Keratoconus associated with continual eye rubbing due to punctal agenesis.

PURPOSE: To highlight a possible causal effect of eye rubbing in the etiology of keratoconus. METHODS: A 43-year-old man presented to the practice of one of the authors (I.F.G.) with the complaint of gradual onset reading difficulty. History revealed the patient to have experienced constant epiphora in the right eye throughout his life as a result of punctal agenesis, which necessitated frequent wiping of this eye. Vision in the patient's right eye had been reduced for approximately 20 years. RESULTS: Based on ocular examination, the patient was diagnosed as having unilateral keratoconus in the right eye. CONCLUSION: It is thought by some that keratoconus is associated with, or indeed caused by, persistent rubbing of the anterior eye. While a number of studies support a genetic basis for keratoconus in some patients, it is possible that mechanical factors play a role in the development of this condition in other patients. This paper presents a case of unilateral keratoconus, where there is a confirmed history of habitual eye rubbing and wiping of excess tears as a result of punctal agenesis in the ipsilateral eye, thereby suggesting a possible causal relationship of eye rubbing in the etiology of keratoconus.

Videokeratoscopy in contact lens practice.

Videokeratoscopy is an important addition to contact lens practice, where a better understanding of corneal contour obviously helps the practitioner to achieve an optimal fitting relationship between the contact lens and the cornea. A variety of topographical maps, encompassing a large range of corneal conditions, are presented in this study to illustrate the different corneal contours the contact lens clinician is likely to encounter in practice. Interpretation of these corneal maps is outlined, with an emphasis on how one determines the appropriate contact lens fitting strategy based on the videokeratoscopic image.

Oral nalbuphine for the treatment of pain after dental extractions.

A randomized, double-blind comparison of nalbuphine 30 mg or 60 mg by mouth and dihydrocodeine 30 mg by mouth was conducted in 75 patients with moderate to severe pain after surgery for dental extractions under general anaesthesia. A significant reduction in pain intensity followed each treatment and persisted throughout the 4-h observation period after nalbuphine, but only for 3 h after dihydrocodeine was given. Reduction in pain intensity was significantly greater 2, 3 and 4 h after the use of nalbuphine 60 mg than following dihydrocodeine 30 mg, and the mean total pain intensity difference was greater following nalbuphine 60 mg than following dihydrocodeine. Nalbuphine 60 mg effectively provided complete or good pain relief in more than 50% of the patients and only three patients in this group required additional analgesia during the period of observation, compared with nine patients in each of the other groups. However, the patients who received nalbuphine 30 mg had a significantly higher mean pain intensity before treatment than those in the other groups. The side-effects encountered were those typical of opioid medication; there were no statistically significant differences between the groups.

Reconstruction of the medial collateral ligament for tarsocrural luxation in the dog: a preliminary study.

Seven cases of tarsocrural subluxation/luxation resulting from ruptures of the medial collateral ligament were treated by double prosthetic replacement. The technique was a revision of an earlier described method without the use of metallic implants. Six (100%) of six cases not involving additional joint fractures had excellent clinical results with minimal compromise to range of joint motion. In three (50%) of six cases where braided polyester sutures were implanted as the prosthesis, fistulating tracts developed. Drainage resolved with removal of the suture in each of these three cases, and two of the three proceeded to excellent results after replacing the braided suture with monofilament suture.

Morphological variants in keratoconus: anatomical observation or aetiologically significant?

PURPOSE: Two morphological cone variants are identified in keratoconus; nipple and oval. The present study was designed to assess the impact of aetiological factors on cone morphology. METHODS: As part of a prospective controlled study, keratoconic subjects from a suburban practice (n = 89) underwent videokeratograph examination and completed a questionnaire detailing aetiological factors. RESULTS: Comparison of 95% confidence limits (CL; bootstrap method) for apical power between the two cone morphology groups showed no statistical significance. Oval cones were located at a greater eccentricity than nipple cones, as their definitions suggest. Associations between aetiological factors examined and the morphology of the cone were not significant (bootstrapped 95% CL). CONCLUSION: Despite the suggestion of morphological variants in keratoconus, the results of the present study suggest a common cone aetiology.

Soft lens movement: temporal characteristics.

The time-course of on-eye hydrogel lens movement has not been carefully scrutinized, despite the importance of lens movement in optimizing lens fit and corneal physiology. We conducted a study to define the time-course of soft lens movement using 26 subjects. Video slitlamp recordings were made of lens movement at 5-min intervals for 30-min wear and after 8-h wear of 38 or 67% water content lenses (N = 14 and 12, respectively). Lens mobility profiles were statistically indistinguishable for high and low water content lenses, and for experienced and neophyte lens wearers. Lens movement displayed biphasic temporal characteristics, decreasing significantly over the first 25 min from a median of 0.6 to 0.3 mm (Wilcoxon matched-pairs signed-rank test, p = 0.002), then increasing significantly to 0.5 mm after 8 h of wear (p = 0.03). Although some subjects exhibited little alteration in lens movement, 31% showed a decrease in lens movement > 0.25 mm during the first half-hour of wear. Optimal predictability of lens mobility after 8-h wear was achieved 5 min after insertion, with 77% of subjects displaying lens movement within +/- 0.25 mm of the final value. In-office assessment of lens movement is best achieved 5 min after insertion, although clinical and real world lens mobility will differ significantly in about one in four patients.