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Purpose: To evaluate the compression characteristics of the human lens nucleocortex in relation to its LOCSIII clinical grading., Methods: Sixteen subjects undergoing planned extracapsular cataract surgery had pre-operative slit-lamp examination and assessment of cataract LOCSIII grade followed by postoperative in vitro evaluation of the nucleus with measurement of 'linear compressibility' by a purpose-designed caliper incorporating a strain gauge, enabling the derivation of a graph of nuclear compression (D (mm) against applied force (F (N))., Results: Nuclear colour correlates with the force required to compress a lens to 75% of its original depth (F75) (R = 0.625, P = 0.017). Nuclear opalescence correlates with the force required to compress a lens to 75% of its original depth (R = 0.651, P = 0.012) and inversely with linear compressibility (DeltaD/DeltaF, the slope of the graph of nuclear compression against applied force) (R = -0.610, P = 0.014). F75 is a direct and linear compressibility is an inverse related parameter of lens nucleus 'hardness'., Conclusion: A new instrument is described which allows measurement of 'hardness'-related compression characteristics of the human cataract in vitro. There is a relationship between the LOCSIII clinical classification of nuclear cataracts and mechanical compression characteristics of the cataractous lens. LOCSIII classification may aid the preoperative planning of an appropriate surgical approach to an individual cataract.

Biometry allows determination of the final refractive outcome following cataract extraction with intraocular lens implantation. We compared the accuracy of axial length measurement performed with the slit-lamp supported biometry probe versus a hand-held technique. The two methods of biometry were performed on 32 patients undergoing endocapsular cataract extraction with lens implantation. One of the methods was selected at random in order to predict implant power for a desired refractive outcome using the SRK-T formula. There was no difference in 'within-subject' variance of axial length measurement between the two methods (t = 1.74, p = 0.091), and there was no difference in refractive outcome when the power calculations for the two techniques were compared (t = 0.12, p = 0.906). The hand-held technique provides a useful alternative method of biometry in 'difficult' patients.

Medical audit is now a well-established part of the routine of ophthalmology departments. Accomplishing a complete audit is a complex task and its effectiveness depends on how it is performed. In order to evaluate the procedure in our department a retrospective analysis of 18 audits was carried out with particular reference to the level, objectives, beneficial effects, and effects on current practice. Our practice was critically analysed using these factors. One audit fulfilled the criteria for a full audit. Eleven (60%) were partial or potential and six (30%) were an attempt in planning an audit. The majority omitted plans for implementing change or targets for future assessment. Seven had educational benefit. There was little effect on patient care, cost-effectiveness or communication. Medical audit can be clinically effective, educational and stimulating. Failure to complete all stages affects the outcome. This study identifies the difficulties involved in performing complete audits and suggests improving the procedure by auditing audits on a regular basis.

Following cataract surgery, entrapment of the iris within the surgical wound is often managed by intensive use of miotics. As the radial fibres stretch, only a small amount of fraction is exerted upon the entrapped iris. Application of a combination of phenylephrine and pilocarpine drops causes simultaneous contraction of the pupil sphincter and the radial muscle fibres. This study investigated the relative magnitude of forces induced in the iris periphery by pilocarpine and phenylephrine and the effectiveness of adding g. phenylephrine 10% to g. pilocarpine 4% drops in the treatment of postoperative irido-corneal adhesions. The investigation was divided into two parts. First, the forces induced in the iris periphery upon exposure to pilocarpine and phenylephrine were measured in 6 cadaver irises. The mean force was 27.5 +/- 5.7 x 10(-3) N for pilocarpine and 23.3 +/- 4.0 x 10(-3) N for phenylephrine. The combination of the two drugs produced a force of 54.2 +/- 6.6 x 10(-3) N (p < 0.05). In the second part of the study intensive pilocarpine 4% drops were administered to 17 patients who had iris-wound entrapment on the first post-operative day. Patients with persistent adhesion were commenced on intensive g. phenylephrine 10% and assessed after 90 minutes. Of the 17 patients, 6 responded to pilocarpine drops alone; in a further 7 the irido-corneal adhesion was released only by the addition of phenylephrine drops, and in 4 patients drops were ineffective in relieving the adhesion. This study indicates that addition of phenylephrine 10% to pilocarpine 4% drops enhances the effectiveness of pharmacological treatment of post-operative irido-corneal adhesion.

A cataract is said to be mature when all the cortical fibres become opaque. Depending on the pathophysiological processes that cause the cortical fibre opacification this phenomenon may be associated with a varying degree of nuclear sclerosis. A relationship between lens hardness and degree of nuclear sclerosis in non-mature cataracts has been demonstrated previously. This study aimed to investigate the relationship between the hardness of mature cataracts and the transmitted nuclear colour, age and rate of progression of the cataract. Thirty-eight patients with mature cataracts were assessed prior to extracapsular cataract surgery. The nuclear colour that was transmitted through the opaque cortex was graded using reference photographs. Age and duration of visual symptoms were recorded and lens hardness was measured by a specially designed lens guillotine. Multivariate analysis of data indicates a relationship between hardness of a mature cataract and the transmitted nuclear colour and age (adjusted R2 = 0.59). There is also a tendency for hardening of the lens as the duration of visual symptoms increases. By considering these clinical markers, the cataract surgeon can estimate the hardness of the lens and therefore its suitability for phacoemulsification.

With the increasing trend towards phacoemulsification a perceived increased complication rate during the learning curve gives rise to a dilemma as to the best stage at which a surgeon-in-training can safely learn the technique. We prospectively analysed the complications and visual outcome of the first 160 phacoemulsification procedures performed by three surgeons-in-training. The main outcome measures included posterior capsule tear, vitreous and nuclear loss, surgical re-intervention rate and visual outcome. Posterior capsule tear occurred in 7 eyes (4.4%) and vitreous loss in 6 (3.8%). No nucleus was lost in the vitreous. Surgical re-intervention was required in 1 eye. Best corrected visual acuity was 6/12 or better in 88% of eyes. These results compare favourably with reports of surgeons-in-training learning extracapsular surgery and also with recently reported phacoemulsification series. This study indicates that with careful case selection and supervision phacoemulsification can be a safe procedure.

Hardening of a cataractous lens is associated with the clinical appearance of brunescence and advancing age. Alterations in the nature and concentration of proteins, lens fibre compaction and other biochemical changes may all be contributing factors towards increased hardness. As the nucleus confers most of the rigidity to the lens and water content decreases towards the centre of the nucleus, the hardness might be thought to be related to total water content. To study the relationship between water content, hardness and the clinical appearance of cataract, 135 lenses were obtained from eyes undergoing extracapsular cataract surgery. The cataracts were assessed and classified pre-operatively. Lens hardness was determined by a specially designed guillotine and water content was measured by weighing the lens before and after desiccation. A regression analysis was carried out to look at the variation of lens water content with hardness, degree of nuclear sclerosis, extent of cortical and posterior subcapsular cataract, vacuolation and age. Multivariate analysis of data demonstrated a relationship between lens hardness and lens water content, degree of nuclear sclerosis and age (R2 = 0.59). An association could not be detected between lens water content and age, degree of nuclear sclerosis, extent of cortical and posterior subcapsular cataract and vacuoles. This study suggests that hardening of the lens is reflected by a respective decrease in water content. Increased hardness is associated with coloration and advancing age.

Acanthosis nigricans classically presents with pigmented skin lesions over the neck, groin and axillae. It may involve the mucosal surfaces, particularly the oral mucosa. Conjunctival involvement is very rare, especially in the variety associated with malignancy. We report a case of acanthosis nigricans associated with squamous cell carcinoma of the bronchus where bilateral papillary conjunctivitis, progressing to hypertrophic papillary conjunctival and lid margin lesions, was the presenting feature. Topical treatment with corticosteroid and artificial tear drops resulted in the partial improvement of the ocular symptoms.

'Hardness' of the cataractous lens is one of the major factors influencing the suitability of a patient for phacoemulsification. Surgeons should be able to estimate hardness when choosing patients for this method of cataract extraction. The aims of the study were to investigate the relationship between the clinical appearance of cataracts and their hardness. Ninety-one lenses were studied from patients undergoing endocapsular cataract extraction. Lenses were assessed using a classification based on the Lens Opacities Classification System II and hardness was assessed using an automated lens guillotine. The degree of nuclear sclerosis and the age of the patient were found to influence lens hardness. Regression analysis showed that 56% of the variation in hardness could be explained in terms of age and the degree of nuclear sclerosis. The presence of posterior subcapsular and cortical cataract did not influence hardness. These findings confirm our clinical suspicions and enable surgeons to make a more objective analysis of hardness prior to phacoemulsification.