (11 eyes). RESULTS: The corneal sensitivity was significantly lower at the superior and temporal limbal incision sites after surgery than at the other sites (p<0.05). That sensitivity recovered 90% of its preoperative level 30 days post-operative. CONCLUSIONS: Corneal sensitivity decreased following cataract surgery using limbal incision. There were no significant differences in either the rate of decrease or recovery of corneal sensitivity according to the incision sites.

Effect of Difference of Binocular Retinal Illuminance on Stereopsis

PURPOSE: We examined the effect of induced interocular difference of retinal illuminanace on stereopsis. METHODS: Fifty adults who have normal binocularity were examined with neutral density filters. The mean age was 29.1 years. While the monocular retinal illuminance was gradually reduced by increasing the value of neutral density filters, we measured the best corrected visual acuity and stereoacuity with Titmus test and Lang test. We used neutral density filter from 1.0 neutral density (ND, 10% transmit) to 3.0ND (0.1% transmit) with intervals of 0.2ND. RESULTS: The best corrected visual acuity began to decrease significantly when the value of neutral density filter reached 2.0ND (1% transmit). Stereoacuity also began to decline when the value was 1.4ND(4% transmit) with Titmus test and 1.6ND (2.5% transmit) with Lang test. CONCLUSIONS: Change of retinal illuminance effects more on stereoacuity than visual acuity as stereoacuity decreased earlier by increasing the value of density filters. These results imply that the stereopsis test could be more useful than visual acuity test for detecting ocular abnormalities influencing the retinal illuminance.

Necrotizing Conjunctival Ulceration following Subconjunctival Atropine Depot Injection

PURPOSE: To report a case of severe conjunctival necrosis associated with scleral melting following subconjunctival atropine depot injection in treating posterior synechiae associated with uveitis. METHODS: A 31-year-old male patient visited our clinic after subconjunctival injection of 1% atropine, 0.4 ml, in treating circular posterior synechiae associated with uveitis in his left eye. The marked conjunctival injection and chemosis around the limbus were noted. Three days after first visit to our clinic, remarkable necrosis had developed around the whole limbus, and newly developed whitish necrotic tissue was noted over sclera and episclera. We debrided the necrotic conjunctiva and episclera, and the exposed sclera was grafted with amniotic membrane. REUSLTS: After 4 weeks, the complete re-epithelization of necrotized defect was shown and there were no evidence of inflammation, symblepharon, or scleral melting. CONCLUSIONS: In usage of atropine, especially to eyes locally, subconjunctival injection should be avoided due to direct toxicity to the conjunctiva and sclera to form necrosis and melting. The damaged lesions of conjunctiva and sclera due to usage of this drug generally cause chronic inflammation and persistent surface defect. In order to restore and re-epithelize the necrotic defect, more aggressive treatment such as an amniotic membrane transplantation would be needed.

Visual function and quality of life in Korean patients with glaucoma

The relationship between visual acuity, the level of visual field impairment, visual functioning, and the quality of life was evaluated in Korean patients with glaucoma. Forty-three consecutive glaucoma patients from the glaucoma service at Severance Eye and Ear Hospital were included in this study. Each subject underwent a vision-specific functional status questionnaire (VF-14), a modified VF-14 (VF'-14) and general quality-of-life questionnaires of the Medical Outcomes Study 36-Items Short Form Health Survey (SF-36). The visual acuity and visual field measurements with a Humphrey automated perimeter were taken within one month of the initial visit. The mean age of the subjects was 57.9 +/- 17.8. Among these patients, there were 23 males and 20 females. The mean deviation (MD) and the corrected pattern standard deviation (CPSD) by the automated perimeter in the eye with the better visual acuity were -5.87 +/- 5.16 dB and 3.92 +/- 2.74 dB respectively. The VF-14 and SF-36 scores were 41.28 +/- 14.56 and 52.39 +/- 6.61 respectively. There were significant correlations between the VF-14, VF'-14, and the MD of the better eye (p < 0.05). In Korean patients with glaucoma, the VF-14 and VF'-14 have significant relationship with the MD of the better eye in the visual field.

Comparison of surgical outcomes between small collagen and chromic catgut implants in deep sclerectomy

In deep sclerectomy, collagen implant has been used to maintain space under the scleral flap. However, the effect of other implants has not been studied. In this retrospective study, we compared surgical outcomes between small collagen and chromic catgut used as implants in deep sclerectomy. Deep sclerectomy was performed on 23 patients (25 eyes) who either had an open angle and a high intraocular pressure (IOP) (> 22 mmHg) in spite of receiving the maximal tolerable medical treatment, or who were intolerant to medications. Our study consisted of 14 patients (15 eyes) in the small collagen group and 8 (9 eyes) in the chromic catgut group. The mean follow-up period was 8.6 +/- 3.3 months in the small collagen group and 4.4 +/- 1.2 months in the chromic catgut group. The mean preoperative IOP was not significantly different between the two groups. The complete success rate of the small collagen group was significantly better than that of the chromic catgut group at the final follow-up when data were analyzed using the Kaplan-Meier survival curve (87% versus 30%; P = .01). As for the qualified success rate, the small collagen group showed significantly better results at the final follow-up (93% versus 80%; P = .046). The mean number of postoperative medications was significantly lower in the small collagen group (0.26 versus 1.10; P < .05). These results confirmed that the use of small collagen implant in deep sclerectomy produced a higher success rate and a lowered need for postoperative medication compared to the use of chromic catgut implant. Because equal sized implants were used, the difference in biochemical properties, particularly the severity of inflammation caused by the implant, is presumed to be the cause of the different surgical outcomes.