[Validation of the Russian version of the ureteral stent symptoms questionnaire (USSQ) for the evaluation of quality of life and stent-related symptoms]

INTRODUCTION

Ureteral stents are frequently used in urology practice and have a significant impact on health-related quality of life (QoL). In 2003 . Joshi et al. developed the specific questionnaire for evaluation of QoL and stent-related symptoms, namely Ureteral Stent Symptoms Questionnaire (USSQ). USSQ consists of 40 questions and 2 visual analog scales (VAS), divided into 6 domains. Over the past decade, this questionnaire has been translated into 9 languages. A Russian version of the questionnaire has not been developed yet.

AIM

To perform linguistic validation of the Russian version of the USSQ.

MATERIAL AND METHODS

Linguistic validation of the original USSQ was performed through a standard process including translation, back translation and pilot study. A total of 103 patients undergone ureteral stent placement and successfully filled in the Russian USSQ at weeks 1 and 4 after stenting, and at week 4 after stent removal. In addition, 30 healthy people filled in the same questionnaires twice at 3-week intervals, as a control group. To evaluate reliability, validity and sensitivity to change of the Russian USSQ, statistical analysis was performed. External criteria included validated questionnaires (EQ-5D, IPSS and pain VAS).

RESULTS

Content validity was approved by experts and proved during patients interviewing. Reliability test-retest was satisfactory for urinary symptoms, body pain, general health, and work performance domains (p<0,001 between test and retest evaluation). USSQ domains showed good correlations between each other (correlation coefficient was 0,80-0,94). Cronbach's alpha coefficient of internal reliability was 0.73-0.95. Correlation between other instruments and corresponding USSQ domains was good (p<0,001), proving criterial validity. Sensitivity to changes after stenting and stent removal was also good for most domains (p less or equal 0,001).

CONCLUSION

Russian version of USSQ is a valid, reliable and sensitive instrument for the assessment of QoL and stent-related symptoms and is ready for application in the routine clinical practice.

The impact of urinary stone disease and their treatment on patients' quality of life: a qualitative study

Urinary stone disease is a common, often recurrent disease, that can have a negative impact on patients’ health-related quality of life (HRQoL), often effecting working, productive members of society. The literature lacks data from structured, qualitative research which could give unique insight into patients’ HRQoL. The objective is to understand the impact of urinary stone disease and treatments on patients’ HRQoL, from patients’ and their relatives’ perspective using qualitative and quantitative methodologies. Semi-structured interviews and a focus group were used to understand the HRQoL issues of patients with urinary stones disease, covering the American Urology Association index stone categories. Thematic analysis was performed (using qualitative data analysis software). Familial impact was assessed using the family-related outcome measure (FROM-16©). 62 patients with stone disease and interventions (mean age 51, range 19–92) participated. Data collection stopped when data saturation was achieved. Analysis revealed negative impact of stone disease and interventions on the patients’ HRQoL, affecting domains of pain, physical symptoms, outlook on life, work/career, change in lifestyle/diet, social life, difficulties of daily living, travel/holiday problems, relationships and family member impact (106 themes grouped under ten broad headings). Sub-group analyses revealed similar impact in either sex, ureteric and renal stone groups. Recurrent stones were associated with work/financial concerns and treatment preferences varied accordingly. Our qualitative study presents detailed insights into the multidimensional impact of urinary calculi and their treatments on various domains of the HRQoL, confirming previous findings and adding new observations. The findings are expected to help in the development of patient-centric measures and communication tools.

Linguistic and cultural validation of Ureteral Stent Symptom Questionnaire in Hindi

Introduction:

In the year 2003, Joshi et al. developed a validated outcome assessment tool to measure the ureteral stent-related symptoms. The original English language Ureteral Stent Symptom Questionnaire (USSQ) has been validated in various languages worldwide. Our objective was to develop the USSQ in Hindi, a commonlyused language in India, by validating it in patients undergoing ureteroscopic lithotripsy.

Materials and Methods:

A final Hindi version of the USSQ was derived from the original English version to apply to the study population by translation, back translation, and face-to-face interviews. The Hindi and English versions were completed by 70 patients undergoing ureteroscopic lithotripsy with stent in situ, on postoperative days 7 and 8, and 4 weeks after stent removal. Similarly, discriminant validity was checked among 50 healthy individuals. A detailed statistical analysis was used to correlate results (Cronbach's α coefficient, Spearman's correlation, and Mann–Whitney U-test).

Results:

A total of 70 patients were enrolled in the study and 61 completed the final assessment. The median age was 35 years (range: 18–60 years). The USSQ domain scores with the stent in situ were higher than poststent status. The test–retest reliability checked by Cronbach's α coefficient (>0.44) and Spearman's correlation coefficient (>0.44) were acceptable to good. We found high discriminant validity of the questionnaire between patients with stent and the healthy controls (P < 0.05).

Conclusion:

Our results demonstrate satisfactory validity for the Hindi version of the USSQ for the assessment of quality of life in patients with stent. This is ready for application in the clinical studies and the future stent-related research in Hindi language.

Investigating detrusor muscle concentrations of oxybutynin after intravesical delivery in an ex vivo porcine model

Intravesical oxybutynin is highly effective in the treatment of overactive bladder. Traditionally the mechanism of action was explained by antagonism of muscarinic receptors located in the detrusor, however evidence now suggests antimuscarinics may elicit their effect by modifying afferent pathways in the mucosal region. This study aimed to investigate the bladder wall distribution of oxybutynin in an ex vivo setting providing tissue - layer specific concentrations of drug achieved after intravesical delivery. Whole ex vivo porcine bladders were intravesically instilled with 0.167 mg mL(-1) oxybutynin solution. After 60 min, tissue samples were excised, serially sectioned parallel to the urothelial surface and extracted drug quantified. Drug distribution into the urothelium, lamina propria and detrusor was determined. Oxybutynin permeated into the bladder wall at a higher rate than other drugs previously investigated (apparent transurothelial Kp = 1.36 × 10(-5) cm s(-1) ). After 60 min intravesical instillation, concentrations achieved in the urothelium (298.69 μg g(-1) ) and lamina propria (43.65 μg g(-1) ) but not the detrusor (0.93 μg g(-1) ) were greater than reported IC50 values for oxybutynin. This work adds to the increasing body of evidence suggesting antimuscarinics elicit their effects via mechanisms other than direct inhibition of detrusor contraction.

The Italian linguistic validation of the ureteral stent symptoms questionnaire

PURPOSE

We validated the Italian version of the Ureteral Stent Symptoms Questionnaire in male and female patients with an indwelling ureteral stent.

MATERIALS AND METHODS

A double-back translation of the original Ureteral Stent Symptoms Questionnaire was performed by 3 urologists and 4 professional translators. A total of 78 patients (cases) with and 35 healthy subjects without (controls) an indwelling ureteral stent were asked to complete the Italian version of the Ureteral Stent Symptoms Questionnaire and a visual analog scale for pain as well as the International Prostate Symptom Score (men) and Urogenital Distress Inventory-6 plus Incontinence Impact Questionnaire-7 (women). Cases were evaluated at weeks 1 and 4 after stent placement, and at week 4 after removal, while controls were evaluated once. The psychometric properties of the questionnaire were analyzed.

RESULTS

A total of 66 cases and 30 controls were suitable for analysis. The questionnaire showed good internal consistency in all domains except global quality of life compared with that of the International Prostate Symptom Score (Cronbach's alpha >0.75). Test-retest reliability was good except for the sexual matters domain (Pearson's coefficient >0.7). Relatively high correlation coefficients (greater than 0.65) were found for the visual analog scale for pain, the International Prostate Symptom Score, the Urogenital Distress Inventory-6 and the Incontinence Impact Questionnaire-7 with the corresponding Ureteral Stent Symptoms Questionnaire domains, suggesting good convergent validity. Sensitivity to change and discriminant validity were also good (p <0.001).

CONCLUSIONS

The Italian version of the Ureteral Stent Symptoms Questionnaire is a reliable and robust instrument that can be self-administered to male and female Italian patients with an indwelling ureteral stent in the clinical and research settings.

A PROSPECTIVE RANDOMIZED SINGLE-BLIND COMPARISON OF URETERAL STENTS COMPOSED OF FIRM AND SOFT POLYMER

PURPOSE

Ureteral stents are composed of different polymers and it is unclear if stent composition influences patient comfort. We compared the impact of stents composed of firm and soft polymer on patient health related quality of life.

MATERIALS AND METHODS

A total of 130 patients requiring insertion of ureteral stents during the treatment of urinary calculi were randomized to receive a stent composed of firm (Percuflex, group 1) or soft (Contour, group 2) polymer. Patients were asked to complete the Ureteric Stent Symptoms Questionnaire, a validated instrument, at weeks 1 and 4 with the stent in situ and 4 weeks after its removal, this served as the main outcome measure. Additional assessments included difficulty in stent insertion and the need for early stent removal.

RESULTS

There were 78 men and 38 women in total (61 in group 1 and 55 in group 2) with a mean age of 51 years (range 22 to 79) and no difference in age between the 2 groups (p = 0.9). Comparison of the results of the Ureteric Stent Symptoms Questionnaire survey at weeks 1 and 4 with stent in situ revealed no significant differences in the domain scores of urinary symptoms (p = 0.9 and p = 0.8), pain (p = 0.8 and p = 0.6) and general health (p = 0.6 and p = 0.4). Similarly, there were no differences in the number of days with reduced activities, work performance (p = 0.7) and sexual dysfunction between the 2 groups. A similar number of patients (8 and 7 in groups 1 and 2, respectively) required stent removal earlier than planned due to stent related symptoms.

CONCLUSIONS

This randomized study showed no difference in the impact on patient quality of life between ureteral stents composed of firm or soft polymer.

Ureteral stent symptom questionnaire: development and validation of a multidimensional quality of life measure

PURPOSE

We developed the ureteral stent symptom questionnaire (USSQ), a psychometrically valid measure to evaluate symptoms and impact on quality of life of ureteral stents.

MATERIALS AND METHODS

A total of 309 patients were asked to participate during different phases of our study. In phase 1 a structured literature search, 9 patient interviews and studies of 90 patients using existing instruments formed the foundation for the initial draft of our new questionnaire. In phase 2 the USSQ was pilot tested, reviewed by experts and field tested in 40 patients to produce a final 38-item draft. In phase 3 formal validation studies were performed in 55 patients to assess validity, reliability and sensitivity to change. Discriminant validation was performed by administering the questionnaire to 3 groups of patients without stents.

RESULTS

The final draft addressed various domains of health (6 sections and 38 items) affected by stents covering urinary symptoms, pain, general health, work performance, sexual matters and additional problems. The validation studies showed the questionnaire to be internally consistent (Cronbach's alpha > 0.7) with good test-retest reliability (Pearson's coefficient > 0.84). The questionnaire demonstrated good construct validity and sensitivity to change shown by significant changes in the score with and after removal of stents. The new USSQ discriminated patients with stents from healthy controls (p < 0.001) and patients with urinary calculi without stents and lower urinary tract symptoms.

CONCLUSIONS

Indwelling ureteral stents have a significant impact on health related quality of life. The new USSQ is a valid and reliable instrument that is expected to become a standard outcome measure to evaluate the impact and compare different types of stents.

Indwelling ureteral stents: evaluation of symptoms, quality of life and utility

PURPOSE

We report the prevalence of symptoms associated with ureteral stents, their impact on health related quality of life and utility analysis based on the validation studies of the new ureteral stent symptom questionnaire (USSQ).

MATERIALS AND METHODS

A total of 85 consecutive adult patients with unilateral indwelling ureteral stents who were asked to participate during the validation phases of the USSQ were considered for this analysis. They were asked to complete the USSQ and the EuroQol, a weighted utility instrument, 4 weeks after stent insertion and removal. In addition, 40 patients were asked to complete these questionnaires 1 week after stent insertion to assess the prevalence of symptoms and utility values at different times.

RESULTS

Of the 85 patients 62 (73%) with a mean age of 50 years completed the necessary questionnaires. Urinary symptoms and pain that affected work performance and general health were important stent related problems. Of the patients 78% reported bothersome urinary symptoms that included storage symptoms, incontinence and hematuria. More than 80% of patients experienced stent related pain affecting daily activities, 32% reported sexual dysfunction, and 58% reported reduced work capacity and negative economic impact. The mean EuroQol utility values, which indicate patient satisfaction with treatment, were significantly reduced following stent insertion.

CONCLUSION

Urinary symptoms and pain associated with indwelling ureteral stents interfere with daily activities and result in reduced quality of life in up to 80% of patients. Stents are associated with negative functional capacity and reduced utility values. The results have implications in terms of routine clinical practice, patient counseling and future stent research.

Endoluminal ultrasonography with reusable probe: preliminary results

BACKGROUND AND PURPOSE

Endoluminal ultrasound probes have been disposable, making their regular use costly. We describe the technique and preliminary results of a reusable endoluminal ultrasound probe for examining ureteral anatomy.

PATIENTS AND METHODS

The 2.4-mm (7.2F) or 3-mm (9F) probe (Olympus, Tokyo) is passed up the ureter after a retrograde ureteropyelogram has been obtained. No intraoperative preparation of the probe is needed. An axial image as little as 1 cm or as much as 10 cm around the ureter can be obtained. Over the last 20 months, 50 procedures using endoluminal ultrasonography were performed in our unit: 36 (72%) for uretero-pelvic junction (UPJ) obstruction, 10 (20%) for upper-tract filling defects, and the remaining 4 (8%) for ureteral strictures.

RESULTS

Endoluminal ultrasonography detected crossing vessels at the UPJ in 19 (53%) and a septum in 9 (25%) of the 36 renal units with UPJ obstruction. In eight of the 36 renal units with UPJ obstruction (22%), endopyelotomy was not done because of the presence of crossing vessels. A further 4 renal units (11%) had the direction of the incision modified because of the ultrasound findings. In the cases with upper-tract transitional-cell carcinoma, images correlated well with the nephroureterectomy specimen. The probe had to be replaced twice.

CONCLUSIONS

This endoluminal ultrasound system produces clear images of the ureteral and periureteral anatomy. The reusable aspect of the probe removes an important obstacle to its common use for evaluating a variety of upper urinary tract abnormalities.

Characterization of urinary symptoms in patients with ureteral stents

OBJECTIVES

To prospectively assess the prevalence and bother of various urinary tract symptoms caused by indwelling ureteral stents using validated questionnaires.

METHODS

The study consisted of 60 patients with unilateral ureteral stents. Of these, 30 patients were asked to complete the International Prostate Symptoms Score questionnaire, with additional questions on dysuria, hematuria, and loin pain. The remaining 30 patients were asked to complete the International Continence Society questionnaire. These patients were also asked to complete frequency volume charts and undergo uroflowmetry studies. The questionnaires were completed with a stent in situ and 6 weeks after its removal.

RESULTS

Forty-eight patients (36 men and 12 women, mean age 52.8 years) completed the study. A large proportion (80%) of patients reported one or more urinary symptoms. Analysis of the IPSS data revealed impaired global quality of life owing to these urinary symptoms. The responses to additional questions on dysuria and hematuria showed a statistically significant difference, but most International Prostate Symptoms Score questions did not. The results of the International Continence Society study identified storage symptoms, incontinence (60%), and bladder pain (80%) as important bothersome problems. The results of the frequency volume charts were in agreement with the storage symptoms.

CONCLUSIONS

Patients with indwelling ureteral stents have a wide range of urinary symptoms that affect their quality of life. Storage symptoms, bladder pain, and hematuria pose a major bother. None of the existing questionnaires covered the entire range of symptoms. The results are useful in better understanding the urinary symptoms associated with stents and in providing patient counseling.

The development and validation of a patient-information booklet on ureteric stents

OBJECTIVE

To report a scientific approach incorporating patient preferences towards the development of a patient-information booklet about ureteric stents.

PATIENTS AND METHODS

Phase 1 of the study included 35 adult patients with ureteric stents who were surveyed using semi-structured interviews (four patients) and a questionnaire (31 patients) to assess various issues relating to information given to patients about ureteric stents. In addition, published papers were assessed and clinicians' opinions sought. The results formed the basis for a comprehensive patient-information booklet about ureteric stents that incorporated patients' views and preferences. In phase 2, the booklet was tested and formally validated by inviting 30 patients, a panel of 20 urologists and general practitioners, and five stent manufacturers to assess the booklet for adequacy, coverage and readability of the content.

RESULTS

Of the 35 patients, 30 (19 men and 11 women, mean age 49 years, range 20-78) participated in the initial survey; 80% of patients reported dissatisfaction about the information they received. Patients wanted more information about the use, adverse events and effects of stents on daily life; 85% preferred all relevant information about the stents to be in a written format with illustrative drawings. An eight-page booklet was thus developed. The validation study revealed that the booklet matched patients' experiences (approval score of 9/10, range 8-10) and was reported as satisfactory by clinicians and manufacturers.

CONCLUSIONS

A validated information booklet on ureteric stents was developed, incorporating patients' expectations and views. This booklet is expected to be an effective tool for patient communication that would help patients cope better with indwelling stents and be useful in counselling patients. A similar approach could be adopted for the development of other patient-information packs.

Nephrostomy tube or 'JJ' ureteric stent in ureteric obstruction: assessment of patient perspectives using quality-of-life survey and utility analysis

INTRODUCTION

Upper urinary tract obstruction is often relieved by either a percutaneous nephrostomy tube (PCN) or a ureteric stent. Both can cause considerable morbidity and reduce patient's health-related quality of life (QoL). We have compared the QoL in these 2 groups.

PATIENTS AND METHODS

34 patients (21 stent and 13 PCN) with unilateral ureteric obstruction were prospectively studied. Each patient completed a questionnaire, which included a common single health index (EuroQol EQ-5D) and intervention-specific questions to assess pain, urinary symptoms and day-to-day problems.

RESULTS

There were 22 male and 12 female patients [mean age 56+/-9 years (PCN) and 55+/-14 years (stent)]. The mean duration between the intervention and conduct of the survey was 12+/-5 days for PCN and 28+/-14 days for stent. There was no different in the mean EuroQol score (p = 0.199) and analogue score (p = 0.596) indicating no differences in the gross defects in physical and psychosocial function and the utility between the 2 groups. There was a significant difference in the urinary symptoms (p<0.0001) with patients who had a stent experiencing significantly more irritative urinary symptoms. This group also suffered discomfort for a greater duration and in various postures requiring more analgesia (although not significant with Bonferroni correction). Patients with PCN required more help in the daily care of the nephrostomy tube. There was no difference in the incidence of infections and the need for antibiotics.

CONCLUSIONS

Patients with 'JJ' stents have significantly more irritative urinary symptoms and a high chance of local discomfort than patients with nephrostomy tubes (PCN). However, based on the EuroQol analysis, there is no significant difference in the gross impact on the health-related QoL or the utility between these groups indicating no patient preference for either modality of treatment.

Citric acid (solution R) irrigation in the treatment of refractory infection (struvite) stone disease: is it useful?

OBJECTIVE

Citric acid, in varying concentrations, has been used in the dissolution treatment of struvite renal calculi. Solution R (Uro-trainer), which contains 6% citric acid, is a solution licensed for use in the management of struvite stone disease in the UK. We report our experience.

METHODS

23 kidneys in 22 patients (10 male and 12 female patients, mean age 45, range 15-60 years) underwent solution R irrigation following debulking of the stone with percutaneous nephrolithotomy (n = 20), ureteroscopy and shock wave lithotripsy (n = 2) combined with open procedures (n = 4) between 1994 and 1998. The original stone configuration consisted of 14 staghorn, 4 partial staghorn and 5 large burden stones. Irrigation was performed through a nephrostomy tube (n = 20) or in a retrograde fashion (n = 3) using a closed infusion pump system (40 ml/h). The response to treatment was checked using a nephrostogram and/or plain X-ray.

RESULTS

In 6 (26%) kidneys, after an average duration of 2 (1-5) days, irrigation had to be abandoned due to loin pain, leak or sepsis. The average duration of irrigation was 6.4 (1-20) days. At the end of irrigation, a total of 4 (17.4%) kidneys had complete radiographic clearance, while the stone was reduced to calyceal dust in 3 (13%). Partial response was seen in 11 (47.8%) and no response in 5 (21.8%) kidneys. Following additional alternative intervention(s) in 6 (26%) kidneys (4 with partial and 2 with no response) further clearance was achieved in 3 (13%) and calyceal dust status in 3 (13%). The response was better if the stone was reduced to less than 10mm prior to irrigation. At the mean follow-up of 2.44 (1-4) years, of 13 kidneys with stone clearance or calyceal dust, 9 suffered recurrence or re-growth, 5 of which required further interventions. Only 4 (17.4%) of 23 kidneys remained stone free.

CONCLUSIONS

In patients with complex stone disease, adjuvant solution R irrigation can reduce the stone burden. There is a considerable potential for side effects necessitating close monitoring for sepsis and electrolyte abnormalities. However, the overall success rate for solution R is limited.

Indwelling ureteral stents: evaluation of quality of life to aid outcome analysis

BACKGROUND

Ureteral stents cause various side effects. We have evaluated health-related quality of life (HRQoL) in patients with stents using validated questionnaires and developed a new stent symptom (intervention)-specific questionnaire (SSQ).

PATIENTS AND METHODS

Along with structured literature review and in-depth interviews, prospective sub-studies were carried out using generic (SF-36 [N = 30], EuroQol [N = 40], and Functional Status Questionnaire FSQ [N = 20]) and symptom-specific (IPSS [N = 30] and International Continence Society ICS [N = 30]) questionnaires both with a stent in situ and after removal. The results of these studies formed the foundation for a new SSQ that was pilot tested (N = 10) and field tested (N = 20) in order to develop a final draft of the questionnaire that is formally validated.

RESULTS

The qualitative research identified a range of problems. Urinary symptoms, pain, work performance, and general health were the most important. Most patients (80%) experienced bothersome urinary symptoms and stent-related pain. Storage symptoms and incontinence were significant urinary symptoms affecting quality of life. As many as 40% of patients experienced sexual dysfunction. The stent had a significant impact on patients' general health. None of the existing measures evaluated the complete impact. The SSQ includes five sections covering urinary symptoms, pain, sexual matters, general health, and work performance. The preliminary results showed it to be valid, reliable (alpha > 0.7) and responsive to the change in scores (p < 0.05) after stent removal.

CONCLUSIONS

Indwelling ureteral stents are associated with significant morbidity, resulting in a reduced HRQoL in 80% of patients. The SSQ is a reliable intervention-specific instrument that would be useful as an outcome measure to evaluate the impact of stents.

Leiomyoma of the female urethra with upper tract dilation and treatment with transurethral resection: a case report and literature review

Leiomyoma of the female urethra is a rare condition. It is a benign mesenchymal tumor that commonly presents with recurrent urinary tract infections and various lower urinary tract symptoms. We report a case of urethral leiomyoma and review the literature. A 44-year-old woman presented with severe irritative voiding symptoms without urinary tract infection and bilateral upper urinary tract dilation. Ultrasound and cystoscopy revealed a smooth mass arising from the urethra and projecting into the bladder. Transurethral resection of the mass was performed and 32 g of tissue was removed. There were no complications and the symptoms resolved completely, indicating this to be a safe approach. Histopathology showed the tumor to be leiomyoma.

A comparative analysis of nephrostomy, JJ stent and urgent in situ extracorporeal shock wave lithotripsy for obstructing ureteric stones

OBJECTIVES

To determine the optimal method of treatment for ureteric stones causing complete obstruction, treated by insertion of a JJ stent or a nephrostomy tube, followed by extracorporeal shock wave lithotripsy (ESWL) or by urgent in situ ESWL if readily available.

PATIENTS AND METHODS

The study comprised a retrospective analysis of 82 consecutive patients who presented with ureteric stones causing complete obstruction. Twenty-six had a percutaneous nephrostomy (PCN, group 1) and 40 had a JJ stent (group 2) placed to relieve the obstruction, and the stones were subsequently treated by ESWL. Sixteen patients underwent urgent in situ ESWL without recourse to either a JJ stent or a PCN (group 3). The choice of the procedure was not determined by stone size, site or other factors, but mainly by the attending surgeon's preference or the availability of urgent ESWL. The success rate was measured by the disintegration of the stone and spontaneous passage after ESWL; failure was defined as the need for additional procedure(s) for stone extraction.

RESULTS

Urgent in situ ESWL (group 3) had a median (95% confidence interval) success rate of 81 (54-96)%, compared with 70 (53-83)% in group 2 and 54 (33-73)% in group 1.

CONCLUSION

If facilities are available, urgent in situ ESWL appears to be the choice of treatment for obstructing ureteric stones. If such facilities are not available, a JJ stent may offer better success than a PCN. A prospective controlled trial is necessary to confirm these findings.

Scleral changes in chicks with form-deprivation myopia

The sclera in myopic regions of chick eyes was studied histologically and compared to the sclera in corresponding regions of normal fellow eyes. Chicks had been monocularly deprived of form vision in the nasal half of the retina from hatching. The fellow control eye and the temporal retina of the deprived eye had normal vision. With this treatment, the resulting form-deprivation myopia and eye enlargement are restricted to the retinal region that had been form deprived. We found that the cartilaginous sclera in the myopic nasal region exhibited several differences from that in the corresponding non-myopic region: it was thicker, its cell density was lower, and the number of chondrocytes and binucleate cells was higher. In contrast, the fibrous sclera was thinner. These changes suggest that form-deprivation myopia causes an increased production of extracellular matrix and an increased level of mitotic activity in the cartilaginous sclera. As expected, the non-myopic temporal regions of experimental and control eyes did not differ in any of these parameters. The findings of the present study suggest that the eye enlargement accompanying form-deprivation myopia is not the consequence of scleral stretching but of abnormal growth.