Objective morphological assessment of macular hole surgery by scanning laser tomography

AIM

To assess the morphological change in retinal topography using a scanning laser tomographer following macular hole surgery. To compare the results of scanning laser tomography with clinical evaluation and visual function assessment.

METHODS

The sample for this pilot study comprised four eyes exhibiting different stages of macular hole formation preoperatively. Subjects were assessed preoperatively and at 1 and 3 months postoperatively. Each assessment included visual acuity, letter contrast sensitivity, clinical examination (including automated static perimetry), and scanning laser tomography. The Heidelberg retina tomograph (HRT) was used to acquire digitised scanning laser tomography images of the macula (10 degrees and 20 degrees fields). Surgery essentially comprised vitrectomy, peeling of the posterior hyaloid face, if still attached, and intraocular gas tamponade. The magnitude and significance of topographic change were determined postoperatively using the HRT topographic difference facility.

RESULTS

Topographic difference analysis of the right and left eyes of case 1 showed a significant reduction in the height of the retina postoperatively. Topographic difference analysis of case 2 showed no significant change in topography. Topographic difference analysis of case 3 showed a significant increase in the height of the retina postoperatively. Scanning laser tomography agreed with clinical assessment based upon fundus biomicroscopy in three of the four eyes studied; the postoperative closure of the stage 2 macular hole (as noted by clinical assessment) proved to be too small to reach statistical significance. Scanning laser tomography agreed with the assessment of visual function in two eyes; the agreement between scanning laser tomography and visual function depends, in part, on the stage of development of the macular hole.

CONCLUSION

Scanning laser tomography provides an objective evaluation of the outcome of macular hole surgery. Studies employing larger sample sizes are required to fully determine the clinical worth of the technique.

Topical analgesia for superficial corneal injuries

OBJECTIVE

To assess the analgesic effects of a topical non-steroidal anti-inflammatory agent, flurbiprofen 0.03%, during healing after superficial corneal injuries.

METHODS

401 patients treated for corneal abrasion in a five month period were randomly allocated to one of four treatment groups: polyvinyl alcohol alone (control), homatropine 2%, flurbiprofen 0.03%, or homatropine 2% followed by flurbiprofen 0.03%. Treatments were given for 48 h. Ocular pain was recorded on a visual analogue scale by the patients over the first 24 h, and use of oral analgesics was also recorded. Usable responses were received from 224 patients (55.8%).

RESULTS

Patients treated with flurbiprofen had significantly lower pain scores for the 24 h duration of the study than controls (P < 0.05).

CONCLUSIONS

Flurbiprofen eye drops provide more effective pain relief than traditional treatments for superficial corneal injuries.

Pain and corneal foreign bodies

The commonest cause for ocular pain, presenting to an ophthalmic emergency centre, is due to corneal foreign bodies. Although the problem is transient, the degree of morbidity is often underestimated. The object of this study was to assess the degree of pain associated with these lesions.

Single medial injection peribulbar anaesthesia using prilocaine

A prospective randomised study is reported comparing a single peribulbar injection into the medial compartment of the orbit and the standard two injection peribulbar technique. One hundred and seven patients undergoing elective intra-ocular surgery were randomly allocated to receive either a single medial injection, or two injections, using prilocaine 3% with felypressin. Akinesia and pain during surgery were assessed following the injection(s). There was no significant difference in pain during surgery and globe akinesia between the two groups. The single medial peribulbar injection is as effective as two injections using prilocaine 3%.

A comparative study of the elastic properties of continuous tear curvilinear capsulorhexis versus capsulorhexis produced by radiofrequency endodiathermy

Capsulorhexis using radio-frequency endodiathermy may confer some advantages over continuous tear curvilinear capsulorhexis (CTCC) in certain clinical situations. It is unclear whether a capsulorhexis produced in this fashion has the clinically advantageous elasticity and resistance to tearing that a CTCC has been demonstrated to have. To investigate this, a test of capsular elasticity was carried out on pairs of eyes obtained from an eye bank, 42 eyes of 21 patients in total, using modified digital vernier calipers. One eye of each pair had a CTCC, the other a diathermy capsulorhexis (DC). The elasticity of the capsule in both groups was expressed by comparing the circumference of the capsulotomy at rest with its circumference at rupture. The mean capsular elasticity of the CTCC group was significantly greater than that of the DC group (p << 0.001). The capsular edge in both groups was examined using scanning electron microscopy, and the difference in morphology appears to be the source of the difference in elasticity.